TY - CONF TI - S.Teotónio- Aljezur- Sinceira Fault System: A Seismogenic source at SW Portugal? C2 - 2009/// C3 - 1st SHARE (Seismic Hazard Harmonization in Europe) Iberian Workshop for Active Faults and Seismogenic Sources DA - 2009/// ER - TY - CONF TI - Late Pliocene to Pleistocene tectonic activity in SW Portugal: New data from field observations and trenching C2 - 2009/// C3 - 6th Symposium on the Iberian Atlantic Margin DA - 2009/// ER - TY - CONF TI - Actividade Tectónica Plistocénica no SW de Portugal: O sistema de falhas São Teotónio – Aljezur – Sinceira e evidências de levantamento ao longo do Litoral. C2 - 2009/// C3 - VII Meeting Iberian Quaternary, GTPEQ & AEQUA DA - 2009/// ER - TY - JOUR TI - US GODAE: Global Ocean Prediction with the HYbrid Coordinate Ocean Model (HYCOM) AU - Chassignet, Eric AU - Hurlburt, Harley AU - Metzger, E. Joseph AU - Smedstad, Ole AU - Cummings, James AU - Halliwell, George AU - Bleck, Rainer AU - Baraille, Remy AU - Wallcraft, Alan AU - Lozano, Carlos AU - Tolman, Hendrik AU - Srinivasan, Ashwanth AU - Hankin, Steve AU - Cornillon, Peter AU - Weisberg, Robert AU - Barth, Alexandra AU - He, Ruoying AU - Werner, Francisco AU - Wilkin, John T2 - Oceanography AB - Abstract : The main objective is to use the HYbrid Coordinate Ocean Model (HYCOM) with data assimilation in an eddy-resolving, fully global ocean prediction system with transition to the Naval Oceanographic Office (NAVOCEANO) at .08 deg equatorial (~7 km mid-latitude) resolution in 2007 and .04 deg resolution by 2011. The model will include shallow water to a minimum depth of 5 m and provide boundary conditions to finer resolution coastal and regional models that may use HYCOM or a different model. In addition, HYCOM will be coupled to atmospheric, ice and bio-chemical models, with transition to the Fleet Numerical Meteorology and Oceanography Center (FNMOC) for the coupled ocean-atmosphere prediction. Basin-scale configurations will also form the backbone of the NOAA/NCEP/MMAB Ocean Forecast System. All the systems will be transitioned with assimilation of sea surface height (SSH) from satellite altimeters, sea surface temperature (SST) and temperature (T)/salinity (S) profiles, including profiles from ARGO floats. In addition, 30-day forecasts are planned once a week. The global system will include two-way coupling to an ice model and a version with two-way coupling to an atmospheric model for transition to FNMOC. The project will ensure that an accurate and generalized ocean model nesting capability is in place to support regional and littoral applications when global HYCOM becomes operational. This will include the capability to provide boundary conditions to nested models with fixed depth z-level coordinates, terrain following coordinates, generalized coordinates (HYCOM), and unstructured grids. To facilitate this goal, HYCOM will be developed into a full-featured coastal ocean model in collaboration with a partnering project. The project will participate in the multinational Global Ocean Data Assimilation Experiment (GODAE) and international GODAE-related ocean prediction system intercomparison projects. DA - 2009/6/1/ PY - 2009/6/1/ DO - 10.5670/oceanog.2009.39 VL - 22 IS - 2 SP - 64-75 ER - TY - JOUR TI - Isotopic evidence for dead fish maintenance of Florida red tides, with implications for coastal fisheries over both source regions of the West Florida shelf and within downstream waters of the South Atlantic Bight T2 - Progress in Oceanography DA - 2009/// PY - 2009/// VL - 80 IS - 1-2 SP - 51-73 ER - TY - JOUR TI - Isotopic evidence for dead fish maintenance of Florida red tides, with implications for coastal fisheries over both source regions of the West Florida shelf and within downstream waters of the South Atlantic Bight T2 - Progress in Oceanography DA - 2009/// PY - 2009/// VL - 80 IS - 1-2 SP - 51-73 ER - TY - JOUR TI - Investigation of the 2006 Alexandrium fundyense bloom in the Gulf of Maine: in-situ observations and numerical modeling T2 - Continental shelf research DA - 2009/// PY - 2009/// VL - 29 IS - 17 SP - 2069-2082 ER - TY - JOUR TI - Internal Tides and Internal Solitary Waves in the Northern South China Sea AU - Kim, Sungphil DA - 2009/// PY - 2009/// UR - http://www.lib.ncsu.edu/resolver/1840.16/1758 N1 - Large-amplitude internal solitary waves (ISWs) are frequently observed in the northern South China Sea (SCS). In a project sponsored by the US Office of Naval Research, four moorings were deployed between the Luzon Strait and the Chinese continental shelf by Steve Ramp of the Naval Postgraduate School and David Tang of National Taiwan University from late April 2005 to May 2006. Several CTD sections were taken during April and July in 2005. Satellite pictures were also collected during that period. In this study, these data were used to examine the characteristics, generation, and propagation of ISWs. In the satellite images, monthly change in stratification may cause northward shift of the propagation path, and ISWs are more frequently observed in July than in April and May. Speed estimation shows that ISWs propagate faster in the deep basin than over the continental margin and near the ridge. The generation of internal tides correlates with the eastward tidal flow over the ridge, while ISWs are produced by northwestward tidal currents over the ridges in the Luzon Strait. RN - Large-amplitude internal solitary waves (ISWs) are frequently observed in the northern South China Sea (SCS). In a project sponsored by the US Office of Naval Research, four moorings were deployed between the Luzon Strait and the Chinese continental shelf by Steve Ramp of the Naval Postgraduate School and David Tang of National Taiwan University from late April 2005 to May 2006. Several CTD sections were taken during April and July in 2005. Satellite pictures were also collected during that period. In this study, these data were used to examine the characteristics, generation, and propagation of ISWs. In the satellite images, monthly change in stratification may cause northward shift of the propagation path, and ISWs are more frequently observed in July than in April and May. Speed estimation shows that ISWs propagate faster in the deep basin than over the continental margin and near the ridge. The generation of internal tides correlates with the eastward tidal flow over the ridge, while ISWs are produced by northwestward tidal currents over the ridges in the Luzon Strait. ER - TY - JOUR TI - Characterizing the South Atlantic Bight seasonal variability and cold-water event in 2003 using a daily cloud-free SST and chlorophyll analysis AU - Miles, Travis N AU - He, Ruoying AU - Li, Mingkui T2 - Geophysical Research Letters DA - 2009/// PY - 2009/// VL - 36 IS - 2 ER - TY - CONF TI - Geology of the Höh Serh Range, Mongolian Altai AU - Bader, N.E. AU - Bayasgalan, A. AU - Carson, R.J. AU - Frankel, K.L. AU - Wegmann, K.W. A2 - Wet, A. C2 - 2009/// C3 - Proceedings of the Twenty-Second Annual Keck Research Symposium in Geology: Lancaster, Keck Geology Consortium DA - 2009/// SP - 219–225 UR - https://keckgeology.org/files/pdf/symvol/22nd/mongolia/Bader_et_al219-225.pdf ER - TY - JOUR TI - Stratus 9/VOCALS ninth setting of the Stratus Ocean Reference Station and VOCALS Regional Experiment AU - Whelan, Sean P. AU - Galbraith, Nancy AU - Weller, Robert AU - Farrar, John T. AU - Grant, David AU - Grados, Carmen AU - Szoeke, Simon P. AU - Moffat, Carlos AU - Zappa, Chris AU - Yang, Mingxi AU - Straneo, Fiamma AU - Fairall, Chris AU - Zuidema, Paquita AU - Wolfe, Dan AU - Miller, Matthew AU - Covert, David AB - Funding was provided by the National Oceanic and Atmospheric Administration under Grant No. NA17RJ1223 for the Cooperative Institute for Climate and Ocean Research (CICOR). DA - 2009/// PY - 2009/// DO - 10.1575/1912/2841 ER - TY - CHAP TI - Interactions between air quality and climate change AU - Renner, E. AU - Zhang, Y. T2 - Air Pollution Modeling and its Application XX PY - 2009/12/11/ DO - 10.1007/978-90-481-3812-8_6 SP - 479-518 OP - PB - Springer Netherlands SN - 9789048138104 9789048138128 UR - http://dx.doi.org/10.1007/978-90-481-3812-8_6 DB - Crossref ER - TY - JOUR TI - Probing into regional ozone and particulate matter pollution in the United States: 1. A 1 year CMAQ simulation and evaluation using surface and satellite data AU - Zhang, Yang AU - Vijayaraghavan, Krish AU - Wen, Xin-Yu AU - Snell, Hilary E. AU - Jacobson, Mark Z. T2 - Journal of Geophysical Research AB - As part 1 in a series of papers describing long‐term simulations using the Community Multiscale Air Quality (CMAQ) modeling system and subsequent process analyses and sensitivity simulations, this paper presents a comprehensive model evaluation for the full year of 2001 over the continental U.S. using both ground‐based and satellite measurements. CMAQ is assessed for its ability to reproduce concentrations and long‐term trends of major criteria pollutants such as surface ozone (O 3 ) and fine particulate matter (PM 2.5 ) and related variables such as indicator species, wet deposition fluxes, and column mass abundances of carbon monoxide (CO), nitrogen oxides (NO 2 ), tropospheric ozone residuals (TORs), and aerosol optical depths (AODs). The domain‐wide and site‐specific evaluation of surface predictions shows an overall satisfactory performance in terms of normalized mean biases for annual mean maximum 1 h and 8 h average O 3 mixing ratios (−11.6 to 0.1% and −4.6 to 3.0%, respectively), 24 h average concentrations of PM 2.5 (4.2–35.3%), sulfate (−13.0 to 43.5%), and organic carbon (OC) (−37.6 to 24.8%), and wet deposition fluxes (−13.3 to 31.6%). Larger biases, however, occur in the concentrations and wet deposition fluxes of ammonium and nitrate domain‐wide and in the concentrations of PM 2.5 , sulfate, black carbon, and OC at some urban/suburban sites. The reasons for such model biases may be errors in emissions, chemistry, aerosol processes, or meteorology. The evaluation of column mass predictions shows a good model performance in capturing the seasonal variations and magnitudes of column CO and NO 2 , but relatively poor performance in reproducing observed spatial distributions and magnitudes of TORs for winter and spring and those of AODs in all seasons. Possible reasons for the poor column predictions include the underestimates of emissions, inaccurate upper layer boundary conditions, lack of model treatments of sea salt and dust, and limitations and uncertainties in satellite data. DA - 2009/11/25/ PY - 2009/11/25/ DO - 10.1029/2009JD011898 VL - 114 IS - D22 J2 - J. Geophys. Res. LA - en OP - SN - 0148-0227 UR - http://dx.doi.org/10.1029/2009JD011898 DB - Crossref ER - TY - JOUR TI - Aging of black carbon in outflow from anthropogenic sources using a mixing state resolved model: Model development and evaluation AU - Oshima, N. AU - Koike, M. AU - Zhang, Y. AU - Kondo, Y. AU - Moteki, N. AU - Takegawa, N. AU - Miyazaki, Y. T2 - Journal of Geophysical Research AB - The mixing state of black carbon (BC) aerosols, namely, the degree to which BC particles are coated with other aerosol components, has been recognized as important for evaluating aerosol radiative forcing. In order to resolve the BC mixing state explicitly in model simulations, a two‐dimensional aerosol representation, in which aerosols are given for individual particle diameters and BC mass fractions, is introduced. This representation was incorporated into an aerosol module, the Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution (MADRID), and a new box model, MADRID‐BC, was developed. MADRID‐BC can accurately simulate changes in the entire BC mixing state resulting from condensation/evaporation processes. Aircraft observations conducted in March 2004 show that the mass fraction of thickly coated BC particles increased in air horizontally transported out from an urban area in Japan over the ocean. MADRID‐BC generally reproduces this feature well when observed bulk aerosol concentrations are used as constraints. The model simulations in this particular case show that for particles with BC core diameters of 100–200 nm, the particle diameters, including both core and coating materials, had already increased by a factor of 1.6 on average when they left the source region and by as large as a factor of 1.9 of the BC core diameters after their transport over the ocean for a half day. The model simulations also show that 58% of the total condensed mass was partitioned onto BC‐free particles during transport, indicating their importance for the BC mixing state. Although the model simulations are applied to a limited number of the observations in this study, they clearly show the time evolution of the coating thicknesses of BC‐containing particles, which is necessary for calculating aerosol optical properties and cloud condensation nuclei activities. DA - 2009/3/27/ PY - 2009/3/27/ DO - 10.1029/2008JD010680 VL - 114 IS - D6 J2 - J. Geophys. Res. LA - en OP - SN - 0148-0227 UR - http://dx.doi.org/10.1029/2008JD010680 DB - Crossref ER - TY - JOUR TI - A quantitative assessment of human impacts on decrease in sediment flux from major Chinese rivers entering the western Pacific Ocean AU - Chu, Z. X. AU - Zhai, S. K. AU - Lu, X. X. AU - Liu, J. P. AU - Xu, J. X. AU - Xu, K. H. T2 - Geophysical Research Letters AB - Major rivers with high sediment or water discharge act as natural integrators of surficial processes, including human activities within their drainage basins, and they are also the primary sources of terrestrial materials entering the ocean. The river‐derived materials flux entering the coastal oceans, however, has been strongly affected by anthropogenic activities. Recent studies related to human impacts on river sediment flux have mainly focused on qualitative descriptions. Here we present a quantitative assessment of human impacts on decrease in sediment flux from nine major Chinese rivers entering the western Pacific Ocean, including Changjiang (Yangtze), Huanghe (Yellow), Zhujiang (Pearl), Songhuajiang, Liaohe, Haihe, Huaihe, Qiantangjiang, and Minjiang. During 1959–2007, dams and reservoirs, soil and water conservation programs, water consumption, as well as sand mining decreased the amount of sediment delivered to the ocean by 28, 11.5, 7.5 and 3 gigatons (Gt), respectively. If combined (50 Gt for the period 1959–2007), this reduction was close to the total decreased sediment flux (43 Gt) measured from these nine major rivers over the same period. Besides, the temporal variations in water and sediment fluxes into the ocean from these rivers generally during 1953–2007 were presented. These results are useful for further studies on Chinese and even global river‐derived material flux to the ocean and associated ecological risks. DA - 2009/10/9/ PY - 2009/10/9/ DO - 10.1029/2009GL039513 VL - 36 IS - 19 J2 - Geophys. Res. Lett. LA - en OP - SN - 0094-8276 UR - http://dx.doi.org/10.1029/2009GL039513 DB - Crossref ER - TY - CONF TI - Predictability of the Moisture Regime During the Pre-onset Period of Sahelian Rains AU - Mera, Roberto J. AU - Semazzi, F.H.M. T2 - 10th Weather Research and Forecasting Model User’s Workshop C2 - 2009/// CY - Boulder, Colorado