TY - CONF TI - Late Pliocene to Pleistocene tectonic activity in SW Portugal: The S. Teotónio -Aljezur - Sinceira fault system – a review C2 - 2008/// C3 - 1st Inter. Meeting of Young Researchers in Structural Geol. and Tect DA - 2008/// ER - TY - CONF TI - Late Pliocene to Pleistocene tectonic activity in SW Portugal: The S. Teotonio-Aljezur-Sinceira fault system and evidence for coastal uplift. C2 - 2008/12// C3 - American Geophysical Union Fall Meeting DA - 2008/12// ER - TY - CONF TI - Using a coupled wave and ocean circulation modeling system to investigate the impacts of Hurricane Isabel AU - Armstrong, BN AU - Warner, JC AU - He, R C2 - 2008/// C3 - AGU Fall Meeting Abstracts DA - 2008/// ER - TY - JOUR TI - Historic 2005 toxic bloom of Alexandrium fundyense in the western Gulf of Maine: 2. Coupled biophysical numerical modeling AU - He, Ruoying AU - McGillicuddy, Dennis J AU - Keafer, Bruce A AU - Anderson, Donald M T2 - Journal of Geophysical Research: Oceans DA - 2008/// PY - 2008/// VL - 113 IS - C7 ER - TY - JOUR TI - Saharan dust and phosphatic fidelity: A three-dimensional biogeochemical model of Trichodesmium as a nutrient source for red tides on the West Florida Shelf AU - Lenes, JM AU - Darrow, BA AU - Walsh, JJ AU - Prospero, JM AU - He, R AU - Weisberg, RH AU - Vargo, GA AU - Heil, CA T2 - Continental Shelf Research DA - 2008/// PY - 2008/// VL - 28 IS - 9 SP - 1091-1115 ER - TY - JOUR TI - Gulf of Maine harmful algal bloom in summer 2005--Part 2: Coupled bio-physical numerical modeling AU - He, Ruoying AU - McGillicuddy, Dennis J AU - Keafer, Bruce A AU - Anderson, Donald M T2 - Journal of geophysical research DA - 2008/// PY - 2008/// VL - 113 IS - C7 ER - TY - THES TI - Tectonic Geomorphology above Mediterranean Subduction Zones: Northeastern Apennines of Italy and Crete, Greece AU - Wegmann, K.W. DA - 2008/// PY - 2008/// SP - 169 M3 - Ph.D. Dissertation PB - Lehigh University ER - TY - JOUR TI - Holocene depocenter shift in the middle-lower Changjiang River basins and coastal area in response to sea level change AU - Wang, Zhanghua AU - Liu, Jingpu AU - Zhao, Baocheng T2 - Frontiers of Earth Science in China DA - 2008/3// PY - 2008/3// DO - 10.1007/S11707-008-0017-X VL - 2 IS - 1 SP - 17-26 J2 - Front. Earth Sci. China LA - en OP - SN - 1673-7385 1673-7490 UR - http://dx.doi.org/10.1007/S11707-008-0017-X DB - Crossref ER - TY - CONF TI - An Extended Procedure for the RelativeOperating Characteristics Graphical Method AU - Mera, Roberto J. AU - Semazzi, F.H.M. T2 - Climate Prediction Application Science Workshop C2 - 2008/// CY - Chapel Hill, North Carolina DA - 2008/// PY - 2008/3// ER - TY - CONF TI - Investigating a 3-way coupled model of a landfalling tropical cyclone AU - Zambon, J.B. T2 - Department of Marine, Earth and Atmospheric Sciences (MEAS) Seminar C2 - 2008/// CY - North Carolina State University, Raleigh, NC DA - 2008/// PY - 2008/// ER - TY - CONF TI - Investigation of coastal ocean response to landfalling hurricane using a Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) model: realistic hindcast AU - He, R. AU - Warner, J.C. AU - Armstrong, B. AU - Zambon, J.B. T2 - American Geophysical Union (AGU) Fall Meeting C2 - 2008/// C3 - AGU Fall Meeting Abstracts CY - San Francisco, CA DA - 2008/// PY - 2008/// ER - TY - CONF TI - Using a Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) modeling system to investigate impacts of storms on coastal systems AU - Warner, J.C. AU - Armstrong, B. AU - He, R. AU - Zambon, J.B. T2 - American Geophysical Union (AGU) Fall Meeting C2 - 2008/// C3 - AGU Fall Meeting Abstracts CY - San Francisco, CA DA - 2008/// PY - 2008/// ER - TY - CONF TI - Investigation of coastal ocean response to landfalling hurricane using Coupled-Ocean-Atmosphere-Wave-SedimentTransport (COAWST) model: idealized experiments AU - Zambon, J.B. AU - He, R. AU - Warner, J.C. T2 - American Geophysical Union (AGU) Fall Meeting C2 - 2008/// CY - San Francisco, CA DA - 2008/// PY - 2008/// ER - TY - CONF TI - Characterizing sulfur compound emissions from a hog farm in eastern North Carolina AU - Rumsey, I.C. AU - Aneja, V.P. AU - Lonneman, W.A. C2 - 2008/// C3 - Air and Waste Management Association: Symposium on Air Quality Measurement Methods and Technology 2008 DA - 2008/// SP - 484-490 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-70349976913&partnerID=MN8TOARS ER - TY - CONF TI - An apparent paradox: Agricultural ammonia emissions and the National Atmospheric Deposition Network AU - Gore, M.L. AU - Aneja, V.P. AU - Konarik, S. AU - Blunden, J. C2 - 2008/// C3 - Air and Waste Management Association: Symposium on Air Quality Measurement Methods and Technology 2008 DA - 2008/// SP - 380-383 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-70349900136&partnerID=MN8TOARS ER - TY - JOUR TI - Compendium of Veterinary Standard Precautions for Zoonotic Disease Prevention in Veterinary Personnel AU - Elchos, B.L. AU - Scheftel, J.M. AU - Cherry, B. AU - Debess, E.E. AU - Hopkins, Hunter L. AU - Levine, J.F. AU - Williams, C.J. AU - Bell, M.R. AU - Dvorak, G.D. AU - Flora, C.A. AU - Hofmann, J. AU - Pavlin, B.I. AU - Samples, O.M. AU - Snow, J.L. AU - Stinson-Dixon, R.E. T2 - Journal of the American Veterinary Medical Association DA - 2008/8/1/ PY - 2008/8/1/ DO - 10.2460/javma.233.3.415 VL - 233 IS - 3 SP - 415–432 ER - TY - CONF TI - Use of T-RFLP Analysis to Categorize the Microbial Diversity in Native Bivalve Streams in a North Carolina River Basin AU - Bucci, J AU - Caldwell, JM AU - Szempruch, AJ AU - Levine, JF T2 - NC Society For Microbiology C2 - 2008/10// CY - Greensboro, North Carolina DA - 2008/10// PY - 2008/10// ER - TY - MGZN TI - Photo of Wilson Bay AU - Levine, J.F. T2 - NC Alumni Magazine, Talking Trash DA - 2008/// PY - 2008/// M1 - spring ER - TY - JOUR TI - Rapid Enzyme-linked Immunosorbent Assay for Detection of the Algal Toxin Domoic Acid AU - Litaker, R. Wayne AU - Stewart, Thomas N. AU - Eberhart, Bich-Thuy L. AU - Wekell, John C. AU - Trainer, Vera L. AU - Kudela, Raphael M. AU - Miller, Peter E. AU - Roberts, Alice AU - Hertz, Cassandra AU - Johnson, Tyler A. AU - Frankfurter, Greg AU - Smith, G. Jason AU - Schnetzer, Astrid AU - Schumacker, Joe AU - Bastian, Jonnette L. AU - Odell, Anthony AU - Gentien, Patrick AU - Gal, Dominique Le AU - Hardison, D. Ransom AU - Tester, Patricia A. T2 - Journal of Shellfish Research AB - Domoic acid (DA) is a potent toxin produced by bloom-forming phytoplankton in the genus Pseudo-nitzschia, which is responsible for causing amnesic shellfish poisoning (ASP) in humans. ASP symptoms include vomiting, diarrhea, and in more severe cases confusion, loss of memory, disorientation, and even coma or death. This paper describes the development and validation of a rapid, sensitive, enzyme linked immunosorbent assay test kit for detecting DA using a monoclonal antibody. The assay gives equivalent results to those obtained using standard high performance liquid chromatography, fluorenylmethoxycarbonyl high performance liquid chromatography, or liquid chromatography—mass spectrometry methods. It has a linear range from 0.1–3 ppb and was used successfully to measure DA in razor clams, mussels, scallops, and phytoplankton. The assay requires approximately 1.5 h to complete and has a standard 96-well format where each strip of eight wells is removable and can be stored at 4°C until needed. The first two wells of each strip serve as an internal control eliminating the need to run a standard curve. This allows as few as 3 or as many as 36 duplicate samples to be run at a time enabling real-time sample processing and limiting degradation of DA, which can occur during storage. There was minimal cross-reactivity in this assay with glutamine, glutamic acid, kainic acid, epi- or iso-DA. This accurate, rapid, cost-effective, assay offers environmental managers and public health officials an effective tool for monitoring DA concentrations in environment samples. DA - 2008/12// PY - 2008/12// DO - 10.2983/0730-8000-27.5.1301 VL - 27 IS - 5 SP - 1301-1310 UR - http://dx.doi.org/10.2983/0730-8000-27.5.1301 KW - ASP KW - domoic acid poisoning KW - ELISA KW - mussels KW - scallops KW - razor clams KW - test kit ER - TY - CHAP TI - Evaluating PAH Biodegradation Relative to Total Bacterial Carbon Demand in Coastal Ecosystems: Are PAHs Truly Recalcitrant? AU - Boyd, T.J. AU - Smith, D.C. AU - Apple, J.K. AU - Hamdan, L.J. AU - Osburn, C.L. AU - Montgomery, M.T T2 - Microbial Ecology Research Trends A2 - Van Dijk, T. PY - 2008/// SP - 1–38 PB - NOVA Science Publishers Inc ER - TY - JOUR TI - Sensitivity of future ozone concentrations in the northeast USA to regional climate change AU - Kunkel, K. E. AU - Huang, H.-C. AU - Liang, X.-Z. AU - Lin, J.-T. AU - Wuebbles, D. AU - Tao, Z. AU - Williams, A. AU - Caughey, M. AU - Zhu, J. AU - Hayhoe, K. T2 - Mitigation and Adaptation Strategies for Global Change AB - An air quality modeling system was used to simulate the effects on ozone concentration in the northeast USA from climate changes projected through the end of the twenty-first century by the National Center for Atmospheric Research’s (NCAR’s) parallel climate model, a fully coupled general circulation model, under a higher and a lower scenario of future global changes in concentrations of radiatively active constituents. The air quality calculations were done with both a global chemistry-transport model and a regional air quality model focused on the northeast USA. The air quality simulations assumed no changes in regional anthropogenic emissions of the chemical species primarily involved in the chemical reactions of ozone creation and destruction, but only accounted for changes in the climate. Together, these idealized global and regional model simulations provide insights into the contribution of possible future climate changes on ozone. Over the coming century, summer climate is projected to be warmer and less cloudy for the northeast USA. These changes are considerably larger under the higher scenario as compared with the lower. Higher temperatures also increase biogenic emissions. Both mean daily and 8-h maximum ozone increase from the combination of three factors that tend to favor higher concentrations: (1) higher temperatures change the rates of reactions and photolysis rates important to the ozone chemistry; (2) lower cloudiness (higher solar radiation) increases the photolysis reaction rates; and (3) higher biogenic emissions increase the concentration of reactive species. Regional model simulations with two cumulus parameterizations produce ozone concentration changes that differ by approximately 10%, indicating that there is considerable uncertainty in the magnitude of changes due to uncertainties in how physical processes should be parameterized in the models. However, the overall effect of the climate changes simulated by these models – in the absence of reductions in regional anthropogenic emissions – would be to increase ozone concentrations. DA - 2008/6// PY - 2008/6// DO - 10.1007/S11027-007-9137-Y VL - 13 IS - 5-6 SP - 597–606 SN - 1381-2386 1573-1596 UR - http://dx.doi.org/10.1007/S11027-007-9137-Y ER - TY - JOUR TI - Impacts of long-range transport of global pollutants and precursor gases on U.S. air quality under future climatic conditions AU - Huang, Ho-Chun AU - Lin, Jintai AU - Tao, Zhining AU - Choi, Hyun AU - Patten, Kenneth AU - Kunkel, Kenneth AU - Xu, Min AU - Zhu, Jinhong AU - Liang, Xin-Zhong AU - Williams, Allen AU - Caughey, Michael AU - Wuebbles, Donald J. AU - Wang, Julian T2 - Journal of Geophysical Research AB - The U.S. air quality is impacted by emissions both within and outside the United States. The latter impact is manifested as long‐range transport (LRT) of pollutants across the U.S. borders, which can be simulated by lateral boundary conditions (LBC) into a regional modeling system. This system consists of a regional air quality model (RAQM) that integrates local‐regional source emissions and chemical processes with remote forcing from the LBC predicted by a nesting global chemical transport model (model for ozone and related chemical tracers (MOZART)). The present‐day simulations revealed important LRT effects, varying among the five major regions with ozone problems, i.e., northeast United States, midwest United States, Texas, California, and southeast United States. To determine the responses of the LRT impacts to projected global climate and emissions changes, the MOZART and RAQM simulations were repeated for future periods (2048–2052 and 2095–2099) under two emissions scenarios (IPCC A1Fi and B1). The future U.S. air quality projected by the MOZART is less sensitive to the emissions scenarios than that simulated by the RAQM with or without incorporating the LRT effects via the LBC from the MOZART. The result of RAQM with the LRT effects showed that the southeast United States has the largest sensitivity of surface ozone mixing ratio to the emissions changes in the 2095–2099 climate (−24% to +25%) followed by the northeast and midwest United States. The net increase due to the LRT effects in 2095–2099 ranges from +4% to +13% in daily mean surface ozone mixing ratio and +4% to +11% in mean daily maximum 8‐h average ozone mixing ratios. Correspondingly, the LRT effects in 2095–2099 cause total column O 3 mixing ratio increases, ranging from +7% to +16%, and also 2 to 3 more days with the surface ozone exceeding the national standard. The results indicate that future U.S. air quality changes will be substantially affected by global emissions. DA - 2008/10/15/ PY - 2008/10/15/ DO - 10.1029/2007JD009469 VL - 113 IS - D19 J2 - J. Geophys. Res. LA - en OP - SN - 0148-0227 UR - http://dx.doi.org/10.1029/2007JD009469 DB - Crossref ER - TY - JOUR TI - Regional climate models downscaling analysis of general circulation models present climate biases propagation into future change projections AU - Liang, Xin-Zhong AU - Kunkel, Kenneth E. AU - Meehl, Gerald A. AU - Jones, Richard G. AU - Wang, Julian X. L. T2 - Geophysical Research Letters AB - A suite of eighteen simulations over the U.S. and Mexico, representing combinations of two mesoscale regional climate models (RCMs), two driving global general circulation models (GCMs), and the historical and four future anthropogenic forcings were intercompared. The RCMs' downscaling reduces significantly driving GCMs' present‐climate biases and narrows inter‐model differences in representing climate sensitivity and hence in simulating the present and future climates. Very high spatial pattern correlations of the RCM minus GCM differences in precipitation and surface temperature between the present and future climates indicate that major model present‐climate biases are systematically propagated into future‐climate projections at regional scales. The total impacts of the biases on trend projections also depend strongly on regions and cannot be linearly removed. The result suggests that the nested RCM‐GCM approach that offers skill enhancement in representing the present climate also likely provides higher credibility in downscaling the future climate projection. DA - 2008/4/22/ PY - 2008/4/22/ DO - 10.1029/2007GL032849 VL - 35 IS - 8 J2 - Geophys. Res. Lett. LA - en OP - SN - 0094-8276 UR - http://dx.doi.org/10.1029/2007GL032849 DB - Crossref ER - TY - JOUR TI - Water interaction with hydrophobic and hydrophilic soot particles AU - Popovicheva, Olga AU - Persiantseva, Natalia M. AU - Shonija, Natalia K. AU - DeMott, Paul AU - Koehler, Kirsten AU - Petters, Markus AU - Kreidenweis, Sonia AU - Tishkova, Victoria AU - Demirdjian, Benjamin AU - Suzanne, Jean T2 - Physical Chemistry Chemical Physics AB - The interaction of water with laboratory soots possessing a range of properties relevant for atmospheric studies is examined by two complementary methods: gravimetrical measurement of water uptake coupled with chemical composition and porosity analysis and HTDMA (humidified tandem differential mobility analyzer) inference of water uptake accompanied by separate TEM (transmission electron microscopy) analysis of single particles. The first method clarifies the mechanism of water uptake for bulk soot and allows the classification of soot with respect to its hygroscopicity. The second method highlights the dependence of the soot aerosol growth factor on relative humidity (RH) for quasi-monodisperse particles. Hydrophobic and hydrophilic soot are qualitatively defined by their water uptake and surface polarity: laboratory soot particles are thus classified from very hydrophobic to very hydrophilic. Thermal soot particles produced from natural gas combustion are classified as hydrophobic with a surface of low polarity since water is found to cover only half of the surface. Graphitized thermal soot particles are proposed for comparison as extremely hydrophobic and of very low surface polarity. Soot particles produced from laboratory flame of TC1 aviation kerosene are less hydrophobic, with their entire surface being available for statistical monolayer water coverage at RH ∼ 10%. Porosity measurements suggest that, initially, much of this surface water resides within micropores. Consequently, the growth factor increase of these particles to 1.07 at RH > 80% is attributed to irreversible swelling that accompanies water uptake. Hysteresis of adsorption/desorption cycles strongly supports this conclusion. In contrast, aircraft engine soot, produced from burning TC1 kerosene in a gas turbine engine combustor, has an extremely hydrophilic surface of high polarity. Due to the presence of water soluble organic and inorganic material it can be covered by many water layers even below water saturation conditions. This soot demonstrates a gradual diameter growth factor (Dwet/Ddry) increase up to 1.22 at 93% relative humidity, most likely due to the presence of single particles with water soluble material heterogeneously distributed over their surface. DA - 2008/// PY - 2008/// DO - 10.1039/b718944n VL - 10 IS - 17 SP - 2332 J2 - Phys. Chem. Chem. Phys. LA - en OP - SN - 1463-9076 1463-9084 UR - http://dx.doi.org/10.1039/b718944n DB - Crossref ER - TY - JOUR TI - Aerosol hygroscopicity and cloud droplet activation of extracts of filters from biomass burning experiments AU - Carrico, Christian M. AU - Petters, Markus D. AU - Kreidenweis, Sonia M. AU - Collett, Jeffrey L., Jr. AU - Engling, Guenter AU - Malm, William C. T2 - Journal of Geophysical Research AB - In this laboratory closure study, we compare sub‐ and supersaturated water uptake properties for aerosol particles possessing a range of hygroscopicity. Measurements for water sub‐saturated conditions used a hygroscopic tandem differential mobility analyzer (HTDMA). Simultaneously, measurements of particle critical supersaturation were conducted on the same sample stream with a continuous flow cloud condensation nuclei (CCN) counter. For these experiments, we used filter‐collected samples of biomass smoke generated in the combustion of two common wildland fire fuels, western sagebrush and Alaskan duff core. Extractions of separate sections of the filter were performed using two solvents, ultrapure water and methanol. The extracts were subsequently atomized, producing aerosols having a range of hygroscopic responses. HTDMA and CCN measurements were fit to a single‐parameter model of water uptake, in which the fit parameter is denoted κ , the hygroscopicity parameter. Here, for the four extracts we observed mean values of the hygroscopicity parameter of 0.06 < κ < 0.30, similar to the range found previously for numerous pure organic compounds. Particles generated from the aqueous extracts of the filters had consistently larger κ than methanol extracts, while western sagebrush extract aerosols κ exceeded those from Alaskan duff core. HTDMA‐ and CCN‐derived values of κ for each experiment agreed within approximately 20%. Applicability of the κ ‐parameterization to other multicomponent aerosols relevant to the atmosphere remains to be tested. DA - 2008/4/22/ PY - 2008/4/22/ DO - 10.1029/2007JD009274 VL - 113 IS - D8 J2 - J. Geophys. Res. LA - en OP - SN - 0148-0227 UR - http://dx.doi.org/10.1029/2007JD009274 DB - Crossref ER - TY - JOUR TI - A three-dimensional biophysical model of Karenia brevis dynamics on the west Florida shelf: A look at physical transport and potential zooplankton grazing controls AU - Milroy, Scott P. AU - Dieterle, Dwight A. AU - He, Ruoying AU - Kirkpatrick, Gary J. AU - Lester, Kristen M. AU - Steidinger, Karen A. AU - Vargo, Gabriel A. AU - Walsh, John J. AU - Weisberg, Robert H. T2 - Continental Shelf Research AB - Abstract The development of accurate predictive models of toxic dinoflagellate blooms is of great ecological importance, particularly in regions that are most susceptible to their detrimental effects. This is especially true along the west Florida shelf (WFS) and coast, where episodic bloom events of the toxic dinoflagellate Karenia brevis often wreak havoc on the valuable commercial fisheries and tourism industries of west Florida. In an effort to explain the dynamics at work within the maintenance and termination phases of a red tide, a simple three-dimensional coupled biophysical model was used in the analysis of the October 1999 red tide offshore Sarasota, Florida. Results of the numerical experiments indicate that: (1) measured and modeled flowfields were capable of transporting the observed offshore inoculum of K. brevis to within 16 km of the coastal boundary; (2) background concentrations (1000 cells L−1) of K. brevis could grow to a red tide of over 2×106 cells L−1 in little more than a month, assuming an estuarine initiation site with negligible offshore advection, no grazing losses, negligible competition from other phytoplankton groups, and no nutrient limitation; (3) maximal grazing pressure could not prevent the initiation of a red tide or cause its termination, assuming no other losses to algal biomass and a zooplankton community ingestion rate similar to that of Acartia tonsa; and (4) the light-cued ascent behavior of K. brevis served as an aggregational mechanism, concentrating K. brevis at the 55 μE m−2 s−1 isolume when mean concentrations of K. brevis exceeded 100,000 cells L−1. Further improvements in model fidelity will be accomplished by the future inclusion of phytoplankton competitors, disparate nutrient availability and limitation schemes, a more realistic rendering of the spectral light field and the attendant effects of photo-inhibition and compensation, and a mixed community of vertically-migrating proto- and metazoan grazers. These model refinements are currently under development and shall be used to aid progress toward an operational model of red tide forecasting along the WFS. DA - 2008/1// PY - 2008/1// DO - 10.1016/j.csr.2007.04.013 VL - 28 IS - 1 SP - 112-136 J2 - Continental Shelf Research LA - en OP - SN - 0278-4343 UR - http://dx.doi.org/10.1016/j.csr.2007.04.013 DB - Crossref KW - mathematical models KW - red tides KW - algal blooms KW - phytoplankton KW - Karenia brevis ER - TY - JOUR TI - Seismic identification of along-axis hydrothermal flow on the East Pacific Rise AU - Tolstoy, M. AU - Waldhauser, F. AU - Bohnenstiehl, D. R. AU - Weekly, R. T. AU - Kim, W.-Y. T2 - Nature DA - 2008/1// PY - 2008/1// DO - 10.1038/nature06424 VL - 451 IS - 7175 SP - 181-184 J2 - Nature LA - en OP - SN - 0028-0836 1476-4687 UR - http://dx.doi.org/10.1038/nature06424 DB - Crossref ER - TY - JOUR TI - Ocean urea fertilization for carbon credits poses high ecological risks AU - Glibert, Patricia M. AU - Azanza, Rhodora AU - Burford, Michele AU - Furuya, Ken AU - Abal, Eva AU - Al-Azri, Adnan AU - Al-Yamani, Faiza AU - Andersen, Per AU - Anderson, Donald M. AU - Beardall, John AU - Berg, G. Mine AU - Brand, Larry AU - Bronk, Deborah AU - Brookes, Justin AU - Burkholder, JoAnn M. AU - Cembella, Allan AU - Cochlan, William P. AU - Collier, Jackie L. AU - Collos, Yves AU - Diaz, Robert AU - Doblin, Martina AU - Drennen, Thomas AU - Dyhrman, Sonya AU - Fukuyo, Yasuwo AU - Furnas, Miles AU - Galloway, James AU - Granéli, Edna AU - Ha, Dao Viet AU - Hallegraeff, Gustaaf AU - Harrison, John AU - Harrison, Paul J. AU - Heil, Cynthia A. AU - Heimann, Kirsten AU - Howarth, Robert AU - Jauzein, Cécile AU - Kana, Austin A. AU - Kana, Todd M. AU - Kim, Hakgyoon AU - Kudela, Raphael AU - Legrand, Catherine AU - Mallin, Michael AU - Mulholland, Margaret AU - Murray, Shauna AU - O’Neil, Judith AU - Pitcher, Grant AU - Qi, Yuzao AU - Rabalais, Nancy AU - Raine, Robin AU - Seitzinger, Sybil AU - Salomon, Paulo S. AU - Solomon, Caroline AU - Stoecker, Diane K. AU - Usup, Gires AU - Wilson, Joanne AU - Yin, Kedong AU - Zhou, Mingjiang AU - Zhu, Mingyuan T2 - Marine Pollution Bulletin AB - The proposed plan for enrichment of the Sulu Sea, Philippines, a region of rich marine biodiversity, with thousands of tonnes of urea in order to stimulate algal blooms and sequester carbon is flawed for multiple reasons. Urea is preferentially used as a nitrogen source by some cyanobacteria and dinoflagellates, many of which are neutrally or positively buoyant. Biological pumps to the deep sea are classically leaky, and the inefficient burial of new biomass makes the estimation of a net loss of carbon from the atmosphere questionable at best. The potential for growth of toxic dinoflagellates is also high, as many grow well on urea and some even increase their toxicity when grown on urea. Many toxic dinoflagellates form cysts which can settle to the sediment and germinate in subsequent years, forming new blooms even without further fertilization. If large-scale blooms do occur, it is likely that they will contribute to hypoxia in the bottom waters upon decomposition. Lastly, urea production requires fossil fuel usage, further limiting the potential for net carbon sequestration. The environmental and economic impacts are potentially great and need to be rigorously assessed. DA - 2008/6// PY - 2008/6// DO - 10.1016/j.marpolbul.2008.03.010 VL - 56 IS - 6 SP - 1049-1056 J2 - Marine Pollution Bulletin LA - en OP - SN - 0025-326X UR - http://dx.doi.org/10.1016/j.marpolbul.2008.03.010 DB - Crossref KW - urea dumping KW - ocean fertilization KW - carbon credits KW - Sulu Sea KW - carbon sequestration KW - harmful algae KW - toxic dinoflagellates KW - cyanobacteria KW - hypoxia ER - TY - JOUR TI - Eutrophication and harmful algal blooms: A scientific consensus AU - Heisler, J. AU - Glibert, P.M. AU - Burkholder, J.M. AU - Anderson, D.M. AU - Cochlan, W. AU - Dennison, W.C. AU - Dortch, Q. AU - Gobler, C.J. AU - Heil, C.A. AU - Humphries, E. AU - Lewitus, A. AU - Magnien, R. AU - Marshall, H.G. AU - Sellner, K. AU - Stockwell, D.A. AU - Stoecker, D.K. AU - Suddleson, M. T2 - Harmful Algae AB - In January 2003, the US Environmental Protection Agency sponsored a "roundtable discussion" to develop a consensus on the relationship between eutrophication and harmful algal blooms (HABs), specifically targeting those relationships for which management actions may be appropriate. Academic, federal, and state agency representatives were in attendance. The following seven statements were unanimously adopted by attendees based on review and analysis of current as well as pertinent previous data: 1) Degraded water quality from increased nutrient pollution promotes the development and persistence of many HABs and is one of the reasons for their expansion in the U.S. and the world; 2) The composition - not just the total quantity - of the nutrient pool impacts HABs; 3) High biomass blooms must have exogenous nutrients to be sustained; 4) Both chronic and episodic nutrient delivery promote HAB development; 5) Recently developed tools and techniques are already improving the detection of some HABs, and emerging technologies are rapidly advancing toward operational status for the prediction of HABs and their toxins; 6) Experimental studies are critical to further the understanding of the role of nutrients in HAB expression, and will strengthen prediction and mitigation of HABs; and 7) Management of nutrient inputs to the watershed can lead to significant reduction in HABs. Supporting evidence and pertinent examples for each consensus statement is provided herein. DA - 2008/12// PY - 2008/12// DO - 10.1016/j.hal.2008.08.006 VL - 8 IS - 1 SP - 3-13 J2 - Harmful Algae LA - en OP - SN - 1568-9883 UR - http://dx.doi.org/10.1016/j.hal.2008.08.006 DB - Crossref KW - Eutrophication KW - Harmful algal blooms KW - HABs KW - Management of nutrients KW - Nutrient loading KW - Nutrient composition KW - Nutrient pollution KW - US EPA KW - Water quality ER - TY - JOUR TI - Phylogenetic diversity of cyanobacterial narB genes from various marine habitats AU - Paerl, Ryan W. AU - Foster, Rachel A. AU - Jenkins, Bethany D. AU - Montoya, Joseph P. AU - Zehr, Jonathan P. T2 - Environmental Microbiology AB - Nitrate, the most abundant combined, dissolved form of inorganic nitrogen in global oceans, is a common source of nitrogen (N) for phytoplankton including cyanobacteria. Using a nested polymerase chain reaction (PCR) method, the diversity of the cyanobacterial nitrate reductase gene, narB, was examined in plankton samples from a variety of marine habitats. A total of 480 narB gene fragment sequences were obtained from a coastal coral reef (Heron Island, Australia), open-ocean tropical and subtropical oceanic waters (Atlantic and Pacific Oceans) and a temperate N. Pacific Ocean site (34 degrees N, 129 degrees W). Phylogenetic analyses distinguished eight picocyanobacterial narB clades comprised of DNA sequences derived from the nutrient-replete coastal, nutrient-deplete pelagic and tidally influenced coral reef habitats. The phylogeny of recovered narB gene sequences was consistent with 16S rRNA and ITS sequence phylogenies, suggesting minimal horizontal gene transfer of the narB gene. Depending on sampled habitat, environmental narB sequence types segregated into three divisions: non-picocyanobacterial, coastal picocyanobacterial and open-ocean picocyanobacterial sequences. Using a reverse transcription PCR method, narB mRNA sequences were amplified from Heron Island samples, indicating that narB expression can be detected in environmental samples. DA - 2008/12// PY - 2008/12// DO - 10.1111/j.1462-2920.2008.01741.x VL - 10 IS - 12 SP - 3377–3387 SN - 1462-2912 1462-2920 UR - http://dx.doi.org/10.1111/j.1462-2920.2008.01741.x ER - TY - JOUR TI - Tidal marshes as a source of optically and chemically distinctive colored dissolved organic matter in the Chesapeake Bay AU - Tzortziou, Maria AU - Neale, Patrick J. AU - Osburn, Christopher L. AU - Megonigal, J. Patrick AU - Maie, Nagamitsu AU - Jaffé, Rudolf T2 - Limnol. Oceangr. AB - The role of tidal marshes as a source of dissolved organic carbon (DOC) and colored dissolved organic matter (CDOM) for adjacent estuarine waters was studied in the Rhode River subestuary of the Chesapeake Bay. Water in a tidal creek draining brackish, high‐elevation marshes was sampled every hour during several semidiurnal tidal cycles in order to examine the tidal exchange of dissolved organic matter (DOM). Water leaving the marsh during ebbing tide was consistently enriched in DOC compared to water entering the marsh during flooding tide. There was a net DOC export from the marsh to the estuary during seasons of both low and high marsh plant biomass. Optical analysis demonstrated that, in addition to contributing to the carbon budgets, the marsh had a strong influence on the estuary’s CDOM dynamics. Marsh‐exported CDOM had optical properties that were consistently and markedly different from those of CDOM in the adjacent estuary. Specifically, marsh CDOM had: (1) considerably stronger absorption, (2) larger DOC‐specific absorption, (3) lower exponential spectral slope, (4) larger fluorescence signal, (5) lower fluorescence per unit absorbance, and (6) higher fluorescence at wavelengths >400 nm. These optical characteristics are indicative of relatively complex, high‐molecular‐weight, aromatic‐rich DOM, and this was confirmed by results of molecular‐weight‐distribution analysis. Our findings illustrate the importance of tidal marshes as sources of optically and chemically distinctive dissolved organic compounds, and their influence on CDOM dynamics, DOC budgets, and, thus, photochemical and biogeochemical processes, in adjacent estuarine ecosystems. DA - 2008/// PY - 2008/// DO - 10.4319/lo.2008.53.1.0148 VL - 53 IS - 1 SP - 148-159 ER - TY - JOUR TI - Bacterial production and microbial food web structure in a large arctic river and the coastal Arctic Ocean AU - Vallières, Catherine AU - Retamal, Leira AU - Ramlal, Patricia AU - Osburn, Christopher L. AU - Vincent, Warwick F. T2 - Journal of Marine Systems AB - Globally significant quantities of organic carbon are stored in northern permafrost soils, but little is known about how this carbon is processed by microbial communities once it enters rivers and is transported to the coastal Arctic Ocean. As part of the Arctic River-Delta Experiment (ARDEX), we measured environmental and microbiological variables along a 300 km transect in the Mackenzie River and coastal Beaufort Sea, in July–August 2004. Surface bacterial concentrations averaged 6.7 × 105 cells mL− 1 with no significant differences between sampling zones. Picocyanobacteria were abundant in the river, and mostly observed as cell colonies. Their concentrations in the surface waters decreased across the salinity gradient, dropping from 51,000 (river) to 30 (sea) cells mL− 1. There were accompanying shifts in protist community structure, from diatoms, cryptophytes, heterotrophic protists and chrysophytes in the river, to dinoflagellates, prymnesiophytes, chrysophytes, prasinophytes, diatoms and heterotrophic protists in the