DA - 2009/// PY - 2009/6// ER - TY - CONF TI - Application of WRF to investigate the moisture regime associated with the pre-onset of Sahelian rains AU - Mera, Roberto J. AU - Semazzi, F.H.M. T2 - 5th Education and Science Forum of the National Oceanic and Atmospheric Administration Educational Partnership Program C2 - 2009/// CY - Washington, DC DA - 2009/// PY - 2009/11/12/ ER - TY - CONF TI - Short-term weather forecasts to help allocate meningitis vaccine AU - Pandya, R. AU - Adams-Forgor, A. AU - Columbini, A. AU - Hayden, M. AU - Hodgson, A. AU - Hopson, T. AU - Lamptey, B. AU - Lazo, J. AU - Mera, Roberto J. AU - Rice, J. AU - Semazzi, F. AU - Thomson, M. AU - Trazka, S. AU - Warner, T. AU - Yoksas, T. T2 - 3rd MERIT Technical Meeting and National Workshop C2 - 2009/// CY - Niamey, Niger DA - 2009/// PY - 2009/11/9/ ER - TY - THES TI - An examination of tropical cyclone dynamics utilizing the 3-Way coupled ocean atmosphere wave sediment transport (COAWST) model AU - Zambon, J.B. DA - 2009/// PY - 2009/// SP - 154 M3 - Masters Thesis PB - North Carolina State University UR - http://repository.lib.ncsu.edu/ir/handle/1840.16/475 ER - TY - CONF TI - Investigation of tropical cyclone using a new Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) model AU - Zambon, J.B. T2 - Masters Thesis Defense to the Department of Marine, Earth and Atmospheric Sciences (MEAS C2 - 2009/// CY - North Carolina State University, Raleigh, NC DA - 2009/// PY - 2009/// ER - TY - CONF TI - Numerical investigation of Hurricane Ivan AU - Zambon, J.B. T2 - Mid-Atlantic Bight Physical Oceanography and Meteorology and Southeast Coastal Oceanography and Meteorology (MABPOM SECOM) Conference C2 - 2009/// CY - North Carolina State University, Raleigh, NC DA - 2009/// PY - 2009/// ER - TY - CONF TI - Numerical investigation of Hurricane Isabel Impacts AU - Warner, J.C. AU - He, R. AU - Armstrong, B. AU - Zambon, J.B. T2 - Mid-Atlantic Bight Physical Oceanography and Meteorology and Southeast Coastal Oceanography and Meteorology (MABPOM SECOM) Conference C2 - 2009/// CY - North Carolina State University, Raleigh, NC DA - 2009/// PY - 2009/// ER - TY - CONF TI - Detecting change in atmospheric ammonia following emission changes AU - Erisman, J.W. AU - Bleeker, A. AU - Neftel, A. AU - Aneja, V. AU - Hutchings, N. AU - Kinsella, L. AU - Tang, Y.S. AU - Webb, J. AU - Sponar, M. AU - Raes, C. AU - Mitosinkova, M. AU - Vidic, S. AU - Andersen, H.V. AU - Klimont, Z. AU - Pinder, R. AU - Baker, S. AU - Reidy, B. AU - Flechard, C. AU - Horvath, L. AU - Lewandowska, A. AU - Gillespie, C. AU - Wallasch, M. AU - Gehrig, R. AU - Ellerman, T. C2 - 2009/// C3 - Atmospheric Ammonia: Detecting Emission Changes and Environmental Impacts - Results of an Expert Workshop under the Convention on Long-Range Transboundary Air Pollution DA - 2009/// SP - 383-390 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84900525664&partnerID=MN8TOARS ER - TY - CONF TI - Linking ammonia emission trends to measured concentrations and deposition of reduced nitrogen at different scales AU - Bleeker, A. AU - Sutton, M.A. AU - Acherman, B. AU - Alebic-Juretic, A. AU - Aneja, V.P. AU - Ellermann, T. AU - Erisman, J.W. AU - Fowler, D. AU - Fagerli, H. AU - Gauger, T. AU - Harlen, K.S. AU - Hole, L.R. AU - Horvath, L. AU - Mitosinkova, M. AU - Smith, R.I. AU - Tang, Y.S. AU - Van Pul, A. C2 - 2009/// C3 - Atmospheric Ammonia: Detecting Emission Changes and Environmental Impacts - Results of an Expert Workshop under the Convention on Long-Range Transboundary Air Pollution DA - 2009/// SP - 123-180 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84900541568&partnerID=MN8TOARS ER - TY - CHAP TI - Linking ammonia emission trends to measured concentrations and deposition of reduced nitrogen at different scales AU - Bleeker, A. AU - Sutton, M.A. AU - Acherman, B. AU - Alebic-Juretic, A. AU - Aneja, V.P. AU - Ellermann, T. AU - Erisman, J.W. AU - Fowler, D. AU - Fagerli, H. AU - Gauger, T. AU - Harlen, K.S. AU - Hole, L.R. AU - Horvath, L. AU - Mitosinkova, M. AU - Smith, R.I. AU - Tang, Y.S. AU - Van Pul, A. T2 - Atmospheric Ammonia: Detecting Emission Changes and Environmental Impacts PY - 2009/// DO - 10.1007/978-1-4020-9121-6_11 SP - 123-180 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84885706269&partnerID=MN8TOARS ER - TY - CHAP TI - Detecting change in atmospheric ammonia following emission changes AU - Erisman, J.W. AU - Bleeker, A. AU - Neftel, A. AU - Aneja, V. AU - Hutchings, N. AU - Kinsella, L. AU - Tang, Y.S. AU - Webb, J. AU - Sponar, M. AU - Raes, C. AU - Mitosinkova, M. AU - Vidic, S. AU - Andersen, H.V. AU - Klimont, Z. AU - Pinder, R. AU - Baker, S. AU - Reidy, B. AU - Flechard, C. AU - Horvath, L. AU - Lewandowska, A. AU - Gillespie, C. AU - Wallasch, M. AU - Gehrig, R. AU - Ellerman, T. T2 - Atmospheric Ammonia: Detecting Emission Changes and Environmental Impacts AB - The Working Group discussed the progress on the state of knowledge on deriving trends from measurements and their use to verify abatement measures or other causes for decrease in emissions of ammonia to the atmosphere. The conclusions from the 2000 Berne meeting (Menzi and Achermann 2001), the background review (Bleeker et al. 2008) and presentations during the session (Horvath et al. 2008; Tang et al. 2008; Webb et al. 2008), as well as the discussions served as input for the conclusions of this report. We have seen some clear advancement in closing the gap between the observed and expected values for reduced nitrogen, where we do get a better understanding of the reasons behind it. The long-term measurements that are available follow the emission trend. Current measurements make it possible to evaluate policy progress on ammonia emission abatement. Especially in those countries where there were big (>25%) changes in emissions, such as in the Netherlands and Denmark the trend is followed quite closely, especially when meteorology is well taken into account. In order countries, such as the UK, the trend was much smaller, but there was no gap between measurements and model estimates. In the Netherlands there still is an ammonia gap: a significant (30%) difference between emissions based ammonia concentrations and measurements. The trend is the same. The difference might be due to either an underestimation of the emission or an overestimation of the dry deposition. It is recommended to further explore this gap, especially by investigating the high temporal resolution measurements, improving the emission/deposition modeling, by having a model intercomparison with countries that use models that do not show a gap and finally by doing a thorough uncertainty analysis. PY - 2009/// DO - 10.1007/978-1-4020-9121-6_23 SP - 383-390 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84857729937&partnerID=MN8TOARS ER - TY - RPRT TI - Propagation and Culture of Federally Listed Freshwater Mussel Species AU - Levine, J.F. AU - Eads, C.B. AU - Greiner, R. AU - Bogan, A.E. A3 - NC Department of Transportation DA - 2009/// PY - 2009/// PB - NC Department of Transportation ER - TY - JOUR TI - Comparison of traditional thermocouples and data loggers for simplified temperature monitoring using shellstock oysters as a model AU - Drake, S.L AU - Beverely, R. AU - Chawla, A AU - Janes, M. AU - Supan, J. AU - Bell, J AU - Levine, JF AU - Jaykus, L.A. T2 - Journal of Food Protection and Trends DA - 2009/5// PY - 2009/5// VL - 29 SP - 268–271 ER - TY - JOUR TI - Defining DNA-Based Operational Taxonomic Units for Microbial-Eukaryote Ecology AU - Caron, David A. AU - Countway, Peter D. AU - Savai, Pratik AU - Gast, Rebecca J. AU - Schnetzer, Astrid AU - Moorthi, Stefanie D. AU - Dennett, Mark R. AU - Moran, Dawn M. AU - Jones, Adriane C. T2 - Applied and Environmental Microbiology AB - DNA sequence information has increasingly been used in ecological research on microbial eukaryotes. Sequence-based approaches have included studies of the total diversity of selected ecosystems, studies of the autecology of ecologically relevant species, and identification and enumeration of species of interest for human health. It is still uncommon, however, to delineate protistan species based on their genetic signatures. The reluctance to assign species-level designations based on DNA sequences is in part a consequence of the limited amount of sequence information presently available for many free-living microbial eukaryotes and in part a consequence of the problematic nature of and debate surrounding the microbial species concept. Despite the difficulties inherent in assigning species names to DNA sequences, there is a growing need to attach meaning to the burgeoning amount of sequence information entering the literature, and there is a growing desire to apply this information in ecological studies. We describe a computer-based tool that assigns DNA sequences from environmental databases to operational taxonomic units at approximately species-level distinctions. This approach provides a practical method for ecological studies of microbial eukaryotes (primarily protists) by enabling semiautomated analysis of large numbers of samples spanning great taxonomic breadth. Derivation of the algorithm was based on an analysis of complete small-subunit (18S) rRNA gene sequences and partial gene sequences obtained from the GenBank database for morphologically described protistan species. The program was tested using environmental 18S rRNA data sets for two oceanic ecosystems. A total of 388 operational taxonomic units were observed for 2,207 sequences obtained from samples collected in the western North Atlantic and eastern North Pacific oceans. DA - 2009/9/15/ PY - 2009/9/15/ DO - 10.1128/aem.00298-09 VL - 75 IS - 18 SP - 5797-5808 UR - http://dx.doi.org/10.1128/aem.00298-09 ER - TY - CONF TI - Detection of mitochondrial DNA with the compact bead array sensor system (cBASS) AU - Mulvaney, Shawn P. AU - Ibe, Carol N. AU - Caldwell, Jane M. AU - Levine, Jay F. AU - Whitman, Lloyd J. AU - Tamanaha, Cy R. T2 - SPIE BiOS A2 - Fauchet, Philippe M. T3 - Proceedings AB - Enteric pathogens are a significant contaminant in surface waters used for recreation, fish and shellfish harvesting, crop irrigation, and human consumption. The need for water monitoring becomes more pronounced when industrial, agricultural, and residential lands are found in close proximity. Fecal contamination is particularly problematic and identification of the pollution source essential to remediation efforts. Standard monitoring for fecal contamination relies on indicator organisms, but the technique is too broad to identify the source of contamination. Instead, real-time PCR of mitochondrial DNA (mtDNA) is an emerging method for identification of the contamination source. Presented herein, we evaluate an alternative technology, the compact Bead Array Sensor System (cBASS®) and its assay approach Fluidic Force Discrimination (FFD), for the detection of mtDNA. Previously, we achieved multiplexed, attomolar detection of toxins and femtomolar detection of nucleic acids in minutes with FFD assays. More importantly, FFD assays are compatible with a variety of complex matrices and therefore potentially applicable for samples where the matrix would interfere with PCR amplification. We have designed a triplex assay for the NADH gene found in human, swine, and bovine mtDNA and demonstrated the specific detection of human mtDNA spiked into a waste water sample. C2 - 2009/2/12/ C3 - Frontiers in Pathogen Detection: From Nanosensors to Systems CY - San Jose, California, United States DA - 2009/2/12/ PY - 2009/// DO - 10.1117/12.806433 PB - SPIE UR - http://dx.doi.org/10.1117/12.806433 KW - mitochondrial DNA KW - Fluidic Force Discrimination (FFD) KW - bead assay KW - biosensor KW - point source pollution ER - TY - BOOK TI - Palaeoseismology of the Vilariça segment of the Manteigas-Bragança fault in northeastern Portugal AU - Rockwell, T. AU - Fonseca, J. AU - Madden, C. AU - Dawson, T. AU - Owen, L.A. AU - Vilanova, S. AU - Figueiredo, P. DA - 2009/// PY - 2009/// DO - 10.1144/SP316.15 VL - 316 SE - 237-258 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-70349173409&partnerID=MN8TOARS ER - TY - JOUR TI - The geometry of volcano flank terraces on Mars AU - Byrne, Paul K. AU - van Wyk de Vries, Benjamin AU - Murray, John B. AU - Troll, Valentin R. T2 - Earth and Planetary Science Letters AB - Flank terraces are subtle, expansive structures on the slopes of many large Martian shield volcanoes. Several terrace formation hypotheses — including self-loading, lithospheric flexure, magma chamber tumescence, volcano spreading, and shallow gravitational slumping — have been suggested. Terraces are not readily visible on photogeological data; consequently, terrace geometry has not yet been comprehensively described. Terrace provenance, therefore, is poorly understood. We used three-dimensional Mars Orbiter Laser Altimeter (MOLA) data to characterise the geometry of these elusive structures, with a view to understanding better the role that flank terraces play in the tectonic evolution of volcanoes on Mars. Terraces have a broad, convex-upward profile in section, and a systematic “fish scale” imbricate stacking pattern in plan. They are visible at all elevations, on at least nine disparate Martian volcanoes. Terrace-like features also occur on three shield volcanoes on Earth, an observation not recorded before. Analysis of a suite of morphometric parameters for flank terraces showed that they are scale-invariant, with similar proportions to thrust faults on Earth. We compared predicted formation geometries to our terrace observations, and found that only lithospheric flexure can fully account for the morphology, distribution, and timing of terraces. As a volcano flexes into the lithosphere beneath it, its upper surface will experience a net reduction in area, resulting in the formation of outward verging thrusts. We conclude, therefore, that flank terraces are fundamental volcanotectonic structures, that they are the surface expressions of thrust faults, probably formed by lithospheric flexure, and that they are not restricted to Mars. DA - 2009/4// PY - 2009/4// DO - 10.1016/j.epsl.2009.01.043 VL - 281 IS - 1-2 SP - 1-13 J2 - Earth and Planetary Science Letters LA - en OP - SN - 0012-821X UR - http://dx.doi.org/10.1016/j.epsl.2009.01.043 DB - Crossref KW - volcano KW - flank KW - terrace KW - volcanotectonic KW - Mars KW - Earth ER - TY - JOUR TI - A new look at lake-effect snowfall trends in the Laurentian Great Lakes using a temporally homogeneous data set AU - Kunkel, Kenneth E. AU - Ensor, Leslie AU - Palecki, Michael AU - Easterling, David AU - Robinson, David AU - Hubbard, Kenneth G. AU - Redmond, Kelly T2 - Journal of Great Lakes Research AB - Snowfall data are subject to quality issues that affect their usefulness for detection of climate trends. A new analysis of lake-effect snowfall trends utilizes a restricted set of stations identified as suitable for trends analysis based on a careful quality assessment of long-term observation stations in the lake-effect snowbelts of the Laurentian Great Lakes. An upward trend in snowfall was found in two (Superior and Michigan) of