Beaufort Sea. Size-fractionated bacterial production, as measured by 3H–leucine uptake, varied from 76 to 416 ng C L− 1 h− 1. The contribution of particle-attached bacteria (> 3 µm fraction) to total bacterial production decreased from > 90% at the Mackenzie River stations to < 20% at an offshore marine site, and the relative importance of this particle-based fraction was inversely correlated with salinity and positively correlated with particulate organic carbon concentrations. Glucose enrichment experiments indicated that bacterial metabolism was carbon limited in the Mackenzie River but not in the coastal ocean. Prior exposure of water samples to full sunlight increased the biolability of dissolved organic carbon (DOC) in the Mackenzie River but decreased it in the Beaufort Sea. Estimated depth-integrated bacterial respiration rates in the Mackenzie River were higher than depth-integrated primary production rates, while at the marine stations bacterial respiration rates were near or below the integrated primary production rates. Consistent with these results, PCO2 measurements showed surface water supersaturation in the river (mean of 146% of air equilibrium values) and subsaturation or near-saturation in the coastal sea. These results show a well-developed microbial food web in the Mackenzie River system that will likely convert tundra carbon to atmospheric CO2 at increasing rates as the arctic climate continues to warm. DA - 2008/// PY - 2008/// DO - 10.1016/j.jmarsys.2007.12.002 VL - 74 IS - 3-4 SP - 756-773 ER - TY - JOUR TI - Increased Capacity for Polycyclic Aromatic Hydrocarbon Mineralization in Bioirrigated Coastal Marine Sediments AU - Montgomery, Michael T. AU - Osburn, Christopher L. AU - Furukawa, Yoko AU - Gieskes, Joris M. T2 - Bioremediation Journal AB - ABSTRACT Bioirrigation of marine sediments by benthic infauna has the potential to increase both the rate and depth of bacterial mineralization of polycyclic aromatic hydrocarbons (PAHs) by recirculating oxygenated bottom water into sediment burrows. Rates of heterotrophic bacterial production and mineralization of PAHs (naphthalene, phenanthrene, and fluoranthene) were measured in sections of sediment cores sampled from stations in San Diego Bay. Data suggest that rates of PAH biodegradation and bacterial heterotrophy were influenced by bioirrigation by benthic infauna. PAH mineralization and heterotrophic production were higher in core sections where sulfide was not detected relative to core sections containing sulfide. Depth-integrated capacity of the upper 17 cm of sediment to mineralize PAHs was 4 to 10 times higher at the station with bioirrigation coefficients that increased with depth. Remedial dredging of sediments to remove contaminant mass (and presumable lower ecological risk) will also remove benthic infauna. Removal of infauna and the subsequent lowering of bioirrigation in surface sediments would be expected to lower the capacity of intrinsic PAH bioremediation. This could cause local increases in ambient PAH concentration and consequently increase the ecological risk at the site and potentially degrade the health of the ecosystem by removing a sink for PAHs. DA - 2008/5// PY - 2008/5// DO - 10.1080/10889860802060469 VL - 12 IS - 2 SP - 98-110 ER - TY - BOOK TI - Open source GIS: A GRASS GIS approach AU - Neteler, M. AU - Mitasova, H. AB - With this third edition of Open Source GIS: A GRASS GIS Approach, we enter the new era of GRASS6, the first release that includes substantial new code developed by the International GRASS Development DA - 2008/// PY - 2008/// DO - 10.1007/978-0-387-68574-8 SE - 1-406 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84892062276&partnerID=MN8TOARS ER - TY - BOOK TI - Chapter Ten Free and Open Source Geospatial Tools for Environmental Modelling and Management AU - Jolma, A. AU - Ames, D.P. AU - Horning, N. AU - Mitasova, H. AU - Neteler, M. AU - Racicot, A. AU - Sutton, T. AB - Geospatial (geographical) software systems (GIS) are used for creating, viewing, managing, analysing and utilising geospatial data. Geospatial data can include socioeconomic, environmental, geophysical, and technical data about the Earth and societal infrastructure and it is pivotal in environmental modelling and management (EMM). Desktop, web-based, and embedded geospatial systems have become an essential part of EMM, providing pre- or post-processing of geospatial data, analysis and visualisation of results or a graphical user interface (GUI). Many local, regional, national, and international efforts are underway to create geospatial data infrastructures and tools for viewing and using geospatial data. When environmental attribute data is linked to these infrastructures, powerful tools for environmental management are instantly created. The growing culture of free/libre and open source software (FOSS) provides an alternative approach to software development for the field of GIS (FOSS4G). To provide an overview of FOSS4G for EMM, we analyse platforms, software stacks, and EMM workflows. In the FOSS world the barriers to interoperability are low and thus the software stack tends to be thicker than in the proprietary platform. The FOSS4G world thrives on the evolution of software stacks and platforms. We provide examples of software stacks built from current FOSS4G that support EMM workflows and highlight the advantages of FOSS4G solutions including opportunities to redistribute resulting modelling tools freely to end-users and to support general goals of openness and transparency with respect to modelling tools. DA - 2008/// PY - 2008/// DO - 10.1016/S1574-101X(08)00610-8 VL - 3 SE - 163-180 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-51449107965&partnerID=MN8TOARS ER - TY - BOOK TI - Discussing Earth AU - Kimberley, Michael M. DA - 2008/// PY - 2008/// PB - Hoboken, NJ: John Wiley & Sons Inc. ER - TY - JOUR TI - Validation and Application of Lipofuscin-Based Age Determination for Chesapeake Bay Blue Crabs Callinectes sapidus AU - Puckett, Brandon J. AU - Secor, David H. AU - Ju, Se-Jong T2 - TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY AB - Abstract Quantifying lipofuscin (LF), a metabolic byproduct that accumulates in postmitotic cells, serves as one of the principal approaches for aging crustaceans, but the accuracy of this method remains an important issue. Here, we quantified LF accumulation as a function of chronological age and temperature (degree‐days) in an economically important crustacean, the blue crab Callinectes sapidus , to test the accuracy of LF‐based age estimates and determine the age‐specific partial recruitment of juveniles to summer and fall commercial fisheries. Three known‐age juvenile cohorts (63‐83 d) were reared in ponds up to 1.8 years of age. Field collections were conducted in two subestuaries of Chesapeake Bay from June to October during 2003 and 2004. Lipofuscin accumulation oscillated seasonally in known‐age cohorts. Significant (log e transformed) LF accumulation occurred at average intervals of 2.5 months, with the exception of winter months (mean temperature = 8°C). Seasonalized von Bertalanffy functions accurately depicted age‐specific LF accumulation but were cohort specific. The relationship between LF and temperature degree‐day (TD day) was similar among cohorts and genders, and a single LF‐TD day model was applied to field‐collected crabs. The mean age prediction error of this model was 2.0 months. Lipofuscin‐based age composition of field collections indicated that the peeler‐soft crab and hard crab fisheries were predominately composed of recruits less than age 1.5 from August to October. The consequences of this short (approximately annual) generation time is that recruitment and landings will be responsive to environmental factors affecting growth and the annual variations in egg production, settlement, and postsettlement survival. DA - 2008/11// PY - 2008/11// DO - 10.1577/T07-278.1 VL - 137 IS - 6 SP - 1637-1649 SN - 1548-8659 ER - TY - JOUR TI - Hemolymph as a nonlethal and minimally invasive source for DNA for molecular systematic studies of freshwater mussels AU - Raley, M. E. AU - Levine, J. F. AU - Bogan, A. E. T2 - Tentacle. The Newsletter of the IUCN/SSC Mollusc Specialist Group DA - 2008/// PY - 2008/// VL - 14 SP - 33–34 ER - TY - JOUR TI - Urban effects of Chennai on sea breeze induced convection and precipitation AU - Simpson, Matthew AU - Raman, Sethu AU - Suresh, R. AU - Mohanty, U. C. T2 - JOURNAL OF EARTH SYSTEM SCIENCE AB - Doppler radar derived wind speed and direction profiles showed a well developed sea breeze circulation over the Chennai, India region on 28 June, 2003. Rainfall totals in excess of 100 mm resulted from convection along the sea breeze front. Inland propagation of the sea breeze front was observed in radar reflectivity imagery. High-resolution MM5 simulations were used to investigate the influence of Chennai urban land use on sea breeze initiated convection and precipitation. A comparison of observed and simulated 10m wind speed and direction over Chennai showed that the model was able to simulate the timing and strength of the sea breeze. Urban effects are shown to increase the near surface air temperature over Chennai by 3.0K during the early morning hours. The larger surface temperature gradient along the coast due to urban effects increased onshore flow by 4.0m s−1. Model sensitivity study revealed that precipitation totals were enhanced by 25mm over a large region 150 km west of Chennai due to urban effects. Deficiency in model physics related to night-time forecasts are addressed. DA - 2008/12// PY - 2008/12// DO - 10.1007/s12040-008-0075-1 VL - 117 IS - 6 SP - 897-909 SN - 0253-4126 KW - Convection KW - sea breeze KW - urban heat island ER - TY - JOUR TI - Topographic features around Zhongshan Station, southeast of Prydz Bay AU - Feng, S. Z. AU - Xue, Z. AU - Chi, W. Q. T2 - Chinese Journal of Oceanology and Limnology = Zhongguo Hai Yang Hu Zhao Xue Bao DA - 2008/// PY - 2008/// VL - 26 IS - 4 SP - 469-474 ER - TY - JOUR TI - The FOODBANCS project: Introduction and sinking fluxes of organic carbon, chlorophyll-a and phytodetritus on the western Antarctic Peninsula continental shelf AU - Smith, Craig R. AU - Mincks, Sarah AU - DeMaster, David J. T2 - DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY AB - The impact of the highly seasonal Antarctic primary production cycle on shelf benthic ecosystems remains poorly evaluated. Here we describe a times-series research project on the West Antarctic Peninsula (WAP) shelf designed to evaluate the seafloor deposition, and subsequent ecological and biogeochemical impacts, of the summer phytoplankton bloom along a transect crossing the Antarctic shelf near Anvers Island. During this project, entitled Food for Benthos on the Antarctic Continental Shelf (FOODBANCS), we deployed replicate sediment traps 150–170 m above the seafloor (total water-column depth of 590 m) on the central shelf from December 1999 to March 2001, recovering trap samples every 3–4 months. In addition, we used a seafloor time-lapse camera system, as well as video surveys conducted at 3–4 months intervals, to monitor the presence and accumulation of phytodetritus at the sediment–water interface. The fluxes of particulate organic carbon and chlorophyll-a into sediment traps (binned over 3–4 month intervals) showed patterns consistent with seasonal variability, with average summer fluxes during the first year exceeding winter fluxes by a factor of ∼2–3. However, inter-annual variability in summer fluxes was even greater than seasonal variability, with 4–10-fold differences in the flux of organic carbon and chlorophyll-a between the summer seasons of 1999–2000 and 2000–2001. Phytodetrital accumulation at the shelf floor also exhibited intense inter-annual variability, with no visible phytodetritus from essentially December 1999 to November 2000, followed by pulsed accumulation of 1–2 cm of phytodetritus over a ∼30,000 km2 shelf area by March 2001. Comparisons with other studies suggest that the levels of inter-annual variability we observed are typical of the Antarctic shelf over decadal time scales. We conclude that fluxes of particulate organic carbon, chlorophyll-a and phytodetritus to WAP-shelf sediments vary intensely on seasonal to inter-annual time scales, yielding dramatic temporal variability in the flux of food for detritivores to the Antarctic shelf floor. DA - 2008/11// PY - 2008/11// DO - 10.1016/j.dsr2.2008.06.001 VL - 55 IS - 22-23 SP - 2404-2414 SN - 1879-0100 KW - Pelagic-benthic coupling KW - Organic carbon flux KW - Phytodetritus KW - Antarctic benthos KW - Sediment traps KW - Time series ER - TY - JOUR TI - Testing the FOODBANCS hypothesis: Seasonal variations in near-bottom particle flux, bioturbation intensity, and deposit feeding based on Th-234 measurements AU - McClintic, Mark A. AU - DeMaster, David J. AU - Thomas, Carrie J. AU - Smith, Craig R. T2 - DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY AB - Naturally occurring 234Th (24-d half-life) was used on the West Antarctic continental shelf to evaluate temporal variations in the flux of particulate material reaching the seabed, bioturbation intensity, the seasonal continuity of feeding by benthic fauna, and trends in particle selection during ingestion for six common detritivores (four surface deposit feeders and two subsurface deposit feeders). These measurements were made at three stations during the five FOODBANCS cruises (December 1999, March, June, and October 2000, and March 2001) to assess the nature of pelagic–benthic coupling on the shelf and to evaluate the seabed as a potential food bank for deposit feeders when surface primary production is minimal. Two summer regimes were sampled (March 2000 and March 2001) with the latter exhibiting a distinct 1–2-cm-thick phytodetritus layer in nearly all sediment core samples. At site B, the 234Th fluxes into the near-bottom (150/170 mab) sediment traps were indistinguishable for the December–March 2000, March–June 2000, and June–October 2000 sampling intervals (fluxes ranging from 170 to 280 dpm m−2 d−1). However, the sediment-trap 234Th flux measured for the October 2000–March 2001 interval (1000 dpm m−2 d−1) was ∼5-fold greater than during the other three sampling periods, consistent with the deposition of a phytodetritus layer. The steady-state 234Th fluxes derived from seabed inventories at site B were 2.4–2.7 times greater than the sediment-trap 234Th fluxes, indicating substantial scavenging of this particle-reactive radiotracer in the bottom 150 m of the water column and/or lateral transport near the seabed. The seabed 234Th inventories at the three stations showed no variation during the first four cruises, but were significantly greater during cruise FB-V (March 2001), when the phytodetritus layer occurred. Based on 234Th distributions in the seabed, bioturbation intensities (quantified using the diffusive mixing coefficient, Db) varied from 0.5 to 97 cm2 yr−1. Mixing coefficients were significantly lower during FB-II than during FB-III, but no other time comparisons were statistically significant (p>0.05). 234Th Dbs showed no distinct seasonality, and no correlation with either organic carbon flux into the sediment traps or 234Th inventory in the seabed. The four surface deposit feeders examined, an echiuran worm and three holothurians (Protelpidia murrayi, Bathyplotes fuscivinculum, and Peniagone vignoni), exhibited greater particle selection for recently deposited sediment during ingestion than the two subsurface deposit feeders studied (a head-down deposit feeding holothurian, Molpadia musculus, and an irregular urchin, Amphipneustes lorioli). All six deposit feeders contained excess 234Th activity in gut sediments during all five cruises, indicating sediment ingestion year round, even during the austral winter. The lack of seasonal variation in bioturbation intensity and the demonstration of year-round feeding in deposit feeders are consistent with the hypothesis that the seafloor sediments accumulate labile organic matter produced during periods of high primary production and that deposit feeders utilize this food source as a food bank on a year-round basis. DA - 2008/11// PY - 2008/11// DO - 10.1016/j.dsr2.2008.06.003 VL - 55 IS - 22-23 SP - 2425-2437 SN - 1879-0100 KW - Bioturbation KW - Antarctic shelf KW - Th-234 (or Th-234) KW - Deposit feeder KW - Particle selection KW - Particle flux ER - TY - JOUR TI - Preface and brief synthesis for the FOODBANCS volume AU - Smith, Craig R. AU - DeMaster, David J. T2 - DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY AB - In this volume we present results from the FOODBANCS Project, which examined the fate and benthic community impact of summer bloom material on the West Antarctic Peninsula shelf floor. The project involved a 5-cruise, 15-month time-series program in which sediment-trap moorings, core sampling, radiochemical profiling, sediment respirometry, bottom photography, and bottom trawling were used to evaluate: (1) seafloor deposition and lability of POC, (2) patterns of labile POC consumption and sediment mixing by benthos, and (3) seasonal and inter-annual variations in biotic abundance, biomass, reproductive condition, recruitment, and sediment community respiration. We find that the seafloor flux and accumulation of particulate organic carbon on the West Antarctic Peninsula shelf exhibit intense seasonal and interannual variability. Nonetheless, many key benthic processes, including organic-matter degradation, bioturbation, deposit feeding, and faunal abundance, reproduction and recruitment, show relatively muted response to this intense seasonal and inter-annual variability in export flux. We thus hypothesize that benthic ecosystems on the Antarctic shelf act as “low-pass” filters, and may be extremely useful in resolving the impacts of climatic change over periods of years to decades in Antarctic Peninsula region. DA - 2008/11// PY - 2008/11// DO - 10.1016/j.dsr2.2008.08.001 VL - 55 IS - 22-23 SP - 2399-2403 SN - 1879-0100 KW - Pelagic-benthic coupling KW - Climate change KW - Organic carbon flux KW - Antarctic benthos KW - Sediment food bank ER - TY - JOUR TI - Mixotrophy, a major mode of nutrition for harmful algal species in eutrophic waters AU - Burkholder, JoAann M. AU - Glibert, Patricia M. AU - Skelton, Hayley M. T2 - HARMFUL ALGAE AB - Historically most harmful algal species (HAS) have been thought to be strictly phototrophic. Mixotrophy, the use of phototrophy and heterotrophy in combination, has been emphasized as operative mainly in nutrient-poor habitats as a mechanism for augmenting nutrient supplies. Here we examine an alternate premise, that many harmful algae which thrive in eutrophic habitats are mixotrophs that respond both directly to nutrient inputs, and indirectly through high abundance of bacterial and algal prey that are stimulated by the elevated nutrients. From review and synthesis of the available data, mixotrophy occurs in all HAS examined thus far in the organic substrate- and prey-rich habitats of eutrophic estuarine and marine coastal waters. Where data are available comparing phototrophy versus mixotrophy, mixotrophy in eutrophic habitats generally is significant in nutrient acquisition and growth of HAS and, therefore, likely important in the development and maintenance of their blooms. In eutrophic habitats phagotrophic mixotrophs, in particular, have been shown to attain higher growth than when in phototrophic mode. Yet for many HAS, quantitative data about the role of mixotrophy in nutrition, growth, and blooms are lacking, especially relating laboratory information to natural field assemblages, so that the relative importance of photosynthesis, dissolved organic nutrients, and ingestion of prey largely remain unknown. Research is needed to assess simultaneously the roles of phototrophy, osmotrophy and phagotrophy in the nutritional ecology of HAS in eutrophic habitats, spanning bloom initiation, development and senescence. From these data, models that include the role of mixotrophy can be developed to gain more realistic insights about the nutritional factors that control harmful algae in eutrophic waters, and to strengthen predictive capability in predicting their blooms. An overall forecast that can be tested, as well, is that harmful mixotrophic algae will become more abundant as their food supplies increase in many estuaries and coastal waters that are sustaining chronic, increasing cultural eutrophication. DA - 2008/12// PY - 2008/12// DO - 10.1016/j.hal.2008.08.010 VL - 8 IS - 1 SP - 77-93 SN - 1878-1470 KW - Eutrophication KW - Harmful algae KW - Mixotrophy KW - Nutrients KW - Osmatrophy KW - Phagotrophy KW - Phototroph ER - TY - JOUR TI - Influence of seasonal phytodetritus deposition on biogenic silica dissolution in marine sediments-Potential effects on preservation AU - Gallinari, M. AU - Ragueneau, O. AU - DeMaster, D. J. AU - Hartnett, H. AU - Rickert, D. AU - Thomas, C. T2 - DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY AB - The deposition of fresh phytoplankton detritus (phytodetritus) following phytoplankton blooms may influence biogenic silica (BSi) dissolution in marine sediments. We studied BSi dissolution properties before, during, and after periods of phytodetritus deposition during time-series field programs in the abyssal North Atlantic (the BENGAL project), and on the West Antarctic Peninsula Shelf (the FOODBANCS project). Dissolution experiments, performed by means of flow-through reactors, showed temporal variations in the dissolution properties of BSi in the sediment column after phytodetritus deposition. This non-steady-state character of benthic silica dynamics is an important aspect of pelagic–benthic coupling. The last FOODBANCS cruise occurred after a phytodetritus deposition event, and yielded high pore-water dissolved silica (DSi) concentrations and DSi effluxes in the upper centimetres of the sediment column, suggesting a rapid turnover of recently deposited siliceous material. Higher dissolution rates were measured in the phytodetritus-rich sediments relative to surface sediments collected during previous seasons on earlier FOODBANCS cruises. During the BENGAL project, high dissolution rates were measured at depth in the sediment column only after a summer phytodetritus deposition event. In the highly detrital sediment matrix of the abyssal North Atlantic Ocean, resolution of increased dissolution rates and experimental artefacts of the flow-through reactors can be difficult because of the low abundance of BSi. Depending on the sediment matrix, bioturbation can play a crucial role in transporting fresh BSi particles to depth, where DSi concentrations are close to experimentally determined BSi solubilities. The potential impacts of such processes on BSi preservation are discussed. We suggest that future models of BSi early diagenesis should include the rapid mixing of freshly deposited particles if we want to describe further the preservation of BSi in marine sediments. DA - 2008/11// PY - 2008/11// DO - 10.1016/j.dsr2.2008.06.005 VL - 55 IS - 22-23 SP - 2451-2464 SN - 1879-0100 KW - Biogenic silica KW - Dissolution KW - Phytodetritus KW - Flow-through reactors ER - TY - JOUR TI - Harmful algal blooms and eutrophication: Examining linkages from selected coastal regions of the United States AU - Anderson, Donald M. AU - Burkholder, Joann M. AU - Cochlan, William P. AU - Glibert, Patricia M. AU - Gobler, Christopher J. AU - Heil, Cynthia A. AU - Kudela, Raphael M. AU - Parsons, Michael L. AU - Rensel, J. E. Jack AU - Townsend, David W. AU - Trainer, Vera L. AU - Vargo, Gabriel A. T2 - HARMFUL ALGAE AB - Coastal waters of the United States (U.S.) are subject to many of the major harmful algal bloom (HAB) poisoning syndromes and impacts. These include paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), ciguatera fish poisoning (CFP) and various other HAB phenomena such as fish kills, loss of submerged vegetation, shellfish mortalities, and widespread marine mammal mortalities. Here, the occurrences of selected HABs in a selected set of regions are described in terms of their relationship to eutrophication, illustrating a range of responses. Evidence suggestive of changes in the frequency, extent or magnitude of HABs in these areas is explored in the context of the nutrient sources underlying those blooms, both natural and anthropogenic. In some regions of the U.S., the linkages between HABs and eutrophication are clear and well documented, whereas in others, information is limited, thereby highlighting important areas for further research. DA - 2008/12// PY - 2008/12// DO - 10.1016/j.hal.2008.08.017 VL - 8 IS - 1 SP - 39-53 SN - 1878-1470 KW - Eutrophication KW - Harmful algal blooms (HABs) KW - Nitrogen KW - Nutrients KW - Phosphorus KW - Red tides ER - TY - JOUR TI - Eutrophication and harmful algal blooms: A scientific consensus AU - Heisler, J. AU - Glibert, P. M. AU - Burkholder, J. M. AU - Anderson, D. M. AU - Cochlan, W. AU - Dennison, W. C. AU - Dortch, Q. AU - Gobler, C. J. AU - Heil, C. A. AU - Humphries, E. AU - Lewitus, A. AU - Magnien, R. AU - Marshall, H. G. AU - Sellner, K. AU - Stockwell, D. A. AU - Stoecker, D. K. T2 - Harmful Algae DA - 2008/// PY - 2008/// VL - 8 IS - 1 SP - 3-13 ER - TY - JOUR TI - Disturbance-induced 'spill-in' of Caribbean spiny lobster to marine reserves AU - Eggleston, David B. AU - Parsons, Darren M. T2 - MARINE ECOLOGY PROGRESS SERIES AB - MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 371:213-220 (2008) - DOI: https://doi.org/10.3354/meps07699 Disturbance-induced ‘spill-in’ of Caribbean spiny lobster to marine reserves David B. Eggleston1,2,*, Darren M. Parsons1,3 1North Carolina State University, Department of Marine, Earth and Atmospheric Sciences, Raleigh, North Carolina 27695-8208, USA 2North Carolina State University, Center for Marine Sciences and Technology, 303 College Circle, Morehead City, North Carolina 28557, USA 3National Institute of Water and Atmospheric Research, Private Bag 99940, Auckland, New Zealand *Email: eggleston@ncsu.edu ABSTRACT: Marine reserves have the potential to enhance fisheries productivity by increasing total spawning potential or by spillover, the migration of juveniles and adults from reserves to non-reserve areas. Spillover has been the focus of many studies and has been an important argument in promoting the benefits of marine reserves to gain public support. Few studies, however, have examined mechanisms for colonization or migrations into marine reserves. The present study provides direct field evidence that disturbance from a sport diving fishery can elevate the abundance of Caribbean spiny lobster Panulirus argus in nearby marine reserves—particularly in reserves containing relatively high densities of non-disturbed lobsters—presumably through conspecific attraction where lobsters follow chemical cues to undisturbed sites in marine reserves. Population redistribution following fishery disturbance has implications for marine reserve design and application. For example, risk-averse fishery management strategies might locate reserves adjacent to intensely fished areas to enhance spill-in of mobile species. KEY WORDS: Animal behavior · Caribbean spiny lobster · Disturbance · Fisheries management · Sociality · Marine protected areas · Marine reserves · Predation · Spill-in · Spillover · Sport divers Full text in pdf format PreviousNextCite this article as: Eggleston DB, Parsons aDM (2008) Disturbance-induced ‘spill-in’ of Caribbean spiny lobster to marine reserves. Mar Ecol Prog Ser 371:213-220. https://doi.org/10.3354/meps07699 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 371. Online publication date: November 19, 2008 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2008 Inter-Research. DA - 2008/// PY - 2008/// DO - 10.3354/meps07699 VL - 371 SP - 213-220 SN - 1616-1599 KW - Animal behavior KW - Caribbean spiny lobster KW - Disturbance KW - Fisheries management KW - Sociality KW - Marine protected areas KW - Marine reserves KW - Predation KW - Spill-in KW - Spillover KW - Sport divers ER - TY - JOUR TI - Distribution of axial lava domes along a superfast overlapping spreading center, 27-32 degrees S on the East Pacific Rise AU - Bohnenstiehl, D. R. AU - Howell, J. K. AU - Hey, R. N. T2 - GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS AB - Deep‐towed DSL‐120 bathymetric data are used to investigate the pattern of lava dome formation along a superfast spreading portion of the southern East Pacific Rise (EPR), including the overlapping limbs of a giant (120 × 120 km) propagator near 29°S. Along the 670 km of the axis surveyed, 1172 small domes were identified using a closed contour algorithm. Their abundance, defined by spatial density, is well correlated with the along‐axis relief of the ridge crest. Where the western and eastern limbs plunge toward the overlap zone, densities are high (3–6 km −2 ); however, where the axial depth profile is shallow and flat, densities are comparably low (0.4 km −2 ). Volcanic domes within the low abundance areas are characterized by lower ratios of height to basal radius (0.15 versus 0.22), smaller maximum heights (18 versus 40 m), and a larger relative percentage of small versus large mounds. The zone of high dome abundance encompasses the overlapping limbs of the rift and extends more than 100 km to the north and south beyond the overlap zone. Domes form dominantly during low effusion rate, point‐source eruptions, which suggests that discontinuous melt lenses underlie the ridge axis proximal to the overlapper. Conversely, fissure‐fed sheet flows dominate along the more distal segments, implying the presence of a more continuous axial magma lens. Throughout the survey area, dome abundance increases systematically near second‐order segment boundaries. Within the high abundance zone, some third‐order offsets also correlate with increased dome production, but local peaks in abundance are not tied exclusively to higher‐order ridge offsets. Where dome abundance is low, domes are clustered tightly near second‐order offsets and there is no increase in dome abundance near third‐order segment boundaries. DA - 2008/12/12/ PY - 2008/12/12/ DO - 10.1029/2008gc002158 VL - 9 SP - SN - 1525-2027 KW - seamounts KW - lava domes KW - propagating rifts ER - TY - JOUR TI - C-14 as a tracer of labile organic matter in Antarctic benthic food webs AU - Purinton, Brett L. AU - DeMaster, David J. AU - Thomas, Carrie J. AU - Smith, Craig R. T2 - DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY AB - 14C measurements were made on surface plankton, particle-trap material, surface sediment, benthic invertebrate gut contents, and body tissue samples to assess the effectiveness of this radioisotope as a tracer of labile organic carbon in Antarctic benthic food webs. Samples were collected on five cruises to the West Antarctic Peninsula (WAP) shelf between November 1999 and March 2001 as part of the Food for Benthos on the ANtarctic Continental-Shelf (FOODBANCS) Project. The 14C contents of the body tissues from a variety of deposit feeders (−126±13 per mil) were substantially enriched relative to the surface sediment (−234±13 per mil) and statistically similar to the organic matter collected in plankton tows (−135±10 per mil), indicating that recently produced marine plankton are the primary source of nutrition for these deposit feeders on the West Antarctic shelf. Selective ingestion was the primary feeding strategy used by echiuran worms and certain holothurians (i.e. Peniagone vignoni) for incorporating labile organic carbon into their tissues as demonstrated by the large differences (105±13 per mil) between surface sediment and gut content 14C activities. In contrast, digestive and/or assimilatory selection was the predominant strategy used by an irregular urchin (Amphipneustes lorioli) and several other holothurians (Protelpidia murrayi, Bathyplotes fuscivinculum and the head-down conveyor belt feeder, Molpadia musculus), as demonstrated by large differences (42±7 per mil) between the 14C activities of their foregut or whole-gut organic contents and their body tissues. Despite large fluctuations in carbon export from the euphotic zone, benthic feeding strategies remained essentially constant over the 15-month sampling period. No seasonal variation was evident in either the 14C abundance of the deposit-feeder body tissues, or in the 14C abundance of their gut contents. The mean 14C abundance in the body tissues of the two sub-surface deposit feeders (A. lorioli and M. musculus; mean=−136.2±8.5 per mil) was distinct (p=0.0008) from the mean 14C abundance in the body tissues of the four surface deposit feeders (echiuran worm, P. vignoni, P. murrayi, and B. fusciviculum; −122.6±12.3 per mil). The mean 14C abundance of the gut contents from the sub-surface deposit feeders (−178.0±18.6 per mil) also was significantly depleted (p=0.0009) relative to that of the surface deposit feeders (−149.5±26.6 per mil). The 14C measurements proved to be a much more sensitive tracer for tracking labile organic carbon during ingestive and assimilatory processes than the stable isotopes of carbon or nitrogen. DA - 2008/11// PY - 2008/11// DO - 10.1016/j.dsr2.2008.06.004 VL - 55 IS - 22-23 SP - 2438-2450 SN - 1879-0100 KW - FOODBANCS KW - Labile organic matter KW - Radiocarbon KW - Feeding strategies of deposit feeders KW - West Antarctic Peninsula Continental Shelf KW - Benthic carbon cycling ER - TY - JOUR TI - Benthic oxygen fluxes and denitrification rates from high-resolution porewater profiles from the Western Antarctic Peninsula continental shelf AU - Hartnett, Hilairy AU - Boehme, Susan AU - Thomas, Carrie