the four snowbelt areas. The trends for Lakes Erie and Ontario depended on the period of analysis. Although these results are qualitatively similar to outcomes of other recent studies, the magnitude of the upward trend is about half as large as trends in previous findings. The upward trend in snowfall was accompanied by an upward trend in liquid water equivalent for Superior and Michigan, while no trend was observed for Erie and Ontario. Air temperature has also trended upward for Superior and Michigan, suggesting that warmer surface waters and less ice cover are contributing to the upward snowfall trends by enhancing lake heat and moisture fluxes during cold air outbreaks. However, a more comprehensive study is needed to definitely determine cause and effect. Overall, this study finds that trends in lake-effect snowfall are not as large as was believed based on prior research. DA - 2009/3// PY - 2009/3// DO - 10.1016/j.jglr.2008.11.003 VL - 35 IS - 1 SP - 23-29 J2 - Journal of Great Lakes Research LA - en OP - SN - 0380-1330 UR - http://dx.doi.org/10.1016/j.jglr.2008.11.003 DB - Crossref KW - Snowfall KW - Trends KW - Lake-effect KW - Great Lakes ER - TY - JOUR TI - How spatially coherent and statistically robust are temporal changes in extreme precipitation in the contiguous USA? AU - Pryor, S. C. AU - Howe, J. A. AU - Kunkel, K. E. T2 - International Journal of Climatology AB - Abstract Century‐long precipitation records from stations in the contiguous USA indicate an increased frequency of rainy days over the past century and some evolution in the probability distributions of precipitation amount. Temporal trends in eight metrics of the precipitation climate are of similar magnitude and sign regardless of whether they are derived from bootstrapping of regression residuals or using the Kendall's tau statistic, though the bootstrap technique generally resolved a larger number of ‘significant’ trends. There is substantial variability in terms of the magnitude, significance and sign of the linear trends with specific metrics, and they are sensitive to recording bias of light precipitation events in the early part of the 20th century. The majority of stations that exhibit significant linear trends show evidence of increases in the intensity of events above the 95th percentile. The resolved trends tend to have a larger magnitude at the end of the century. Spatial variability as manifest in the spatial autocorrelation in the interannual variability and trends in extreme metrics is manifest at a range of scales, but in general the correlation between stations is significant only for separation of distances of a few tens of kilometres. The largest trends towards increased annual total precipitation, number of rainy days and intense precipitation (e.g. fraction of precipitation derived from events in excess of the 90th percentile value) are focussed on the Central Plains/northwestern Midwest. Copyright © 2008 Royal Meteorological Society DA - 2009/1// PY - 2009/1// DO - 10.1002/joc.1696 VL - 29 IS - 1 SP - 31-45 J2 - Int. J. Climatol. LA - en OP - SN - 0899-8418 1097-0088 UR - http://dx.doi.org/10.1002/joc.1696 DB - Crossref KW - extreme precipitation KW - probability distribution KW - trends ER - TY - JOUR TI - Cloud condensation nuclei and ice nucleation activity of hydrophobic and hydrophilic soot particles AU - Koehler, Kirsten A. AU - DeMott, Paul J. AU - Kreidenweis, Sonia M. AU - Popovicheva, Olga B. AU - Petters, Markus D. AU - Carrico, Christian M. AU - Kireeva, Elena D. AU - Khokhlova, Tatiana D. AU - Shonija, Natalia K. T2 - Physical Chemistry Chemical Physics AB - Cloud condensation nuclei (CCN) activity and ice nucleation behavior (for temperatures ≤−40 °C) of soot aerosols relevant for atmospheric studies were investigated. Soots were chosen to represent a range of physico-chemical properties, from hydrophobic through a range of hydrophilicity, to hygroscopic. These characteristics were achieved through generation by three different combustion sources; three soots from natural gas pyrolysis (original: TS; graphitized: GTS; and oxidized: TOS), soot from a diffusion flame in an oil lamp burning aviation kerosene (TC1), and soot from a turbulent diffusion flame in an aircraft engine combustor (AEC). All of the samples exhibited some heterogeneity in our experiments, which showed evidence of two or more particle sub-types even within a narrow size cut. The heterogeneity could have resulted from both chemical and sizing differences, the latter attributable in part to particle non-sphericity. Neither GTS nor TS, hydrophobic particles distinguished only by the lower porosity and polarity of the GTS surface, showed CCN activity at or below water supersaturations required for wettable, insoluble particles (the Kelvin limit). TC1 soot particles, despite classification as hydrophilic, did not show CCN activity at or below the Kelvin limit. We attribute this result to the microporosity of this soot. In contrast, oxidized, non-porous, and hydrophilic TOS particles exhibited CCN activation at very near the Kelvin limit, with a small percentage of these particles CCN-active even at lower supersaturations. Due to containing a range of surface coverage of organic and inorganic hydrophilic and hygroscopic compounds, up to ∼35% of hygroscopic AEC particles were active as CCN, with a small percentage of these particles CCN-active at lower supersaturations. In ice nucleation experiments below −40 °C, AEC particles nucleated ice near the expected condition for homogeneous freezing of water from aqueous solutions. In contrast, GTS, TS, and TC1 required relative humidity well in excess of water saturation at −40 °C for ice formation. GTS particles required water supersaturation conditions for ice activation even at −51 °C. At −51 to −57 °C, ice formation in particles with electrical mobility diameter of 200 nm occurred in up to 1 in 1000 TS and TC1 particles, and 1 in 100 TOS particles, at relative humidities below those required for homogeneous freezing in aqueous solutions. Our results suggest that heterogeneous ice nucleation is favored in cirrus conditions on oxidized hydrophilic soot of intermediate polarity. Simple considerations suggest that the impact of hydrophilic soot particles on cirrus cloud formation would be most likely in regions of elevated atmospheric soot number concentrations. The ice formation properties of AEC soot are reasonably consistent with present understanding of the conditions required for aircraft contrail formation and the proportion of soot expected to nucleate under such conditions. DA - 2009/// PY - 2009/// DO - 10.1039/b905334b VL - 11 IS - 36 SP - 7906 J2 - Phys. Chem. Chem. Phys. LA - en OP - SN - 1463-9076 1463-9084 UR - http://dx.doi.org/10.1039/b905334b DB - Crossref ER - TY - JOUR TI - Timescale for hygroscopic conversion of calcite mineral particles through heterogeneous reaction with nitric acid AU - Sullivan, Ryan C. AU - Moore, Meagan J. K. AU - Petters, Markus D. AU - Kreidenweis, Sonia M. AU - Roberts, Greg C. AU - Prather, Kimberly A. T2 - Physical Chemistry Chemical Physics AB - Atmospheric heterogeneous reactions can potentially change the hygroscopicity of atmospheric aerosols as they undergo chemical aging processes in the atmosphere. A particle’s hygroscopicity influences its cloud condensation nuclei (CCN) properties with potential impacts on cloud formation and climate. In this study, size-selected calcite mineral particles were reacted with controlled amounts of nitric acid vapour over a wide range of relative humidities in an aerosol flow tube to study the conversion of insoluble and thus apparently non-hygroscopic calcium carbonate into soluble and hygroscopic calcium nitrate. The rate of hygroscopic change particles undergo during a heterogeneous reaction is derived from experimental measurements for the first time. The chemistry of the reacted particles was determined using an ultrafine aerosol time-of-flight mass spectrometer (UF-ATOFMS) while the particles’ hygroscopicity was determined through measuring CCN activation curves fit to a single parameter of hygroscopicity, κ. The reaction is rapid, corresponding to atmospheric timescales of hours. At low to moderate HNO3 exposures, the increase in the hygroscopicity of the particles is a linear function of the HNO3(g) exposure. The experimentally observed conversion rate was used to constrain a simple but accurate kinetic model. This model predicts that calcite particles will be rapidly converted into hygroscopic particles (κ > 0.1) within 4 h for low HNO3 mixing ratios (10 pptv) and in less than 3 min for 1000 pptv HNO3. This suggests that the hygroscopic conversion of the calcite component of atmospheric mineral dust aerosol will be controlled by the availability of nitric acid and similar reactants, and not by the atmospheric residence time. DA - 2009/// PY - 2009/// DO - 10.1039/b904217b VL - 11 IS - 36 SP - 7826 J2 - Phys. Chem. Chem. Phys. LA - en OP - SN - 1463-9076 1463-9084 UR - http://dx.doi.org/10.1039/b904217b DB - Crossref ER - TY - JOUR TI - Relative roles of biogenic emissions and Saharan dust as ice nuclei in the Amazon basin AU - Prenni, Anthony J. AU - Petters, Markus D. AU - Kreidenweis, Sonia M. AU - Heald, Colette L. AU - Martin, Scot T. AU - Artaxo, Paulo AU - Garland, Rebecca M. AU - Wollny, Adam G. AU - Pöschl, Ulrich T2 - Nature Geoscience DA - 2009/5/3/ PY - 2009/5/3/ DO - 10.1038/ngeo517 VL - 2 IS - 6 SP - 402-405 J2 - Nature Geosci LA - en OP - SN - 1752-0894 1752-0908 UR - http://dx.doi.org/10.1038/ngeo517 DB - Crossref ER - TY - JOUR TI - Ice nucleation behavior of biomass combustion particles at cirrus temperatures AU - DeMott, Paul J. AU - Petters, Markus D. AU - Prenni, Anthony J. AU - Carrico, Christian M. AU - Kreidenweis, Sonia M. AU - Collett, Jeffrey L., Jr. AU - Moosmüller, Hans T2 - Journal of Geophysical Research AB - Measurements of ice formation by biomass combustion particles generated in controlled laboratory burns were made using a continuous flow diffusion chamber operating in the temperature range between −45 and −60°C. These measurements are the first of their kind to investigate the role that such particles may play in ice formation in upper tropospheric clouds. Measurements of aerosol water uptake were used to examine the role of hygroscopicity in low‐temperature ice nucleation by biomass combustion particles. Ice formation by the smoke particles at below −45°C and below water saturation followed the temperature and relative humidity dependencies predicted for water activity‐based homogeneous freezing within measurement uncertainties. As predicted, relative humidity dependence of homogeneous freezing fractions on hygroscopicity was weak in comparison with the temperature dependence for biomass particles of typical atmospheric sizes. The action of heterogeneous ice nucleation in or on these small smoke particles in the haze particle regime could not be distinguished within measurement uncertainties. Impedance of homogeneous freezing below −50°C was inferred for freezing higher number fractions of predominantly organic smoke particles separately reported to contain an abundance of large organic molecules, consistent with the recently predicted onset conditions for and impact of viscous or glassy aerosol phase states. Finally, we note that precision and accuracy requirements of instrumentation for resolving modest impacts (a few degrees less supercooling or a few percent lower relative humidity) of heterogeneous freezing, as compared with homogeneous freezing in the upper tropospheric temperature regime present difficulties for validating aerosol impacts on cirrus. DA - 2009/8/27/ PY - 2009/8/27/ DO - 10.1029/2009JD012036 VL - 114 IS - D16 J2 - J. Geophys. Res. LA - en OP - SN - 0148-0227 UR - http://dx.doi.org/10.1029/2009JD012036 DB - Crossref ER - TY - JOUR TI - Hygroscopicity and cloud droplet activation of mineral dust aerosol AU - Koehler, K. A. AU - Kreidenweis, S. M. AU - DeMott, P. J. AU - Petters, M. D. AU - Prenni, A. J. AU - Carrico, C. M. T2 - Geophysical Research Letters AB - Hygroscopicity and cloud condensation nucleus (CCN) activity were measured for three mineral dust samples: one from the Canary Islands, representing North African dust transported across the Atlantic; one from outside Cairo, representing North African dust transported to the eastern Mediterranean; and Arizona Test Dust, representing dust in the southwestern United States. To reaerosolize bulk samples, dust samples were either suspended in high purity water and particles generated by atomization, or samples were resuspended in dry air using a fluidized bed. Only the Canary Island sample generated from aqueous suspension showed appreciable hygroscopic growth at subsaturated conditions; all other samples exhibited diameter growth factors of less than 1.1 for relative humidities ≤90%. Despite their low hygroscopicities at subsaturated conditions, all samples activated as cloud droplets at supersaturations lower than required for insoluble particles. We suggest that the CCN activity of these mineral dusts are well‐represented using the hygroscopicity parameter 0.01 ≤ κ ≤ 0.08. DA - 2009/4/17/ PY - 2009/4/17/ DO - 10.1029/2009GL037348 VL - 36 IS - 8 J2 - Geophys. Res. Lett. LA - en OP - SN - 0094-8276 UR - http://dx.doi.org/10.1029/2009GL037348 DB - Crossref ER - TY - JOUR TI - Ice nuclei emissions from biomass burning AU - Petters, Markus D. AU - Parsons, Matthew T. AU - Prenni, Anthony J. AU - DeMott, Paul J. AU - Kreidenweis, Sonia M. AU - Carrico, Christian M. AU - Sullivan, Amy P. AU - McMeeking, Gavin R. AU - Levin, Ezra AU - Wold, Cyle E. AU - Collett, Jeffrey L., Jr. AU - Moosmüller, Hans T2 - Journal of Geophysical Research AB - [1] Biomass burning is a significant source of carbonaceous aerosol in many regions of the world. When present, biomass burning particles may affect the microphysical properties of clouds through their ability to function as cloud condensation nuclei or ice nuclei. We report on measurements of the ice nucleation ability of biomass burning particles performed on laboratory-generated aerosols at the second Fire Lab at Missoula Experiment. During the experiment we generated smoke through controlled burns of 21 biomass fuels from the United States and Asia. Using a Colorado State University continuous flow diffusion chamber, we measured the condensation/immersion freezing potential at temperatures relevant to cold cumulus clouds (−30°C). Smokes from 9 of the 21 fuels acted as ice nuclei at fractions of 1:10,000 to 1:100 particles in at least one burn of each fuel; emissions from the remaining fuels were below the ice nuclei detection limit for all burns of each fuel. Using a bottom-up emission model, we estimate that smokes that emit ice nuclei fractions exceeding 1:10,000 particles can perturb ice nuclei concentrations on a regional scale. DA - 2009/4/15/ PY - 2009/4/15/ DO - 10.1029/2008JD011532 VL - 114 IS - D7 J2 - J. Geophys. Res. LA - en OP - SN - 0148-0227 UR - http://dx.doi.org/10.1029/2008JD011532 DB - Crossref ER - TY - JOUR TI - Heterogeneous ice nucleation measurements of secondary organic aerosol generated from ozonolysis of alkenes