AU - DeMaster, David AU - Smith, Craig T2 - DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY AB - Benthic fluxes of dissolved oxygen and nitrate were calculated from high-resolution porewater profiles collected on the continental margin of the Western Antarctic Peninsula. Profiles were collected in four seasons between March 2000 and February 2001 as part of the FOODBANCS program. Oxygen consumption rates ranged from 0.92 to 3.11 mmol O2 m−2 d−1 over the course of the year with an average annual oxygen consumption rate of 1.74 mmol O2 m−2 d−1. The oxygen fluxes follow a trend similar to the particulate carbon export flux with smaller fluxes during the winter and larger fluxes during the spring bloom period. However, the range in oxygen fluxes is substantially smaller than the range in the particulate carbon export. Denitrification rates ranged from 0.66 to 1.46 mmol N m−2 d−1, and the average annual denitrification rate was 1.29 mmol N m−2 d−1. The O2 consumption and denitrification rates are of similar magnitude to rates measured on other deep (∼500 m) continental margins. Denitrification rates are strongly coupled to nitrification rates, with coupled nitrification–denitrification accounting for more than 80% of the total denitrification rate in these sediments. The Antarctic continental-margin sediment denitrification rates correspond to ∼3–5 Tg N yr−1, and thus these continental-margin sediments account for roughly 1–2% of the global sediment denitrification signal. DA - 2008/11// PY - 2008/11// DO - 10.1016/j.dsr2.2008.06.002 VL - 55 IS - 22-23 SP - 2415-2424 SN - 1879-0100 KW - Benthic flux KW - Denitrification KW - Oxygen consumption KW - Carbon oxidation KW - Biogeochemistry KW - Respiration ER - TY - JOUR TI - Advances and insights in the complex relationships between eutrophication and HABs: Preface to the special issue AU - Glibert, Patricia M. AU - Burkholder, JoAnn M. AU - Graneli, Edna AU - Anderson, Donald M. T2 - HARMFUL ALGAE AB - Dinoflagellate algal blooms (DABs), with Lingulodinium polyedrum as the dominant species, have increased over the past few years in coastal areas off Baja California, Mexico. Vertical and temporal variability of particulate cadmium (Cdp), dissolved Cd (Cdd), PO43 − and Cdd/PO43 − were investigated during two intense DABs of L. polyedrum that occurred during the fall of 2011 and 2012 in Todos Santos Bay. Results were then, compared with data gathered in the absence of algal blooms during the autumn of 2013. In both algal blooms, L. polyedrum tended to be concentrated near the surface throughout the duration; however, during DAB 2011 the number of cells was twice as abundant ([10.0 ± 8.0] × 105 cells L− 1) as in DAB 2012 ([5.0 ± 4.4] × 105 cells L− 1). During DAB 2011, Cdp increased significantly (up to 1.02 ± 0.99 nmol kg− 1) and was positively correlated with the cell abundance of L. polyedrum, suggesting that this dinoflagellate is able to assimilate and concentrate Cdd. Likewise, Cdd (up to 0.71 ± 0.17 nM) increased in the days of highest cell abundance, which could be attributed to uptake and subsequent regeneration of Cdd resulting from the remineralization of organic particulate matter produced during the bloom, as well as with the presence of organic ligands secreted by L. polyedrum that could keep Cdd in solution. During DAB 2011, dissolved Cdd/PO43 − ratios exhibited high vertical and temporal variability in the upper 5 m of the water column, but remained virtually constant near the bottom, suggesting a depth-dependent decoupling between these two dissolved components during the bloom development. Given the observed differences in the vertical and temporal variability of Cdd, Cdp, and PO43 − between these two intense DABs, we propose the existence of an abundance threshold of approximately 106 cells L− 1 of L. polyedrum above which Cd and PO43 − significantly increased due to remineralization in coastal waters during the bloom development. DA - 2008/12// PY - 2008/12// DO - 10.1016/j.hal.2008.08.020 VL - 8 IS - 1 SP - 1-2 SN - 1568-9883 ER - TY - JOUR TI - Flux and fate of small mountainous rivers derived sediments into the Taiwan Strait AU - Liu, J.P. AU - Liu, C.S. AU - Xu, K.H. AU - Milliman, J.D. AU - Chiu, J.K. AU - Kao, S.J. AU - Lin, S.W. T2 - Marine Geology AB - High-resolution CHIRP sonar profiles across the Taiwan Strait reveal a large silt–sand-dominated deltaic clinoform, up to 50-m thick, overlying the postglacial transgressive sea floor across the southeastern, central, and northern strait. Delta-like configuration and internal depositional sequences indicate a northwestward progradation from western Taiwan, primarily from the Choshui (Zhuoshui) River. Grain-size and mineral data confirm the sediment's Taiwanese derivation. The CHIRP profiles, together with existing radiocarbon and geomagnetic dates, suggest that the clinoform has formed over the past 10 kyr. The estimated volume of 375 km3 of sediment (mainly sand and silt) suggests a mean annual accumulation of 60 × 106 t/yr. Presumably much of fine mud delivered by Taiwanese rivers has been washed away by the local currents, and escaped either northeastward into the Southern Okinawa Trough or southward into the South China Sea. Numerous shallow borings onshore over the central western Taiwan coastal plain reveal an additional 350 km3 of fluvial sediment that has accumulated over the past 10 kyr. The combined onshore–offshore Holocene accumulation, together with an unknown amount of finer sediment that escapes the system, indicates that the long-term sediment flux from Western Taiwanese rivers exceeds 100 × 106 t/yr, which is not different from the present-day combined annual discharges from the Choshui, Tsengwen, Ehrjen and Wu rivers into the Taiwan Strait. DA - 2008/12// PY - 2008/12// DO - 10.1016/j.margeo.2008.09.007 VL - 256 IS - 1-4 SP - 65-76 J2 - Marine Geology LA - en OP - SN - 0025-3227 UR - http://dx.doi.org/10.1016/j.margeo.2008.09.007 DB - Crossref KW - Taiwan Strait KW - Choshui River KW - subaqueous delta KW - hyperpycnal KW - Chirp Sonar ER - TY - JOUR TI - Topographic effects on the path and evolution of Loop Current eddies AU - Hyun, K. H. AU - Hogan, P. J. T2 - Journal of Geophysical Research. Oceans DA - 2008/// PY - 2008/// VL - 113 IS - C12 ER - TY - JOUR TI - The Initiation and Evolution of Multiple Modes of Convection within a Meso-Alpha-Scale Region AU - French, Adam J. AU - Parker, Matthew D. T2 - WEATHER AND FORECASTING AB - Abstract On 30 March 2006, a convective episode occurred featuring isolated supercells, a mesoscale convective system (MCS) with parallel stratiform (PS) precipitation, and an MCS with leading stratiform (LS) precipitation. These three distinct convective modes occurred simultaneously across the same region in eastern Kansas. To better understand the mechanisms that govern such events, this study examined the 30 March 2006 episode through a combination of an observation-based case study and numerical simulations. The convective mode was found to be very sensitive to both the environmental thermodynamic and wind shear profiles, with variations in either leading to different convective modes within the numerical simulations. Strong vertical shear and moderate instability led to the development of supercells in western Oklahoma. Strong shear oriented parallel to a surface dryline, coupled with dry air in the middle and upper levels, led to the development of the PS linear MCS in central Kansas. Meanwhile, moderate wind shear coupled with high instability and strong linear forcing led to the development of the LS MCS in eastern Kansas. Absent linear forcing, the moderate shear environment in eastern Kansas was supportive of isolated supercells in the numerical experiments. This suggests that the linear initiation mechanism was key to the development of the LS linear MCS. From the results of this study it is concuded that, for this event, localized environmental variations were largely responsible for the eventual convective mode, with the method of storm initiation having an impact only within the weaker shear environment of eastern Kansas. DA - 2008/12// PY - 2008/12// DO - 10.1175/2008WAF2222136.1 VL - 23 IS - 6 SP - 1221-1252 SN - 1520-0434 ER - TY - JOUR TI - Miocene sharks in the Kendeace and Grand Bay formations of Carriacou, The Grenadines, Lesser Antilles AU - Portell, R. W. AU - Hubbell, G. AU - Donovan, S. K. AU - Green, J. L. AU - Harper, D. A. T. AU - Pickerill, R. T2 - Caribbean Journal of Science DA - 2008/// PY - 2008/// VL - 44 IS - 3 SP - 279-286 ER - TY - JOUR TI - Inherently Conservative Nonpolynomial-Based Remapping Schemes: Application to Semi-Lagrangian Transport AU - Norman, Matthew R. AU - Nair, Ramachandran D. T2 - MONTHLY WEATHER REVIEW AB - Abstract A group of new conservative remapping schemes based on nonpolynomial approximations is proposed. The remapping schemes rely on the conservative cascade scheme (CCS), which employs an efficient sequence of 1D remapping operations to solve a multidimensional problem. The present study adapts three new nonpolynomial-based reconstructions of subgrid variation to the CCS: the Piecewise Hyperbolic Method (PHM), the Piecewise Double Hyperbolic Method (PDHM), and the Piecewise Rational Method (PRM) for comparison with the baseline method: the Piecewise Parabolic Method (PPM). Additionally, an adaptive hybrid approximation scheme, PPM-Hybrid (PPM-H), is constructed using monotonic PPM for smooth data and local extrema and using PHM for steep jumps where PPM typically suffers large accuracy degradation because of its original monotonic filter. Smooth and nonsmooth data profiles are transported in 1D, 2D Cartesian, and 2D spherical frameworks under uniform advection, solid-body rotation, and deformational flow. Accuracy is compared via the L1 global error norm. In general, PPM outperformed PHM, but when the majority of the error came from PPM degradation at sharp derivative changes (e.g., the vicinity near sine wave extrema), PHM was more accurate. PRM performed very similarly to PPM for nonsmooth functions, but the order of convergence was worse than PPM for smoother data. PDHM performed the worst of all of the nonpolynomial methods for nearly every test case. PPM-H outperformed PPM and all of the nonpolynomial methods for all test cases in all geometries, offering a robust advantage in the CCS scheme with a negligible increase in computational time. DA - 2008/12// PY - 2008/12// DO - 10.1175/2008MWR2499.1 VL - 136 IS - 12 SP - 5044-5061 SN - 1520-0493 ER - TY - JOUR TI - Convectively Coupled Kelvin Waves over Tropical Africa during the Boreal Summer: Structure and Variability AU - Mekonnen, Ademe AU - Thorncroft, Chris D. AU - Aiyyer, Anantha R. AU - Kiladis, George N. T2 - JOURNAL OF CLIMATE AB - Abstract The structure and variability of convectively coupled Kelvin waves during the boreal summer are explored using satellite-observed brightness temperature data and ECMWF reanalyses. Kelvin wave activity is most prominent between the central and eastern Pacific, across Africa, and the Indian Ocean. Composite analysis shows that over sub-Saharan Africa Kelvin wave convection is peaked north of the equator, while the dynamical fields tend to be symmetric with respect to the equator. Convectively coupled Kelvin waves propagate faster over the Pacific and western Atlantic (∼24 m s−1), and slow down over tropical Africa (∼14 m s−1), consistent with stronger coupling between the dynamics and convection over tropical Africa. The Kelvin waves observed over Africa generally propagate into the region from anywhere between the eastern Pacific and the Atlantic, and decay over the eastern Indian Ocean basin. Results show marked interannual variability of Kelvin wave activity over Africa. Anomalously high Kelvin wave variance tends to occur during dry years, while low variance occurs during wet years. African Kelvin wave activity is positively correlated with SST anomalies in the equatorial east Pacific. The same warm SST anomalies that are favorable for enhanced Kelvin wave activity suppress the mean rainfall over tropical Africa via a more slowly varying teleconnection and associated subsidence. A brief analysis of an intense Kelvin wave in August 1987 (a dry year) shows a clear impact of the wave on convective development and daily rainfall over tropical Africa. This Kelvin wave was also associated with a series of easterly wave initiations over tropical Africa. DA - 2008/12// PY - 2008/12// DO - 10.1175/2008JCLI2008.1 VL - 21 IS - 24 SP - 6649-6667 SN - 1520-0442 ER - TY - JOUR TI - Numerical study on salinity stratification in the Pamlico River Estuary AU - Xu, Hongzhou AU - Lin, Jing AU - Wang, Dongxiao T2 - ESTUARINE COASTAL AND SHELF SCIENCE AB - The variations of current circulation, salt intrusion, and vertical stratification under different river flow and wind conditions in the Pamlico River Estuary (PRE) were investigated in this paper using a three-dimensional numerical model. The model was calibrated and verified against water level variation, temperature, and salinity variations during 2003 and 2001, respectively. Eight sensitivity tests were conducted with different river flow and wind conditions specified in the model. Model results show that salinity intruded further upstream under scenarios with low flow, downriver local wind, and remote-wind-caused water level set-up conditions. In contrast, the responses of salinity stratification to different environmental forcing functions were different in different portions of the estuary. Salinity stratification was enhanced under high flow condition at the lower part of the estuary, under upriver wind near the river mouth, under downriver wind at the upstream to middle portion of the estuary, and under remote-wind-caused water level set-up condition at the majority of the estuary except near the river mouth. Model results also show that across-channel wind tended to reduce salt intrusion and salinity stratification in the PRE through increased vertical mixing. DA - 2008/10/20/ PY - 2008/10/20/ DO - 10.1016/j.ecss.2008.07.014 VL - 80 IS - 1 SP - 74-84 SN - 1096-0015 KW - salinity stratification KW - estuarine circulation KW - wind KW - river discharge KW - Pamlico River Estuary ER - TY - JOUR TI - Magnetic resonance imaging of live freshwater mussels (Unionidae) AU - Holliman, F. Michael AU - Davis, Denise AU - Bogan, Arthur E. AU - Kwak, Thomas J. AU - Cope, W. Gregory AU - Levine, Jay F. T2 - INVERTEBRATE BIOLOGY AB - Abstract. We examined the soft tissues of live freshwater mussels, Eastern elliptio Elliptio complanata , via magnetic resonance imaging (MRI), acquiring data with a widely available human whole‐body MRI system. Anatomical features depicted in the profile images included the foot, stomach, intestine, anterior and posterior adductor muscles, and pericardial cavity. Noteworthy observations on soft tissue morphology included a concentration of lipids at the most posterior aspect of the foot, the presence of hemolymph‐filled fissures in the posterior adductor muscle, the presence of a relatively large hemolymph‐filled sinus adjacent to the posterior adductor muscle (at the ventral‐anterior aspect), and segmentation of the intestine (a diagnostic description not reported previously in Unionidae). Relatively little is known about the basic biology and ecological physiology of freshwater mussels. Traditional approaches for studying anatomy and tissue processes, and for measuring sub‐lethal physiological stress, are destructive or invasive. Our study, the first to evaluate freshwater mussel soft tissues by MRI, clarifies the body plan of unionid mussels and demonstrates the efficacy of this technology for in vivo evaluation of the structure, function, and integrity of mussel soft tissues. DA - 2008/// PY - 2008/// DO - 10.1111/j.1744-7410.2008.00143.x VL - 127 IS - 4 SP - 396-402 SN - 1744-7410 KW - MRI KW - morphology KW - bivalve KW - soft tissue KW - unionid ER - TY - JOUR TI - Composite semiconductor H2WO4 center dot H2O/AgCl as an efficient and stable photocatalyst under visible light AU - Wang, P. AU - Huang, B. B. AU - Zhang, X. Y. AU - Qin, X. Y. AU - Dai, Y. AU - Jin, H. AU - Wei, J. Y. AU - Whangbo, M. H. T2 - Chemistry (Weinheim An Der Bergstrasse, Germany) DA - 2008/// PY - 2008/// VL - 14 IS - 34 SP - 10543-10546 ER - TY - JOUR TI - AXENIC CULTIVATION OF THE HETEROTROPHIC DINOFLAGELLATE PFIESTERIA SHUMWAYAE AND OBSERVATIONS ON FEEDING BEHAVIOR AU - Skelton, Hayley M. AU - Burkholder, JoAnn M. AU - Parrow, Matthew W. T2 - JOURNAL OF PHYCOLOGY AB - Pfiesteria shumwayae Glasgow et J. M. Burkh. [= Pseudopfiesteria shumwayae (Glasgow et J. M. Burkh.) Litaker, Steid., P. L. Mason, Shields et P. A. Tester] is a heterotrophic dinoflagellate commonly found in temperate, estuarine waters. P. shumwayae can feed on other protists, fish, and invertebrates, but research on the biochemical requirements of this species has been restricted by the lack of axenic cultures. An undefined, biphasic culture medium was formulated that supported the axenic growth of two of three strains of P. shumwayae . The medium contained chicken egg yolk as a major component. Successful growth depended on the method used to sterilize the medium, and maximum cell yields (10 4 · mL −1 ) were similar to those attained in previous research when P. shumwayae was cultured with living fish or microalgae. Additionally, P. shumwayae flagellate cells ingested particles present in the biphasic medium, allowing detailed observations of feeding behavior. This research is an initial step toward a chemically defined axenic culture medium and determination of P. shumwayae metabolic requirements. DA - 2008/12// PY - 2008/12// DO - 10.1111/j.1529-8817.2008.00601.x VL - 44 IS - 6 SP - 1614-1624 SN - 1529-8817 KW - axenic culture KW - dinoflagellate KW - heterotrophic KW - Pfiesteria KW - phagotrophy ER - TY - JOUR TI - Unintended facilitation between marine consumers generates enhanced mortality for their shared prey AU - Fodrie, F. J. AU - Kenworthy, M. D. AU - Powers, S. P. T2 - Ecology (Brooklyn, New York, N.Y.) DA - 2008/// PY - 2008/// VL - 89 IS - 12 SP - 3268-3274 ER - TY - JOUR TI - Modeling thermal stratification in fan-ventilated greenhouses AU - Li, S. AU - Willits, D. H. T2 - Transactions of the ASABE AB - A two-dimensional thermal model was developed to investigate the thermal stratification in fan-ventilated greenhouses. Model inputs include outside weather (air temperature, humidity, and solar radiation), geometric parameters of crop rows and leaf area index, greenhouse ground and roof temperatures, ventilation rate, and operation of evaporative cooling pads. Comparing predictions with observed data indicated that the air temperature and relative humidity were modeled at acceptable accuracies, with air temperature underpredicted by 1.3C and relative humidity overpredicted by 9%, on average for a planted greenhouse. For an unplanted greenhouse, the air temperature was predicted with an absolute error of 0.7C, while for relative humidity the absolute error was 3%. Vertical temperature variation, defined as maximum temperature minus minimum temperature at approximately the central location of greenhouse, was predicted with an absolute error of 0.1C and a relative absolute error of 10% for the planted greenhouse, while for an unplanted greenhouse it was 0.6C for the absolute error and 12% for the relative absolute error. Simulations with the model suggest that increasing ventilation rate reduced the vertical temperature gradient. Increased ventilation reduced air temperature more at the top than the bottom of the greenhouse. Greater air temperature variation was produced when using evaporative pad cooling than not. Air temperature was reduced more at the bottom than at the top with evaporative pad cooling. The presence of a canopy altered the vertical air temperature distribution and reduced the temperature variation. A sample simulation showed that on a typical summer day at Raleigh, North Carolina, the presence of a canopy row with a height of 1.75 m occupying 69% of the ground area reduced the air temperature variation from 11.5C to 1.8C in a fan-ventilated greenhouse operating with a ventilation rate of 0.087 m3 m-2 s-1 and using evaporative pad cooling. The peak air temperature generally occurred at the top of canopy or somewhat below the canopy top. This finding may have some significance in establishing the location of temperature control sensors in future control systems. DA - 2008/// PY - 2008/// DO - 10.13031/2013.25307 VL - 51 IS - 5 SP - 1735-1746 ER - TY - JOUR TI - Parameterization of N2O5 reaction probabilities on the surface of particles containing ammonium, sulfate, and nitrate AU - Davis, J. M. AU - Bhave, P. V. AU - Foley, K. M. T2 - ATMOSPHERIC CHEMISTRY AND PHYSICS AB - Abstract. A parameterization was developed for the heterogeneous reaction probability (γ) of N2O5 as a function of temperature, relative humidity (RH), particle composition, and phase state, for use in advanced air quality models. The reaction probabilities on aqueous NH4HSO4, (NH4)2SO4, and NH4NO3 were modeled statistically using data and uncertainty values compiled from seven different laboratory studies. A separate regression model was fit to laboratory data for dry NH4HSO4 and (NH4)2SO4 particles, yielding lower γ values than the corresponding aqueous parameterizations. The regression equations reproduced 80% of the laboratory data within a factor of two and 63% within a factor of 1.5. A fixed value was selected for γ on ice-containing particles based on a review of the literature. The combined parameterization was applied under atmospheric conditions representative of the eastern United States using 3-dimensional fields of temperature, RH, sulfate, nitrate, and ammonium. The resulting spatial distributions of γ were contrasted with three other parameterizations that have been applied in air quality models in the past and with atmospheric observational determinations of γ. Our equations lay the foundation for future research that will parameterize the suppression of γ when inorganic ammoniated particles are mixed or coated with organic material. Our analyses draw attention to a major uncertainty in the available laboratory data at high RH and highlight a critical need for future laboratory measurements of γ at low temperature and high RH to improve model simulations of N2O5 hydrolysis during wintertime conditions. DA - 2008/// PY - 2008/// DO - 10.5194/acp-8-5295-2008 VL - 8 IS - 17 SP - 5295-5311 SN - 1680-7324 ER - TY - JOUR TI - Impacts of Road Crossings on Fish Movement and Community Structure AU - Vander Pluym, Jenny L. AU - Eggleston, David B. AU - Levine, Jay F. T2 - Journal of Freshwater Ecology AB - ABSTRACT We quantified the impact of four commonly used road crossings (bridge, arch culvert, box culvert, and pipe culvert) on stream fish community structure and movement in the Piedmont region of the Cape Fear River basin of North Carolina, USA during summer 2004. We focused on non-perched crossings, which did not present a physical barrier to fish movement. With the exception of species richness, all response variables (fish population size, species diversity, fish index of biotic integrity, and conditional percentage of movement) did not vary significantly with crossing type, position (upstream and downstream), or month. Streams with arch culverts contained significantly higher species richness than streams with bridges. The general lack of stream fish abundance and diversity responses to road crossings may be due to the insensitivity of stream fish community variables to anthropogenic effects, the insensitivity of fish communities to the presence of crossings, the overall resilience of fish communities, or the shifting baseline theory (fish communities having shifted to a different community prior to sampling). Triple-pass electrofishing results suggest that these road crossings had no detectable effect on fish abundance or diversity. DA - 2008/12// PY - 2008/12// DO - 10.1080/02705060.2008.9664244 VL - 23 IS - 4 SP - 565-574 J2 - Journal of Freshwater Ecology LA - en OP - SN - 0270-5060 2156-6941 UR - http://dx.doi.org/10.1080/02705060.2008.9664244 DB - Crossref ER - TY - JOUR TI - Estimating upper ocean phosphate concentrations using ARGO float temperature profiles AU - Kamykowski, Daniel T2 - DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS AB - The ARGO free-drifting profiling float array, with >3125 floats deployed between 60°N and 60°S latitudes at about 3° resolution as of May 2008 and each float profiling through 2000 m every 10 days, provides a comprehensive four-dimensional view of temperature and salinity in the world ocean. The resulting dataset complements satellite-based sea surface temperature (SST) measurements and similarly will complement future satellite-based sea surface salinity measurements. Although plans exist to add biogeochemical sensors to future floats, cost and depth restrictions may limit comprehensive upgrades to a fraction of all floats deployed after 2008. Temperature–nutrient (TN) relationships provide a mechanism to estimate nutrient concentrations from temperature to supplement sparser nutrient concentration measurements potentially obtained using non-chemical approaches like ISUS-based nitrate. Both negative and positive aspects of applying a temperature–phosphate (TP) linear regression matrix with global coverage (70°N and 70°S) are examined. The TP linear regression matrix was derived by combining an existing 1° latitude and longitude table of phosphate depletion temperatures (PDT) or X-intercepts with representative TP linear regression slopes derived from the GEOSECS dataset. Temperatures from datasets with associated latitude and longitude coordinates and, in some cases, measured phosphate concentrations ([PO4]) were matched with calculated TP linear regression slopes and Y-intercepts in the global matrix with 1° resolution using MSExcel Lookup worksheet functions to calculate TP-estimated [PO4]. The mean deviation of TP-estimated [PO4] <3.0 μM from measured [PO4] is 0.18±0.18 μM at Hawaii (HOT) and 0.04±0.08 μM at Bermuda (BATS) time series stations and 0.28±0.27 μM over all considered World Ocean Circulation Experiment (WOCE) stations representing the different ocean basins. In general, TP-estimated [PO4] represents measured [PO4] more accurately in the southern hemisphere than in the northern hemisphere. For the World Ocean Atlas 2005 (WOA05), a TP-estimated [PO4] map based on annual statistical mean SST approximates an annual statistical mean measured [PO4] map in overall geographic pattern but less so in absolute concentration. ARGO 0–10 m temperature data and derived TP-estimated [PO4] maps from all 2006 compare more favorably with the WOA05 annual statistical mean SST and measured [PO4] maps. For winter 2006, ARGO 0–10 m temperature and derived TP-estimated [PO4] maps favorably compare with MODIS mean SST and derived TP-estimated [PO4] maps. ARGO 30–50 m and 75–100 m temperatures from winter 2006 and derived TP-estimated [PO4] demonstrate that the ARGO dataset provides a subsurface nutrient complement to nutrient inferences based on MODIS SST. The TP-estimated [PO4] approach is responsive to changing conditions since the independent variable, temperature, integrates ambient environmental variability as expressed in the vertical thermal structure at the time of the ARGO profile. TP-estimated [PO4] can enhance the interpretation of developing ARGO-based ecosystem applications by providing more specific estimates of nutrient availability than temperature alone. DA - 2008/11// PY - 2008/11// DO - 10.1016/j.dsr.2008.05.017 VL - 55 IS - 11 SP - 1580-1589 SN - 1879-0119 KW - Subsurface drifters KW - Nutrients (mineral) KW - Near-surface layer KW - Thermocline KW - Oceans KW - 60 degrees N-60 degrees S ER - TY - JOUR TI - Uncertainties in the oxygen isotopic composition of barium sulfate induced by coprecipitation of nitrate AU - Michalski, Greg AU - Kasem, Michelle AU - Rech, Jason A. AU - Adieu, Sabine AU - Showers, William S. AU - Genna, Bernie AU - Thiemens, Mark T2 - RAPID COMMUNICATIONS IN MASS SPECTROMETRY AB - Coprecipitation of nitrate and sulfate by barium has probably resulted in significant error in numerous studies dealing with the oxygen isotopic composition of natural sulfates using chemical/thermal conversion of BaSO(4) and analysis by isotope ratio mass spectrometry. In solutions where NO(3) (-)/SO(4) (2-) molar ratios are above 2 the amount of nitrate coprecipitated with BaSO(4) reaches a maximum of approximately 7% and decreases roughly linearly as the molar ratio decreases. The fraction of coprecipitated nitrate appears to increase with decreasing pH and is also affected by the nature of the cations in the precipitating solution. The size of the oxygen isotope artifact in sulfate depends both on the amount of coprecipitated nitrate and the delta(18)O and Delta(17)O values of the nitrate, both of which can be highly variable. The oxygen isotopic composition of sulfate extracted from atmospheric aerosols or rain waters are probably severely biased because photochemical nitrate is usually also present and it is highly enriched in (18)O (delta(18)O approximately 50-90 per thousand) and has a large mass-independent isotopic composition (Delta(17)O approximately 20-32 per thousand). The sulfate delta(18)O error can be 2-5 per thousand with Delta(17)O artifacts reaching as high as 4.0 per thousand. DA - 2008/10// PY - 2008/10// DO - 10.1002/rcm.3687 VL - 22 IS - 19 SP - 2971-2976 SN - 1097-0231 ER - TY - JOUR TI - The influence of mesoscale mountains on vortex tracks: shallow-water modeling study AU - Huang, C. -Y. AU - Lin, Y. -L. T2 - METEOROLOGY AND ATMOSPHERIC PHYSICS DA - 2008/9// PY - 2008/9// DO - 10.1007/s00703-007-0284-1 VL - 101 IS - 1-2 SP - 1-20 SN - 1436-5065 ER - TY - JOUR TI - Perspectives of university faculty regarding faculty reading circles: A study using Q methodology AU - Ramlo, S. E. AU - McConnell, D. A. T2 - Journal of Faculty Development DA - 2008/// PY - 2008/// VL - 22 IS - 1 SP - 25-32 ER - TY - JOUR TI - Modeling studies of ammonia dispersion and dry deposition at some hog farms in North Carolina AU - Bajwa, Kanwardeep S. AU - Arya, S. Pal AU - Aneja, Viney P. T2 - JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION AB - A modeling study was conducted on dispersion and dry deposition of ammonia taking one hog farm as a unit. The ammonia emissions used in this study were measured under our OPEN (Odor, Pathogens, and Emissions of Nitrogen) project over a waste lagoon and from hog barns. Meteorological data were also collected at the farm site. The actual layout of barns and lagoons on the farms was used to simulate dry deposition downwind of the farm. Dry deposition velocity, dispersion, and dry deposition of ammonia were studied over different seasons and under different stability conditions using the short-range dispersion/air quality model, AERMOD. Dry deposition velocities were highest under near-neutral conditions and lowest under stable conditions. The highest deposition at short range occurred under nighttime stable conditions and the lowest occurred during daytime unstable conditions. Significant differences in deposition over crop and grass surfaces were observed under stable conditions. DA - 2008/9// PY - 2008/9// DO - 10.3155/1047-3289.58.9.1198 VL - 58 IS - 9 SP - 1198-1207 SN - 1047-3289 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-53849137372&partnerID=MN8TOARS ER - TY - JOUR TI - Measurement, analysis, and modeling of fine particulate matter in eastern North Carolina AU - Goetz, Stephen AU - Aneja, Viney P. AU - Zhang, Yang T2 - JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION AB - An analysis of fine particulate data in eastern North Carolina was conducted to investigate the impact of the hog industry and its emissions of ammonia into the atmosphere. The fine particulate data are simulated using ISORROPIA, an equilibrium thermodynamic model that simulates the gas and aerosol equilibrium of inorganic atmospheric species. The observational data analyses show that the major constituents of fine particulate matter (PM2.5) are organic carbon, elemental carbon, sulfate, nitrate, and ammonium. The observed PM2.5 concentration is positively correlated with temperature but anticorrelated with wind speed. The correlation between PM2.5 and wind direction at some locations suggests an impact of ammonia emissions from hog facilities on PM2.5 formation. The modeled results are in good agreement with observations, with slightly better agreement at urban sites than at rural sites. The predicted total inorganic particulate matter (PM) concentrations are within 5% of the observed values under conditions with median initial total PM species concentrations, median relative humidity (RH), and median temperature. Ambient conditions with high PM precursor concentrations, low temperature, and high RH appear to favor the formation of secondary PM. DA - 2008/9// PY - 2008/9// DO - 10.3155/1047-3289.58.9.1208 VL - 58 IS - 9 SP - 1208-1214 SN - 1047-3289 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-53149087232&partnerID=MN8TOARS ER - TY - JOUR TI - Evaluating an Inquiry-based Bioinformatics Course Using Q Methodology AU - Ramlo, Susan E. AU - McConnell, David AU - Duan, Zhong-Hui AU - Moore, Francisco B. T2 - JOURNAL OF SCIENCE EDUCATION AND TECHNOLOGY DA - 2008/6// PY - 2008/6// DO - 10.1007/s10956-008-9090-x VL - 17 IS - 3 SP - 219-225 SN - 1059-0145 KW - Bioinformatics KW - Q methodology KW - Assessment KW - Subjectivity KW - Course evaluation ER - TY - JOUR TI - Development of the flux-adjusting surface data assimilation system for mesoscale models AU - Alapaty, Kiran AU - Niyogi, Dev AU - Chen, Fei AU - Pyle, Patrick AU - Chandrasekar, Anantharman AU - Seaman, Nelson T2 - JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY AB - Abstract The flux-adjusting surface data assimilation system (FASDAS) is developed to provide continuous adjustments for initial soil moisture and temperature and for surface air temperature and water vapor mixing ratio for mesoscale models. In the FASDAS approach, surface air temperature and water vapor mixing ratio are directly assimilated by using the analyzed surface observations. Then, the difference between the analyzed surface observations and model predictions of surface layer temperature and water vapor mixing ratio are converted into respective heat fluxes, referred to as adjustment heat fluxes of sensible and latent heat. These adjustment heat fluxes are then used in the prognostic equations for soil temperature and moisture via indirect assimilation in the form of several new adjustment evaporative fluxes. Thus, simulated surface fluxes for the subsequent model time step are affected such that the predicted surface air temperature and water vapor mixing ratio conform more closely to observations. The simultaneous application of indirect and direct data assimilation maintains greater consistency between the soil temperature–moisture and the surface layer mass-field variables. The FASDAS is coupled to a land surface submodel in a three-dimensional mesoscale model and tests are performed for a 10-day period with three one-way nested domains. The FASDAS is applied in the analysis nudging mode for two coarse-resolution nested domains and in the observational nudging mode for a fine-resolution nested domain. Further, the effects of FASDAS on two different initial specifications of a three-dimensional soil moisture field are also studied. Results indicate that the FASDAS consistently improved the accuracy of the model simulations. DA - 2008/9// PY - 2008/9// DO - 10.1175/2008JAMC1831.1 VL - 47 IS - 9 SP - 2331-2350 SN - 1558-8432 ER - TY - JOUR TI - Comparing low-pressure and high-pressure fogging systems in naturally ventilated greenhouses AU - Li, S. AU - Willits, D. H. T2 - BIOSYSTEMS ENGINEERING AB - The cooling performance of a low-pressure (405 kPa working pressure) and a high-pressure fogging system (6.89 MPa) was evaluated. Experiments were conducted in two empty, naturally ventilated greenhouses under summer conditions for a period of about two months. One greenhouse was used as the treatment greenhouse (fogged house) and another was used as the control house (un-fogged house). Cooling efficiency was defined by the ratio of the temperature difference between the un-fogged and fogged greenhouses to the difference between the temperature in un-fogged house and the wet-bulb temperature in the fogged greenhouse. Evaporation efficiency was defined as the ratio of fog evaporation rate to spray rate. Cooling efficiency and evaporation efficiency were compared for the low-pressure and high-pressure systems after accounting for differences in weather conditions under which the two systems were operated. It is suggested that on average evaporation efficiency for the high-pressure system was at least 64% greater than the low-pressure system; cooling efficiency for the high-pressure system was at least 28% greater than for the low-pressure system. DA - 2008/9// PY - 2008/9// DO - 10.1016/j.biosystemseng.2008.06.004 VL - 101 IS - 1 SP - 69-77 SN - 1537-5129 ER - TY - JOUR TI - Characterizing ammonia emissions from swine farms in eastern north carolina: Part 1-conventional lagoon and spray technology for waste treatment AU - Aneja, Viney P. AU - Arya, S. Pal AU - Kim, D. -S. AU - Rumsey, Ian C. AU - Arkinson, H. L. AU - Semunegus, H. AU - Bajwa, K. S. AU - Dickey, D. A. AU - Stefanski, L. A. AU - Todd, L. AU - Mottus, K. AU - Robarge, W. P. AU - Williams, C. M. T2 - JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION AB - Abstract Ammonia (NH3) fluxes from waste treatment lagoons and barns at two conventional swine farms in eastern North Carolina were measured. The waste treatment lagoon data were analyzed to elucidate the temporal (seasonal and diurnal) variability and to derive regression relationships between NH3 flux and lagoon temperature, pH and ammonium content of the lagoon, and the most relevant meteorological parameters. NH3 fluxes were measured at various sampling locations on the lagoons by a flow-through dynamic chamber system interfaced to an environmentally controlled mobile laboratory. Two sets of open-path Fourier transform infrared (FTIR) spectrometers were also used to measure NH3 concentrations for estimating NH3 emissions from the animal housing units (barns) at the lagoon and spray technology (LST) sites.Two different types of ventilation systems were used at the two farms. Moore farm used fan ventilation, and Stokes farm used natural ventilation. The early fall and winter season intensive measurement campaigns were conducted during September 9 to October 11, 2002 (lagoon temperature ranged from 21.2 to 33.6 °C) and January 6 to February 2, 2003 (lagoon temperature ranged from 1.7 to 12 °C), respectively. Significant differences in seasonal NH3 fluxes from the waste treatment lagoons were found at both farms. Typical diurnal variation of NH3 flux with its maximum value in the afternoon was observed during both experimental periods. Exponentially increasing flux with increasing surface lagoon temperature was observed, and a linear regression relationship between logarithm of NH3 flux and lagoon surface temperature (T l) was obtained. Correlations between lagoon NH3 flux and chemical parameters, such as pH, total Kjeldahl nitrogen (TKN), and total ammoniacal nitrogen (TAN) were found to be statistically insignificant or weak. In addition to lagoon surface temperature, the difference (D) between air temperature and the lagoon surface temperature was also found to influence the NH3 flux, especially when D > 0 (i.e., air hotter than lagoon). This hot-air effect is included in the statistical-observational model obtained in this study, which was used further in the companion study (Part II), to compare the emissions from potential environmental superior technologies to evaluate the effectiveness of each technology. DA - 2008/9// PY - 2008/9// DO - 10.3155/1047-3289.58.9.1130 VL - 58 IS - 9 SP - 1130-1144 SN - 1047-3289 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-53849107841&partnerID=MN8TOARS ER - TY - JOUR TI - Characterizing ammonia emissions from swine farms in eastern North Carolina: Part 2 - Potential environmentally superior technologies for waste treatment AU - Aneja, Viney P. AU - Arya, S. Pal AU - Rumsey, Ian C. AU - Kim, D. -S. AU - Bajwa, K. AU - Arkinson, H. L. AU - Semunegus, H. AU - Dickey, D. A. AU - Stefanski, L. A. AU - Todd, L. AU - Mottus, K. AU - Robarge, W. P. AU - Williams, C. M. T2 - JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION AB - The need for developing environmentally superior and sustainable solutions for managing the animal waste at commercial swine farms in eastern North Carolina has been recognized in recent years. Program OPEN (Odor, Pathogens, and Emissions of Nitrogen), funded by the North Carolina State University Animal and Poultry Waste Management Center (APWMC), was initiated and charged with the evaluation of potential environmentally superior technologies (ESTs) that have been developed and implemented at selected swine farms or facilities. The OPEN program has demonstrated the effectiveness of a new paradigm for policy-relevant environmental research related to North Carolina's animal waste management programs. This new paradigm is based on a commitment to improve scientific understanding associated with a wide array of environmental issues (i.e., issues related to the movement of N from animal waste into air, water, and soil media; the transmission of odor and odorants; disease-transmitting vectors; and airborne pathogens). The primary focus of this paper is on emissions of ammonia (NH3) from some potential ESTs that were being evaluated at full-scale swine facilities. During 2-week-long periods in two different seasons (warm and cold), NH3 fluxes from water-holding structures and NH3 emissions from animal houses or barns were measured at six potential EST sites: (1) Barham farm--in-ground ambient temperature anaerobic digester/energy recovery/greenhouse vegetable production system; (2) BOC #93 farm--upflow biofiltration system--EKOKAN; (3) Carrolls farm--aerobic blanket system--ISSUES-ABS; (4) Corbett #1 farm--solids separation/ gasification for energy and ash recovery centralized system--BEST; (5) Corbett #2 farm--solid separation/ reciprocating water technology--ReCip; and (6) Vestal farm--Recycling of Nutrient, Energy and Water System--ISSUES-RENEW. The ESTs were compared with similar measurements made at two conventional lagoon and spray technology (LST) farms (Moore farm and Stokes farm). A flow-through dynamic chamber system and two sets of open-path Fourier transform infrared (OP-FTIR) spectrometers measured NH3 fluxes continuously from water-holding structures and emissions from housing units at the EST and conventional LST sites. A statistical-observational model for lagoon NH3 flux was developed using a multiple linear regression analysis of 15-min averaged NH3 flux data against the relevant environmental parameters measured at the two conventional farms during two different seasons of the year. This was used to compare the water-holding structures at ESTs with those from lagoons at conventional sites under similar environmental conditions. Percentage reductions in NH3 emissions from different components of each potential EST, as well as the whole farm on which the EST was located were evaluated from the estimated emissions from water-holding structures, barns, etc., all normalized by the appropriate nitrogen excretion rate at the potential EST farm, as well as from the appropriate conventional farm. This study showed that ammonia emissions were reduced by all but one potential EST for both experimental periods. However, on the basis of our evaluation results and analysis and available information in the scientific literature, the evaluated alternative technologies may require additional technical modifications to be qualified as unconditional ESTs relative to NH3 emissions reductions. DA - 2008/9// PY - 2008/9// DO - 10.3155/1047-3289.58.9.1145 VL - 58 IS - 9 SP - 1145-1157 SN - 2162-2906 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-53849100726&partnerID=MN8TOARS ER - TY - JOUR TI - Back-trajectory analysis and source-receptor relationships: Particulate matter and nitrogen isotopic composition in rainwater AU - Occhipinti, Chris AU - Aneja, Viney P. AU - Showers, William AU - Niyogi, Dev T2 - JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION AB - The southeastern portion of North Carolina features a dense crop and animal agricultural region; previous research suggests that this agricultural presence emits a significant portion of the state's nitrogen (i.e., oxides of nitrogen and ammonia) emissions. These findings indicate that transporting air over this region can affect nitrogen concentrations in precipitation at sites as far as 50 mi away. The study combined nitrate nitrogen isotope data with back-trajectory analysis to examine the relationship between regional nitrogen emission estimates independent of pollutant concentration information. In 2004, the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to determine potential sources of nitrogen in rainwater collected at an urban receptor site in Raleigh, NC. The delta 15N isotope ratio signatures of each sample were used to further differentiate between sources of the rainwater nitrate. This study examined the importance of pollution sources, including animal agricultural activity, and meteorology on rainfall chemistry as well as the implications in fine particulate matter (PM2.5) formation. Samples that transited the dense crop and animal (swine) agricultural region of east-southeastern North Carolina (i.e., the source region) had lower delta 15N isotope ratios in the nitrate ion (average = -2.1 +/- 1.7 per thousand) than those from a counterpart nonagricultural region (average = 0.1 +/- 3 per thousand.) An increase in PM2.5 concentrations in the urban receptor site (yearly average = 15.1 +/- 5.8 microg/m3) was also found to correspond to air transport over the dense agricultural region relative to air that was not subjected to such transport (yearly average = 11.7 +/- 5.8 microg/m3). DA - 2008/9// PY - 2008/9// DO - 10.3155/1047-3289.58.9.1215 VL - 58 IS - 9 SP - 1215-1222 SN - 1047-3289 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-53849144360&partnerID=MN8TOARS ER - TY - JOUR TI - Acute toxicity and tissue distributions of malathion in Ambystoma tigrinum AU - Henson-Ramsey, H. AU - Kennedy-Stoskopf, S. AU - Levine, J. F. AU - Taylor, S. K. AU - Shea, D. AU - Stoskopf, M. K. T2 - ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY DA - 2008/10// PY - 2008/10// DO - 10.1007/s00244-007-9091-4 VL - 55 IS - 3 SP - 481-487 SN - 1432-0703 ER - TY - JOUR TI - A special issue of JA&WMA on agricultural air quality: State of the science - Introduction AU - Aneja, Viney P. AU - Schlesinger, William H. T2 - JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION AB - The world’s population has grown, from approximately 1.5 billion at the beginning of the 20th century to more than 6 billion today. This population increase has been accompanied by the rapid growth of intensive agriculture with its associated, significant impacts on the environment. Over the next 50 yr, the Earth’s human population is predicted to increase from the current level to more than 9 billion, creating a parallel or disproportionate increase in demand for agricultural commodities— both crop and animal. Without scientific research to inform policy decisions, there will likely be greater environmental impacts associated with this future growth.1–3 Though in transition, U.S. agriculture is still diverse, ranging from large, highly intensive and specialized commercial holdings to subsistence (i.e., family owned) farming, using mainly traditional practices. Consequently, impacts on the environment vary in scale and intensity and may be positive or negative. However, an increasing body of evidence shows that the increased size and geographical concentration of animal-feeding operations and agri DA - 2008/9// PY - 2008/9// DO - 10.3155/1047-3289.58.9.1113 VL - 58 IS - 9 SP - 1113-1115 SN - 2162-2906 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-53849121300&partnerID=MN8TOARS ER - TY - JOUR TI - Valve Gape Response to Turbidity in Two Freshwater Bivalves (Corbicula flumineaandLampsilis radiata) AU - Bucci, John P. AU - Showers, William J. AU - Levine, Jay F. AU - Usry, Brian T2 - Journal of Freshwater Ecology AB - ABSTRACT In a laboratory study with a simulated storm event, we found a significant difference (p<0.05) in valve gape response to the turbidity between Corbicula fluminea and Lampsilis radiata. Valves of C. fluminea opened more intensively during the peak turbidity period and closed significantly more during a following chronic turbidity period. L. radiata exhibited little change in valve gape response with change in turbidity. DA - 2008/9// PY - 2008/9// DO - 10.1080/02705060.2008.9664229 VL - 23 IS - 3 SP - 479-483 J2 - Journal of Freshwater Ecology LA - en OP - SN - 0270-5060 2156-6941 UR - http://dx.doi.org/10.1080/02705060.2008.9664229 DB - Crossref ER - TY - JOUR TI - The mesoscale characteristics of tropical oceanic precipitation during Kelvin and mixed Rossby-gravity wave events AU - Holder, Christopher T. AU - Yuter, Sandra E. AU - Sobel, Adam H. AU - Aiyyer, Anantha R. T2 - MONTHLY WEATHER REVIEW AB - Abstract Precipitation structures within Kelvin and mixed Rossby–gravity (MRG) wave troughs near Kwajalein Atoll during the 1999–2003 rainy seasons are analyzed using three-dimensional ground-based radar data and upper-air sounding data. Consistent with previous work, wave troughs are preferred locations for precipitation and typically yield 1.3 times more rain area compared to the overall rainy season climatology. Although the contiguous areas of cold cloudiness associated with tropical wave troughs are large and long lived, the underlying precipitation structure is most frequently small, isolated convection from mixed-phase clouds. This mismatch in instantaneous cold cloudiness area versus radar-observed precipitation area indicates differences in the rate and nature of evolution between the mesoscale anvil cloud and the underlying precipitating portion of the cloud. Mesoscale convective systems (MCSs) were identified during portions of 32 of the 39 wave trough events examined. Convective cells are frequently embedded within stratiform regions. Reflectivity holes or pores in contiguous radar echo have been frequently observed in other regions but are quantified for the first time in this study. Based on characteristics such as total size of precipitating area and occurrence of convective lines, MCSs within Kelvin troughs are slightly more organized than those occurring within MRG troughs. Similar to the west Pacific warm pool region, there is a well-defined separation between observed and unobserved stratiform area fraction and convective precipitation area, each as a function of total precipitation area. At precipitation area sizes near 40% of the radar domain, the maximum observed convective area changes from increasing to decreasing with increasing precipitation area. The maximum observed convective precipitation area occupied ∼20% of the radar domain. These characteristics suggest that the atmosphere in the west Pacific can sustain a limited area of updrafts capable of supporting precipitation growth by collision/coalescence and riming. DA - 2008/9// PY - 2008/9// DO - 10.1175/2008MWR2350.1 VL - 136 IS - 9 SP - 3446-3464 SN - 1520-0493 ER - TY - JOUR TI - The Ellsworth terrane, coastal Maine: Geochronology, geochemistry, and Nd-Pb isotopic composition - Implications for the rifting of Ganderia AU - Schulz, K. J. AU - Stewart, D. B. AU - Tucker, R. D. AU - Pollock, J. C. AU - Ayuso, R. A. T2 - Geological Society of America Bulletin DA - 2008/// PY - 2008/// VL - 120 IS - 9-10 SP - 1134-1158 ER - TY - JOUR TI - Stokes drift-induced and direct wind energy inputs into the Ekman layer within the Antarctic Circumpolar Current AU - Wu, K. J. AU - Liu, B. T2 - Journal of Geophysical Research. Oceans DA - 2008/// PY - 2008/// VL - 113 IS - C10 ER - TY - JOUR TI - Spatial and temporal variability of streambed hydraulic conductivity in West Bear Creek, North Carolina, USA AU - Genereux, David P. AU - Leahy, Scott AU - Mitasova, Helena AU - Kennedy, Casey D. AU - Corbett, D. Reide T2 - JOURNAL OF HYDROLOGY AB - The hydraulic conductivity (K) of the streambed is an important variable influencing water and solute exchange between streams and surrounding groundwater systems. However, there are few detailed data on spatial variability in streambed K and almost none on temporal variability. The spatial and temporal variability of streambed K in a North Carolina stream were investigated with 487 field measurements of K over a 1-year period. Measurements were made bimonthly from December 2005 to December 2006 at 46 measurement locations in a 262.5 m reach (the “large reach”). To give a more detailed picture of spatial variability, closely-spaced one-time measurements were made in two 62.5 m reaches (the “small reaches”, one investigated in July 2006 and the other in August 2006) that were part of the large reach. Arithmetic mean K for the large reach was ∼16 m/day (range was 0.01 to 66 m/day). Neither K nor lnK was normally distributed, and K distributions appeared somewhat bimodal. There was significant spatial variability over horizontal length scales of a few m. Perhaps the clearest feature within this variability was the generally higher K in the center of the channel. This feature may be an important control on water and chemical fluxes through the streambed (e.g., other measurements show generally higher water seepage velocity, but lower porewater nitrate concentration, in the center of the streambed). Grain size analysis of streambed cores showed that layers of elevated fines (silt + clay) content were less common in the center of the channel (overall, the streambed was about 94% sand). Results also suggest a modest but discernable difference in average streambed K upstream and downstream of a small beaver dam: K was about 23% lower upstream, when the dam was present during the first few months of the study. This upstream/downstream difference in K disappeared after the dam collapsed, perhaps in response to re-mobilization of fine sediments or leaf matter that had accumulated in quiet waters ponded on the upstream side of the dam. Temporal variability was significant and followed a variety of different patterns at the 46 measurement locations in the large reach. Temperature data show that variation in streambed and groundwater temperature was not an important cause of the observed temporal variability in K. Measurements of changes in the elevation of the streambed surface suggest erosion and deposition played an important role in causing the observed temporal variability in streambed K (of which the change described above following collapse of the beaver dam was a special case), though other potentially time-varying factors (e.g., gas content, bioturbation, or biofilms in the streambed) were not explicitly addressed and cannot be ruled out as contributors to the temporal variability in streambed K. Temporal variability in streambed K merits additional study as a potentially important control on temporal variability in the magnitudes and spatial patterns of water and solute fluxes between groundwater and surface water. From the data available it seems appropriate to view streambed K as a dynamic attribute, variable in both space and time. DA - 2008/9/5/ PY - 2008/9/5/ DO - 10.1016/j.jhydrol.2008.06.017 VL - 358 IS - 3-4 SP - 332-353 SN - 1879-2707 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-48849088675&partnerID=MN8TOARS KW - hydraulic conductivity KW - streambed KW - permeameter KW - semi-variogram KW - erosion KW - grain size ER - TY - JOUR TI - Inter-annual variability of hypoxic conditions in a shallow estuary AU - Lin, Jing AU - Xu, Hongzhou AU - Cudaback, Cynthia AU - Wang, Dongxiao T2 - JOURNAL OF MARINE SYSTEMS AB - Water quality data from two monitoring programs in the Pamlico River Estuary (PRE) were analyzed for dissolved oxygen (DO), salinity, temperature, and nutrient concentrations. Data were collected bi-weekly at 8 stations from 1997 to 2003 by East Carolina University and continuously at three stations from 1999 to 2003 by the U.S. Geological Survey. Hypoxic conditions were observed mostly in the upper to middle estuary, but the frequency of hypoxic events varied between years. During June to October in 1997–1999 (referred to as the oxic summers) bottom water hypoxia (DO < 2 mg l− 1) was found in 8.7% of the observations. By contrast, during June to October in 2001–2003 (referred to as the hypoxic summers), 37.9% of the total measurements had DO concentrations less than 2 mg l− 1. The more frequent and/or prolonged hypoxic conditions during the hypoxic summers were closely associated with stronger salinity stratification and greater loadings of nutrient and particulate matter. Salinity stratification appeared to be governed by patterns of freshwater discharge, and frequency of wind mixing events. The “oxic” summers were characterized by continuous low freshwater inflow (except one extremely high flow event due to hurricanes), stronger northeastward wind, and more frequent wind mixing events. In contrast, the hypoxic summers were characterized by frequent moderate freshwater inflow events, and fewer wind mixing events. The greater loadings of nutrient (nitrate, ammonium, and phosphate) and particulate matter during the hypoxic summers were primarily due to higher river discharges. At the head of the PRE, no significant differences were found in concentrations of nutrient and particulate nitrogen between the oxic and the hypoxic summers. In addition, chlorophyll a concentrations were averaged above 30 μg l− 1 (maximum 167 μg l− 1) during the hypoxic summers, significantly higher than those during the oxic summers (averaged around 15 μg l− 1). DA - 2008/9// PY - 2008/9// DO - 10.1016/j.jmarsys.2007.10.011 VL - 73 IS - 1-2 SP - 169-184 SN - 1879-1573 KW - hypoxia KW - dissolved oxygen KW - inter-annual variability KW - estuary KW - Pamlico River ER - TY - JOUR TI - An experimental evaluation of thermal stratification in a fan-ventilated greenhouse AU - Li, S. AU - Willits, D. H. T2 - Transactions of the ASABE AB - Experiments were performed to investigate air velocity and vertical air temperature distributions in a fan-ventilated greenhouse. The effects of ventilation rate and canopy size on the allocation of airflow between canopy and non-canopy areas were examined. The data suggested that the ratio of the air velocity within the canopy to the mean velocity of the entire greenhouse cross-section depended on not only the area ratio of canopy to greenhouse cross-section, but also ventilation rate. The ratio of canopy air velocity to greenhouse average velocity decreased if ventilation rate increased. The effects of outside solar radiation, ventilation rate, evaporative cooling pads, and presence of a canopy on the vertical air temperature variations were also investigated. The vertical air temperature variation increased approximately linearly with solar radiation. Use of an evaporative pad increased the temperature variation. Increasing ventilation rate resulted in reduced air temperature variation. The presence of a canopy modified the vertical temperature distribution and reduced temperature variations as well. DA - 2008/// PY - 2008/// DO - 10.13031/2013.25237 VL - 51 IS - 4 SP - 1443-1448 ER - TY - JOUR TI - The Relationship between Anvil Clouds and Convective Cells: A Case Study in South Florida during CRYSTAL-FACE AU - Rickenbach, Thomas AU - Kucera, Paul AU - Gentry, Megan AU - Carey, Larry AU - Lare, Andrew AU - Lin, Ruei-Fong AU - Demoz, Belay AU - Starr, David O'C. T2 - MONTHLY WEATHER REVIEW AB - One of the important goals of NASA’s Cirrus Regional Study of Tropical Anvils and Cirrus Layers–Florida Area Cirrus Experiment (CRYSTAL-FACE) was to further the understanding of the evolution of tropical anvil clouds generated by deep convective systems. An important step toward understanding the radiative properties of convectively generated anvil clouds is to study their life cycle. Observations from ground-based radar, geostationary satellite radiometers, aircraft, and radiosondes during CRYSTAL-FACE provided a comprehensive look at the generation of anvil clouds by convective systems over South Florida during July 2002. This study focused on the relationship between convective rainfall and the evolution of the anvil cloud shield associated with convective systems over South Florida on 23 July 2002, during the CRYSTAL-FACE experiment. Anvil clouds emanating from convective cells grew downwind (to the southwest), reaching their maximum area at all temperature thresholds 1–2 h after the active convective cells collapsed. Radar reflectivity data revealed that precipitation-sized anvil particles extended downwind with the cloud tops. The time lag between maximum rainfall and maximum anvil cloud area increased with system size and rainfall. Observations from airborne radar and analysis of in situ cloud particle size distribution measurements in the anvil region suggested that gravitational size sorting of cloud particles dispersed downshear was a likely mechanism in the evolution of the anvil region. Linear regression analysis suggested a positive trend between this time lag and maximum convective rainfall for this case, as well as between the time lag and maximum system cloud cover. The injection of condensate into the anvil region by large areas of intense cells and dispersal in the upper-level winds was a likely explanation to cause the anvil cloud-top area to grow for 1–2 h after the surface convective rainfall began to weaken. In future work these relationships should be evaluated in differing regimes of shear, stability, or precipitation efficiency, such as over the tropical oceans, in order to generalize the results. The results of this study implied that for these cloud systems, the maximum in latent heating (proportional to rainfall) may precede the peak radiative forcing (related to anvil cloud height and area) by a lead time that was proportional to system size and strength. Mesoscale modeling simulations of convective systems on this day are under way to examine anvil evolution and growth mechanisms. DA - 2008/10// PY - 2008/10// DO - 10.1175/2008MWR2441.1 VL - 136 IS - 10 SP - 3917-3932 SN - 1520-0493 ER - TY - JOUR TI - Ammonia emissions from a beef cattle feedyard on the southern High Plains AU - Todd, Richard W. AU - Cole, N. Andy AU - Clark, R. Nolan AU - Flesch, Thomas K. AU - Harper, Lowry A. AU - Baek, Bok H. T2 - ATMOSPHERIC ENVIRONMENT AB - Concentrated animal feeding operations (CAFOs) are major sources of ammonia emitted into the atmosphere. There is considerable literature on ammonia emissions from poultry and swine CAFO, but few comprehensive studies have investigated large, open lot beef cattle feedyards. Ammonia emission rates and emission factors for a 77-ha, 45 000-head commercial beef cattle feedyard on the southern High Plains were quantified using measured profiles of ammonia concentration, wind speed and air temperature, and an inverse dispersion model. Mean summer emission rate was 7420 kg NH3 d−1, and winter emission rate was about half that, at 3330 kg NH3 d−1. Annual NH3–N emission rate was 4430 kg NH3–N d−1, which was 53% of the N fed to cattle. Daily per capita NH3–N losses increased by 10–64% after the daily per capita N in feed rations increased by 15–26%. Annual emission factors for the pen area of the feedyard were 19.3 kg NH3 (head fed)−1, or 70.2 kg NH3 Mg−1 biomass produced. Annual emission factors for the retention pond of the feedyard were estimated to be 0.9 kg NH3 (head fed)−1, or 3.2 kg NH3 Mg−1 biomass produced. DA - 2008/9// PY - 2008/9// DO - 10.1016/j.atmosenv.2008.05.013 VL - 42 IS - 28 SP - 6797-6805 SN - 1352-2310 KW - Ammonia KW - Emission rate KW - Emission factor KW - Beef cattle KW - Feedyard KW - Feedlot KW - Micrometeorology KW - Inverse dispersion model ER - TY - JOUR TI - Wind impact on pollutant transport in a shallow estuary AU - Xu, H. Z. AU - Lin, J. AU - Shen, J. AU - Wang, D. X. T2 - Acta Oceanologica Sinica DA - 2008/// PY - 2008/// VL - 27 IS - 3 SP - 147-160 ER - TY - JOUR TI - The influence of the Gulf Stream induced SST gradients on the US East Coast winter storm of 24-25 January 2000 AU - Jacobs, N. A. AU - Raman, S. AU - Lackmann, G. M. AU - Childs, P. P., Jr. T2 - INTERNATIONAL JOURNAL OF REMOTE SENSING AB - This study presents an investigation of the influence of remotely sensed high resolution sea surface temperature (SST) and the SST gradient on the formation and evolution of the 24–25 January 2000 East Coast winter storm. A numerical model was employed for experimental simulation replaced SST analysis with a 1.1 km gridded data set. The most significant improvements were seen in the forecast deepening rate and track. Reduced development of the storm in the control simulation, as compared to the experimental simulation, appears to be due to the coarse grid SST representation, which fails to capture key thermal gradient features of the Gulf Stream. The simulations suggest that the high resolution remotely sensed SST data affect the track by changing the location of lower‐tropospheric frontal boundaries through thermally‐induced near‐surface convergence and differential turbulent heat flux. Enhanced vortex stretching associated with the convergence along the lower frontal boundary appears to contribute to a stronger storm in the experimental simulations. DA - 2008/// PY - 2008/// DO - 10.1080/01431160802175561 VL - 29 IS - 21 SP - 6145-6174 SN - 0143-1161 ER - TY - JOUR TI - Modeling hydrogen sulfide emissions across the gas-liquid interface of an anaerobic swine waste treatment storage system AU - Blunden, Jessica AU - Aneja, Viney P. AU - Overton, John H. T2 - ATMOSPHERIC ENVIRONMENT AB - Hydrogen sulfide (H2S) is a colorless gas emitted during decomposition of hog manure that produces an offensive “rotten egg” smell and is considered a toxic manure gas. In the southeastern United States, anaerobic waste treatment lagoons are widely used to store and treat hog excreta at commercial hog farms. Hydrogen sulfide is produced as manure decomposes anaerobically, resulting from the mineralization of organic sulfur compounds as well as the reduction of oxidized inorganic sulfur compounds by sulfur-reducing bacteria. The process of H2S emissions from anaerobic waste treatment lagoons are investigated utilizing a two-film model with three different modeling approaches: Coupled Mass Transfer with Chemical Reactions Model with the assumption (1) pH remains constant in the liquid film (MTCR Model I) and (2) pH may change throughout the liquid film due to diffusion processes that occur within the film (MTCR Model II); and (3) a Mass Transfer Model which neglects chemical reactions (MTNCR Model) in the gas and liquid films. Results of model predictions are consistent with previous works, which show that flux is largely dependent on the physicochemical lagoon properties including sulfide