AU - Prenni, Anthony J. AU - Petters, Markus D. AU - Faulhaber, Annelise AU - Carrico, Christian M. AU - Ziemann, Paul J. AU - Kreidenweis, Sonia M. AU - DeMott, Paul J. T2 - Geophysical Research Letters AB - Ice nuclei (IN) are those particles which catalyze ice nucleation in the atmosphere. Ambient measurements suggest that the main particle types that function as IN are metal oxides and dust. However, carbonaceous particles often are the next most abundant IN particle type, although the source and exact chemical compositions of these particles are unknown. Here we explore the ice nucleating ability of one potential source of carbonaceous IN to the atmosphere, secondary organic aerosol (SOA). We generated SOA by ozonolysis of 25 different organic precursors in the presence of an OH scavenger. For all experiments, ice nucleation was not observed in detectable quantities. We conclude that SOA generated from ozonolysis of alkenes is an unlikely source of IN to the atmosphere. DA - 2009/3/26/ PY - 2009/3/26/ DO - 10.1029/2008GL036957 VL - 36 IS - 6 J2 - Geophys. Res. Lett. LA - en OP - SN - 0094-8276 UR - http://dx.doi.org/10.1029/2008GL036957 DB - Crossref ER - TY - JOUR TI - Tracking toxins T2 - Nature Geoscience DA - 2009/3/31/ PY - 2009/3/31/ DO - 10.1038/NGEO488 VL - 2 IS - 4 SP - E5-E5 J2 - Nature Geosci LA - en OP - SN - 1752-0894 1752-0908 UR - http://dx.doi.org/10.1038/NGEO488 DB - Crossref ER - TY - JOUR TI - Rapid downward transport of the neurotoxin domoic acid in coastal waters AU - Sekula-Wood, Emily AU - Schnetzer, Astrid AU - Benitez-Nelson, Claudia R. AU - Anderson, Clarissa AU - Berelson, William M. AU - Brzezinski, Mark A. AU - Burns, Justina M. AU - Caron, David A. AU - Cetinic, Ivona AU - Ferry, John L. AU - Fitzpatrick, Elizabeth AU - Jones, Burton H. AU - Miller, Peter E. AU - Morton, Steve L. AU - Schaffner, Rebecca A. AU - Siegel, David A. AU - Thunell, Robert T2 - Nature Geoscience DA - 2009/3/22/ PY - 2009/3/22/ DO - 10.1038/ngeo472 VL - 2 IS - 4 SP - 272-275 J2 - Nature Geosci LA - en OP - SN - 1752-0894 1752-0908 UR - http://dx.doi.org/10.1038/ngeo472 DB - Crossref ER - TY - JOUR TI - Sources of gravity waves in the lower stratosphere above South Pole AU - Li, Z. AU - Robinson, W. AU - Liu, A. Z. T2 - Journal of Geophysical Research AB - Five‐year (2001–2005) high‐resolution radiosonde data were processed to obtain the gravity wave (GW) variabilities in the lower stratosphere over South Pole (SP). Our results show that GW activities in the lowermost section (10–15 km) are strongest in May and September and weakest in the austral summer, whereas in the altitude range of 15–25 km, strongest/weakest GW kinetic energy is observed around September/January. We also explored the relationships of GWs to the synoptic‐scale variations in the troposphere and the ageostrophic motions in the upper troposphere over the Antarctic, which are expected to be significant mechanisms for GW generation. A ray‐tracing model (GROGRAT) was used to explore the relationship between GW propagation and the background field. In the altitude of 15–25 km, the annual cycle of GW activity resembles that of adjustment process. Below 15 km, the annual cycle of GW activity has two peaks in May and September. Our analysis suggests that these two peaks are due to the variation of topographic GW generation and filtering of background atmosphere. Due to critical‐level filtering in the lowermost section, topographic GWs cannot propagate upward, which makes the shape of GW annual cycle at higher altitudes closer to the annual cycle of adjustment processes. The analysis suggests that the minimum of GW activity at SP during the austral summer may be due to the combination of weaker wave generation from adjustment processes associated with synoptic‐scale systems, flow over topography, and unfavorable background field for GW propagation. DA - 2009/7/22/ PY - 2009/7/22/ DO - 10.1029/2008JD011478 VL - 114 IS - D14 J2 - J. Geophys. Res. LA - en OP - SN - 0148-0227 UR - http://dx.doi.org/10.1029/2008JD011478 DB - Crossref ER - TY - JOUR TI - Downward influence of stratospheric final warming events in an idealized model AU - Sun, Lantao AU - Robinson, Walter A. T2 - Geophysical Research Letters AB - The stratospheric final warming is the final transition of the zonal winds from wintertime westerlies to summertime easterlies as solar heating of the high latitude stratosphere increases. Here the stratospheric influence on the tropospheric circulation during the stratospheric final warming events is investigated through ensemble model integrations of a simple dynamical core general circulation model. When the radiative equilibrium temperature in the stratosphere alone is gradually changed from a winter to a summer profile, the model generates realistic final warmings. As in the observations, the simulated final warmings occur at different “dates” in different realizations. Following previously published analyses of observed final warmings, we form a climatological springtime transition and compute composite anomalies centered on the final warmings. Simulations for both non‐topographic and topographic cases show that starting five days before the final warming, the stratospheric zonal wind rapidly decelerates, in association with a strong upward Eliassen‐Palm (EP) flux anomaly and EP flux convergence. Precursor events of wave driven zonal‐wind deceleration occur, but at different times in simulations with and without topography. The composite zonal wind anomalies for final warmings with and without topography are compared with each other and with observations. In both cases, a statistically significant zonal wind anomaly extends downward to the surface, similarly to what is observed in the Northern Hemisphere (NH). These tropospheric zonal wind anomalies are stronger in the simulations with topography. Tropospheric geopotential height anomalies across the final warming also resemble NH observations. DA - 2009/2// PY - 2009/2// DO - 10.1029/2008GL036624 VL - 36 IS - 3 SP - n/a-n/a J2 - Geophys. Res. Lett. LA - en OP - SN - 0094-8276 UR - http://dx.doi.org/10.1029/2008GL036624 DB - Crossref ER - TY - JOUR TI - WITHDRAWN: Dispersal and transformation of organic carbon across an episodic, high sediment discharge continental margin, Waipaoa Sedimentary System, New Zealand AU - Brackley, Hannah L. AU - Blair, Neal E. AU - Trustrum, Noel A. AU - Carter, Lionel AU - Leithold, Elana L. AU - Canuel, Elizabeth A. AU - Johnston, James H. AU - Tate, Kevin R. T2 - Marine Geology AB - The Publisher regrets that this article is an accidental duplication of an article that has already been published, doi: 10.1016/j.margeo.2009.11.001 . The duplicate article has therefore been withdrawn. DA - 2009/12// PY - 2009/12// DO - 10.1016/j.margeo.2009.11.008 J2 - Marine Geology LA - en OP - SN - 0025-3227 UR - http://dx.doi.org/10.1016/j.margeo.2009.11.008 DB - Crossref ER - TY - JOUR TI - Desalination technology waste streams: Effect of pH and salinity on metabolism of marine microbial assemblages AU - Montgomery, M.T. AU - Boyd, T.J. AU - Osburn, C.L. AU - Plummer, R.E. AU - Masutani, S.M. AU - Coffin, R.B. T2 - Desalination AB - Effluents from desalination technologies may influence natural bacterial assemblages due to changes in salinity, pH, dissolved organic carbon concentration (DOC), DOC quality and cellular hydrostatic pressure. Salinity, pH, and pressure change effects on heterotrophic bacterial production (as measured by leucine incorporation) were examined in experiments with surface water from the Delaware Bay, Atlantic Ocean and Pacific Ocean. Bacterial production decreased by 57–67% when salinity of Atlantic Ocean and Delaware Bay surface water samples were increased from ambient to 60 PSU. Decreasing ambient seawater pH from 8.0 to below 5.0 with CO2 gas reduced production by 96–100%. Decreasing seawater pH by 1.5 units at 33 PSU caused equivalent inhibition to increasing salinity by 27 PSU (pH 8.0). Bacterial production in Pacific Ocean surface water pressurized for 72 h was decreased 40% by increasing salinity, when measured 1 h after decompression. However, production increased 43% with increasing salinity when measured 24 h after decompression. One explanation for these divergent effects between the 1- and 24-h sampling at ambient pH may be community adaptation. Strains amongst the natural assemblage that survived the pressurization by saturating their membrane phospholipids would likely be better adapted to compete for available nutrients under elevated salinity. DA - 2009/12// PY - 2009/12// DO - 10.1016/j.desal.2009.03.018 VL - 249 IS - 2 SP - 861-864 J2 - Desalination LA - en OP - SN - 0011-9164 UR - http://dx.doi.org/10.1016/j.desal.2009.03.018 DB - Crossref KW - Hydrates KW - Bacterial production KW - pH KW - Salinity KW - Depressurization ER - TY - JOUR TI - Distribution, origin and cycling of carbon in the Tana River (Kenya): a dry season basin-scale survey from headwaters to the delta AU - Bouillon, S. AU - Abril, G. AU - Borges, A. V. AU - Dehairs, F. AU - Govers, G. AU - Hughes, H. J. AU - Merckx, R. AU - Meysman, F. J. R. AU - Nyunja, J. AU - Osburn, C. AU - Middelburg, J. J. T2 - Biogeosciences AB - Abstract. The Tana River basin (TRB) is the largest in Kenya (~120 000 km2). We conducted a survey during the dry season throughout the TRB, analyzing a broad suite of biogeochemical parameters. Biogeochemical signatures in headwater streams were highly variable. Along the middle and lower river course, total suspended matter (TSM) concentrations increased more than 30-fold despite the absence of tributary inputs, indicating important resuspension events of internally stored sediment. These resuspended sediment inputs were characterized by a lower and 14C-depleted OC content, suggesting selective degradation of more recent material during sediment retention. Masinga Dam (a large reservoir on the upper river) induced a strong nutrient retention (~50% for inorganic N, ~72% for inorganic phosphate, and ~40% for dissolved silicate). Moreover, while DOC pools and δ13C signatures were similar above, in and below the reservoir, the POC pool in Masinga surface waters was dominated by 13C-depleted phytoplankton, which contributed to the riverine POC pool immediately below the dam, but rapidly disappeared further downstream, suggesting rapid remineralization of this labile C pool in the river system. Despite the generally high turbidity, the combination of relatively high oxygen saturation levels, low δ18O signatures of dissolved O2 (all <+24.2‰), and the relatively low pCO2 values suggest that in-stream primary production was significant, even though pigment data suggest that phytoplankton makes only a minor contribution to the total POC pool in the Tana River. DA - 2009/11/5/ PY - 2009/11/5/ DO - 10.5194/bg-6-2475-2009 VL - 6 IS - 11 SP - 2475-2493 J2 - Biogeosciences LA - en OP - SN - 1726-4189 UR - http://dx.doi.org/10.5194/bg-6-2475-2009 DB - Crossref ER - TY - JOUR TI - Metagenomic potential of microbial assemblages in the surface waters of the central Pacific Ocean tracks variability in oceanic habitat AU - Hewson, Ian AU - Paerl, Ryan W. AU - Tripp, H. James AU - Zehr, Jonathan P. AU - Karl, David M. T2 - Limnology and Oceanography AB - Oceanic habitats may select for different organisms, thereby tuning genomic capabilities to local environmental conditions. To understand the relationship between microbial assemblage composition, functional capability, and habitat, a random genome shotgun sequencing (metagenomic) survey was conducted with surface‐water microbial assemblages (0.2–5‐µm size fraction) collected at seven locations along a meridional transect from the northern edge of the South Pacific subtropical gyre to the southern edge of the North Pacific subtropical gyre (16°S–13.5°N). A total of 1.1 million unique sequence reads were obtained, of which ~45% could be annotated to metabolic category. Microbial assemblages in equatorial divergence and countercurrent habitats were distinct phylogenetically from those in gyre waters. Ecotypes of dominant Cyanobacteria ( Prochlorococcus and Synechococcus ) had distinct distributions congruent with their physiological characteristics in cultivation. The metagenomic distribution of genes among metabolic pathways was very similar at all stations despite phylogenetic differences, but was unrelated to physicochemical habitat, suggesting that dominant microorganisms have a core suite of genes necessary for life in the open ocean. Among metabolic genes that varied across the transect, several patterns were observed. For example, phosphate (PO 4 3‐ ) stress response genes were more common in gyre waters than at the equator. The variability in frequency of several metabolic pathways (e.g., chlorophyll biosynthesis, PO 4 3‐ metabolism, and transcription initiation bacterial sigma factors) was related to physicochemical conditions, most of which were related to taxonomic differences among habitats. Microbial communities in the central Pacific Ocean are phylogenetically distinct to the oceanic provinces which they inhabit. DA - 2009/8/27/ PY - 2009/8/27/ DO - 10.4319/lo.2009.54.6.1981 VL - 54 IS - 6 SP - 1981-1994 J2 - Limnol. Oceanogr. LA - en OP - SN - 0024-3590 UR - http://dx.doi.org/10.4319/lo.2009.54.6.1981 DB - Crossref ER - TY - JOUR TI - In situ transcriptomic analysis of the globally important keystone N2-fixing taxon Crocosphaera watsonii AU - Hewson, Ian AU - Poretsky, Rachel S AU - Beinart, Roxanne A AU - White, Angelicque E AU - Shi, Tuo AU - Bench, Shellie R AU - Moisander, Pia H AU - Paerl, Ryan W AU - Tripp, H James AU - Montoya, Joseph P AU - Moran, Mary Ann AU - Zehr, Jonathan P T2 - The ISME Journal AB - The diazotrophic cyanobacterium Crocosphaera watsonii supplies fixed nitrogen (N) to N-depleted surface waters of the tropical oceans, but the factors that determine its distribution and contribution to global N(2) fixation are not well constrained for natural populations. Despite the heterogeneity of the marine environment, the genome of C. watsonii is highly conserved in nucleotide sequence in contrast to sympatric planktonic cyanobacteria. We applied a whole assemblage shotgun transcript sequencing approach to samples collected from a bloom of C. watsonii observed in the South Pacific to understand the genomic mechanisms that may lead to high population densities. We obtained 999 C. watsonii transcript reads from two metatranscriptomes prepared from mixed assemblage RNA collected in the day and at night. The C. watsonii population had unexpectedly high transcription of hypothetical protein genes (31% of protein-encoding genes) and transposases (12%). Furthermore, genes were expressed that are necessary for living in the oligotrophic ocean, including the nitrogenase cluster and the iron-stress-induced protein A (isiA) that functions to protect photosystem I from high-light-induced damage. C. watsonii transcripts retrieved from metatranscriptomes at other locations in the southwest Pacific Ocean, station ALOHA and the equatorial Atlantic Ocean were similar in composition to those recovered in the enriched population. Quantitative PCR and quantitative reverse transcriptase