concentration, pH, and lagoon temperature. Air temperature and low wind velocities (e.g., <3.25 m s−1) have negligible impact on flux. Results also indicate that flux values decrease with increased film thickness. The flux was primarily influenced by variations in the liquid film thickness, signifying that the H2S flux is driven by liquid-phase parameters. Model results were compared with H2S flux measurements made at a swine waste treatment storage lagoon in North Carolina using a dynamic emission flux chamber system in order to evaluate model accuracy in calculating lagoon H2S emissions. The MTCR Model II predicted the highest increase in emission rates as aqueous sulfide concentration was increased. The MTNCR Model showed the highest dependence on pH. All three models showed good agreement in diurnal comparison with flux measurements; however, each model significantly over predicted the measured flux rates. The MTNCR Model estimates were closest to experimental values, predicting 3–35 times the actual measured values. DA - 2008/7// PY - 2008/7// DO - 10.1016/j.atmosenv.2008.03.016 VL - 42 IS - 22 SP - 5602-5611 SN - 1873-2844 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-46749153762&partnerID=MN8TOARS KW - two-film theory KW - hydrogen sulfide KW - process-based model KW - lagoon flux KW - mass transfer ER - TY - JOUR TI - Impacts of regional climate change on biogenic emissions and air quality AU - Zhang, Yang AU - Hu, Xiao-Ming AU - Leung, L. Ruby AU - Gustafson, William I., Jr. T2 - JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES AB - Regional air quality simulations are conducted at a horizontal grid resolution of 36 km for four summers (2001, 2002, 2051, and 2052) to examine the sensitivity of air quality to potential regional climate change in the United States. In response to the predicted warmer climate in 2051/2052, the emissions of isoprene and terpene increase by 20–92% and 20–56%, respectively, over most of the domain. Surface O 3 increases by up to 19–20%. Such increases are largely driven by changes in temperature, solar radiation, and cloud fraction over most of the domain. PM 2.5 , its compositions, and visibility exhibit an overall negative sensitivity (decrease by up to 40%), resulting from the competition of the negative temperature effect and positive emission/temperature effects. While the response of dry deposition is governed by the negative sensitivity of surface resistances, that of wet deposition is either positive or negative, depending on the relative dominancy of changes in PM 2.5 and precipitation. Overall the net climatic effect due to changes in climatic variables alone dominates changes in O 3 , PM 2.5 , and wet and total deposition, and the net biogenic emission effect due to changes in biogenic emissions alone as a result of climate change is important for isoprene, organic matter, visibility, and dry deposition over several regions. Models that do not include secondary organic aerosol formation from isoprene may underestimate by at least 20% of the responses of organic aerosols to future climate changes over many areas of the modeling domain. Both regional climate and air quality exhibit interannual variability, particularly in temperature, isoprene emissions, and PM 2.5 concentrations, indicating a need for long‐term simulations to predict future air quality. Compared with results from global models, stronger regional climate change signals may cause projected local impacts of climate change that are stronger or even different in sign. DA - 2008/9/25/ PY - 2008/9/25/ DO - 10.1029/2008jd009965 VL - 113 IS - D18 SP - SN - 2169-8996 ER - TY - JOUR TI - Frequency-magnitude distribution of microearthquakes beneath the 9 degrees 50 ' N region of the East Pacific Rise, October 2003 through April 2004 AU - Bohnenstiehl, D. R. AU - Waldhauser, F. AU - Tolstoy, M. T2 - GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS AB - Relocated hypocentral data from a 7‐month deployment (October 2003 to April 2004) of ocean bottom seismometers provide an opportunity to map microearthquake frequency‐magnitude distributions (FMDs) along the 9°49–52′N region on the East Pacific Rise. These analyses, which incorporate more than 9000 earthquakes, represent the first investigation of the 3‐D spatial and temporal patterns of FMDs along any mid‐ocean ridge spreading center. The data are described well by a Gutenberg‐Richter model, indicating a power law or fractal relationship between earthquake size and frequency. The scaling exponent, or b value, shows significant spatial variability, exceeding a value of 2.0 at the shallowest depths on axis and dropping below 1.0 away from the axial trough. This spatial pattern is consistent with an inverse relationship between b value and ambient stress conditions, with the lowest stress levels at shallow depths and relatively high stress levels (or low pore pressures) observed away from the axial zone. Intermediate b values are observed on‐axis above the ridge system's melt lens; however, within this region there also exists significant spatial variability. This indicates that stress conditions and/or structural heterogeneity may vary at subkilometer scales within the hydrothermal circulation cell. Although the observational period is characterized by increasing seismicity rates, building toward an eruptive episode in January 2006, the first‐order spatial pattern of b values is sustained, with no overall temporal trend. As a byproduct of this b value analysis, the detection capabilities of the array are assessed empirically. DA - 2008/10/21/ PY - 2008/10/21/ DO - 10.1029/2008gc002128 VL - 9 SP - SN - 1525-2027 KW - b values KW - microearthquakes KW - hydrothermal circulation KW - East Pacific Rise KW - mid-ocean ridge seismicity ER - TY - JOUR TI - Diurnal characteristics of precipitation features over the tropical east Pacific: A comparison of the EPIC and TEPPS regions AU - Cifelli, R. AU - Nesbitt, S. W. AU - Rutledge, S. A. AU - Petersen, W. A. AU - Yuter, S. T2 - JOURNAL OF CLIMATE AB - Abstract This study examines the diurnal cycle of precipitation features in two regions of the tropical east Pacific where field campaigns [the East Pacific Investigation of Climate Processes in the Coupled Ocean–Atmosphere System (EPIC) and the Tropical Eastern Pacific Process Study (TEPPS)] were recently conducted. EPIC (10°N, 95°W) was undertaken in September 2001 and TEPPS (8°N, 125°W) was carried out in August 1997. Both studies employed C-band radar observations on board the NOAA ship Ronald H. Brown (RHB) and periodic upper-air sounding launches to observe conditions in the surrounding environment. Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and Geostationary Operational Environmental Satellite (GOES) IR data are used to place the RHB data in a climatological context and Tropical Atmosphere Ocean (TAO) buoy data are used to evaluate changes in boundary layer fluxes in context with the observed diurnal cycle of radar observations of precipitation features. Precipitation features are defined as contiguous regions of radar echo and are subdivided into mesoscale convective system (MCS) and sub-MCS categories. Results show that MCSs observed in EPIC and TEPPS have distinct diurnal signatures. Both regions show an increase in intensity starting in the afternoon hours, with the timing of maximum rain intensity preceding maxima in rain area and accumulation. In the TEPPS region, MCS rain rates peak in the evening and rain area and accumulation in the late night–early morning hours. In contrast, EPIC MCS rain rates peak in the late night–early morning, and rain area and accumulation are at a maximum near local sunrise. The EPIC observations are in agreement with previous satellite studies over the Americas, which show a phase lag response in the adjacent oceanic regions to afternoon–evening convection over the Central American landmass. Sub-MCS features in both regions have a broad peak extending through the evening to late night–early morning hours, similar to that for MCSs. During sub-MCS-only periods, the rainfall patterns of these features are closely linked to diurnal changes in SST and the resulting boundary layer flux variability. DA - 2008/8// PY - 2008/8// DO - 10.1175/2007JCLI2020.1 VL - 21 IS - 16 SP - 4068-4086 SN - 1520-0442 ER - TY - JOUR TI - Data analysis and numerical simulation of moisture source and transport associated with summer precipitation in the Yangtze River Valley over China AU - Xu, X. D. AU - Shi, X. Y. AU - Wang, Y. Q. AU - Peng, S. Q. AU - Shi, X. H. T2 - Meteorology and Atmospheric Physics DA - 2008/// PY - 2008/// DO - 10.1007/s00703-008-0305-8 VL - 100 IS - 1-4 SP - 217-231 ER - TY - JOUR TI - Application of an adaptive nudging scheme in air quality forecasting in China AU - Xu, Xiangde AU - Xie, Lian AU - Cheng, Xinghong AU - Xu, Jianming AU - Zhou, Xiuji AU - Ding, Guoan T2 - JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY AB - Abstract A major challenge for air quality forecasters is to reduce the uncertainty of air pollution emission inventory. Error in the emission data is a primary source of error in air quality forecasts, much like the effect of error in the initial conditions on the accuracy of weather forecasting. Data assimilation has been widely used to improve weather forecasting by correcting the initial conditions with weather observations. In a similar way, observed concentrations of air pollutants can be used to correct the errors in the emission data. In this study, a new method is developed for estimating air pollution emissions based on a Newtonian relaxation and nudging technique. Case studies for the period of 1–25 August 2006 in 47 cities in China indicate that the nudging technique resulted in improved estimations of sulfur dioxide (SO2) and nitrogen dioxide (NO2) emissions in the majority of these cities. Predictions of SO2 and NO2 concentrations in January, April, August, and October using the emission estimations derived from the nudging technique showed remarkable improvements over those based on the original emission data. DA - 2008/8// PY - 2008/8// DO - 10.1175/2008JAMC1737.1 VL - 47 IS - 8 SP - 2105-2114 SN - 1558-8424 ER - TY - JOUR TI - Anticyclonic Eddies in the Northeastern South China Sea during Winter 2003/2004 AU - Wang, Dongxiao AU - Xu, Hongzhou AU - Lin, Jing AU - Hu, Jianyu T2 - JOURNAL OF OCEANOGRAPHY DA - 2008/12// PY - 2008/12// DO - 10.1007/s10872-008-0076-3 VL - 64 IS - 6 SP - 925-935 SN - 1573-868X KW - Two anticyclonic eddies KW - northeastern South China Sea KW - Kuroshio intrusion KW - sea level anomaly KW - satellite-tracked buoy ER - TY - JOUR TI - MJO and tropical cyclogenesis in the Gulf of Mexico and eastern Pacific: Case study and idealized numerical modeling AU - Aiyyer, Anantha AU - Molinari, John T2 - JOURNAL OF THE ATMOSPHERIC SCIENCES AB - Abstract The role of the Madden–Julian oscillation (MJO) in modulating the frequency and location of tropical cyclogenesis over the eastern Pacific and the Gulf of Mexico during August–September 1998 is examined. During the nonconvective phase of the MJO, convection and low-level cyclonic vorticity occurred primarily in conjunction with the intertropical convergence zone (ITCZ). During the convective phase, convection, low-level cyclonic vorticity, and convergence expanded into the northeastern Pacific and the Gulf of Mexico. This was accompanied by enhanced eddy kinetic energy and barotropic energy conversions as compared to the nonconvective phase, consistent with previous research. During the nonconvective phase of the MJO, vertical shear was relatively weaker but tropical cyclones tended to form mainly within the ITCZ. On the contrary, during the convective phase, vertical wind shear exceeded 10 m s−1 over much of this region and tropical cyclone development occurred north of the ITCZ, near the Mexican Pacific coast and the Gulf of Mexico. Idealized numerical experiments are conducted using a barotropic model with time-invariant basic states representative of the nonconvective and convective phases of the MJO. The simulations indicate that the propagation paths as well as the amplification of the eddies differ substantially between the two phases. During the nonconvective phase, the waves tend to propagate westward into the eastern Pacific. During the convective phase, stronger southerlies steer the waves into the Gulf of Mexico. The MJO-related modulation of tropical cyclogenesis in the eastern Pacific and Gulf of Mexico thus appears to involve anomalous convergence, cyclonic vorticity, vertical wind shear, and differing tracks of easterly waves. DA - 2008/8// PY - 2008/8// DO - 10.1175/2007JAS2348.1 VL - 65 IS - 8 SP - 2691-2704 SN - 0022-4928 ER - TY - JOUR TI - Lack of correlation between chlorophyll a and cloud droplet effective radius in shallow marine clouds AU - Miller, Matthew A. AU - Yuter, Sandra E. T2 - GEOPHYSICAL RESEARCH LETTERS AB - The hypothesis that areas of high oceanic productivity affect the physical properties of shallow marine clouds via the production of secondary organic aerosols is evaluated using satellite data. The correlation between chlorophyll a concentrations, an indication of oceanic productivity, and low cloud droplet liquid phase effective radius ( R e ) is examined for several ocean regions and time periods. While a strong correlation between chlorophyll a and low R e can occur for specific periods in some locations, the correlation is not reproducible in other regions and time periods. The intermittent correlation between high concentrations of chlorophyll a and low R e is a coincidence and is not representative of a dominant, monotonic, causative relation between secondary organic aerosols and marine shallow cloud properties. DA - 2008/7/8/ PY - 2008/7/8/ DO - 10.1029/2008gl034354 VL - 35 IS - 13 SP - SN - 1944-8007 ER - TY - JOUR TI - Juvenile fish densities in Florida Keys mangroves correlate with landscape characteristics AU - Drew, C. Ashton AU - Eggleston, David B. T2 - MARINE ECOLOGY PROGRESS SERIES AB - MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 362:233-243 (2008) - DOI: https://doi.org/10.3354/meps07430 Juvenile fish densities in Florida Keys mangroves correlate with landscape characteristics C. Ashton Drew1,*, David B. Eggleston2 1Department of Zoology, North Carolina State University, 127 David Clark Labs, Raleigh, North Carolina 27695-7617, USA 2Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, 2800 Faucette Drive, Room 1125 Jordan Hall, Raleigh, North Carolina 27695-8208, USA *Email: cadrew@ncsu.edu ABSTRACT: Ecological patterns and processes are often scale-dependent. Understanding organisms’ perceptions of and responses to landscape heterogeneity and connectivity is essential for effective conservation and management. We used multiple regression models with backward elimination to test relationships between juvenile fish density and diversity, quantified visually by snorkelers, and site- (100s m) and landscape-scale (1 km) habitat characteristics of mangroves in the Great White Heron National Wildlife Refuge (GWHNWR) in the lower Florida Keys, USA. We compared site and landscape model performance using Akaike’s information criterion (AIC) and adjusted R2 values. Our results demonstrate the following: (1) juvenile fish density in mangrove backreef habitats correlated with landscape characteristics; (2) relationships between fish density and site or landscape characteristics differed greatly among species; and (3) juvenile fish diversity was not strongly correlated to either site or landscape characteristics. We therefore advise caution when (1) selecting fish species and sites for experiments to test nursery habitat hypotheses given the scale- and species-specific relationships between fish and mangrove habitats observed in the present study, and (2) implementing conservation strategies based upon habitat surrogates or quotas (e.g. protect 20% of mangrove habitat to conserve fish species) because landscape context might strongly, and uniquely, influence individual fish species’ juvenile density. In light of our results, we argue in support of landscape analyses and individual-based modeling as useful tools to prioritize conservation of backreef nursery habitats. KEY WORDS: Backreef habitats · Nursery role · Habitat quality · Spatial scale · Conservation · Coral reef fish · Landscape ecology Full text in pdf format PreviousNextCite this article as: Drew CA, Eggleston DB (2008) Juvenile fish densities in Florida Keys mangroves correlate with landscape characteristics. Mar Ecol Prog Ser 362:233-243. https://doi.org/10.3354/meps07430 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 362. Online publication date: June 30, 2008 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2008 Inter-Research. DA - 2008/// PY - 2008/// DO - 10.3354/meps07430 VL - 362 SP - 233-243 SN - 1616-1599 KW - backreef habitats KW - nursery role KW - habitat quality KW - spatial scale KW - conservation KW - coral reef fish KW - landscape ecology ER - TY - JOUR TI - A numerical study of storm surge in the Cape Fear River Estuary and adjacent coast AU - Xia, Meng AU - Xie, Lian AU - Pietrafesa, Leonard J. AU - Peng, Machuan T2 - JOURNAL OF COASTAL RESEARCH AB - The Cape Fear River Estuary (CFRE) region is a coastal domain that has experienced considerable threats and impacts from tropical cyclones. It is also an important nursery for juvenile fish, crabs, shrimp, and other biological species. Thus, predictions about the physical responses of the CFRE system to extreme weather events are important to the protection of life and property and to the economical well-being of local residents. In this study, the Princeton Ocean Model (POM) is used to simulate tropical cyclone storm–induced surge, inundation, and coastal circulation in the CFRE and the adjacent Long Bay using a three-level nesting approach. Hindcasts of the hydrodynamic responses of the CFRE system to historic events were performed for Hurricanes Fran, Floyd, Bertha, and Charley. Comparisons were also made for the modeling results and the observations. DA - 2008/// PY - 2008/// DO - 10.2112/06-0795.1 VL - 24 IS - 4C SP - 159-167 SN - 1551-5036 KW - Cape Fear KW - storm surge KW - POM ER - TY - JOUR TI - Workshop on Agricultural Air Quality: State of the science AU - Aneja, Viney P. AU - Blunden, Jessica AU - Roelle, Paul A. AU - Schlesinger, William H. AU - Knighton, Raymond AU - Niyogi, Dev AU - Gilliam, Wendell AU - Jennings, Greg AU - Duke, Clifford S. T2 - ATMOSPHERIC ENVIRONMENT AB - The first Workshop on Agricultural Air Quality: State of the Science was held at the Bolger Center in Potomac, Maryland from 4 to 8 June 2006. This international conference assembled approximately 350 people representing 25 nations from 5 continents, with disciplines ranging from atmospheric chemistry to soil science. The workshop was designed as an open forum in which participants could openly exchange the most current knowledge and learn about numerous international perspectives regarding agricultural air quality. Participants represented many stakeholder groups concerned with the growing need to assess agricultural impacts on the atmosphere and to develop beneficial policies to improve air quality. The workshop focused on identifying methods to improve emissions inventories and best management practices for agriculture. Workshop participants also made recommendations for technological and methodological improvements in current emissions measurement and modeling practices. The workshop commenced with a session on agricultural emissions and was followed by international perspectives from the United States, Europe, Australia, India, and South America. This paper summarizes the findings and issues of the workshop and articulates future research needs. These needs were identified in three general areas: (1) improvement of emissions measurement; (2) development of appropriate emission factors; and (3) implementation of best management practices (BMPs) to minimize negative environmental impacts. Improvements in the appropriate measurements will inform decisions regarding US farming practices. A need was demonstrated for a national/international network to monitor atmospheric emissions from agriculture and their subsequent depositions to surrounding areas. Information collected through such a program may be used to assess model performance and could be critical for evaluating any future regulatory policies or BMPs. The workshop concluded that efforts to maximize benefits and reduce detrimental effects of agricultural production need to transcend disciplinary, geographic, and political boundaries. Also, such efforts should involve natural and social scientists, economists, engineers, business leaders, and decision makers. The workshop came to the conclusion that through these collaborative efforts improvements in air quality from agricultural practices will begin to take effect. DA - 2008/4// PY - 2008/4// DO - 10.1016/j.atmosenv.2007.07.043 VL - 42 IS - 14 SP - 3195-3208 SN - 1873-2844 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-41449102642&partnerID=MN8TOARS KW - nitrogen KW - ammonia KW - sulfur KW - hydrocarbons KW - biogenic VOCs KW - odor KW - emissions KW - emission factor KW - transport KW - transformation KW - crop and animal agriculture KW - measurements KW - modeling KW - best management practices KW - policy ER - TY - JOUR TI - Trends in agricultural ammonia emissions and ammonium concentrations in precipitation over the Southeast and Midwest United States AU - Stephen, Konarik AU - Aneja, Viney P. T2 - ATMOSPHERIC ENVIRONMENT AB - Emissions from agricultural activities, both crop and animal, are known to contain gaseous ammonia (NH3) which through chemical reaction in rainwater changes into ammonium ion (NH4+). Using wet deposition data of ammonium from several National Atmospheric Deposition Program/National Trends Network (NADP/NTN) and ambient levels of ammonium from Clean Air Status Trends Network (CAST Net) sites as well as calculated NH3 emissions from North Carolina, and the Southeast and Midwest regions of the United States, trends in ammonium concentrations in precipitation were analyzed for the period of 1983–2004. The beginning of 1997 coincides with the implementation of a swine population moratorium in the state of North Carolina. Results from the analysis in North Carolina indicate a lessening in the rate of increases in NH4+ concentration in precipitation since the moratorium went into effect. Sampson County, NC, saw stable NH4+ concentrations from 1983 to 1989, an average rise of 9.5% from 1989 to 1996, and an average increase of only 4% from 1997 to 2004. In addition, HYSPLIT back-trajectory model was used to determine that when ambient air in downwind sites arrived from the high NH3 emissions source region, ammonium concentrations in precipitation were enhanced. For the Southeast United States domain, analysis shows that NH4+ concentrations generally increased with increasing NH3 emissions from within the same region. Similar analysis has been performed over the Midwest United States and compared to the results from the Southeast United States. Emissions from the Midwest are attributed to larger animals, including hogs and cattle, whereas the Southeast has a higher percentage of emissions coming from smaller livestock, such as chickens. In addition, the states of the Midwest United States have a much more uniform spatial distribution of emissions. DA - 2008/4// PY - 2008/4// DO - 10.1016/j.atmosenv.2007.05.062 VL - 42 IS - 14 SP - 3238-3252 SN - 1873-2844 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-41449098963&partnerID=MN8TOARS KW - ammonia emissions KW - North Carolina hog moratorium KW - ammonium wet deposition ER - TY - JOUR TI - Sonication of bacteria, phytoplankton and zooplankton: Application to treatment of ballast water AU - Holm, Eric R. AU - Stamper, David M. AU - Brizzolara, Robert A. AU - Barnes, Laurie AU - Deamer, Nora AU - Burkholder, JoAnn M. T2 - MARINE POLLUTION BULLETIN AB - We investigated the effect of high power ultrasound, at a frequency of 19 kHz, on the survival of bacteria, phytoplankton and zooplankton, in order to obtain estimates of effective exposure times and energy densities that could be applied to design of ultrasonic treatment systems for ballast water. Efficacy of ultrasonic treatment varied with the size of the test organism. Zooplankton required only 3–9 s of exposure time and 6–19 J/mL of ultrasonic energy to realize a 90% reduction in survival. In contrast, decimal reduction times for bacteria and phytoplankton ranged from 1 to 22 min, and decimal reduction energy densities from 31 to 1240 J/mL. Our results suggest that stand-alone ultrasonic treatment systems for ballast water, operating at 19–20 kHz, may be effective for planktonic organisms >100 μm in size, but smaller planktonic organisms such as phytoplankton and bacteria will require treatment by an additional or alternative system. DA - 2008/6// PY - 2008/6// DO - 10.1016/j.marpolbul.2008.02.007 VL - 56 IS - 6 SP - 1201-1208 SN - 1879-3363 KW - ultrasound KW - ballast water treatment KW - bacteria KW - phytoplankton KW - zooplankton ER - TY - JOUR TI - Ocean urea fertilization for carbon credits poses high ecological risks AU - Glibert, P. M. AU - Azanza, R. AU - Burford, M. AU - Furuya, K. T2 - Marine Pollution Bulletin DA - 2008/// PY - 2008/// VL - 56 IS - 6 SP - 1049-1056 ER - TY - JOUR TI - Modeling atmospheric transport and fate of ammonia in North Carolina-Part I: Evaluation of meteorological and chemical predictions AU - Wu, S.-Y. AU - Krishnan, S. AU - Zhang, Y. AU - Aneja, Viney T2 - Atmospheric Environment AB - The atmospheric transport and fate of ammonia (NH3) depend on both meteorological and chemical conditions once it is emitted into the atmosphere. The largest source contributing to NH3 emission is the agricultural production, in particular animal operation, in North Carolina (NC). In this study, three-dimensional numerical meteorological and air quality models are applied to study the transport and fate of NH3 in the atmosphere in an area in southeast US centered over NC. One summer and one winter month simulations with a 4-km horizontal grid were conducted to simulate the meteorological and chemical environments for the transport and transformation of the reduced nitrogen, NHx (=NH3+NH4+) and to examine its seasonal variations and interactions with other chemical species (e.g., ozone and fine particular matter, PM2.5). The model performance for simulated meteorology and air quality was evaluated against observations in terms of spatial distributions, temporal variations, and statistical trends. MM5/CMAQ gave an overall good performance for meteorological variables and O3 mixing ratios and a reasonably good performance for PM2.5. The simulations show that 10–40% of total NH3 was converted to NH4+ at/near source and 40–100% downwind in August, and the conversion rates were 20–50% at/near source and 50–98% downwind in December. While the 3-D atmospheric models demonstrate some skills in capturing synoptic meteorological patterns, diurnal variations of concentrations of oxidants and PM2.5, and regional transport and transformation of NHx, reproducing meteorological and chemical features at a local scale and the magnitudes of hourly concentrations of oxidants and PM2.5 remain challenging due to uncertainties in model inputs and treatments. DA - 2008/// PY - 2008/// DO - 10.1016/j.atmosenv.2007.04.031 VL - 42 IS - 14 SP - 3419-3436 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-41449096822&partnerID=MN8TOARS ER - TY - JOUR TI - Modeling atmospheric transport and fate of ammonia in North Carolina - Part II: Effect of ammonia emissions on fine particulate matter formation AU - Wu, Shiang-Yuh AU - Hu, Jian-Lin AU - Zhang, Yang AU - Aneja, Viney P. T2 - ATMOSPHERIC ENVIRONMENT AB - Accurate estimates of ammonia (NH3) emissions are needed for reliable predictions of fine particulate matter (PM2.5) by air quality models (AQMs), but the current estimates contain large uncertainties in the temporal and spatial distributions of NH3 emissions. In this study, the US EPA Community Multiscale Air Quality (CMAQ) modeling system is applied to study the contributions of the agriculture–livestock NH3 (AL-NH3) emissions to the concentration of PM2.5 and the uncertainties in the total amount and the temporal variations of NH3 emissions and their impact on the formation of PM2.5 for August and December 2002. The sensitivity simulation results show that AL-NH3 emissions contribute significantly to the concentration of PM2.5, NH4+, and NO3−; their contributions to the concentrations of SO42− are relatively small. The impact of NH3 emissions on PM2.5 formation shows strong spatial and seasonal variations associated with the meteorological conditions and the ambient chemical conditions. Increases in NH3 emissions in August 2002 resulted in >10% increases in the concentrations of NH4+ and NO3−; reductions in NH3 emissions in December 2002 resulted in >20% decreases in their concentrations. The large changes in species concentrations occur downwind of the high NH3 emissions where the ambient environment is NH3-poor or neutral. The adjustments in NH3 emissions improve appreciably the model predictions of NH4+ and NO3− both in August and December, but resulted in negligible improvements in PM2.5 in August and a small improvement in December, indicating that other factors (e.g., inaccuracies in meteorological predictions, emissions of other primary species, aerosol treatments) might be responsible for model biases in PM2.5. DA - 2008/4// PY - 2008/4// DO - 10.1016/j.atmosenv.2007.04.022 VL - 42 IS - 14 SP - 3437-3451 SN - 1873-2844 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-41449110003&partnerID=MN8TOARS KW - ammonia emissions KW - agriculture KW - livestock KW - PM2.5 KW - CMAQ KW - sensitivity study ER - TY - JOUR TI - Modeling agricultural air quality: Current status, major challenges, and outlook AU - Zhang, Yang AU - Wu, Shiang-Yuh AU - Krishnan, Srinath AU - Wang, Kai AU - Queen, Ashley AU - Aneja, Viney P. AU - Arya, S. Pal T2 - ATMOSPHERIC ENVIRONMENT AB - Agricultural air quality is an important emerging area of atmospheric sciences that represents significant challenges in many aspects of research including measurements, modeling, regulations, emission control, and operation managements. This work presents a review of current status, major challenges, and future research needs and opportunities of several important aspects of agricultural air quality modeling including chemical species, concentration and deposition measurements for model verification, emission inventories, major physical and chemical processes, model application and evaluation, and policy implications. DA - 2008/4// PY - 2008/4// DO - 10.1016/j.atmosenv.2007.01.063 VL - 42 IS - 14 SP - 3218-3237 SN - 1873-2844 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-41549095063&partnerID=MN8TOARS KW - agriculture KW - air quality KW - ammonia KW - reduced nitrogen KW - 3-D modeling ER - TY - JOUR TI - Measurement and analysis of ammonia and hydrogen sulfide emissions from a mechanically ventilated swine confinement building in North Carolina AU - Blunden, Jessica AU - Aneja, Viney P. AU - Westerman, Phillip W. T2 - ATMOSPHERIC ENVIRONMENT AB - Emissions of atmospheric ammonia–nitrogen (NH3–N, where NH3–N=(1417)NH3) and hydrogen sulfide (H2S) were measured from a finishing swine confinement house at a commercial pig farm in eastern North Carolina. Continuous simultaneous NH3–N and H2S emissions were made for ∼1-week period during four different seasons. The number of pigs contained in the house varied from ∼850 to 900 with average weights ranging from ∼38 to 88 kg. Average NH3–N concentrations were highest during the winter and spring sampling periods, 8.91±4.61 and 8.44±2.40 ppm, respectively, and lower during the summer and fall, 2.45±1.14 and 4.27±0.71 ppm, respectively. Measured average H2S concentrations were 673±282, 429±223, 47±18, and 304±88 ppb during winter, spring, summer, and fall, respectively. Generally, the H2S concentrations were approximately an order of magnitude less than NH3–N during winter, spring, and fall, and two orders of magnitude smaller during the summer season. The average ambient temperature ranged from 5.5 to 22.3 °C while the average barn temperature measured at the outlet fans ranged from 19.0 to 26.0 °C in the winter and summer, respectively. The average fan ventilation rates varied from 253 m3 min−1 during the fall sampling period to 1024 m3 min−1 during summer. Calculated total emission rates for both NH3–N and H2S were highest during the spring, 4519±1639 g N day−1 and 481±142 g day−1, respectively. Emissions were lowest during the fall season for NH3–N (904±568 g N day−1) and the summer season for H2S (82±49 g day−1). Normalized NH3–N emission rates were highest in winter and spring (33.6±21.9 and 30.6±11.1 g N day−1 AU−1, where 1 AU (animal unit)=500 kg) and lowest during summer and fall (24.3±12.4 and 11.8±7.4 g N day−1 AU−1). Normalized H2S emissions were highest during the winter and spring seasons (4.2±2.1 and 3.3±1.0 g day−1 AU−1) and were lowest in summer and fall (1.2±0.7 and 1.7±0.5 g day−1 AU−1). DA - 2008/4// PY - 2008/4// DO - 10.1016/j.atmosenv.2007.06.040 VL - 42 IS - 14 SP - 3315-3331 SN - 1352-2310 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-41449109456&partnerID=MN8TOARS KW - ammonia KW - hydrogen sulfide KW - swine barns KW - CAFOs ER - TY - JOUR TI - Inferential model estimates of ammonia dry deposition in the vicinity of a swine production facility AU - Walker, John AU - Spence, Porche' AU - Kimbrough, Sue AU - Robarge, Wayne T2 - ATMOSPHERIC