PCR were used to confirm the high expression of these genes within the bloom, but transcription patterns varied at shallower and deeper horizons. These data represent the first transcript study of a rare individual microorganism in situ and provide insight into the mechanisms of genome diversification and the ecophysiology of natural populations of keystone organisms that are important in global nitrogen cycling. DA - 2009/2/19/ PY - 2009/2/19/ DO - 10.1038/ismej.2009.8 VL - 3 IS - 5 SP - 618-631 J2 - ISME J LA - en OP - SN - 1751-7362 1751-7370 UR - http://dx.doi.org/10.1038/ismej.2009.8 DB - Crossref KW - metatranscriptome KW - Crocosphaera KW - gene expression KW - transposase KW - diazotroph KW - oligotrophic ER - TY - JOUR TI - Phytoplankton productivity across prairie saline lakes of the Great Plains (USA): a step toward deciphering patterns through lake classification models AU - Prairie, Yves AU - Salm, Courtney R. AU - Saros, Jasmine E. AU - Fritz, Sherilyn C. AU - Osburn, Christopher L. AU - Reineke, David M. T2 - Can. J. Fish. Aquat. Sci. AB - We investigated patterns of primary production across prairie saline lakes in the central and northern Great Plains of the United States. Based on comparative lake sampling in 2004, seasonal predictors of algal primary productivity were identified within subsets of similar lakes using a combination of Akaike’s information criterion (AIC) and classification and regression trees (CART). These models indicated complex patterns of nutrient limitation by nitrogen (N), phosphorus (P), and iron (Fe) within different lake groups. Nutrient enrichment assays (control, + Fe, + N, + P, + N + P) were performed in spring and summer of 2006 to determine if phytoplankton in selected lakes followed predicted patterns of nutrient limitation. Both the comparative lake sampling and experimental results indicated that N limitation was widespread in these prairie lakes, with evidence for secondary P limitation in certain lakes. In the experiments, iron did not stimulate primary production. Our results suggest that given the diverse geochemical nature of these lakes, classification models that separate saline lakes into subsets may be an effective method for improving predictions of algal production. DA - 2009/9// PY - 2009/9// DO - 10.1139/f09-083 VL - 66 IS - 9 SP - 1435-1448 ER - TY - JOUR TI - PAH mineralization and bacterial organotolerance in surface sediments of the Charleston Harbor estuary AU - Montgomery, Michael T. AU - Boyd, Thomas J. AU - Osburn, Christopher L. AU - Smith, David C. T2 - Biodegradation AB - Semi-volatile organic compounds (SVOCs) in estuarine waters can adversely affect biota but watershed sources can be difficult to identify because these compounds are transient. Natural bacterial assemblages may respond to chronic, episodic exposure to SVOCs through selection of more organotolerant bacterial communities. We measured bacterial production, organotolerance and polycyclic aromatic hydrocarbon (PAH) mineralization in Charleston Harbor and compared surface sediment from stations near a known, permitted SVOC outfall (pulp mill effluent) to that from more pristine stations. Naphthalene additions inhibited an average of 77% of bacterial metabolism in sediments from the more pristine site (Wando River). Production in sediments nearest the outfall was only inhibited an average of 9% and in some cases, was actually stimulated. In general, the stations with the highest rates of bacterial production also were among those with the highest rates of PAH mineralization. This suggests that the capacity to mineralize PAH carbon is a common feature amongst the bacterial assemblage in these estuarine sediments and could account for an average of 5.6% of bacterial carbon demand (in terms of production) in the summer, 3.3% in the spring (April) and only 1.2% in winter (December). DA - 2009/9/17/ PY - 2009/9/17/ DO - 10.1007/s10532-009-9298-3 VL - 21 IS - 2 SP - 257-266 J2 - Biodegradation LA - en OP - SN - 0923-9820 1572-9729 UR - http://dx.doi.org/10.1007/s10532-009-9298-3 DB - Crossref KW - Naphthalene KW - Organotolerance KW - Bacterial production KW - SVOC KW - PAH mineralization ER - TY - CONF TI - New spatial measures of terrain dynamics derived from time series of lidar data AU - Mitasova, H. AU - Hardin, E. AU - Overton, M. AU - Harmon, R.S. AB - We anticipate that multiyear lidar surveys, currently focused on vulnerable coastal areas, will soon become a common resource for monitoring and analysis of various aspects of regional terrain change. We propose raster based measures for mapping and quantification of discrete and continuous terrain changes by introducing novel concepts, such as core and envelope surfaces, contour evolution band, and evolution regression slope map that can provide insights into the spatial aspects of terrain dynamics and changes in structures. The methodology is applied to a section of North Carolina coast where multiyear time series of lidar data is already available. Dynamics of bare dune and beach systems, changes in structures and vegetation growth are mapped and quantified to evaluate the proposed approach. C2 - 2009/// C3 - 2009 17th International Conference on Geoinformatics, Geoinformatics 2009 DA - 2009/// DO - 10.1109/GEOINFORMATICS.2009.5293539 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-74349107746&partnerID=MN8TOARS ER - TY - CONF TI - Geospatial time series analysis of volumetric change AU - Overton, M. AU - Mitasova, H. AU - Recalde, J.J. C2 - 2009/// C3 - Proceedings of the Coastal Engineering Conference DA - 2009/// SP - 2099-2109 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84873813560&partnerID=MN8TOARS ER - TY - BOOK TI - Geomorphometry in GRASS GIS AU - Hofierka, J. AU - Mitásová, H. AU - Neteler, M. AB - Geographic Resources Analysis Support System (GRASS) is a general-purpose geographic information system (GIS) for the management, processing, analysis, modeling, and visualization of many types of georeferenced data. This chapter is based on GRASS 6.2 version available for all commonly used operating systems. It includes 2D raster and 3D voxel data support, a new topological 2D/3D vector engine and capabilities for vector network analysis. Attributes are managed in a SQL-based DBMS. Advances in mapping technologies, especially the rapid evolution of airborne and ground-based laser scanning, as well as satellite and airborne radar interferometry are bringing significant changes to geomorphic analysis. The point densities exceed the level of detail required for most applications and digital elevation models (DEMs) with resolutions of 3 m and better are becoming common even for large areas. The high mapping efficiency makes repeated mapping at relatively short time intervals feasible, resulting in multi-temporal DEMs. These developments require new concepts and approaches in geomorphometry. In response, GRASS modules are being further enhanced to accommodate very large data sets produced by the new mapping technologies; new tools are added for efficient handling of very dense elevation or bathymetry data, hierarchical watershed analysis and quantification of land-surface change. DA - 2009/// PY - 2009/// DO - 10.1016/S0166-2481(08)00017-2 VL - 33 SE - 387-410 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-77955792959&partnerID=MN8TOARS ER - TY - JOUR TI - Seismic tremor at the 9 degrees 50 ' N East Pacific Rise eruption site AU - Monigle, P. W. AU - Bohnenstiehl, D. R. AU - Tolstoy, M. AU - Waldhauser, F. T2 - GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS AB - Ocean bottom seismic observations within the 9°50′N region of the East Pacific Rise indicate persistent, low‐amplitude tremor activity throughout the October 2003 through February 2007 period of monitoring. These signals exhibit either monochromatic or polychromatic spectral characteristics, with a ∼6 Hz fundamental frequency and up to two harmonics. Individual events cannot be correlated between nearby (<1 km) stations, implying the presence of multiple, small‐amplitude sources positioned within the shallow crust. Tremor exhibits a semidiurnal periodicity, with some stations recording activity during times of increasing tidal extension and others detecting tremor signals during times of increasing compression. The amplitude, duration, and rate of activity also correlate positively with fortnightly changes in the amplitude of the tides. These spatiotemporal patterns are consistent with tremor generation in response to tidally modulated fluid flow within a network of shallow cracks. Tremor energy flux is spatially and temporally heterogeneous; however, there are extended periods of greater and lesser activity that can be tracked across portions of the array. Despite their shallow crustal origin, changes in tremor amplitude and spectral character occur in the months prior to a major microearthquake swarm and inferred seafloor spreading event on 22 January 2006, with an increase in the degree of correlation between tremor activity and tidal strain in the weeks leading up to this event. After the spreading event, two eruption‐surviving stations near the axis continue to show high rates of tremor activity, whereas these signals are suppressed at the single station recovered from the near‐axis flanks. This off‐axis quiescence may result from the dike‐induced closing of cracks or perhaps from the emplacement of impermeable flows near the station. DA - 2009/11/20/ PY - 2009/11/20/ DO - 10.1029/2009gc002561 VL - 10 SP - SN - 1525-2027 KW - seismic tremor KW - East Pacific Rise KW - tidal influences KW - volcanic eruption ER - TY - JOUR TI - Cloud condensation nucleation activity of biomass burning aerosol AU - Petters, Markus D. AU - Carrico, Christian M. AU - Kreidenweis, Sonia M. AU - Prenni, Anthony J. AU - DeMott, Paul J. AU - Collett, Jeffrey L., Jr. AU - Moosmüller, Hans T2 - Journal of Geophysical Research AB - We examine the hygroscopic properties of particles freshly emitted from laboratory biomass burning experiments conducted during the second Fire Lab At Missoula Experiment (FLAME‐II). Values of the hygroscopicity parameter, kappa, were derived from both hygroscopic growth measurements and size‐resolved (30–300 nm in diameter) cloud condensation nuclei (CCN) measurements for smokes emitted by the open combustion of 24 biomass fuels from the United States and Asia. To analyze the complex cloud condensation nuclei response curves we propose a new inversion scheme that corrects for multiple charge effects without the necessity of prior assumptions about the chemical composition and mixing state of the particles. Kappa varied between 0.02 (weakly hygroscopic) and 0.8 (highly hygroscopic). For individual smokes, kappa was a function of particle size, with 250 nm particles being generally weakly hygroscopic and sub‐100 nm particles being more hygroscopic. At any given size the emissions were often externally mixed, showing more and less hygroscopic growth modes and bimodal CCN activation spectra. Comparisons between growth factor‐derived and CCN‐derived hygroscopicities were consistent when taking this heterogeneity into account. A conceptual model of biomass burning emissions suggests that most particles are CCN active at the point of emission and do not require conversion in the atmosphere to more hygroscopic compositions before they can participate in cloud formation and undergo wet deposition. DA - 2009/11/21/ PY - 2009/11/21/ DO - 10.1029/2009JD012353 VL - 114 IS - D22 J2 - J. Geophys. Res. LA - en OP - SN - 0148-0227 UR - http://dx.doi.org/10.1029/2009JD012353 DB - Crossref ER - TY - JOUR TI - Yangtze- and Taiwan-derived sediments on the inner shelf of East China Sea AU - Xu, Kehui AU - Milliman, John D. AU - Li, Anchun AU - Paul Liu, J. AU - Kao, Shuh-Ji AU - Wan, Shiming T2 - Continental Shelf Research AB - X-ray diffraction (XRD) mineralogical and grain-size analyses indicate that inner continental shelf sediments in the East China Sea (ECS) represent a unique mixing of clays derived from the Yangtze River and silts/sands from small western Taiwanese rivers. Taiwanese (e.g., Choshui) clays (<2 μm) display no smectite but the best illite crystallinity and are only distributed along southeastern Taiwan Strait. Both Yangtze and Taiwanese river clays are illite-dominated, but the poor illite crystallinity and the presence of smectite and kaolinite indicate that Taiwan Strait clays are mainly Yangtze-dominated. In contrast, medium silts (20–35 μm) and very fine sands (63–90 μm) in the Taiwan Strait are characterized by low feldspar/quartz, low K-feldspar/plagioclase and high kaolinite/quartz, indicating their provenance from Taiwanese rivers. Taiwanese silts and sands are introduced primarily by the way of typhoon-derived floods and transported northward by the Taiwan Warm Current during summer–fall months. Yangtze clays, in contrast, are widely dispersed southward about 1000 km to the western Taiwan Strait, transported by the China Coastal Current during winter–spring months. Since most Taiwan Strait samples were collected in May 2006, clay results in this paper might only represent the winter–spring pattern of the dispersal of Yangtze sediments. DA - 2009/10// PY - 2009/10// DO - 10.1016/j.csr.2009.08.017 VL - 29 IS - 18 SP - 2240-2256 J2 - Continental Shelf Research LA - en OP - SN - 0278-4343 UR - http://dx.doi.org/10.1016/j.csr.2009.08.017 DB - Crossref KW - Sediment KW - Clay KW - Mineralogy KW - Yangtze River KW - East China Sea KW - Taiwan ER - TY - JOUR TI - Using air quality modeling to study source-receptor relationships between nitrogen oxides emissions and ozone exposures over the United States AU - Tong, Daniel Q. AU - Muller, Nicholas Z. AU - Kan, Haidong AU - Mendelsohn, Robert O. T2 - ENVIRONMENT INTERNATIONAL AB - Human exposure to ambient ozone (O(3)) has been linked to a variety of adverse health effects. The ozone level at a location is contributed by local production, regional transport, and background ozone. This study combines detailed emission inventory, air quality modeling, and census data to investigate the source-receptor relationships between nitrogen oxides (NO(x)) emissions and population exposure to ambient O(3) in 48 states over the continental United States. By removing NO(x) emissions from each state one at a time, we calculate the change in O(3) exposures by examining the difference between the base and the sensitivity simulations. Based on the 49 simulations, we construct state-level and census region-level source-receptor matrices describing the relationships among these states/regions. We find that, for 43 receptor states, cumulative NO(x) emissions from upwind states contribute more to O(3) exposures than the state's own emissions. In-state emissions are responsible for less than 15% of O(3) exposures in 90% of U.S. states. A state's NO(x) emissions can influence 2 to 40 downwind states by at least a 0.1 ppbv change in population-averaged O(3) exposure. The results suggest that the U.S. generally needs a regional strategy to effectively reduce O(3) exposures. But the current regional emission control program in the U.S. is a cap-and-trade program that assumes the marginal damage of every