ENVIRONMENT AB - This project investigates NH3 dry deposition around a commercial swine production facility in eastern North Carolina. Passive diffusion-tube samplers were used to measure weekly integrated NH3 concentrations at 22 locations along horizontal gradients from the barn/lagoon emissions complex (source) out to a distance of 700 m. A two-layer canopy compensation point model was used to predict bi-directional NH3 exchange within a 500 m circular buffer surrounding the source. The model takes into account differences in soil and vegetation emission potential, as well as canopy physical characteristics, among three primary surfaces surrounding the site: forest, crops spray fertilized with swine waste, and other fertilized crops. Between June 2003 and July 2005, mean observed NH3 concentrations ranged from 169.0 μg NH3 m−3 at a distance of 10 m from the source to 7.1 and 13.0 μg NH3 m−3 at 612 and 698 m in the predominant upwind and downwind directions, respectively. Median predicted dry deposition rates ranged from 145 kg NH3–N ha−1 yr−1 at 10 m from the source to 16 kg NH3–N ha−1 yr−1 at 500 m, which is ≈3.5× wet deposition of NH4+–N. Assuming a steady-state emission factor of 7.0 kg NH3 animal−1 yr−1 and a median population of 4900 animals, NH3 dry deposition over the nearest 500 m from the barn/lagoon complex accounted for 10.4% (3567 kg NH3) of annual emissions (34,300 kg NH3). A model sensitivity analysis shows that predicted deposition rates are more sensitive to assumptions regarding cuticular uptake relative to soil and vegetation emission potentials. DA - 2008/4// PY - 2008/4// DO - 10.1016/j.atmosenv.2007.06.004 VL - 42 IS - 14 SP - 3407-3418 SN - 1873-2844 KW - ammonia KW - bi-directional flux KW - compensation point KW - dry deposition KW - resistance model ER - TY - JOUR TI - Increasing frequencies of warm and humid air masses over the conterminous United States from 1948 to 2005 AU - Knight, D. B. AU - Davis, R. E. AU - Sheridan, S. C. AU - Hondula, D. M. AU - Sitka, L. J. AU - Deaton, M. AU - Lee, T. R. AU - Gawtry, S. D. AU - Stenger, P. J. AU - Mazzei, F. AU - Kenny, B. P. T2 - Geophysical Research Letters DA - 2008/// PY - 2008/// VL - 35 IS - 10 ER - TY - JOUR TI - Characterizing ammonia emissions from swine farms in eastern North Carolina: Reduction of emissions from water-holding structures at two candidate superior technologies for waste treatment AU - Aneja, Viney P. AU - Arya, S. Pal AU - Rumsey, Ian C. AU - Kim, D-S. AU - Bajwa, K. S. AU - Williams, C. M. T2 - ATMOSPHERIC ENVIRONMENT AB - Abstract Program OPEN (Odor, Pathogens, and Emissions of Nitrogen) was an integrated study of the emissions of ammonia (NH 3 ), odor and odorants, and pathogens from potential environmentally superior technologies (ESTs) for swine facilities in eastern North Carolina. This paper, as part of program OPEN, focuses on quantifying emissions of NH 3 from water-holding structures at two of the best ESTs and compares them with the projected emissions from two conventional lagoon and spray technologies (LSTs). The evaluated ESTs are: (1) Super Soils at Goshen Ridge; and (2) Environmental Technologies at Red Hill. The water-holding structures for these two ESTs contained no conventional anaerobic lagoon. A dynamic flow-through chamber was used to measure NH 3 fluxes from the water-holding structures at both the ESTs and at the conventional LST farms. In order to compare the emissions from the water-holding structures at the ESTs with those from the lagoons at the conventional sites under similar conditions, a statistical-observational model for lagoon NH 3 emissions was used. A mass-balance approach was used to quantify the emissions. All emissions were normalized by nitrogen-excretion rates. The percentage reductions relative to the conventional lagoons were calculated for the two ESTs. Results showed substantial reductions in NH 3 emissions at both ESTs. Super Soils had reductions of 94.7% for the warm season and 99.0% for the cool season. Environmental Technologies had slightly larger reductions of 99.4% and 99.98% for the cool and warm season, respectively. As a result of such large reductions in ammonia emissions, both technologies meet the criteria to be classified as ESTs for ammonia emissions. DA - 2008/4// PY - 2008/4// DO - 10.1016/j.atmosenv.2007.08.037 VL - 42 IS - 14 SP - 3291-3300 SN - 1352-2310 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-41449117100&partnerID=MN8TOARS KW - ammonia emissions KW - ammonia flux KW - water-holding structures KW - environmentally superior technologies (ESTs) KW - lagoon and spray technologies (LSTs) ER - TY - JOUR TI - Characterizing ammonia and hydrogen sulfide emissions from a swine waste treatment lagoon in North Carolina AU - Blunden, Jessica AU - Aneja, Viney P. T2 - ATMOSPHERIC ENVIRONMENT AB - Emissions of atmospheric ammonia–nitrogen (NH3-N, where NH3-N=(14/17)NH3) and hydrogen sulfide (H2S) from a commercial anaerobic swine waste treatment lagoon (17,150 m2 at normal liquid level) were measured over a 1-year period. Continuous simultaneous measurements were made at the lagoon using a dynamic flow-through chamber system for ∼1 week during four seasons, October–November 2004 (fall), February 2005 (winter), April 2005 (spring), and June 2005 (summer) in an effort to examine diurnal and seasonal variability, and the respective relationships of NH3-N and H2S emissions to lagoon physicochemical properties. Continuously measured lagoon physicochemical parameters include lagoon surface temperature and lagoon pH. Aqueous lagoon samples were collected daily and analyzed for total Kjeldahl nitrogen (TKN), total ammoniacal nitrogen (TAN), and total sulfide concentration. TKN, TAN, and sulfide concentrations ranged from 400–650, 360–590, and 0.1–13.0 mg L−1, respectively. For NH3-N, the largest fluxes were observed during the summer (>4200 μg N m−2 min−1). During the fall and spring, average NH3-N fluxes were 1634±505 and >2495 μg N m−2 min−1, respectively. The lowest fluxes were observed during the winter where average flux values were 1290±246 μg N m−2 min−1. Fluxes for H2S were negligible during the winter season. Average fluxes increased during the fall (0.3±0.1 μg m−2 min−1) and spring (0.5±1.0 μg m−2 min−1), and highest flux values were observed during the summer (5.3±3.2 μg m−2 min−1). The seasonal NH3-N and H2S emission factors ranged from ∼10 to ∼40 kg N AU−1 yr−1 (1 AU=500 kg live animal weight) and ∼0 to ∼0.05 kg H2S AU−1 yr−1, respectively. Generally, the lagoon emissions for H2S were ∼3–4 orders of magnitude less than NH3-N. The gas fluxes were related to various physicochemical parameters including the pH and near-surface temperature of the lagoon, and the aqueous concentration of the respective gas. DA - 2008/4// PY - 2008/4// DO - 10.1016/j.atmosenv.2007.02.026 VL - 42 IS - 14 SP - 3277-3290 SN - 1352-2310 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-41449084288&partnerID=MN8TOARS KW - ammonia KW - hydrogen sulfide KW - emissions KW - dynamic chamber KW - pig manure KW - lagoon ER - TY - JOUR TI - Species names in the PhyloCode: The approach adopted by the international society for phylogenetic nomenclature AU - Dayrat, Benoit AU - Cantino, Philip D. AU - Clarke, Julia A. AU - De Queiroz, Kevin T2 - SYSTEMATIC BIOLOGY AB - Edwards, S. V., L. Liu, and D. K. Pearl. 2007. High resolution species trees without concatenation. Proc. Natl. Acad. Sci. USA 104:5936– 5941. Hennig, W. 1950. Grundzuge Einer Theorie der Phylogenetischen Systematik. Deutscher Zentralverlag, Berlin. [Published in English translation in 1966: Phylogenetic systematics, University of Illinois Press, Urbana, Illinois.] Hudson, R. R. 1983. Testing the constant-rate neutral allele model with protein sequence data. Evolution 37:203–217. Liu, L., and D. K. Pearl. 2007. Species trees from gene trees: Reconstructing Bayesian posterior distributions of a species phylogeny using estimated gene tree distributions. Syst. Biol. 56:504–514. Maddison, W. P. 1997. Gene trees in species trees. Syst. Biol. 46:523– 536. Maddison, W. P., and L. L. Knowles. 2006. Inferring phylogeny despite incomplete lineage sorting. Syst. Biol. 55:21–30. Nei, M. 1987. Molecular evolutionary genetics. Columbia University Press, New York. Neigel, J. E. and J. C. Avise. 1986. Phylogenetic relationships of mitochondrial DNA under various demographic models of speciation. Pages 515–534 in Evolutionary processes and theory (S. Karlin and E. Nevo, eds.). Academic Press, Orlando, Florida. Nichols, R. 2001. Gene trees and species trees are not the same. Trends Ecol. Evol. 16:358–364. DA - 2008/// PY - 2008/// DO - 10.1080/10635150802172176 VL - 57 IS - 3 SP - 507-514 SN - 1076-836X ER - TY - JOUR TI - Saharan dust and phosphatic fidelity: A three-dimensional biogeochemical model of Trichodesmium as a nutrient source for red tides on the West Florida Shelf AU - Lenes, J. M. AU - Darrow, B. A. AU - Walsh, J. J. AU - Prospero, J. M. AU - He, R. AU - Weisberg, R. H. AU - Vargo, G. A. AU - Heil, C. A. T2 - CONTINENTAL SHELF RESEARCH AB - The availability of iron within the surface waters of the broad, oligotrophic West Florida Shelf (WFS) controls periodic blooms of the pelagic marine cyanobacterium Trichodesmium. Summer delivery of Saharan dust provided adequate iron (Fe) to shift limitation of growth to the availability of phosphorus (P). Florida's rivers drain Miocene phosphorus deposits to provide the WFS with freshwater nutrient supplies at molar dissolved inorganic nitrogen/phosphate (DIN/PO4) ratios of <6. These diazotrophs draw upon ubiquitous stocks of dissolved nitrogen gas, once stimulated by Fe-deposition within P-replete waters of the WFS. An extensive in situ data set collected between 1998 and 2001 (NEGOM/ECOHAB) provided plankton taxonomy, hydrographic, nutrient, dissolved organic matter (DOM), pigment, and optical properties on the shelf. We constructed a three-dimensional numerical model to analyze the impact of iron fertilization of the diazotroph Trichodesmium and the resultant effect upon the elemental cycles of N, P, and Fe. The coupled physical and ecological models show that the wet deposition of Fe-rich Saharan dust was necessary to stimulate enough nitrogen fixation to initialize the toxic red tide (Karenia brevis) of ∼20 μg chl a l−1 that occurred in October 1999. The simulation suggests that the magnitude and longevity of the Trichodesmium population, and therefore this source of ‘new’ nitrogen, was controlled by both phosphorus and iron availability. DA - 2008/5/30/ PY - 2008/5/30/ DO - 10.1016/j.csr.2008.02.009 VL - 28 IS - 9 SP - 1091-1115 SN - 1873-6955 KW - nitrogen fixation KW - modeling KW - mineral dust KW - iron KW - phosphorus KW - Trichodesmium KW - red tide ER - TY - JOUR TI - Raindrop size distributions and rain characteristics in California coastal rainfall for periods with and without a radar bright band AU - Martner, Brooks E. AU - Yuter, Sandra E. AU - White, Allen B. AU - Matrosov, Sergey Y. AU - Kingsmill, David E. AU - Ralph, F. Martin T2 - JOURNAL OF HYDROMETEOROLOGY AB - Abstract Recent studies using vertically pointing S-band profiling radars showed that coastal winter storms in California and Oregon frequently do not display a melting-layer radar bright band and inferred that these nonbrightband (NBB) periods are characterized by raindrop size spectra that differ markedly from those of brightband (BB) periods. Two coastal sites in northern California were revisited in the winter of 2003/04 in this study, which extends the earlier work by augmenting the profiling radar observations with collocated raindrop disdrometers to measure drop size distributions (DSD) at the surface. The disdrometer observations are analyzed for more than 320 h of nonconvective rainfall. The new measurements confirm the earlier inferences that NBB rainfall periods are characterized by greater concentrations of small drops and smaller concentrations of large drops than BB periods. Compared with their BB counterparts, NBB periods had mean values that were 40% smaller for mean-volume diameter, 32% smaller for rain intensity, 87% larger for total drop concentration, and 81% larger (steeper) for slope of the exponential DSDs. The differences are statistically significant. Liquid water contents differ very little, however, for the two rain types. Disdrometer-based relations between radar reflectivity (Z) and rainfall intensity (R) at the site in the Coast Range Mountains were Z = 168R1.58 for BB periods and Z = 44R1.91 for NBB. The much lower coefficient, which is characteristic of NBB rainfall, is poorly represented by the Z–R equations most commonly applied to data from the operational network of Weather Surveillance Radar-1988 Doppler (WSR-88D) units, which underestimate rain accumulations by a factor of 2 or more when applied to nonconvective NBB situations. Based on the observed DSDs, it is also concluded that polarimetric scanning radars may have some limited ability to distinguish between regions of BB and NBB rainfall using differential reflectivity. However, differential-phase estimations of rain intensity are not useful for NBB rain, because the drops are too small and nearly spherical. On average, the profiler-measured echo tops were 3.2 km lower in NBB periods than during BB periods, and they extended only about 1 km above the 0°C altitude. The findings are consistent with the concept that precipitation processes during BB periods are dominated by ice processes in deep cloud layers associated with synoptic-scale forcing, whereas the more restrained growth of hydrometeors in NBB periods is primarily the result of orographically forced condensation and coalescence processes in much shallower clouds. DA - 2008/6// PY - 2008/6// DO - 10.1175/2007JHM924.1 VL - 9 IS - 3 SP - 408-425 SN - 1525-755X ER - TY - JOUR TI - Potential transport of harmful algae via relocation of bivalve molluscs AU - Hegaret, Helene AU - Shumway, Sandra E. AU - Wikfors, Gary H. AU - Pate, Susan AU - Burkholder, Joann M. T2 - MARINE ECOLOGY PROGRESS SERIES AB - MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 361:169-179 (2008) - DOI: https://doi.org/10.3354/meps07375 Potential transport of harmful algae via relocation of bivalve molluscs Hélène Hégaret1, Sandra E. Shumway1,*, Gary H. Wikfors2, Susan Pate3, JoAnn M. Burkholder3 1Department of Marine Sciences, University of Connecticut, Groton, Connecticut 06340, USA 2Northeast Fisheries Science Center, National Oceanic and Atmospheric Administration–National Marine Fisheries Service, Milford, Connecticut 06460, USA 3Center for Applied Aquatic Ecology (CAAE), North Carolina State University, Raleigh, North Carolina 27695, USA *Corresponding author. Email: sandra.shumway@uconn.edu ABSTRACT: Aquaculture and restoration activities with bivalve molluscs often involve moving individuals from one body of water to another. Our study tests the hypothesis that harmful algae ingested by source populations of shellfish can be introduced into new environments by means of these shellfish relocations. Cultures of several harmful algal strains, including Prorocentrum minimum, Alexandrium fundyense, Heterosigma akashiwo, Aureococcus anophagefferens, Karenia mikimotoi and Alexandrium monilatum, were fed to various species of bivalve molluscs, Crassostrea virginica, Argopecten irradians irradians, Mercenaria mercenaria, Mytilus edulis, Mya arenaria, Venerupis philippinarum and Perna viridis, to assess the ability of the algal cells to pass intact though the digestive tracts of the shellfish and subsequently multiply in number. Ten individuals of each shellfish species were exposed for 2 d to a simulated harmful algal bloom at a natural bloom concentration. The shellfish were removed after exposure, and maintained for 2 further days in ultra-filtered seawater. Biodeposits (feces) were collected after 24 and 48 additional hours, and observed under light microscopy for the presence or absence of intact, potentially viable algal cells or temporary cysts. Subsamples of biodeposits were transferred into both algal culture medium and filtered seawater and monitored for algal growth. Intact cells of most harmful algal species tested were seen in biodeposits. Generally, harmful algae from the biodeposits collected in the first 24 h after transfer re-established growing populations, but algae could less often be recovered from the biodeposits collected after 48 h. These data provide evidence that transplanted bivalve molluscs may be vectors for the transport of harmful algae and that a short holding period in water without algae may mitigate this risk. Further, preliminary results indicate that emersion may also serve to mitigate the risk of transport. KEY WORDS: Bivalve mollusc · Harmful algal bloom · Toxic algae · Transport · Clam · Scallop · Oyster Full text in pdf format PreviousNextCite this article as: Hégaret H, Shumway SE, Wikfors GH, Pate S, Burkholder JM (2008) Potential transport of harmful algae via relocation of bivalve molluscs. Mar Ecol Prog Ser 361:169-179. https://doi.org/10.3354/meps07375 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 361. Online publication date: June 09, 2008 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2008 Inter-Research. DA - 2008/// PY - 2008/// DO - 10.3354/meps07375 VL - 361 SP - 169-179 SN - 0171-8630 KW - bivalve mollusc KW - harmful algal bloom KW - toxic algae KW - transport KW - clam s KW - scallop KW - oyster ER - TY - JOUR TI - Phytoplankton biomass distribution and identification of productive habitats within the Galapagos Marine Reserve by MODIS, a surface acquisition system, and in-situ measurements AU - Schaeffer, Blake A. AU - Morrison, John M. AU - Kamykowski, Daniel AU - Feldman, Gene C. AU - Xie, Lian AU - Liu, Yanyun AU - Sweet, William AU - McCulloch, Anita AU - Banks, Stuart T2 - REMOTE SENSING OF ENVIRONMENT AB - The Galapagos Marine Reserve (GMR) is one of the most diverse ecosystems in the world. Phytoplankton are the base of the ecosystem food chain for many higher trophic organisms, so identifying phytoplankton biomass distribution is the first step in understanding the dynamic environment for effective management of the GMR. Moderate Resolution Imaging Spectroradiometer (MODIS) and hyperspectral surface acquisition system derived chlorophyll, in-situ chlorophyll fluorescence, nitrate, salinity, and temperature were collected from March 2005 to the onset of a mild El Niño in November 2006. Islands in the eastern GMR, such as San Cristobal and Espanola, are the first to experience impacts of El Niño and southern migration of the Equatorial Front. Productive habitats were defined as surface waters with salinities > 34, temperatures < 24 °C, and chlorophyll a > 0.4 mg m− 3. Six temporally variable productive habitats identified were: west of Isabela Island, southwest of Floreana Island, south of Santa Cruz, between Santiago and Santa Cruz Islands, and on the eastern side near San Cristobal Island. Model results coupled with surface acquisition system derived chlorophyll indicated productive habitats may also occur for short periods and at a distance from islands such as when the Equatorial Undercurrent (EUC) and South Equatorial Current (SEC) collide over the seamounts north of Isabela Island. All productive habitats were related to topographic upwelling from the EUC into surface waters. DA - 2008/6/16/ PY - 2008/6/16/ DO - 10.1016/j.rse.2008.03.005 VL - 112 IS - 6 SP - 3044-3054 SN - 1879-0704 KW - chlorophyll a KW - MODIS KW - surface acquisition system KW - Galapagos Marine Reserve KW - phytoplankton KW - biomass KW - El Nino KW - productive habitats ER - TY - JOUR TI - Online-coupled meteorology and chemistry models: history, current status, and outlook AU - Zhang, Y. T2 - Atmospheric Chemistry and Physics DA - 2008/// PY - 2008/// VL - 8 IS - 11 SP - 2895-2932 ER - TY - JOUR TI - Nitrate contamination in groundwater on an urbanized dairy farm AU - Showers, William J. AU - Genna, Bernard AU - McDade, Timothy AU - Bolich, Rick AU - Fountain, John C. T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - Urbanization of rural farmland is a pervasive trend around the globe, and maintaining and protecting adequate water supplies in suburban areas is a growing problem. Identification of the sources of groundwater contamination in urbanized areas is problematic, but will become important in areas of rapid population growth and development. The isotopic composition of NO3 (δ15NNO3 and δ18O NO3), NH4 (δ15NNH4), groundwater (δ2Hwt and δ18Owt) and chloride/bromide ratios were used to determine the source of nitrate contamination in drinking water wells in a housing development that was built on the site of a dairy farm in the North Carolina Piedmont, U.S. The δ15NNO3 and δ18O NO3 compositions imply that elevated nitrate levels at this site in drinking well water are the result of waste contamination, and that denitrification has not significantly attenuated the groundwater nitrate concentrations. δ15NNO3 and δ18ONO3 compositions in groundwater could not differentiate between septic effluent and animal waste contamination. Chloride/bromide ratios in the most contaminated drinking water wells were similar to ratios found in animal waste application fields, and were higher than Cl/Br ratios observed in septic drain fields in the area. δ18Owt was depleted near the site of a buried waste lagoon without an accompanying shift in δ2Hwt suggesting water oxygen exchange with CO2. This water−CO2 exchange resulted from the reduction of buried lagoon organic matter, and oxidation of the released gases in aerobic soils. δ18Owt is not depleted in the contaminated drinking water wells, indicating that the buried dairy lagoon is not a source of waste contamination. The isotope and Cl/Br ratios indicate that nitrate contamination in these drinking wells are not from septic systems, but are the result of animal waste leached from pastures into groundwater during 35 years of dairy operations which did not violate any existing regulations. Statutes need to be enacted to protect the health of the homeowners that require well water to be tested prior to the sale of homes built on urbanized farmland. DA - 2008/7/1/ PY - 2008/7/1/ DO - 10.1021/es071551t VL - 42 IS - 13 SP - 4683-4688 SN - 0013-936X ER - TY - JOUR TI - Mosaicism, modules, and the evolution of birds: Results from a Bayesian approach to the study of morphological evolution using discrete character data AU - Clarke, Julia A. AU - Middleton, Kevin M. T2 - SYSTEMATIC BIOLOGY AB - The study of morphological evolution after the inferred origin of active flight homologous with that in Aves has historically been characterized by an emphasis on anatomically disjunct, mosaic patterns of change. Relatively few prior studies have used discrete morphological character data in a phylogenetic context to quantitatively investigate morphological evolution or mosaic evolution in particular. One such previously employed method, which used summed unambiguously optimized synapomorphies, has been the basis for proposing disassociated and sequential “modernizing” or “fine-tuning” of pectoral and then pelvic locomotor systems after the origin of flight (“pectoral early–pelvic late” hypothesis). We use one of the most inclusive phylogenetic data sets of basal birds to investigate properties of this method and to consider the application of a Bayesian phylogenetic approach. Bayes factor and statistical comparisons of branch length estimates were used to evaluate support for a mosaic pattern of character change and the specific pectoral early–pelvic late hypothesis. Partitions were defined a priori based on anatomical subregion (e.g., pelvic, pectoral) and were based on those hypothesized using the summed synapomorphy approach. We compare 80 models all implementing the Mk model for morphological data but varying in the number of anatomical subregion partitions, the models for among-partition rate variation and among-character rate variation, as well as the branch length prior. Statistical analysis reveals that partitioning data by anatomical subregion, independently estimating branch lengths for partitioned data, and use of shared or per partition gamma-shaped among-character rate distribution significantly increases estimated model likelihoods. Simulation studies reveal that partitioned models where characters are randomly assigned perform significantly worse than both the observed model and the single-partition equal-rate model, suggesting that only partitioning by anatomical subregion increases model performance. The preference for models with partitions defined a priori by anatomical subregion is consistent with a disjunctive pattern of character change for the data set investigated and may have implications for parameterization of Bayesian analyses of morphological data more generally. Statistical tests of differences in estimated branch lengths from the pectoral and pelvic partitions do not support the specific pectoral early–pelvic late hypothesis proposed from the summed synapomorphy approach; however, results suggest limited support for some pectoral branch lengths being significantly longer only early at/after the origin of flight. DA - 2008/// PY - 2008/// DO - 10.1080/10635150802022231 VL - 57 IS - 2 SP - 185-201 SN - 1076-836X KW - Bayesian analyses KW - birds KW - flight KW - fossils KW - morphological data KW - mosaic evolution KW - quantitative methods ER - TY - JOUR TI - Examining the sensitivity of MM5-CMAQ predictions to explicit microphysics schemes and horizontal grid resolutions, Part III - The impact of horizontal grid resolution AU - Queen, Ashley AU - Zhang, Yang T2 - ATMOSPHERIC ENVIRONMENT AB - Examination of model sensitivity to horizontal grid resolutions can help identify optimal compromise in accuracy and computational efficiency for regulatory and research-grade applications of 3-D atmospheric models. In this Part III paper, the performance and sensitivity of simulated precipitation and wet deposition amounts by the MM5/CMAQ model to three horizontal grid resolutions (4-, 12-, and 36-km) are evaluated over North Carolina (NC). In contrast with simulated O3, PM2.5, and some PM2.5 species such as NH4+, simulated precipitation and wet deposition amounts are quite sensitive to grid resolutions. Compared with results at coarser resolutions, simulated precipitation amounts are lower in both August and December at 4-km, with the largest sensitivities to grid resolutions occurring in mountain and coastal regions of NC. For wet deposition predictions, the model performs the best for NO3− at 4-km and for NH4+ and SO42− at 12-km in August, but the best for NH4+ and NO3− at 36-km and for SO42− at 4-km in December. Such sensitivities and lack of clear trends in model performance at various resolutions can be attributed to seasonalities in meteorology and differences in characteristics of land use, emissions and concentrations of PM precursors, as well as nonlinear responses of chemistry and meteorology to grid resolutions. The overall performance trends demonstrate a high sensitivity in precipitation and wet deposition predictions over complex terrain and the fact that higher grid resolution does not always lead to improved model performance. DA - 2008/5// PY - 2008/5// DO - 10.1016/j.atmosenv.2008.02.035 VL - 42 IS - 16 SP - 3869-3881 SN - 1873-2844 KW - MM5 KW - CMAQ KW - sensitivity KW - horizontal grid resolutions KW - precipitation KW - wet deposition ER - TY - JOUR TI - Examining the sensitivity of MM5-CMAQ predictions to explicit microphysics schemes and horizontal grid resolutions, Part II - PM concentrations and wet deposition predictions AU - Queen, A. AU - Zhang, Y. T2 - Atmospheric Environment AB - This part II paper first evaluates the simulated concentrations and wet deposition amounts of NH4+, NO3−, and SO42− using observations from several networks, then examines their sensitivities to four explicit microphysics schemes: Reisner 1 (R1), Reisner 2 (R2), Dudhia simple ice (SI), and Hsie warm rain (WR). For baseline simulation with R1, the concentrations of NH4+, NO3−, and SO42− are underpredicted in August. Concentrations of SO42− are underpredicted and those of NH4+ and NO3− are overpredicted in December. The wet deposition amounts of NH4+ and SO42− are overpredicted but those of NO3− are underpredicted in August. The wet deposition amounts of NO3− and NH4+ are overpredicted but those of SO42− are underpredicted in December. The simulated wet deposition amounts are sensitive to various schemes, which are most evident in December, with the best results for NH4+ and NO3− by WR and the best for SO42− by SI. A correlation exists between wet deposition amounts and precipitation in both months, with stronger magnitudes in August. Conversely, in December, as the correlation with precipitation decreases, that with aqueous-phase concentrations increases. These results are consistent with meteorological conditions since the summer convective precipitation events having larger intensities and therefore the meteorological forcing is expected to dominate August correlations. As these intensities decrease in December, the chemical forcing becomes more influential. DA - 2008/// PY - 2008/// DO - 10.1016/j.atmosenv.2007.12.066 VL - 42 IS - 16 SP - 3856-3868 ER - TY - JOUR TI - Examining the sensitivity of MM5-CMAQ predictions to explicit microphysics schemes and horizontal grid resolutions, Part I - Database, evaluation protocol, and precipitation predictions AU - Queen, Ashley AU - Zhang, Yang AU - Gilliam, Robert AU - Pleim, Jonathan T2 - ATMOSPHERIC ENVIRONMENT AB - Wet deposition of chemical species is one of the most difficult processes to simulate in three-dimensional (3-D) air quality models, due to the complex interplay among meteorology, cloud, and atmospheric chemistry. Different cloud microphysical treatments and horizontal grid resolutions in 3-D models can directly affect simulated clouds, precipitation, and wet deposition. In this study, the performance and sensitivity of the simulated precipitation, concentrations, and wet deposition to different explicit microphysics schemes and horizontal grid resolutions are evaluated for August and December 2002 for a domain centered over North Carolina (NC). Four explicit microphysics schemes in MM5 are examined: Reisner 1 (R1), Reisner 2 (R2), Dudhia (SI), and Hsie (WR). The precipitation evaluation indicates that monthly-average precipitation amounts are underpredicted by all schemes in both August and December at all sites except for the R1 August simulation that shows overpredictions at National Acid Deposition Program (NADP) sites. An increased sensitivity to microphysics schemes is found at locations in both the coastal plain and mountain regions in August and the mountain region in December. The differences in simulation results in August and December are mainly attributed to seasonal differences in dominant meteorological forcing (mesoscale vs. synoptic, respectively). Among the schemes tested, R2 and SI give the best overall performance in predicting precipitation for both months. These findings are applicable for NC and neighboring states with similar meteorological and emission characteristics. DA - 2008/5// PY - 2008/5// DO - 10.1016/j.atmosenv.2007.12.067 VL - 42 IS - 16 SP - 3842-3855 SN - 1352-2310 KW - MM5 KW - CMAQ KW - explicit microphysics scheme KW - wet deposition KW - precipitation ER - TY - JOUR TI - Effect of sampling density and design on estimation of streambed attributes AU - Kennedy, Casey D. AU - Genereux, David P. AU - Mitasova, Helena AU - Corbett, D. Reide AU - Leahy, Scott T2 - JOURNAL OF HYDROLOGY AB - Underlying questions that are central to field studies of the groundwater–surface water interaction are the extent of error in means and spatial distributions of streambed attributes such as groundwater seepage rate or solute flux, and the relation of this error to the number and location of point measurements. To investigate these questions, spatially intensive point measurements of five streambed attributes were made in two 63-m long stream reaches in the North Carolina Coastal Plain: hydraulic conductivity (K), hydraulic head gradient between groundwater and stream water (J), nitrate concentration in streambed groundwater (C), and groundwater seepage (v = KJ) and nitrate flux (f = vC) through the streambed. In all, 10 datasets (2 reaches, 5 attributes), each with 54 closely-spaced point values, were created (540-point values in all). For each dataset, subsets of 8- to 40-point values were selected from the 54 available to evaluate the effects of sampling density (the number of point values per reach, or per m2 of streambed) and sampling design (the relative number of point values from the right side, left side, and center of the channel) on the mean and the spatial field of the streambed attribute. Specifically, we evaluated the following as a function of sampling density and sampling design: (1) the likelihood of error in the reach-average value of each streambed attribute, (2) the average magnitude of error and distribution of error in the reach-average value of each attribute, (3) the magnitude of error in the prediction of point values of each attribute, and (4) the geometry of interpolated surfaces of two attributes (K and f). In all cases, “error” in a value or interpolated surface based on a subset of points was taken as a deviation from the corresponding result based on the full dataset of 54 points. The probability (p) that error did not occur increased with sampling density for each sampling design and attribute in both reaches, though the effect of “diminishing returns” was evident for sampling densities greater than ∼24 points per reach (roughly 0.05–0.06 points per m2 of streambed). Relative