ton of NO(x) is equal. In this study, the average O(3) exposures caused by one ton of NO(x) emissions ranges from -2.0 to 2.3 ppm-people-hours depending on the state. The actual damage caused by one ton of NO(x) emissions varies considerably over space. DA - 2009/11// PY - 2009/11// DO - 10.1016/j.envint.2009.06.008 VL - 35 IS - 8 SP - 1109-1117 SN - 1873-6750 KW - Ozone exposure KW - Exposure modeling KW - Source-receptor KW - Transboundary transport KW - CMAQ KW - Cap and trade ER - TY - JOUR TI - Statistical validation of a 3-D bio-physical model of the western North Atlantic AU - Lehmann, M. K. AU - Fennel, K. AU - He, R. T2 - BIOGEOSCIENCES AB - Abstract. High-resolution, physical-biological models of coastal and shelf regions typically use a single functional phytoplankton group, which limits their ability to represent ecological gradients (e.g. highly productive shelf systems adjacent to oligotrophic regions), as these are dominated by different functional phytoplankton groups. We implemented a size-structured ecosystem model in a high-resolution, regional circulation model of the northeast North American shelf and adjacent deep ocean in order to assess whether the added functional complexity of two functional phytoplankton groups improves the model's ability to represent surface chlorophyll concentrations along an ecological gradient encompassing five distinct regions. We used satellite-derived SST and sea-surface chlorophyll for our model assessment, as these allow investigation of spatial variability and temporal variations from monthly to interannual, and analyzed three complimentary statistical measures of model-data agreement: model bias, root mean square error and model efficiency (or skill). All three measures were integrated for the whole domain, for distinct subregions and were calculated in a spatially explicit manner. Comparison with a previously published simulation that used a model with a single phytoplankton functional group indicates that the inclusion of an additional phytoplankton group representing picoplankton markedly improves the model's skill. DA - 2009/// PY - 2009/// DO - 10.5194/bg-6-1961-2009 VL - 6 IS - 10 SP - 1961-1974 SN - 1726-4189 ER - TY - JOUR TI - Role of molecular size in cloud droplet activation AU - Petters, M. D. AU - Kreidenweis, S. M. AU - Prenni, A. J. AU - Sullivan, R. C. AU - Carrico, C. M. AU - Koehler, K. A. AU - Ziemann, P. J. T2 - Geophysical Research Letters AB - We examine the observed relationships between molar volume (the ratio of molar mass and density) and cloud condensation nuclei (CCN) activity for sufficiently soluble organic compounds found in atmospheric particulate matter. Our data compilation includes new CCN data for certain carbohydrates and oligoethylene glycols, as well as published data for organic compounds. We compare predictions of CCN activity using water activities based on Raoult's law and Flory‐Huggins theory to observations. The Flory‐Huggins water activity expression, with an assumed surface tension of pure water, generally predicts CCN activity within a factor of two over the full range of molar volumes considered. CCN activity is only weakly dependent on molar volume for values exceeding 600 cm 3 mol −1 , and the diminishing sensitivity to molar volume, combined with the significant scatter in the data, limits the accuracy with which molar volume can be inferred from CCN measurements. DA - 2009/11/17/ PY - 2009/11/17/ DO - 10.1029/2009GL040131 VL - 36 IS - 22 J2 - Geophys. Res. Lett. LA - en OP - SN - 0094-8276 UR - http://dx.doi.org/10.1029/2009GL040131 DB - Crossref ER - TY - JOUR TI - Probing into regional ozone and particulate matter pollution in the United States: 1. A 1 year CMAQ simulation and evaluation using surface and satellite data AU - Zhang, Y. AU - Vijayaraghavan, K. AU - Wen, X. Y. AU - Snell, H. E. AU - Jacobson, M. Z. T2 - Journal of Geophysical Research. Atmospheres (Online) DA - 2009/// PY - 2009/// VL - 114 ER - TY - JOUR TI - Probing into regional O3and particulate matter pollution in the United States: 2. An examination of formation mechanisms through a process analysis technique and sensitivity study AU - Zhang, Yang AU - Wen, Xin-Yu AU - Wang, Kai AU - Vijayaraghavan, Krish AU - Jacobson, Mark Z. T2 - Journal of Geophysical Research AB - Following a comprehensive model evaluation in part 1, this part 2 paper describes results from 1 year process analysis and a number of sensitivity simulations using the Community Multiscale Air Quality (CMAQ) modeling system aimed to understand the formation mechanisms of O 3 and PM 2.5 , their impacts on global environment, and implications for pollution control policies. Process analyses show that the most influential processes for O 3 in the planetary boundary layer (PBL) are vertical and horizontal transport, gas‐phase chemistry, and dry deposition and those for PM 2.5 are primary PM emissions, horizontal transport, PM processes, and cloud processes. Exports of O 3 and O x from the U.S. PBL to free troposphere occur primarily in summer and at a rate of 0.16 and 0.65 Gmoles day −1 , respectively. In contrast, export of PM 2.5 is found to occur during all seasons and at rates of 25.68–34.18 Ggrams day −1 , indicating a need to monitor and control PM 2.5 throughout the year. Among nine photochemical indicators examined, the most robust include PH 2 O 2 /PHNO 3 , HCHO/NO y , and HCHO/NO z in winter and summer, H 2 O 2 /(O 3 + NO 2 ) in winter, and NO y in summer. They indicate a VOC‐limited O 3 chemistry in most areas in winter, but a NO x ‐limited O 3 chemistry in most areas except for major cities in April–November, providing a rationale for nationwide NO x emission control and integrated control of NO x and VOCs emissions for large cities during high O 3 seasons (May–September). For sensitivity of PM 2.5 to its precursors, the adjusted gas ratio provides a more robust indicator than that without adjustment, especially for areas with insufficient sulfate neutralization in winter. NH 4 NO 3 can be formed in most of the domain. Integrated control of emissions of PM precursors such as SO 2 , NO x , and NH 3 are necessary for PM 2.5 attainment. Among four types of VOCs examined, O 3 formation is primarily affected by isoprene and low molecular weight anthropogenic VOCs, and PM 2.5 formation is affected largely by terpenes and isoprene. Under future emission scenarios, surface O 3 may increase in summer; surface PM 2.5 may increase or decrease. With 0.71°C increase in future surface temperatures in summer, surface O 3 may increase in most of the domain and surface PM 2.5 may decrease in the eastern U.S. but increase in the western U.S. DA - 2009/11/25/ PY - 2009/11/25/ DO - 10.1029/2009JD011900 VL - 114 IS - D22 J2 - J. Geophys. Res. LA - en OP - SN - 0148-0227 UR - http://dx.doi.org/10.1029/2009JD011900 DB - Crossref ER - TY - JOUR TI - Investigation of the 2006 Alexandrium fundyense bloom in the Gulf of Maine: In-situ observations and numerical modeling AU - Li, Yizhen AU - He, Ruoying AU - McGillicuddy, Dennis J., Jr. AU - Anderson, Donald M. AU - Keafer, Bruce A. T2 - CONTINENTAL SHELF RESEARCH AB - In-situ observations and a coupled bio-physical model were used to study the germination, initiation, and development of the Gulf of Maine (GOM) Alexandrium fundyense bloom in 2006. Hydrographic measurements and comparisons with GOM climatology indicate that 2006 was a year with normal coastal water temperature, salinity, current and river runoff conditions. A. fundyense cyst abundance in bottom sediments preceding the 2006 bloom was at a moderate level compared to other recent annual cyst survey data. We used the coupled bio-physical model to hindcast coastal circulation and A. fundyense cell concentrations. Field data including water temperature, salinity, velocity time series and surface A. fundyense cell concentration maps were applied to gauge the model's fidelity. The coupled model is capable of reproducing the hydrodynamics and the temporal and spatial distributions of A. fundyense cell concentration reasonably well. Model hindcast solutions were further used to diagnose physical and biological factors controlling the bloom dynamics. Surface wind fields modulated the bloom's horizontal and vertical distribution. The initial cyst distribution was found to be the dominant factor affecting the severity and the interannual variability of the A. fundyense bloom. Initial cyst abundance for the 2006 bloom was about 50% of that prior to the 2005 bloom. As the result, the time-averaged gulf-wide cell concentration in 2006 was also only about 60% of that in 2005. In addition, weaker alongshore currents and episodic upwelling-favorable winds in 2006 reduced the spatial extent of the bloom as compared with 2005. DA - 2009/9/30/ PY - 2009/9/30/ DO - 10.1016/j.csr.2009.07.012 VL - 29 IS - 17 SP - 2069-2082 SN - 1873-6955 KW - Harmful algal bloom KW - Coastal circulation KW - Gulf of Maine KW - Bio-physical interaction ER - TY - JOUR TI - Transition to superparamagnetism in chains of magnetosome crystals AU - Newell, A. J. T2 - GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS AB - Magnetotactic bacteria use chains of magnetic crystals to orient them in the Earth's field. Magnetic measurements show that these chains are in a single‐domain state with all the moments pointing along the chain axis. Yet many of the crystals in the chains fall in either the multidomain (MD) or the superparamagnetic (SP) size range for isolated crystals. Magnetostatic coupling between crystals keeps the magnetization uniform and prevents thermally assisted transitions between states. The SP critical size for a chain of magnetite crystals is calculated using a new algorithm. The network of stable states and transition states connecting them is determined using a homotopy continuation method. This determines the energy barriers between stable states, and the critical size can then be calculated using a master equation. As the number of crystals in the chain increases, the SP critical volume approaches a limit that is nearly independent of the shape of the crystals. The cube root of this volume is about 10 nm. Most magnetosome crystal sizes are well above this limit. About half of the magnetosome crystals found in sediments would be MD in isolation. However, there is also a population of cubo‐octahedral crystals, a large fraction of which would be SP in isolation. Such crystals are also formed in fresh water by bacteria in the genus Magnetospirillum . The difference in size and shape between the populations of isometric and nonisometric crystals may be related to redox conditions and the choice of magnetoaerotaxis mechanism. DA - 2009/11/3/ PY - 2009/11/3/ DO - 10.1029/2009gc002538 VL - 10 SP - SN - 1525-2027 KW - magnetotactic KW - superparamagnetic KW - single-domain KW - bacteria KW - magnetostatic KW - chain ER - TY - JOUR TI - Environmental and Physiological Controls of Blue Crab Avoidance Behavior During Exposure to Hypoxia AU - Bell, Geoffrey W. AU - Eggleston, David B. AU - Noga, Edward J. T2 - BIOLOGICAL BULLETIN AB - Generalizing the impacts of hypoxia on aquatic animal populations is difficult due to differences in behavioral and physiological responses among individuals as well as varying hydrodynamics of hypoxic events. Information on which environmental cues animals use to avoid hypoxia and how abiotic covariates and physiology influence avoidance behavior is lacking. Our laboratory flume studies quantified the interacting effects of hydrography (dissolved oxygen [DO], temperature, and salinity), hydrodynamics (rate of DO decline and current speed), and physiological state on avoidance behaviors of blue crabs (Callinectes sapidus). Changes in DO stimulated increased rates of movement, regardless of whether the change resulted in hypoxia. Increased rates of DO decline stimulated faster movement rates under hypoxic conditions because crabs spent less time in hypoxia compared to crabs under conditions of slow rate of DO decline. Blue crabs that had hemocyanin structures with a high affinity for O2 (hypoxia-tolerant) were less active under hypoxic conditions than conspecifics with hemocyanins with a low O2 affinity, suggesting that physiological state influences behavioral responses to stressors. These results provide a mechanistic understanding of how physiological acclimation and hypoxia hydrodynamics may influence population dynamics. DA - 2009/10// PY - 2009/10// DO - 10.1086/bblv217n2p161 VL - 217 IS - 2 SP - 161-172 SN - 1939-8697 ER - TY - JOUR TI - Significance of New Ediacaran Fossils and U-Pb Zircon Ages from the Albemarle Group, Carolina Terrane of North Carolina AU - Hibbard, James P. AU - Pollock, Jeffrey C. AU - Brennan, Matt AU - Samson, Scott D. AU - Secor, Don T2 - JOURNAL OF GEOLOGY AB - The Albemarle Group is one of the major defining stratigraphic units of the Carolina terrane, the best‐known division of the southern Appalachian peri‐Gondwanan block of Carolinia. As such, the group is a significant factor in the correlation of Carolinia with other peri‐Gondwanan blocks both in the Appalachians and globally. The traditionally held Ediacaran age of the group has been in question for more than a decade because of a report of Late Cambrian and younger fossils from two quarries in the group. The fossil report led to a major revision of the stratigraphy and structural reinterpretation of the Carolina terrane. Our recent studies have focused on the stratigraphy, paleontology, and geochronology of the Cid Formation in the vicinity of one of the reported Paleozoic fossil locales. Contrary to the structural reinterpretation of the Albemarle Group, Cid mudstone is shown to be in conformable and gradational contact with Flat Swamp felsic volcanics of the Cid Formation; we have obtained a precise U‐Pb zircon age of $$547\pm 2$$ Ma for the volcanics at a nearby locality. We also recovered the Ediacaran fossil Aspidella from the Cid mudstone. In conjunction with the new stratigraphic and geochronological data, the new fossil find leads us to consider the Cid Formation to be Ediacaran. These new data support a mainly Neoproterozoic age for the lower half of the Albemarle Group, indicating that major stratigraphic and structural revisions of the Carolina terrane based on the supposed Paleozoic fossils are unwarranted. Confirmation of the stratigraphy of the Albemarle Group has a bearing on the correlation of Carolinia with other peri‐Gondwanan crustal blocks in the Appalachian Orogen. DA - 2009/9// PY - 2009/9// DO - 10.1086/600863 VL - 117 IS - 5 SP - 487-498 SN - 1537-5269 ER - TY - JOUR TI - Regionalization of Climate Change Simulations over the Eastern Mediterranean AU - Oenol, Baris AU - Semazzi, Fredrick H. M. T2 - JOURNAL OF CLIMATE AB - Abstract In this study, the potential role of global warming in modulating the future climate over the eastern Mediterranean (EM) region has been investigated. The primary vehicle of this investigation is the Abdus Salam International Centre for Theoretical Physics Regional Climate Model version 3 (ICTP-RegCM3), which was used to downscale the present and future climate scenario simulations generated by the NASA’s finite-volume GCM (fvGCM). The present-day (1961–90; RF) simulations and the future climate change projections (2071–2100; A2) are based on the Intergovernmental Panel on Climate Change (IPCC) greenhouse gas (GHG) emissions. During the Northern Hemispheric winter season, the general increase in precipitation over the northern sector of the EM region is present both in the fvGCM and RegCM3 model simulations. The regional model simulations reveal a significant increase (10%–50%) in winter precipitation over the Carpathian Mountains and along the east coast of the Black Sea, over the Kackar Mountains, and over the Caucasus Mountains. The large decrease in precipitation over the southeastern Turkey region that recharges the Euphrates and Tigris River basins could become a major source of concern for the countries downstream of this region. The model results also indicate that the autumn rains, which are primarily confined over Turkey for the current climate, will expand into Syria and Iraq in the future, which is consistent with the corresponding changes in the circulation pattern. The climate change over EM tends to manifest itself in terms of the modulation of North Atlantic Oscillation. During summer, temperature increase is as large as 7°C over the Balkan countries while changes for the rest of the region are in the range of 3°–4°C. Overall the temperature increase in summer is much greater than the corresponding changes during winter. Presentation of the climate change projections in terms of individual country averages is highly advantageous for the practical interpretation of the results. The consistence of the country averages for the RF RegCM3 projections with the corresponding averaged station data is compelling evidence of the added value of regional climate model downscaling. DA - 2009/4// PY - 2009/4// DO - 10.1175/2008JCLI1807.1 VL - 22 IS - 8 SP - 1944-1961 SN - 1520-0442 ER - TY - JOUR TI - January 2006 seafloor-spreading event at 9 degrees 50 ' N, East Pacific Rise: Ridge dike intrusion and transform fault interactions from regional hydroacoustic AU - Dziak, Robert P. AU - Bohnenstiehl, Delwayne R. AU - Matsumoto, Haruyoshi AU - Fowler, Matthew J. AU - Haxel, Joseph H. AU - Tolstoy, Maya AU - Waldhauser, Felix T2 - GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS AB - An array of autonomous underwater hydrophones is used to investigate regional seismicity associated with the 22 January 2006 seafloor‐spreading event on the northern East Pacific Rise near 9°50′N. Significant earthquake activity was observed beginning 3 weeks prior to the eruption, where a total of 255 earthquakes were detected within the vicinity of the 9°50′N area. This was followed by a series of 252 events on 22 January and a rapid decline to background seismicity levels during the subsequent 3 days. Because of their small magnitudes, accurate locations could be derived for only 20 of these events, 18 of which occurred during a 1‐h period on 22 January. These earthquakes cluster near 9°45′N and 9°55′N, at the distal ends of the young lava flows identified posteruption, where the activity displays a distinct spatial‐temporal pattern, alternating from the north to the south and then back to the north. This implies either rapid bilateral propagation along the rift or the near‐simultaneous injection of melt vertically from the axial magma lens. Short‐duration T wave risetimes are consistent with the eruption of lavas in the vicinity of 9°50′N on 22 January 2006. Eruptions on 12 and 15–16 January also may be inferred from the risetime data; however, the locations of these smaller‐magnitude events cannot be determined accurately. Roughly 15 h after the last earthquakes were located adjacent to the eruption site, a sequence of 16 earthquakes began to the north‐northeast at a distance of 25–40 km from the 9°50′N site. These events are located in vicinity of the Clipperton Transform and its western inside corner, an area from which the regional hydrophone network routinely detects seismicity. Coulomb stress modeling indicates that a dike intrusion spanning the known eruptive zone to the south (9°46′–9°56′N) would act to promote normal faulting or a combination of normal faulting and transform slip within this region, with stress changes on the order of 1–10 kPa. DA - 2009/6/18/ PY - 2009/6/18/ DO - 10.1029/2009gc002388 VL - 10 SP - SN - 1525-2027 KW - mid-ocean ridge KW - fast spreading KW - earthquakes KW - magma intrusion KW - hydroacoustics KW - hydrophone ER - TY - JOUR TI - INTERTOOTH VARIATION OF ORTHODENTINE MICROWEAR IN ARMADILLOS (CINGULATA) AND TREE SLOTHS (PILOSA) AU - Green, Jeremy L. T2 - JOURNAL OF MAMMALOGY AB - The analysis of orthodentine microwear has recently been established as a proxy for diet in extant and fossil xenarthrans (sloths, armadillos, and their extinct relatives). Previous analyses have relied on standardized comparison of sampling locations between taxa in order to statistically correlate microwear on xenarthran teeth with primary diet; variation in orthodentine microwear across the toothrow and its potential effect on dietary classification in xenarthrans remains unexplored. This study is the 1st to examine intertooth variation of microwear features in extant xenarthrans to test the necessity of standardized tooth comparison in orthodentine microwear analysis of paleodiet in fossil taxa. Statistical mean correlation tests were used to compare microwear variables between different sampling locations in a series of upper and lower teeth in 4 extant xenarthran species (Bradypus tridactylus [pale-throated three-toed sloth], Choloepus didactylus [Linnaeus' two-toed sloth], Dasypus novemcinctus [nine-banded armadillo], and Euphractus sexcinctus [six-banded armadillo]) and showed that microwear distribution between sampling locations is more conserved in three-toed sloths relative to two-toed sloths and armadillos. Significant variation in the latter groups may stem from uneven distribution of bite-force on the dentition in long-faced animals (two-toed sloths and armadillos) relative to short-faced animals (three-toed sloths), although food texture and intraspecific variation in diet may play a role as well. Based on results from extant taxa, standardized tooth comparison is required for analysis of paleodiet in glyptodonts and pampatheres and also is recommended for ground sloths in future studies of microwear. DA - 2009/6// PY - 2009/6// DO - 10.1644/08-MAMM-A-257R1.1 VL - 90 IS - 3 SP - 768-778 SN - 0022-2372 KW - armadillo KW - dental microwear KW - diet KW - ecology KW - orthodentine KW - teeth KW - tree sloth KW - variation KW - xenarthrans ER - TY - JOUR TI - Exploring the differences in cloud properties observed by the Terra and Aqua MODIS sensors AU - Meskhidze, N. AU - Remer, L. A. AU - Platnick, S. AU - Juarez, R. N. AU - Lichtenberger, A. M. AU - Aiyyer, A. R. T2 - Atmospheric Chemistry and Physics AB - Abstract. The aerosol-cloud interaction in different parts of the globe is examined here using multi-year statistics of remotely sensed data from two MODIS sensors aboard NASA's Terra (morning) and Aqua (afternoon) satellites. Simultaneous retrievals of aerosol loadings and cloud properties by the MODIS sensor allowed us to explore morning-to-afternoon variation of liquid cloud fraction (CF) and optical thickness (COT) for clean, moderately polluted and heavily polluted clouds in different seasons. Data analysis for seven-years of MODIS retrievals revealed strong temporal and spatial patterns in morning-to-afternoon variation of cloud fraction and optical thickness over different parts of the global oceans and the land. For the vast areas of stratocumulus cloud regions, the data shows that the days with elevated aerosol abundance were also associated with enhanced afternoon reduction of CF and COT pointing to the possible reduction of the indirect climate forcing. A positive correlation between aerosol optical depth and morning-to-afternoon variation of trade wind cumulus cloud cover was also found over the northern Indian Ocean, though no clear relationship between the concentration of Indo-Asian haze and morning-to-afternoon variation of COT was established. Over the Amazon region during wet conditions, aerosols are associated with an enhanced convective process in which morning shallow warm clouds are organized into afternoon deep convection with greater ice cloud coverage. Analysis presented here demonstrates that the new technique for exploring morning-to-afternoon variability in cloud properties by using the differences in data products from the two daily MODIS overpasses is capable of capturing some of the major features of diurnal variations in cloud properties and can be used for better understanding of aerosol radiative effects. DA - 2009/// PY - 2009/// DO - 10.5194/acp-9-3461-2009 VL - 9 IS - 10 SP - 3461-3475 ER - TY - JOUR TI - A quantitative assessment of human impacts on decrease in sediment flux from major Chinese rivers entering the western Pacific Ocean AU - Chu, Z. X. AU - Zhai, S. K. AU - Lu, X. X. AU - Liu, J. P. AU - Xu, J. X. AU - Xu, K. H. T2 - Geophysical Research Letters DA - 2009/// PY - 2009/// VL - 36 ER - TY - JOUR TI - A numerical study on the effects of wave-current-surge interactions on the height and propagation of sea surface waves in Charleston Harbor during Hurricane Hugo 1989 AU - Liu, Huiqing AU - Xie, Lian T2 - CONTINENTAL SHELF RESEARCH AB - The effects of wave–current interactions on ocean surface waves induced by Hurricane Hugo in and around the Charleston Harbor and its adjacent coastal waters are examined by using a three-dimensional (3D) wave–current coupled modeling system. The 3D storm surge modeling component of the coupled system is based on the Princeton Ocean Model (POM), the wave modeling component is based on the third generation wave model, Simulating WAves Nearshore (SWAN), and the inundation model is adopted from [Xie, L., Pietrafesa, L. J., Peng, M., 2004. Incorporation of a mass-conserving inundation scheme into a three-dimensional storm surge model. J. Coastal Res., 20, 1209–1223]. The results indicate that the change of water level associated with the storm surge is the primary cause for wave height changes due to wave–surge interaction. Meanwhile, waves propagating on top of surge cause a feedback effect on the surge height by modulating the surface wind stress and bottom stress. This effect is significant in shallow coastal waters, but relatively small in offshore deep waters. The influence of wave–current interaction on wave propagation is relatively insignificant, since waves generally propagate in the direction of the surface currents driven by winds. Wave–current interactions also affect the surface waves as a result of inundation and drying induced by the storm. Waves break as waters retreat in regions of drying, whereas waves are generated in flooded regions where no waves would have occurred without the flood water. DA - 2009/6/15/ PY - 2009/6/15/ DO - 10.1016/j.csr.2009.03.013 VL - 29 IS - 11-12 SP - 1454-1463 SN - 0278-4343 KW - Air-sea interaction KW - Wind waves KW - Storm surge KW - Inundation KW - Flooding KW - Hurricane ER - TY - JOUR TI - Truncation and translation of Appalachian promontories: Mid-Paleozoic strike-slip tectonics and basin initiation AU - Hibbard, James AU - Waldron, John W. F. T2 - GEOLOGY AB - Research Article| June 01, 2009 Truncation and translation of Appalachian promontories: Mid-Paleozoic strike-slip tectonics and basin initiation James Hibbard; James Hibbard * 1Department of Marine, Earth and Atmospheric Sciences, Jordan Hall, Faucette Drive, North Carolina State University, Raleigh, North Carolina 27695, USA *E-mails: jim_hibbard@ncsu.edu; john.waldron@ualberta.ca. Search for other works by this author on: GSW Google Scholar John W.F. Waldron John W.F. Waldron * 2Department of Earth and Atmospheric Sciences, University of Alberta, 1-26 Earth Sciences Building, University of Alberta, Edmonton, Alberta T6G 2E3, Canada *E-mails: jim_hibbard@ncsu.edu; john.waldron@ualberta.ca. Search for other works by this author on: GSW Google Scholar Geology (2009) 37 (6): 487–490. https://doi.org/10.1130/G25614A.1 Article history received: 17 Oct 2008 rev-recd: 15 Jan 2009 accepted: 17 Jan 2009 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation James Hibbard, John W.F. Waldron; Truncation and translation of Appalachian promontories: Mid-Paleozoic strike-slip tectonics and basin initiation. Geology 2009;; 37 (6): 487–490. doi: https://doi.org/10.1130/G25614A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Accreted terranes of the Appalachian Iapetan and peri-Gondwanan realms display structural trends that are mainly concordant with promontories and embayments in the Laurentian margin, indicating that during accretion, the shape of the continental margin acted as a template around which accreted terranes were molded. In North Carolina and New-foundland, post-accretion transcurrent motion appears to be recorded by displaced outboard portions of promontories, no longer concordant with those in Laurentia. A bend in structural trends confined to the peri-Gondwanan realm at the North Carolina–South Carolina state line is interpreted to represent the dextrally displaced outboard portion of the Virginia promontory. In Newfoundland, the Hermitage flexure is interpreted as a dextrally displaced Laurentian promontory that originated along strike to the northeast. In both places, promontories were truncated and dextrally translated for ~220–250 km by a Devonian–Mississippian orogen-parallel transcurrent system, which may well have extended for the length of the eastern Laurentian margin. South of the nearby St. Lawrence promontory, extreme thinning of Appalachian crust beneath the Maritimes Basin is consistent with extension at a releasing stepover. Estimates of extension are consistent with those obtained from promontory offsets. You do not have access to this content, please speak to your institutional administrator if you feel you should have access. DA - 2009/6// PY - 2009/6// DO - 10.1130/g25614a.1 VL - 37 IS - 6 SP - 487-490 SN - 0091-7613 ER - TY - JOUR TI - The importance of intraspecific variability in harmful algae-Preface to a collection of topical papers AU - Burkholder, JoAnn M. AU - Glibert, Patricia M. T2 - HARMFUL ALGAE AB - Documenting the immense diversity of single-celled, eukaryotic organisms (protists) has been a formidable challenge for ecologists. These species were originally defined by morphological criteria, but shortcomings of the morphospecies concept, and a bewildering array of sizes and cellular attributes, has made constructing a taxonomy that is useful for ecologists nearly impossible. Consequently, physiological and genetic information has been integrated to address these shortcomings, and to develop the framework of a unifying taxonomy. DNA sequence information, in particular, has revolutionized studies of protistan diversity. However, the exponential increase in sequence-based protistan species richness published from field surveys in recent years raises the question of whether we have moved beyond characterizing species-level diversity and begun to reveal intraspecies diversity. The