to sampling density, sampling design had little effect on values of p. Average error in streambed attributes was generally small (⩽10%) and less than the 95% confidence limits about the reach-average values of the attributes. The ability to estimate unknown point values by interpolation among other point values was poor using both 12- and 36-point subsets, though results suggest the 24 additional known point values (in going from 12 to 36) were helpful in one case in which there was some degree of autocorrelation between the additional known values and the values to be predicted in the interpolation. Visual inspection of 130 contour maps showed that those based on 36-point values were far more realistic in appearance than those based on 12-point values (where the standard for “realistic” appearance was the contour maps based on the full datasets of 54-point values). DA - 2008/6/20/ PY - 2008/6/20/ DO - 10.1016/j.jhydrol.2008.03.018 VL - 355 IS - 1-4 SP - 164-180 SN - 1879-2707 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-43949128733&partnerID=MN8TOARS KW - streambed KW - groundwater KW - sampling KW - error KW - nitrate KW - hydraulic conductivity ER - TY - JOUR TI - Coupling and evaluating gas/particle mass transfer treatments for aerosol simulation and forecast AU - Hu, Xiao-Ming AU - Zhang, Yang AU - Jacobson, Mark Z. AU - Chan, Chak K. T2 - JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES AB - [1] Simulating gas/particle mass transfer in three-dimensional (3-D) air quality models (AQMs) represents one of the major challenges for both hindcasting and forecasting. The lack of an efficient yet accurate gas/particle mass transfer treatment for aerosol simulation and forecast in 3-D AQMs warrants its development, improvement, and evaluation. In this paper, several condensation/evaporation schemes (e.g., the Bott, Trajectory-Grid (T-G), Walcek, and analytical predictor of condensation (APC)) are first tested in a condensation-only case. The APC and Walcek schemes are shown to be more accurate than the Bott and T-G schemes. The Walcek and the APC schemes are then incorporated into the Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution (MADRID) to solve the gas/particle mass transfer process explicitly. The test simulations with MADRID are initialized with measurements available from three sites with representative meteorological and emission characteristics. The results are evaluated using benchmark based on the kinetic approach with 500-section for all cases and available measurements from two sites. The box MADRID tests have shown that the bulk equilibrium approach fails to predict the distribution of semivolatile species (e.g., ammonium, chloride, and nitrate) because of the equilibrium and internal mixture assumptions. The hybrid approach exhibits the same problem for some cases as the bulk equilibrium approach since it assumes bulk equilibrium for fine particles. The kinetic approaches (including the APC and Walcek schemes for the condensation/evaporation equations) predict the most accurate solutions. Among all approaches tested, the bulk equilibrium approach is the most computationally efficient, and the kinetic/Walcek scheme provides an accurate solution but is the slowest due to its requirement for a small time step. Overall, the kinetic/APC and hybrid/APC schemes are attractive for 3-D applications in terms of both accuracy and computational efficiency. DA - 2008/6/12/ PY - 2008/6/12/ DO - 10.1029/2007jd009588 VL - 113 IS - D11 SP - SN - 2169-8996 ER - TY - JOUR TI - Classification of cyclone tracks over the Apennines and the Adriatic Sea AU - Horvath, Kristian AU - Lin, Yuh-Lang AU - Ivanican-Picek, Branka T2 - MONTHLY WEATHER REVIEW AB - Abstract Cyclones that appear in the Adriatic Sea basin strongly influence the climate and weather conditions in the area. In particular, apart from the usually mild climate, cyclone activity in the Adriatic and the central Mediterranean Sea provide both the main hydrological forcing and the trigger mechanisms for a range of extreme weather phenomena. Therefore, a basic understanding of the cyclogenesis over the Adriatic Sea is essential. In particular, the classification of different types of cyclogenesis in the area is fundamental because it will help the understanding and prediction of the relevant weather phenomena. In this study, based on the analysis of the 4-yr (2002–05) operational European Centre for Medium-Range Weather Forecasts T511 dataset, various types of cyclone tracks are classified and the mesocyclogenesis areas in the vicinity of the Adriatic Basin are isolated. This analysis indicates that the following four types of cyclogenesis over the Adriatic Sea can be identified: 1) type A: cyclones connected with preexisting Genoa cyclones [with two subcategories, (A-I) continuous track: Genoa cyclones crossing over the Apennines to the Adriatic Sea, and (A-II) discontinuous track: new surface cyclones generated over the Adriatic Sea under the influence of a parent cyclone generated in the Gulf of Genoa (Genoa cyclones) and moving toward the Adriatic but blocked by the Apennines]; 2) type B: cyclones developed in situ over the Adriatic Sea without any connections with other preexisting cyclones in the surrounding area; 3) type AB: mixed types A and B cyclones, including cases where two cyclones coexist and stride over the Apennines (twin or eyeglass cyclones); and 4) type C: cyclones moving from the Mediterranean Sea, but not from the Gulf of Genoa (non-Genoa cyclones) [with 2 subcategories: (C-I) continuous track: a non-Genoa cyclone is able to cross over the Apennines to the Adriatic Sea continuously, and (C-II) discontinuous track: a non-Genoa cyclone is blocked by the Apennines and a new surface cyclone is generated over the Adriatic Sea]. The relevant dynamics of the above types of cyclones are discussed along with characteristics of the cyclones and their synoptic situations at the lower and upper troposphere. DA - 2008/6// PY - 2008/6// DO - 10.1175/2007MWR2231.1 VL - 136 IS - 6 SP - 2210-2227 SN - 1520-0493 ER - TY - JOUR TI - Osteology of Icadyptes salasi, a giant penguin from the Eocene of Peru AU - Ksepka, Daniel T. AU - Clarke, Julia A. AU - DeVries, Thomas J. AU - Urbina, Mario T2 - JOURNAL OF ANATOMY AB - Abstract We present the first detailed description of the giant Eocene penguin Icadyptes salasi . The species is characterized by a narrow skull with a hyper‐elongate spear‐like beak, a robust cervical column and a powerful flipper. The bony beak tip of Icadyptes is formed by fusion of several elements and is unique among penguins, differing markedly from previously described giant penguin beaks. Vascular canal patterning similar to that of boobies, frigatebirds and albatrosses suggests I. salasi may have had a thin, sheet‐like rhamphotheca unlike the thick rugose rhamphotheca of modern penguins. Together, these features suggest a novel ecology for I. salasi , most likely involving the capture of larger prey items via spearing. As the first described giant penguin specimen to preserve a complete wing skeleton, the I. salasi holotype yields significant insight into the shape, proportions and orientation of the wing in giant penguins. In articulation, the forelimb of I. salasi is straighter, permitting less manus and antibrachium flexion, than previous depictions of giant penguin wings. Cross‐sections of the humerus and ulna reveal a level of osteosclerosis equalling or surpassing that of extant penguins. Based on ontogenetic data from extant penguins and the morphology of the carpometacarpus of I. salasi , we infer the retention of a free alular phalanx in basal penguins. Previously, the status of this element in penguins was disputed. Differences in the proportions of the manual phalanges contribute to a more abruptly tapering wingtip in I. salasi compared with crown penguins. Fossils from Peru, including the I. salasi holotype specimen, document that penguins expanded to nearly the whole of their extant latitudinal range early in their evolutionary history and during one of the warmest intervals in the Cenozoic. DA - 2008/8// PY - 2008/8// DO - 10.1111/j.1469-7580.2008.00927.x VL - 213 IS - 2 SP - 131-147 SN - 1469-7580 KW - alula KW - body size KW - fossil KW - palaeontology KW - Pisco Basin KW - Spheniscidae ER - TY - JOUR TI - Historic 2005 toxic bloom ofAlexandrium fundyensein the west Gulf of Maine: 1. In situ observations of coastal hydrography and circulation AU - He, Ruoying AU - McGillicuddy, Dennis J. T2 - Journal of Geophysical Research AB - An extensive Alexandrium fundyense bloom occurred along the coast of the Gulf of Maine in late spring and early summer 2005. To understand the physical aspects of bloom's initiation and development, in situ observations from both a coast‐wide ship survey and the coastal observing network were used to characterize coastal circulation and hydrography during that time period. Comparisons between these in situ observations and their respective long‐term means revealed anomalous ocean conditions during May 2005: waters were warmer and fresher coast‐wide owing to more surface heating and river runoff; coastal currents were at least 2 times stronger than their climatological means. Surface winds were also anomalous in the form of both episodic bursts of northeast winds and a downwelling‐favorable mean condition. These factors may have favored more vigorous along‐shore transport and nearshore aggregation of toxic A. fundyense cells (a red tide) in 2005. DA - 2008/7// PY - 2008/7// DO - 10.1029/2007jc004601 VL - 113 IS - C7 ER - TY - JOUR TI - Historic 2005 toxic bloom of Alexandrium fundyense in the western Gulf of Maine: 2. Coupled biophysical numerical modeling AU - He, Ruoying AU - McGillicuddy, Dennis J., Jr. AU - Keafer, Bruce A. AU - Anderson, Donald M. T2 - JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS AB - A coupled physical/biological modeling system was used to hindcast a massive Alexandrium fundyense bloom that occurred in the western Gulf of Maine in 2005 and to investigate the relative importance of factors governing the bloom's initiation and development. The coupled system consists of a state‐of‐the‐art, free‐surface primitive equation Regional Ocean Modeling System (ROMS) tailored for the Gulf of Maine (GOM) using a multinested configuration, and a population dynamics model for A. fundyense. The system was forced by realistic momentum and buoyancy fluxes, tides, river runoff, observed A. fundyense benthic cyst abundance, and climatological nutrient fields. Extensive comparisons were made between simulated (both physical and biological) fields and in situ observations, revealing that the hindcast model is capable of reproducing the temporal evolution and spatial distribution of the 2005 bloom. Sensitivity experiments were then performed to distinguish the roles of three major factors hypothesized to contribute to the bloom: (1) the high abundance of cysts in western GOM sediments; (2) strong ‘northeaster' storms with prevailing downwelling‐favorable winds; and (3) a large amount of fresh water input due to abundant rainfall and heavy snowmelt. Model results suggest the following. (1) The high abundance of cysts in western GOM was the primary factor of the 2005 bloom. (2) Wind‐forcing was an important regulator, as episodic bursts of northeast winds caused onshore advection of offshore populations. These downwelling favorable winds accelerated the alongshore flow, resulting in transport of high cell concentrations into Massachusetts Bay. A large regional bloom would still have happened, however, even with normal or typical winds for that period. (3) Anomalously high river runoff in 2005 resulted in stronger buoyant plumes/currents, which facilitated the transport of cell population to the western GOM. While affecting nearshore cell abundance in Massachusetts Bay, the buoyant plumes were confined near to the coast, and had limited impact on the gulf‐wide bloom distribution. DA - 2008/7/26/ PY - 2008/7/26/ DO - 10.1029/2007jc004602 VL - 113 IS - C7 SP - SN - 2169-9291 ER - TY - JOUR TI - Farming pollution AU - Aneja, Viney P. AU - Schlesinger, William H. AU - Erisman, Jan Willem T2 - NATURE GEOSCIENCE DA - 2008/7// PY - 2008/7// DO - 10.1038/ngeo236 VL - 1 IS - 7 SP - 409-411 SN - 1752-0894 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-53849123202&partnerID=MN8TOARS ER - TY - JOUR TI - Compendium of veterinary standard precautions for zoonotic disease prevention in veterinary personnel - National Association of State Public Health Veterinarians Veterinary Infection Control Committee 2008 AU - Elchos, B. L. AU - Scheftel, J. M. AU - Cherry, B. AU - DeBess, E. E. AU - Hopkins, S. G. AU - Levine, J. F. AU - Williams, C. J. AU - Bell, M. R. AU - Dvorak, G. D. AU - Flora, C. A. AU - Hofmann, J. AU - Pavlin, B. I. AU - Samples, O. M. AU - Snow, J. L. AU - Stinson-Dixon, R. E. T2 - Journal of the American Veterinary Medical Association DA - 2008/// PY - 2008/// VL - 233 IS - 3 SP - 415-432 ER - TY - JOUR TI - Benthic-pelagic coupling in sediment-associated populations of Karenia brevis AU - Sinclair, Geoffrey A. AU - Kamykowski, Daniel T2 - JOURNAL OF PLANKTON RESEARCH AB - Nutrient delivery to populations of Karenia brevis in oligotrophic water columns in the Gulf of Mexico remains uncertain. Aggregations of K. brevis near the sediment–water interface suggest that cells derive nutrients from the sediment. Video of cells near the sediment suggest that cells either access nutrients that flux out of the sediment or migrate into the sediment pores where higher nutrient concentrations exist. Experiments tested K. brevis' ability to migrate into the sediment using chambers divided by a 100 μm mesh overlain with a thin layer of sediment. Since the diel vertical migration of K. brevis typically displays a nocturnal descent, experiments tested migration response at night in response to sub-sediment nutrient sources. The experiments suggest that while the sediment affects the progress of descending cells, migration occurs through thin layers of sediment and increases in response to elevated nutrient concentrations below the sediment. Since all cells found below the sediment had significantly higher C/N ratios than those remaining above the sediment, migration appears related to a cell's internal biochemical state. The vertical migration behavior of K. brevis may help alleviate bottom-up controls and permit populations to persist as vegetative cells near the sediment–water interface. DA - 2008/7// PY - 2008/7// DO - 10.1093/plankt/fbn042 VL - 30 IS - 7 SP - 829-838 SN - 1464-3774 ER - TY - JOUR TI - A computationally-efficient secondary organic aerosol module for three-dimensional air quality models AU - Liu, P. AU - Zhang, Y. T2 - ATMOSPHERIC CHEMISTRY AND PHYSICS AB - Abstract. Accurately simulating secondary organic aerosols (SOA) in three-dimensional (3-D) air quality models is challenging due to the complexity of the physics and chemistry involved and the high computational demand required. A computationally-efficient yet accurate SOA module is necessary in 3-D applications for long-term simulations and real-time air quality forecasting. A coupled gas and aerosol box model (i.e., 0-D CMAQ-MADRID 2) is used to optimize relevant processes in order to develop such a SOA module. Solving the partitioning equations for condensable volatile organic compounds (VOCs) and calculating their activity coefficients in the multicomponent mixtures are identified to be the most computationally-expensive processes. The two processes can be speeded up by relaxing the error tolerance levels and reducing the maximum number of iterations of the numerical solver for the partitioning equations for organic species; conditionally activating organic-inorganic interactions; and parameterizing the calculation of activity coefficients for organic mixtures in the hydrophilic module. The optimal speed-up method can reduce the total CPU cost by up to a factor of 31.4 from benchmark under the rural conditions with 2 ppb isoprene and by factors of 10–71 under various test conditions with 2–10 ppb isoprene and >40% relative humidity while maintaining ±15% deviation. These speed-up methods are applicable to other SOA modules that are based on partitioning theories. DA - 2008/// PY - 2008/// DO - 10.5194/acp-8-3985-2008 VL - 8 IS - 14 SP - 3985-3998 SN - 1680-7324 ER - TY - JOUR TI - A climatological study of the sea and land breezes in the Arabian Gulf region AU - Eager, Rebecca E. AU - Raman, Sethu AU - Wootten, Adrienne AU - Westphal, Douglas L. AU - Reid, Jeffrey S. AU - Al Mandoos, Abdulla T2 - JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES AB - This study focuses on observations of the sea and land breeze circulations in the southern Arabian Gulf. During the summer months, the Indian monsoon creates light northwesterly winds over the Arabian Gulf, allowing for the formation of thermally driven circulations. Observations from a network of stations are used to develop a wind climatology for the Arabian Gulf region. Characteristics of the sea and land breeze circulations, such as onset time, duration, and horizontal and vertical extent are described. The dense network of surface stations in the United Arab Emirates (UAE) allows for a fine‐scale observational study in this region. It is found that the sea breeze occurs during all seasons of the year in this region. It occurs in the late afternoon and continues through the evening. A land breeze sets in during the night. Surface offshore winds in the land breeze are strong probably due to drainage flow down the inland hills. DA - 2008/8/2/ PY - 2008/8/2/ DO - 10.1029/2007jd009710 VL - 113 IS - D15 SP - SN - 2169-897X ER - TY - JOUR TI - A class of nonseparable and nonstationary spatial temporal covariance functions AU - Fuentes, Montserrat AU - Chen, Li AU - Davis, Jerry M. T2 - ENVIRONMETRICS AB - Spectral methods are powerful tools to study and model the dependency structure of spatial temporal processes. However, standard spectral approaches as well as geostatistical methods assume separability and stationarity of the covariance function; these can be very unrealistic assumptions in many settings. In this work, we introduce a general and flexible parametric class of spatial temporal covariance models, that allows for lack of stationarity and separability by using a spectral representation of the process. This new class of covariance models has a unique parameter that indicates the strength of the interaction between the spatial and temporal components; it has the separable covariance model as a particular case. We introduce an application with ambient ozone air pollution data provided by the U.S. Environmental Protection Agency (U.S. EPA). DA - 2008/8// PY - 2008/8// DO - 10.1002/env.891 VL - 19 IS - 5 SP - 487-507 SN - 1099-095X KW - nonseparability KW - nonstationarity KW - spatial temporal models KW - ambient ozone KW - spectral density KW - spatial covariance KW - spectral domain KW - non separable covariance KW - ozone modeling ER - TY - JOUR TI - Water quality responses to simulated flow and nutrient reductions in the Cape Fear River Estuary and adjacent coastal region, North Carolina AU - Lin, Jing AU - Xie, Lian AU - Pietrafesa, Leonard J. AU - Xu, Honqzhou AU - Woods, Wendy AU - Mallin, Michael A. AU - Durako, Michael J. T2 - ECOLOGICAL MODELLING AB - In order to examine system responses to high river discharge events and nutrient loading variations from the drainage basin, a coupled three-dimensional hydrodynamic and water quality model was applied in the Cape Fear River Estuary (CFRE) and its adjacent coastal region. An empirical equation was introduced in the model to represent light limitation for phytoplankton growth due to chromophoric dissolved organic matter (CDOM). Model results show that in the upper to middle estuary, light limitation controls phytoplankton growth while in the lower estuary phytoplankton growth appears to be limited by light intensity during high flow periods, but by nutrient availability during low flow periods. In the coastal ocean, nutrient availability is usually the dominant limiting factor for primary production. Two sensitivity model tests were conducted to predict the system response to reductions in nutrient loading from the drainage basin. By reducing river discharge, the model results show that phytoplankton growth was enhanced within CFRE due to alleviated light limitation and increased residence time. More nutrients were consumed within the CFRE, and less were exported to the coastal region. By reducing nutrient concentrations at the head of the estuary, chlorophyll a concentrations within the CFRE were decreased. Less nutrients were consumed within the CFRE, and only slightly less were exported to the coastal region. The supply of light limiting substances during high flow events acted against the effect of riverine nutrient enhancement on phytoplankton growth, creating a negative feedback mechanism. DA - 2008/4/10/ PY - 2008/4/10/ DO - 10.1016/j.ecolmodel.2007.10.026 VL - 212 IS - 3-4 SP - 200-217 SN - 1872-7026 KW - water quality KW - numerical modeling KW - nutrient flux KW - estuary KW - cape fear river ER - TY - JOUR TI - Topical isoflavones provide effective photoprotection to skin AU - Lin, Jing-Yi AU - Tournas, Joshua A. AU - Burch, James A. AU - Monteiro-Riviere, Nancy A. AU - Zielinski, Jan T2 - PHOTODERMATOLOGY PHOTOIMMUNOLOGY & PHOTOMEDICINE AB - Summary Background/purpose: Isoflavones, one main group of phytoestrogens, have antioxidative and photoprotective effects in cellular and mouse studies. The aim of this study is to obtain a more comprehensive understanding of the isoflavone‐mediated photoprotection with the pig skin model, a more human‐resembling model. Methods: The pig skin was treated with five well‐known isoflavone compounds (genistein, equol, daidzein, biochanin A, and formononetin) and one antioxidant combination solution of 15% vitamin C and 1% vitamin E and 0.5% ferulic acid (CEF) daily for 4 days. Skin was irradiated with solar‐simulated UV irradiation, 1 to 5 minimal erythema dose (MED) at 1‐MED intervals. Evaluation was carried out 24 h later by colorimeter‐measured erythema and sunburn cell numbers. Results: Topical application of 0.5% solutions of three individual phytoestrogens – genistein, daidzein, biochanin A – are better than similar solutions of equol or formononetin in protecting pig skin from solar‐simulated ultraviolet (SSUV)‐induced photodamage, as measured by sunburn cell formation and/or erythema. However, the protection was less than that provided by a topical combination antioxidant standard containing 15% L‐ascorbic acid, 1%α‐tocopherol, and 0.5% ferulic acid. Conclusion: Isoflavones provide effective photoprotection and are good candidate ingredients for protection against ultraviolet (UV) photodamage. DA - 2008/4// PY - 2008/4// DO - 10.1111/j.1600-0781.2008.00329.x VL - 24 IS - 2 SP - 61-66 SN - 1600-0781 KW - antioxidants KW - isoflavones KW - photoprotection ER - TY - JOUR TI - Spatial and temporal variations of the Kuroshio east of Taiwan, 1982-2005: A numerical study AU - Hsin, Yi-Chia AU - Wu, Chau-Ron AU - Shaw, Ping-Tung T2 - JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS AB - A 1/8° East Asian Marginal Seas model nested to a larger‐domain North Pacific Ocean model is implemented over a span of 24 years from 1982 to 2005 to investigate the spatial and temporal variations of the Kuroshio east of Taiwan. Between 22 and 25°N, the mean state and variability of the Kuroshio, such as the two paths observed in the trajectories of surface drifters southeast of Taiwan and the branching of the Kuroshio northeast of Taiwan, are well reproduced by the model. Southeast of Taiwan, the Kuroshio is mostly in the top 300 m in the inshore path but extends to 600 m in the offshore path. Northeast of Taiwan, the Kuroshio follows the shelf edge in the East China Sea but may branch along a path south of the Ryukyu Islands. The latter path often meanders southward, and a significant portion of the Kuroshio transport may be diverted to this path. The Kuroshio extends from the coast to 123–123.5°E between 22 and 25°N with currents reaching a depth of 1000 m at some latitudes. The Kuroshio transports averaged over five sections east of Taiwan are 28.4 ± 5.0 Sv and 32.7 ± 4.4 Sv with and without the contribution from the countercurrent, respectively. DA - 2008/4/3/ PY - 2008/4/3/ DO - 10.1029/2007jc004485 VL - 113 IS - C4 SP - SN - 2169-9291 ER - TY - JOUR TI - Potential vorticity (PV) thinking in operations: The utility of nonconservation AU - Brennan, Michael J. AU - Lackmann, Gary M. AU - Mahoney, Kelly M. T2 - WEATHER AND FORECASTING AB - Abstract The use of the potential vorticity (PV) framework by operational forecasters is advocated through case examples that demonstrate its utility for interpreting and evaluating numerical weather prediction (NWP) model output for weather systems characterized by strong latent heat release (LHR). The interpretation of the dynamical influence of LHR is straightforward in the PV framework; LHR can lead to the generation of lower-tropospheric cyclonic PV anomalies. These anomalies can be related to meteorological phenomena including extratropical cyclones and low-level jets (LLJs), which can impact lower-tropospheric moisture transport. The nonconservation of PV in the presence of LHR results in a modification of the PV distribution that can be identified in NWP model output and evaluated through a comparison with observations and high-frequency gridded analyses. This methodology, along with the application of PV-based interpretation, can help forecasters identify aspects of NWP model solutions that are driven by LHR; such features are often characterized by increased uncertainty due to difficulties in model representation of precipitation amount and latent heating distributions, particularly for convective systems. Misrepresentation of the intensity and/or distribution of LHR in NWP model forecasts can generate errors that propagate through the model solution with time, potentially degrading the representation of cyclones and LLJs in the model forecast. The PV framework provides human forecasters with a means to evaluate NWP model forecasts in a way that facilitates recognition of when and how value may be added by modifying NWP guidance. This utility is demonstrated in case examples of coastal extratropical cyclogenesis and LLJ enhancement. Information is provided regarding tools developed for applying PV-based techniques in an operational setting. DA - 2008/2// PY - 2008/2// DO - 10.1175/2007WAF2006044.1 VL - 23 IS - 1 SP - 168-182 SN - 0882-8156 ER - TY - JOUR TI - Assessment of the Effect of Varying Soil Organic Matter Content on the Bioavailability of Malathion to the Common Nightcrawler, Lumbricus terrestris L. AU - Henson-Ramsey, Heather AU - Shea, Damian AU - Levine, Jay F. AU - Kennedy-Stoskopf, Suzanne AU - Taylor, Sharon K. AU - Stoskopf, Michael K. T2 - Bulletin of Environmental Contamination and Toxicology DA - 2008/1/19/ PY - 2008/1/19/ DO - 10.1007/s00128-007-9349-6 VL - 80 IS - 3 SP - 220-224 J2 - Bull Environ Contam Toxicol LA - en OP - SN - 0007-4861 1432-0800 UR - http://dx.doi.org/10.1007/s00128-007-9349-6 DB - Crossref KW - earthworm KW - malathion KW - bioavailability KW - soil organic matter ER - TY - JOUR TI - A Kalman-filter bias correction method applied to deterministic, ensemble averaged and probabilistic forecasts of surface ozone AU - Delle Monache, Luca AU - Wilczak, James AU - McKeen, Stuart AU - Grell, Georg AU - Pagowski, Mariusz AU - Peckham, Steven AU - Stull, Roland AU - Mchenry, John AU - McQueen, Jeffrey T2 - TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY AB - Kalman filtering (KF) is used to estimate systematic errors in surface ozone forecasts. The KF updates its estimate of future ozone-concentration bias using past forecasts and observations. The optimum filter parameter is estimated via sensitivity analysis. KF performance is tested for deterministic, ensemble-averaged and probabilistic forecasts. Eight simulations were run for 56 d during summer 2004 over northeastern USA and southern Canada, with 358 ozone surface stations.KF improves forecasts of ozone-concentration magnitude (measured by root mean square error) and the ability to predict rare events (measured by the critical success index), for deterministic and ensemble-averaged forecasts. It improves the 24-h maximum ozone-concentration prediction (measured by the unpaired peak prediction accuracy), and improves the linear dependency and timing of forecasted and observed ozone concentration peaks (measured by a lead/lag correlation). KF also improves the predictive skill of probabilistic forecasts of concentration greater than thresholds of 10–50 ppbv, but degrades it for thresholds of 70–90 ppbv. KF reduces probabilistic forecast bias. The combination of KF and ensemble averaging presents a significant improvement for real-time ozone forecasting because KF reduces systematic errors while ensemble-averaging reduces random errors. When combined, they produce the best overall ozone forecast. DA - 2008/4// PY - 2008/4// DO - 10.1111/j.1600-0889.2007.00332.x VL - 60 IS - 2 SP - 238-249 SN - 1600-0889 ER - TY - JOUR TI - The Chesapeake Bay blue crab (Callinectes sapidus): A multidisciplinary approach to responsible stock replenishment AU - Zohar, Yonathan AU - Hines, Anson H. AU - Zmora, Oded AU - Johnson, Eric G. AU - Lipcius, Romuald N. AU - Seitz, Rochelle D. AU - Eggleston, David B. AU - Place, Allen R. AU - Schott, Eric J. AU - Stubblefield, John D. AU - Chung, J. Sook T2 - REVIEWS IN FISHERIES SCIENCE AB - The Chesapeake Bay has traditionally been one of North America's most productive fishing grounds, supporting the world's largest blue crab fishery. During the last several decades, fishing mortality and environmental degradation led to ∼ 70% drop in the bay's blue crab abundance, 84% decline in its spawning stock, and historically low levels of juvenile recruitment as well as nursery habitats being below carrying capacity. This situation makes the Chesapeake Bay blue crab an appropriate candidate for responsible stock enhancement. A multidisciplinary, multi-institutional program was developed to study the basic biology and life cycle of the blue crab, develop hatchery and nursery technologies for mass production of blue crab juveniles, and assess the potential of using cultured juveniles to enhance blue crab breeding stocks and, in turn, bay-wide abundance and harvests. Basic biology and culture studies enabled closing the life cycle of the blue crab in captivity. Juvenile crabs have been produced year round, with excellent survival. During 2002–2006, over 290,000 cultured crabs were tagged and experimentally released into the bay's nursery habitats. Cultured crabs survived as well as their wild counterparts, increased local populations at release sites by 50–250%, grew quickly to sexual maturity, mated, and migrated from the release sites to spawning grounds, contributing to the breeding stock as soon as 5 to 6 months post-release. Findings reported in this text and other articles in this volume are indicative of the feasibility of our approach of using hatchery juveniles to replenish the blue crab breeding stocks in the Chesapeake Bay. DA - 2008/// PY - 2008/// DO - 10.1080/10641260701681623 VL - 16 IS - 1-3 SP - 24-34 SN - 1547-6553 KW - breeding stock restoration KW - hatchery KW - tag and recapture KW - release strategies KW - stock enhancement ER - TY - JOUR TI - Pilot evaluation of early juvenile blue crab stock enhancement using a replicated BACI design AU - Eggleston, David B. AU - Johnson, Eric G. AU - Kellison, G. Todd AU - Plaia, Gayle R. AU - Huggett, Cynthia L. T2 - REVIEWS IN FISHERIES SCIENCE AB - We quantified whether local populations of early juvenile blue crabs (J1–2) could be enhanced through the translocation of crabs to underutilized nursery habitats, and if enhancement success, survival, and potential impacts of stocked crabs on their benthic prey varied in a density-dependent manner. Using plankton nets, ∼143,000 blue crab megalopae were collected as they ingressed into Pamlico Sound, NC. Of these, ∼13,800 early juvenile blue crabs (J1–2 stages) were then stocked at potential nursery sites relatively far removed (32–70 km) from their initial settlement areas using a replicated before-after control impact (BACI) experimental design. On average, there was negative enhancement success (−34%) five weeks after local crab enhancement, and no evidence of density-dependent enhancement success, mortality, or impact on potential crab prey. Poor stocking success was likely due to pelagic emigration from enhancement sites relative to controls. Attempts to assess the feasibility of stocking blue crabs at local scales of small coves should (i) probably not consider J1–2 stages because of their apparent propensity to emigrate from these areas, or (ii) further assess the effects of geomorphology and wind fetch of release sites on density-dependent emigration. DA - 2008/// PY - 2008/// DO - 10.1080/10641260701681664 VL - 16 IS - 1-3 SP - 91-100 SN - 1547-6553 KW - BACI KW - blue crabs KW - density-dependence KW - stock enhancement KW - translocation ER - TY - JOUR TI - Insight into diversity, body size and morphological evolution from the largest Early Cretaceous enantiornithine bird AU - Zhou, Zhonghe AU - Clarke, Julia AU - Zhang, Fucheng T2 - JOURNAL OF ANATOMY AB - Abstract Most of Mesozoic bird diversity comprises species that are part of one of two major lineages, namely Ornithurae, including living birds, and Enantiornithes, a major radiation traditionally referred to as ‘opposite birds’. Here we report the largest Early Cretaceous enantiornithine bird from north‐east China, which provides evidence that basal members of Enantiornithes share more morphologies with ornithurine birds than previously recognized. Morphological evolution in these two groups has been thought to be largely parallel, with derived members of Enantiornithes convergent on the ‘advanced’ flight capabilities of ornithurine birds. The presence of an array of morphologies previously thought to be derived within ornithurine and enantiornithine birds in a basal enantiornithine species provides evidence of the complex character evolution in these two major lineages. The cranial morphology of the new specimen is among the best preserved for Mesozoic avians. The new species extends the size range known for Early Cretaceous Enantiornithes significantly and provides evidence of forelimb to hind limb proportions distinct from all other known members of the clade. As such, it sheds new light on avian body size evolution and diversity, and allows a re‐evaluation of a previously proposed hypothesis of competitive exclusion among Early Cretaceous avian clades. DA - 2008/5// PY - 2008/5// DO - 10.1111/j.1469-7580.2008.00880.x VL - 212 IS - 5 SP - 565-577 SN - 1469-7580 KW - bird evolution KW - China KW - Early Cretaceous KW - Enantiornithes ER - TY - JOUR TI - Importance of metapopulation connectivity to restocking and restoration of marine species AU - Lipcius, Romuald N. AU - Eggleston, David B. AU - Schreiber, Sebastian J. AU - Seitz, Rochelle D. AU - Shen, Jian AU - Sisson, Mac AU - Stockhausen, William T. AU - Wang, Harry V. T2 - REVIEWS IN FISHERIES SCIENCE AB - Abstract We examine the impact of spatial processes on the efficacy of restocking in species with varying forms of population or metapopulation structure. Metapopulations are classified based on spatial complexity and the degree of connectedness between populations. Designation of effective restocking sites requires careful attention to metapopulation dynamics; populations in the metapopulation can differ dramatically in demography and connectivity, and the sites they occupy can vary in habitat quality. Source populations, which are optimal for restocking, can be distinct geographically and may be a small percentage of the metapopulation. Sink areas, where restocking is almost certain to be fruitless, can nonetheless serve as productive locations for habitat restoration since larvae from source reefs are likely to recruit to these areas. Effective restocking of metapopulations is most likely to be attained by selection of optimal source populations; inattention to metapopulation dynamics can doom restoration efforts with marine species. Keywords: metapopulation dynamicssource-sink dynamicsrestockingrestoration ACKNOWLEDGEMENTS Funding was provided by (1) the Chesapeake Bay Office of the National Oceanic and Atmospheric Administration through the Blue Crab Advanced Research Consortium, and (2) the Norfolk Office of the Army Corps of Engineers (D. Schulte, Program Manager). We are grateful to Senator Barbara Mikulski for support of the program. This is contribution 2865 from the Virginia Institute of Marine Science. DA - 2008/// PY - 2008/// DO - 10.1080/10641260701812574 VL - 16 IS - 1-3 SP - 101-110 SN - 1547-6553 KW - metapopulation dynamics KW - source-sink dynamics KW - restocking KW - restoration ER - TY - JOUR TI - Detection of spring viraemia of carp virus (SVCV) by loop-mediated isothermal amplification (LAMP) in koi carp, Cyprinus carpio L AU - Shivappa, R B AU - Savan, R AU - Kono, T AU - Sakai, M AU - Emmenegger, E AU - Kurath, G AU - Levine, J F T2 - Journal of Fish Diseases AB - Abstract Spring viraemia of carp virus (SVCV) is a rhabdovirus associated with systemic illness and mortality in cyprinids. Several diagnostic tests are available for detection of SVCV. However, most of these tests are time consuming and are not well adapted for field‐based diagnostics. In this study, a diagnostic tool for SVCV detection based on reverse transcription loop‐mediated isothermal amplification (RT‐LAMP) has been developed. Based on the nucleotide sequence of the glycoprotein (G) gene of SVCV North Carolina (NC) isolate, four sets (each set containing two outer and two inner) of primers were designed. Temperature and time conditions were optimized to 65 °C and 60 min, respectively, for LAMP and RT‐LAMP using one primer set. In vitro specificity was evaluated using four different strains of fish rhabdoviruses and RT‐LAMP was found to be specific to SVCV. Serial dilutions of SVCV NC isolate was used to evaluate the in vitro sensitivity of RT‐LAMP. Sensitivity of the assays was similar to RT‐PCR and detected SVCV even at the lowest dilution of 10 1 TCID 50 mL −1 . The ability of RT‐LAMP to detect SVCV from infected carp was also tested and the assay detected SVCV from all infected fish. The isothermal temperature requirements, high specificity and sensitivity, and short incubation time of the RT‐LAMP assay make it an excellent choice as a field diagnostic test for SVCV. DA - 2008/4// PY - 2008/4// DO - 10.1111/j.1365-2761.2007.00894.x VL - 31 IS - 4 SP - 249-258 J2 - J Fish Diseases LA - en OP - SN - 0140-7775 1365-2761 UR - http://dx.doi.org/10.1111/j.1365-2761.2007.00894.x DB - Crossref KW - detection KW - koi carp KW - loop mediated isothermal amplification KW - spring viraemia of carp virus ER - TY - JOUR TI - Ammonia assessment from agriculture: US status and needs AU - Aneja, Viney P. AU - Blunden, Jessica AU - James, Kristen AU - Schlesinger, William H. AU - Knighton, Raymond AU - Gilliam, Wendell AU - Jennings, Greg AU - Niyogi, Dev AU - Cole, Shawn T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - Recent studies suggest that human activities accelerate the production of reactive nitrogen on a global scale. Increased nitrogen emissions may lead to environmental impacts including photochemical air pollution, reduced visibility, changes in biodiversity, and stratospheric ozone depletion. In the last 50 yr, emissions of ammonia (NH3), which is the most abundant form of reduced reactive nitrogen in the atmosphere, have significantly increased as a result of intensive agricultural management and greater livestock production in many developed countries. These agricultural production practices are increasingly subject to governmental regulations intended to protect air resources. It is therefore important that an accurate and robust agricultural emission factors database exist to provide valid scientific support of these regulations. This paper highlights some of the recent work that was presented at the 2006 Workshop on Agricultural Air Quality in Washington, D.C. regarding NH3 emissions estimates and emission factors from agricultural sources in the U.S. and Europe. In addition, several best management practices are explored as the scientific community attempts to maximize the beneficial use of reactive nitrogen while simultaneously minimizing negative environmental impacts. DA - 2008/// PY - 2008/// DO - 10.2134/jeq2007.0002in VL - 37 IS - 2 SP - 515-520 SN - 1537-2537 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-40849136515&partnerID=MN8TOARS ER - TY - JOUR TI - Response of simulated squall lines to low-level cooling AU - Parker, Matthew D. T2 - JOURNAL OF THE ATMOSPHERIC SCIENCES AB - Abstract Organized convection has long been recognized to have a nocturnal maximum over the central United States. The present study uses idealized numerical simulations to investigate the mechanisms for the maintenance, propagation, and evolution of nocturnal-like convective systems. As a litmus test for the basic governing dynamics, the experiments use horizontally homogeneous initial conditions (i.e., they include neither fronts nor low-level jet streams). The simulated storms are allowed to mature as surface-based convective systems before the boundary layer is cooled. In this case it is then surprisingly difficult to cut the mature convective systems off from their source of near-surface inflow parcels. Even when 10 K of the low-level cooling has been applied, the preexisting system cold pool is sufficient to lift boundary layer parcels to their levels of free convection. The present results suggest that many of the nocturnal convective systems that were previously thought to be elevated may actually be surface based. With additional cooling, the simulated systems do, indeed, become elevated. First, the CAPE of the near-surface air goes to zero: second, as the cold pool’s temperature deficit vanishes, the lifting mechanism evolves toward a bore atop the nocturnal inversion. Provided that air above the inversion has CAPE, the system then survives and begins to move at the characteristic speed of the bore. Interestingly, as the preconvective environment is cooled and approaches the temperature of the convective outflow, but before the system becomes elevated, yet another distinct behavior emerges. The comparatively weaker cold pool entails slower system motion but also more intense lifting, apparently because it is more nearly balanced by the lower-tropospheric shear. This could explain the frequent observation of intensifying convective systems in the evening hours without the need for a nocturnal low-level jet. The governing dynamics of the simulated systems, as well as the behavior of low-level tracers and parcel trajectories, are addressed for a variety of environments and degrees of stabilization. DA - 2008/4// PY - 2008/4// DO - 10.1175/2007JAS2507.1 VL - 65 IS - 4 SP - 1323-1341 SN - 0022-4928 ER - TY - JOUR TI - High-resolution observations and model simulations of the life cycle of an intense mesoscale snowband over the northeastern United States AU - Novak, David R. AU - Colle, Brian A. AU - Yuter, Sandra E. T2 - MONTHLY WEATHER REVIEW AB - Abstract This paper investigates the structural and dynamical evolution of an intense mesoscale snowband occurring 25–26 December 2002 over the northeastern United States. Dual-Doppler, wind profiler, aircraft, and water vapor observations in concert with the fifth-generation Pennsylvania State University–NCAR Mesoscale Model run at 4-km grid spacing are used to highlight evolutionary aspects of a snowband unresolved by previous studies. The high-resolution observations and model simulations show that band formation was coincident with a sharpening of a midlevel trough and associated increase in frontogenesis in an environment of conditional and inertial instability. Band maturity was marked by increasing conditional stability and a threefold increase in frontogenetical forcing. Band dissipation occurred as the midlevel trough and associated frontogenetical forcing weakened, while the conditional stability continued to increase. The effect of changing ascent is shown to dominate over changing moisture in explaining band dissipation in this case. Unconventional aspects of band structure and dynamics revealed by the high-resolution data are discussed, including the location of the band relative to the frontogenesis maximum, increasing stability during the band-formation process, and the presence of inertial instability. The model realistically predicted the band evolution; however, maximum precipitation was underforecast within the banded region by ∼30% at 4-km grid spacing, and the axis of heaviest precipitation was displaced ∼50 km to the southeast of the observed location. Higher horizontal model resolution is shown to contribute toward improved QPF in this case; however, it appears more dramatic improvement may be gained by better simulating the frontogenesis, stability, and moisture evolution. DA - 2008/4// PY - 2008/4// DO - 10.1175/2007MWR2233.1 VL - 136 IS - 4 SP - 1433-1456 SN - 1520-0493 ER - TY - JOUR TI - Environmental conditions, cyanobacteria and microcystin concentrations in potable water supply reservoirs in North Carolina, USA AU - Burkholder, J. M. AU - Touchette, B. W. AU - Allen, E. H. AU - Alexander, J. L. AU - Rublee, P. A. T2 - Cyanobacterial harmful algal blooms: state of the science and research needs DA - 2008/// PY - 2008/// VL - 619 SP - 293-294 ER - TY - JOUR TI - Characteristics of climate change in the "significant impact zone" affected by aerosols over eastern China in warm seasons AU - XiaoHui, Shi AU - XiangDe, Xu AU - LiAn, Xie T2 - SCIENCE IN CHINA SERIES D-EARTH SCIENCES DA - 2008/5// PY - 2008/5// DO - 10.1007/s11430-008-0044-1 VL - 51 IS - 5 SP - 730-739 SN - 1006-9313 KW - warm season KW - significant impact zone of aerosols KW - climate change ER - TY - JOUR TI - A factorial analysis of storm surge flooding in Barrow, Alaska AU - Lynch, Amanda H. AU - Lestak, Leanne R. AU - Uotila, Petteri AU - Cassano, Elizabeth N. AU - Xie, Lian T2 - MONTHLY WEATHER REVIEW AB - Abstract This paper describes work to improve the understanding of the broad range of factors affecting the occurrence of flooding in Barrow, Alaska, using as a basis the series of extreme events that have affected the community over the past 50 years. A numerical weather prediction model and a storm surge inundation model have been applied to the 21 case studies identified in National Weather Service data as high wind events. Based on this simulation work flow, a reduced-form model that adequately describes the flooding response has been developed. Specifically, it was found that when wind is forecast to be greater than 13 m s−1 (30 mph) for at least 20 h, this is the most accurate predictor of the possibility of damaging flood. It was found that wind direction, the magnitude of fetch to the sea ice edge (when present), and maximum wind speed were in contrast relatively small contributors to the likelihood of flooding. DA - 2008/3// PY - 2008/3// DO - 10.1175/2007MWR2121.1 VL - 136 IS - 3 SP - 898-912 SN - 0027-0644 ER - TY - JOUR TI - The effect of wave-current interactions on the storm surge and inundation in Charleston Harbor during Hurricane Hugo 1989 AU - Xie, Lian AU - Liu, Huiqing AU - Peng, Machuan T2 - OCEAN MODELLING AB - The effects of wave–current interactions on the storm surge and inundation induced by Hurricane Hugo in and around the Charleston Harbor and its adjacent coastal regions are examined by using a three-dimensional (3-D) wave–current coupled modeling system. The 3-D storm surge and inundation modeling component of the coupled system is based on the Princeton ocean model (POM), whereas the wave modeling component is based on the third-generation wave model, simulating waves nearshore (SWAN). The results indicate that the effects of wave-induced surface, bottom, and radiation stresses can separately or in combination produce significant changes in storm surge and inundation. The effects of waves vary spatially. In some areas, the contribution of waves to peak storm surge during Hurricane Hugo reached as high as 0.76 m which led to substantial changes in the inundation and drying areas simulated by the storm surge model. DA - 2008/// PY - 2008/// DO - 10.1016/j.ocemod.2007.10.001 VL - 20 IS - 3 SP - 252-269 SN - 1463-5011 KW - storm surge KW - inundation KW - wind waves KW - wave-current interaction KW - Hurricane ER - TY - JOUR TI - Physical-biological interactions in the upper ocean - Preface AU - Yamazaki, Hidekatsu AU - Kamykowski, Daniel AU - Tandon, Amit T2 - JOURNAL OF MARINE SYSTEMS DA - 2008/2// PY - 2008/2// DO - 10.1016/j.jmarsys.2007.02.017 VL - 69 IS - 3-4 SP - 163-163 SN - 1879-1573 ER - TY - JOUR TI - Examining the utility of epoxy replicas of single, natural fractures in dolostone for visualization experiments AU - Bergslien, Elisa AU - Fountain, John T2 - HYDROGEOLOGY JOURNAL DA - 2008/2// PY - 2008/2// DO - 10.1007/s10040-007-0223-8 VL - 16 IS - 1 SP - 43-53 SN - 1435-0157 KW - fractured rocks KW - groundwater flow KW - physical modeling KW - aperture statistics ER - TY - JOUR TI - Mesoscale processes and natural hazards - Preface AU - Sharan, Maithili AU - Raman, Sethu T2 - NATURAL HAZARDS DA - 2008/3// PY - 2008/3// DO - 10.1007/s11069-007-9131-4 VL - 44 IS - 3 SP - 315-316 SN - 1573-0840 ER - TY - JOUR TI - Dynamic forcing and mesoscale variability of heavy precipitation events over the Sierra Nevada mountains AU - Reeves, Heather Dawn AU - Lin, Yuh-Lang AU - Rotunno, Richard T2 - MONTHLY WEATHER REVIEW AB - Abstract The aim of this research is to investigate the causes for an isolated maximum in precipitation that is typically found along the northern half of the Sierra Nevada mountains of California, in the vicinity of Plumas National Forest (PNF), during moderate to heavy precipitation events. Particular attention was paid to the role various mesoscale (i.e., &lt;200 km) terrain features may have played in localizing the precipitation at PNF. Numerical simulations and sensitivity experiments for two cases of heavy precipitation at PNF reveal that the extent to which terrain acts to focus precipitation is case sensitive. In the first case, the upstream flow was characterized by a strong horizontal gradient in wind speed and moisture. This gradient led to differential deflection of airstreams incident to the range and, consequently, localized convergence and enhanced rain rates at PNF. This localized enhancement occurred regardless of whether any terrain variations were present in the simulations or not. The second case was characterized by more a horizontally uniform upstream flow and showed a much stronger sensitivity to terrain variations, in particular, short- and long-wavelength undulations along the leading (west) edge of the Sierra Nevada range. When these undulations were removed, no localized maxima in precipitation occurred. DA - 2008/1// PY - 2008/1// DO - 10.1175/2007MWR2164.1 VL - 136 IS - 1 SP - 62-77 SN - 0027-0644 ER - TY - JOUR TI - Functional response of sport divers to lobsters with application to fisheries management AU - Eggleston, David B. AU - Parsons, Darren M. AU - Kellison, G. Todd AU - Plaia, Gayle R. AU - Johnson, Eric G. T2 - ECOLOGICAL APPLICATIONS AB - Fishery managers must understand the dynamics of fishers and their prey to successfully predict the outcome of management actions. We measured the impact of a two-day exclusively recreational fishery on Caribbean spiny lobster in the Florida Keys, USA, over large spatial scales (>100 km) and multiple years and used a theoretical, predator–prey functional response approach to identify whether or not sport diver catch rates were density-independent (type I) or density-dependent (type II or III functional response), and if catch rates were saturated (i.e., reached an asymptote) at relatively high lobster densities. We then describe how this predator–prey framework can be applied to fisheries management for spiny lobster and other species. In the lower Keys, divers exhibited a type-I functional response, whereby they removed a constant and relatively high proportion of lobsters (0.74–0.84) across all pre-fishing-season lobster densities. Diver fishing effort increased in a linear manner with lobster prey densities, as would be expected with a type-I functional response, and was an order of magnitude lower in the upper Keys than lower Keys. There were numerous instances in the upper Keys where the density of lobsters actually increased from before to after the fishing season, suggesting some type of “spill-in effect” from surrounding diver-disturbed areas. With the exception of isolated reefs in the upper Keys, the proportion of lobsters removed by divers was density independent (type-I functional response) and never reached saturation at natural lobster densities. Thus, recreational divers have a relatively simple predatory response to spiny lobster, whereby catch rates increase linearly with lobster density such that catch is a reliable indicator of abundance. Although diver predation is extremely high (∼80%), diver predation pressure is not expected to increase proportionally with a decline in lobster density (i.e., a depensatory response), which could exacerbate local extinction. Furthermore, management actions that reduce diver effort should have a concomitant and desired reduction in catch. The recreational diver–lobster predator–prey construct in this study provides a useful predictive framework to apply to both recreational and commercial fisheries, and on which to build as management actions are implemented. DA - 2008/1// PY - 2008/1// DO - 10.1890/06-1409.1 VL - 18 IS - 1 SP - 258-272 SN - 1939-5582 KW - Biscayne National Park KW - Caribbean spiny lobster KW - density independence KW - fishery management KW - Florida Keys KW - USA KW - functional response KW - ovetfishing KW - predator-prey theory KW - recreational fishing impacts KW - scuba divers ER - TY - JOUR TI - Early diagenetic cycling, incineration, and burial of sedimentary organic carbon in the central Gulf of Papua (Papua New Guinea) AU - Aller, Robert C. AU - Blair, Neal E. AU - Brunskill, Gregg J. T2 - JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE AB - The clinoform complex of the Gulf of Papua represents a major deltaic system in Oceania. Two seasons largely control seafloor dynamics and sedimentary C cycling: the relatively quiescent NW monsoon, and the SE trades, characterized by remobilization and reoxidation of topset deposits. Surface sediments (∼20 cm) are reactive with ΣCO 2 production fluxes ∼35–42 mmol m −2 d −1 at mangrove channel and topset sites during the monsoon, and ∼10–20 mmol m −2 d −1 on the foreset‐bottomset (>40 m). Fluxes decrease by a factor of ∼0.3 on the topset during the transition period and trades. The 13,14 C isotopic compositions of pore water ΣCO 2 reveal diagenetic fractionation, with dominant utilization of young (Δ 14 C = 1.4–31.1‰), terrestrial C substrates inshore (channels, topset δ 13 C = −29 to −25‰) and a progressive increase of young marine C sources seaward (outer topset, foreset; bottomset δ 13 C = −22.2 to −19.5). Remineralization patterns of terrestrial and marine C org demonstrate cross‐shelf exchange. Multiple tracers show that a suboxic, mobile mud layer, ∼10–60 cm thick (usually ∼10–30 cm), characterizes the central gulf topset and Umuda Valley off the Fly River and unconformably overlies methanic deposits releasing old ΣCO 2 (Δ 14 C = −159 to −229‰). Residual terrestrial C org delivered to the bioturbated foreset continues to be remineralized slowly, generating ΣCO 2 having net Δ 14 C = −270 within sediments deposited 100–200 years ago. The reactivity of C org below ∼0.5 m in the foreset is ∼10–20 times lower than expected based on accumulation rates, reflecting loss of >50% of sedimentary C org on the topset, which functions as a suboxic incinerator. DA - 2008/1/12/ PY - 2008/1/12/ DO - 10.1029/2006jf000689 VL - 113 IS - F1 SP - SN - 2169-9011 ER - TY - JOUR TI - A study of two-dimensional dry convective plume modes with variable critical level height AU - Kiefer, Michael T. AU - Lin, Yuh-Lang AU - Charney, Joseph J. T2 - JOURNAL OF THE ATMOSPHERIC SCIENCES AB - Abstract This study investigates the impact of wind speed and critical level height on dry convection above a prescribed heat source. This is done using the Advanced Regional Prediction System (ARPS) model in its two-dimensional form with an imposed 400-K soil potential temperature perturbation. The result of these experiments is the identification of three modes of convective plumes. The first, termed multicell convective plumes, is analogous to multicell convection generated from squall-line cold pools in the moist atmosphere. The second mode, a deep wave mode, consists of disturbances with wavelengths of 7–10 km and results from the multicell plumes perturbing the dynamically unstable shear flow centered at the critical level. The third mode, termed the intense fire plume, has stronger updrafts than the multicell mode and is marked by quasi-stationary movement and substantial low-level inflow and upper-level outflow. The presence of a critical level is shown to be crucial to the development of both the deep wave and intense plume modes. The intense fire plume mode is most consistent with the so-called fire storm, or conflagration phenomenon, in which strong updrafts and low-level indrafts can produce mesocyclones and tornadic fire whirls capable of significant damage. This study marks an important step in understanding the dynamics behind the fire storm phenomenon, as well as other types of convection (multicell and deep wave) that may be generated by a fire. DA - 2008/2// PY - 2008/2// DO - 10.1175/2007JAS2301.1 VL - 65 IS - 2 SP - 448-469 SN - 0022-4928 ER - TY - JOUR TI - Water level variations in the Neuse and Pamlico Estuaries, North Carolina due to local and remote forcing AU - Reed, Robert E. AU - Dickey, David A. AU - Burkholder, Joann M. AU - Kinder, Carol A. AU - Brownie, Cavell T2 - ESTUARINE COASTAL AND SHELF SCIENCE AB - Water level time series records from the Neuse and Pamlico River Estuaries were statistically compared to local and distant wind field data, water level records within the Pamlico Sound and also coastal ocean sites to determine the relative contribution of each time series to water levels in the Neuse and Pamlico Estuaries. The objectives of this study were to examine these time series data using various statistical methods (i.e. autoregressive, empirical orthogonal function analysis (EOF), exploratory data analysis (EDA)) to determine short- and long-time-scale variability, and to develop predictive statistical models that can be used to estimate past water level fluctuations in both the Neuse Estuary (NE) and Pamlico Estuary (PE). Short- and long-time-scale similarities were observed in all time series of estuarine, Pamlico Sound and subtidal coastal ocean water level and wind component data, due to events (nor'easters, fronts and tropical systems) and seasonality. Empirical orthogonal function analyses revealed a strong coastal ocean and wind field contribution to water level in the NE and PE. Approximately 95% of the variation was captured in the first two EOF components for water level data from the NE, sound and coastal ocean, and 70% for the PE, sound and coastal ocean. Spectral density plots revealed strong diurnal signals in both wind and water level data, and a strong cross correlation and coherency between the NE water level and the North/South wind component. There was good agreement between data and predictions using autoregressive statistical models for the NE (R2 = 0.92) and PE (R2 = 0.76). These methods also revealed significant autoregressive lags for the NE (days 1 and 3) and for the PE (days 1, 2 and 3). Significant departures from predictions are attributed to local meteorological and hydrological events. The autoregressive techniques showed significant predictive improvement over ordinary least squares methods. The results are considered within the context of providing long time-scale hindcast data for the two estuaries, and the importance of these data for multidisciplinary researchers and managers. DA - 2008/1/20/ PY - 2008/1/20/ DO - 10.1016/j.ecss.2007.05.049 VL - 76 IS - 2 SP - 431-446 SN - 1096-0015 KW - water surface elevation KW - lagoonal estuary KW - autoregressive KW - empirical orthogonal function KW - Neuse Estuary KW - Pamlico Estuary KW - Pamlico Sound KW - North Carolina ER - TY - JOUR TI - Reconstruction of sediment flux from the Changjiang (Yangtze River) to the sea since the 1860s AU - Wang, Houjie AU - Yang, Zuosheng AU - Wang, Yan AU - Saito, Yoshiki AU - Liu, J. Paul T2 - Journal of Hydrology AB - The Changjiang (Yangtze River) has been effectively gauged since the 1950s and demonstrates the transformation of a river system due to intensified human activities in its drainage basin over the past 50 yr. However, the 50-yr measurements of water and sediment are inadequate to show the long-term trend of sediment flux from the river to the sea or to capture the transition from natural to human dominance over the sediment flux. In this study we used the existing water discharge and sediment load records (1950s–2005) at the Hankou gauging station, together with water discharge recorded since 1865 at the same station, to reconstruct the changes of sediment flux to the sea since the 1860s. We established rating curves between stream discharge and suspended sediment concentration from the recent 50-yr data sets, which show that human disturbances have had a substantial impact on rating parameters. The commissioning of dams and undertaking of soil-conservation works have decreased sediment supply, leading to a decrease in the rating coefficient a of the rating curve equation Cs = aQb. The decreases in suspended sediment concentration have increased the erosive power of the river, and hence increased the rating exponent b. In particular, the commissioning of the Three Gorges Reservoir in 2003 resulted in a further increase of b, and channel scour in the middle and lower reaches has increased sediment flux to the sea to a level higher than sediment supply from the upper reaches. Our results suggest that the rating curves derived from 1954 to 1968 data are appropriate for estimating sediment loads for the period from 1865 to 1953, since both were periods of minimal human disturbance. This approach provides a time series of sediment loads from 1865 to 2005 at Hankou gauging station, which yields a time series of sediment flux from the Changjiang to the sea over the past 140 yr. The estimated mean annual sediment flux to the sea between 1865 and 1968 was ∼488 Mt/yr, a comparable result to the previously published estimate from Milliman and Syvitski [Milliman, J.D., Syvitski, J.P.M., 1992. Geomorphic/tectonic control of sediment discharge to the ocean: the importance of small mountainous rivers. Journal of Geology 100, 525–544] and to that from an equation proposed by Syvitski and Morehead [Syvitski, J.P.M, Morehead, M.D., 1999. Estimating river-sediment discharge to the ocean: application to the Eel margin, northern California. Marine Geology 154, 13–28]. The long-term variation of annual sediment flux from the Changjiang to the sea shows a transition from a river system mostly dominated by nature (the monsoon-dominated period, 1865–1950s) to one strongly affected by human activities (the human-impacted period, 1950s–present). DA - 2008/2// PY - 2008/2// DO - 10.1016/j.jhydrol.2007.11.005 VL - 349 IS - 3-4 SP - 318-332 J2 - Journal of Hydrology LA - en OP - SN - 0022-1694 UR - http://dx.doi.org/10.1016/j.jhydrol.2007.11.005 DB - Crossref KW - Changjiang (Yangtze River) KW - sediment flux KW - rating curves KW - human activities ER - TY - JOUR TI - Cell cycle behavior of laboratory and field populations of the Florida red tide dinoflagellate, Karenia brevis AU - Van Dolah, Frances M. AU - Leighfield, Tod A. AU - Kamykowski, Daniel AU - Kirkpatrick, Gary J. T2 - CONTINENTAL SHELF RESEARCH AB - As a component of the ECOHAB Florida Regional Field Program, this study addresses cell cycle behavior and its importance to bloom formation of the Florida red tide dinoflagellate, Karenia brevis. The cell cycle of K. brevis was first studied by flow cytometry in laboratory batch cultures, and a laboratory mesocosm column, followed by field populations over the 5-year course of the ECOHAB program. Under all conditions studied, K. brevis displayed diel phased cell division with S-phase beginning a minimum of 6 h after the onset of light and continuing for 12–14 h. Mitosis occurred during the dark, and was generally completed by the start of the next day. The timing of cell cycle phases relative to the diel cycle did not differ substantially in bloom populations displaying radically different growth rates (μmin 0.17–0.55) under different day lengths and temperature conditions. The rhythm of cell cycle progression is independent from the rhythm controlling vertical migration, as similar cell cycle distributions are found at all depths of the water column in field samples. The implications of these findings are discussed in light of our current understanding of the dinoflagellate cell cycle and the development of improved models for K. brevis bloom growth. DA - 2008/1// PY - 2008/1// DO - 10.1016/j.csr.2007.01.030 VL - 28 IS - 1 SP - 11-23 SN - 0278-4343 KW - in situ growth rate KW - circadian rhythm KW - harmful algal bloom KW - USA KW - Gulf of Mexico ER - TY - JOUR TI - A three-dimensional wind and behaviorally driven population dynamics model for Karenia brevis AU - Janowitz, G. S. AU - Kamykowski, D. AU - Liu, G. T2 - CONTINENTAL SHELF RESEARCH AB - The time-dependent three-dimensional distribution of a population of Karenia brevis is explored through the use of an Eulerian model. The model combines a previously developed physiologically based behavioral model of these dinoflagellates with a simple model for a three-dimensional wind driven flow field over a variable-depth continental shelf. The behavioral model is simplified from that used in previous applications and sigma coordinates are utilized in the model. Model results indicate that even for the relatively weak wind driven currents used in our simulation a non-quantized population can develop into two spatially distinct quantized populations in a period as short as 1 day where, for present purposes, a quantized population is one in which all cells are at the same stage of the cell cycle. DA - 2008/1// PY - 2008/1// DO - 10.1016/j.csr.2007.04.016 VL - 28 IS - 1 SP - 177-188 SN - 0278-4343 KW - continental shelf KW - dinoflagellate : behavior KW - modeling : population dynamics KW - west Florida shelf ER - TY - JOUR TI - A regional-scale drought monitoring tool for the Carolinas AU - Carbone, Gregory J. AU - Rhee, Jinyoung AU - Mizzell, Hope P. AU - Boyles, Ryan T2 - BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY DA - 2008/1// PY - 2008/1// DO - 10.1175/BAMS-89-1-20 VL - 89 IS - 1 SP - 20-28 SN - 1520-0477 ER -