answer to that question appears to be ‘yes’, at least for some protistan lineages. The need to document such microdiversity may be justified, but it is important for protistologists to recognize and acknowledge that possibility, and its consequences. DA - 2009/6// PY - 2009/6// DO - 10.1016/j.hal.2009.03.006 VL - 8 IS - 5 SP - 744-745 SN - 1568-9883 ER - TY - JOUR TI - Stable oxygen and carbon isotope profiles in an invasive bivalve (Corbicula fluminea) in North Carolina watersheds (vol 73, pg 3234, 2009) AU - Bucci, J. P. T2 - Geochimica et Cosmochimica Acta DA - 2009/// PY - 2009/// VL - 73 IS - 16 SP - 4918-4918 ER - TY - JOUR TI - Regimes of Dry Convection above Wildfires: Idealized Numerical Simulations and Dimensional Analysis AU - Kiefer, Michael T. AU - Parker, Matthew D. AU - Charney, Joseph J. T2 - JOURNAL OF THE ATMOSPHERIC SCIENCES AB - Abstract Wildfires are capable of inducing atmospheric circulations that result predominantly from large temperature anomalies produced by the fire. The fundamental dynamics through which a forest fire and the atmosphere interact to yield different convective regimes is still not well understood. This study uses the Advanced Regional Prediction System (ARPS) model to investigate the impact of the environmental (i.e., far upstream, undisturbed by fire) wind profile on dry convection above a prescribed heat source of an intensity and spatial scale comparable to a wildfire. Dimensional analysis of the fire–atmosphere problem provides two relevant parameters: a surface buoyancy parameter that addresses the amount of heat a parcel of air receives in transiting above the fire and an advection parameter that addresses the degree to which the environmental wind advects updrafts away from the fire. Two-dimensional simulations are performed in which the upstream surface wind speed and mixed layer mean wind speed are varied independently to better understand the fundamental processes governing the organizational mode and updraft strength. The result of these experiments is the identification of two primary classes of dry convection: plume and multicell. Simulated plume cases exhibit weak advection by the mean wind and are subdivided into intense plume and hybrid classes based on the degree of steadiness within the convection column. Hybrid cases contain columns of largely discrete updrafts versus the more continuous updraft column associated with the intense plume mode. Multicell cases develop with strong mixed layer advection and are subdivided into strong and weak classes based on the depth of convection. Intense plume and strong multicell (hybrid and weak multicell) cases occur when the surface buoyancy is large (small). Parcel analyses are performed to more closely examine the forcing of convection within different areas of the parameter space. The multicell (strong and weak) and intense plume modes are forced by a combination of buoyancy and dynamic pressure gradient forcing associated with the perturbation wind field, whereas the hybrid mode is forced by a combination of buoyancy and dynamic pressure gradient forcing associated with the strong background shear. The paper concludes with a discussion of the degree of nonlinearity that is likely to exist at the fire front for each of the convective modes; nonlinear fire behavior is most likely for the hybrid mode and least likely for the weak multicell mode. Knowledge of the sensitivity of the convective mode to upstream conditions can provide information about the degree of nonlinear or erratic fire behavior expected for a given wind profile upstream of the fire. DA - 2009/4// PY - 2009/4// DO - 10.1175/2008JAS2896.1 VL - 66 IS - 4 SP - 806-836 SN - 1520-0469 ER - TY - PCOMM TI - Ozone exposure and mortality AU - Tong, D. Q. AU - Yu, S. C. AU - Kan, H. D. DA - 2009/// PY - 2009/// SP - 2788-2788 ER - TY - JOUR TI - Measuring Storm Surge with an Airborne Wide-Swath Radar Altimeter AU - Wright, C. W. AU - Walsh, E. J. AU - Krabill, W. B. AU - Shaffer, W. A. AU - Baig, S. R. AU - Peng, M. AU - Pietrafesa, L. J. AU - Garcia, A. W. AU - Marks, F. D., Jr. AU - Black, P. G. AU - Sonntag, J. AU - Beckley, B. D. T2 - JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY AB - Abstract Over the years, hurricane track forecasts and storm surge models, as well the digital terrain and bathymetry data they depend on, have improved significantly. Strides have also been made in the knowledge of the detailed variation of the surface wind field driving the surge. The area of least improvement has been in obtaining data on the temporal/spatial evolution of the mound of water that the hurricane wind and waves push against the shore to evaluate the performance of the numerical models. Tide gauges in the vicinity of the landfall are frequently destroyed by the surge. Survey crews dispatched after the event provide no temporal information and only indirect indications of the maximum water level over land. The landfall of Hurricane Bonnie on 26 August 1998, with a surge less than 2 m, provided an excellent opportunity to demonstrate the potential benefits of direct airborne measurement of the temporal/spatial evolution of the water level over a large area. Despite a 160-m variation in aircraft altitude, an 11.5-m variation in the elevation of the mean sea surface relative to the ellipsoid over the flight track, and the tidal variation over the 5-h data acquisition interval, a survey-quality global positioning system (GPS) aircraft trajectory allowed the NASA scanning radar altimeter carried by a NOAA hurricane research aircraft to demonstrate that an airborne wide-swath radar altimeter could produce targeted measurements of storm surge that would provide an absolute standard for assessing the accuracy of numerical storm surge models. DA - 2009/10// PY - 2009/10// DO - 10.1175/2009JTECHO627.1 VL - 26 IS - 10 SP - 2200-2215 SN - 1520-0426 ER - TY - JOUR TI - IAGC Celebrates 40 Years AU - Harmon, Russell S. T2 - APPLIED GEOCHEMISTRY DA - 2009/6// PY - 2009/6// DO - 10.1016/j.apgeochem.2009.02.018 VL - 24 IS - 6 SP - 1044-1046 SN - 0883-2927 ER - TY - JOUR TI - Growth, uptake, and assimilation of ammonium, nitrate, and urea, by three strains of Karenia brevis grown under low light AU - Sinclair, Geoff AU - Kamykowski, Dan AU - Glibert, Patricia M. T2 - HARMFUL ALGAE AB - Observations of near-bottom populations of Karenia brevis suggest that these cells may derive nutrients from the sediment–water interface. Cells undergoing a metabolic-mediated migration may be in close proximity to enhanced concentrations of nutrients associated with the sediment during at least a fraction of their diel cycle. In this study, the growth, uptake and assimilation rates of ammonium, nitrate, and urea by K. brevis were examined on a diel basis to better understand the potential role of these nutrients in the near-bottom ecology of this species. Three strains of K. brevis, C6, C3, and CCMP 2229, were grown under 12:12 light dark cycle under 30 μmol photons m−2 s−1 delivered to the surface plain of batch cultures. Nitrogen uptake was evaluated using 15N tracer techniques and trichloroacetic acid extraction was used to evaluate the quantity of nitrogen (N) assimilated into cell protein. Growth rates ranged from a low of 0.12 divisions day−1 for C6 and C3 grown on nitrate to a high of 0.18 divisions day−1 for C3 grown on urea. Diurnal maximum uptake rates, ρmax, varied from 0.41 pmol-N cell−1 h−1 for CCMP 2229 grown on nitrate, to 1.29 pmol-N cell−1 h−1 for CCMP 2229 grown on urea. Average nocturnal uptake rates were 29% of diurnal rates for nitrate, 103% of diurnal uptake rates for ammonium and 56% of diurnal uptake rates for urea. Uptake kinetic parameters varied between substrates, between strains and between day and night measurements. Highest maximum uptake rates were found for urea for strains CCMP2229 and C3 and for ammonium for strain C6. Rates of asmilation into protein also varied day and night, but overall were highest for urea. The comparison of maximal uptake rates as well as assimilation efficiencies indicate that ammonium and urea are utilized (taken up and assimilated) more than twice was fast as nitrate on a diel basis. DA - 2009/6// PY - 2009/6// DO - 10.1016/j.hal.2009.02.006 VL - 8 IS - 5 SP - 770-780 SN - 1568-9883 KW - Karenia brevis KW - Diel nitrogen uptake KW - Dinoflagellate physiology ER - TY - JOUR TI - Grazing by Karenia brevis on Synechococcus enhances its growth rate and may help to sustain blooms AU - Glibert, Patricia M. AU - Burkholder, JoAnn M. AU - Kana, Todd M. AU - Alexander, Jeffrey AU - Skelton, Hayley AU - Shilling, Carol T2 - AQUATIC MICROBIAL ECOLOGY AB - AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 55:17-30 (2009) - DOI: https://doi.org/10.3354/ame01279 Grazing by Karenia brevis on Synechococcus enhances its growth rate and may help to sustain blooms Patricia M. Glibert1,*, JoAnn M. Burkholder2, Todd M. Kana1, Jeffrey Alexander1, Hayley Skelton2, Carol Shilling3 1University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge, Maryland 21613, USA 2Center for Applied Aquatic Ecology, North Carolina State University, Raleigh, North Carolina 27695, USA 3Watkins Mill High School, 10301 Apple Ridge Road, Gaithersburg, Maryland 20879, USA *Email: glibert@hpl.umces.edu ABSTRACT: Grazing rates of Karenia brevis Clones CCMP2228 and CCMP2229 were determined in laboratory experiments using Synechococcus sp. Clone CCMP1768 as food. Growth (days to weeks) and uptake rates (hours to days) were assessed. In the growth experiments, K. brevis, previously depleted in nitrogen (N), was grown at 2 light intensities in the presence of varying concentrations of Synechococcus. Under high irradiance (300 µmol photons m–2 s–1; 14 h light:10 h dark cycle), exponential growth rates approximated those of phototrophic growth without Synechococcus (0.26 to 0.35 d–1). At this irradiance, K. brevis cells in all treatments grew for about 10 d. Under lower irradiance (43 µmol photons m–2 s–1), exponential growth rates of K. brevis cells varied with the enrichment level of Synechococcus, with rates under the highest Synechococcus enrichment level being nearly twice (0.58 d–1) those observed for the high irradiance treatments. Short-term uptake experiments (3 experiments, 2 clones) were done to examine the N-specific rates of grazing of 15N-labeled Synechococcus. N-specific rates of grazing ranged from 9.28 × 10–4 h–1 to 1.22 × 10–2 h–1 and varied with the relative proportion of Synechococcus:K. brevis. These rates represent a range of 0.026 to 2.15 pmol-N K. brevis–1 d–1, or 0.96 to 83.8 Synechococcus K. brevis–1 h–1. Evidence of Synechococcus inside K. brevis was provided by confocal microscopy. Grazing by K. brevis thus enhances the range of nutritional substrates available to meet its growth requirements, and may play a substantial role in sustaining natural populations in inorganic N-poor waters. KEY WORDS: Karenia brevis · Synechococcus · Mixotrophy · Grazing rate · Irradiance · Nitrogen source · Harmful algal bloom · Red tide Full text in pdf format PreviousNextCite this article as: Glibert PM, Burkholder JM, Kana TM, Alexander J, Skelton H, Shilling C (2009) Grazing by Karenia brevis on Synechococcus enhances its growth rate and may help to sustain blooms. Aquat Microb Ecol 55:17-30. https://doi.org/10.3354/ame01279 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 55, No. 1. Online publication date: March 18, 2009 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2009 Inter-Research. DA - 2009/// PY - 2009/// DO - 10.3354/ame01279 VL - 55 IS - 1 SP - 17-30 SN - 1616-1564 KW - Karenia brevis KW - Synechococcus KW - Mixotrophy KW - Grazing rate KW - Irradiance KW - Nitrogen source KW - Harmful algal bloom KW - Red tide ER - TY - JOUR TI - Ferromagnetism of undoped GaN mediated by through-bond spin polarization between nitrogen dangling bonds AU - Jin, H. AU - Dai, Y. AU - Huang, B. B. AU - Whangbo, M. H. T2 - Applied Physics Letters DA - 2009/// PY - 2009/// VL - 94 IS - 16 ER - TY - JOUR TI - Faulting and hydration of the Juan de Fuca plate system AU - Nedimovic, Mladen R. AU - Bohnenstiehl, DelWayne R. AU - Carbotte, Suzanne M. AU - Canales, J. Pablo AU - Dziak, Robert P. T2 - EARTH AND PLANETARY SCIENCE LETTERS AB - Multichannel seismic observations provide the first direct images of crustal scale normal faults within the Juan de Fuca plate system and indicate that brittle deformation extends up to ~ 200 km seaward of the Cascadia trench. Within the sedimentary layering steeply dipping faults are identified by stratigraphic offsets, with maximum throws of 110 ± 10 m found near the trench. Fault throws diminish both upsection and seaward from the trench. Long-term throw rates are estimated to be 13 ± 2 mm/kyr. Faulted offsets within the sedimentary layering are typically linked to larger offset scarps in the basement topography, suggesting reactivation of the normal fault systems formed at the spreading center. Imaged reflections within the gabbroic igneous crust indicate swallowing fault dips at depth. These reflections require local alteration to produce an impedance contrast, indicating that the imaged fault structures provide pathways for fluid transport and hydration. As the depth extent of imaged faulting within this young and sediment insulated oceanic plate is primarily limited to approximately Moho depths, fault-controlled hydration appears to be largely restricted to crustal levels. If dehydration embrittlement is an important mechanism for triggering intermediate-depth earthquakes within the subducting slab, then the limited occurrence rate and magnitude of intraslab seismicity at the Cascadia margin may in part be explained by the limited amount of water imbedded into the uppermost oceanic mantle prior to subduction. The distribution of submarine earthquakes within the Juan de Fuca plate system indicates that propagator wake areas are likely to be more faulted and therefore more hydrated than other parts of this plate system. However, being largely restricted to crustal levels, this localized increase in hydration generally does not appear to have a measurable effect on the intraslab seismicity along most of the subducted propagator wakes at the Cascadia margin. DA - 2009/6/30/ PY - 2009/6/30/ DO - 10.1016/j.epsl.2009.04.013 VL - 284 IS - 1-2 SP - 94-102 SN - 1385-013X KW - Juan de Fuca plate system KW - seismic reflection imaging KW - faulting KW - hydration KW - earthquakes ER - TY - JOUR TI - Effects of Agriculture upon the Air Quality and Climate: Research, Policy, and Regulations AU - Aneja, Viney P. AU - Schlesinger, William H. AU - Erisman, Jan Willem T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - Scientific assessments of agricultural air quality, including estimates of emissions and potential sequestration of greenhouse gases, are an important emerging area of environmental science that offers significant challenges to policy and regulatory authorities. Improvements are needed in measurements, modeling, emission controls, and farm operation management. Controlling emissions of gases and particulate matter from agriculture is notoriously difficult as this sector affects the most basic need of humans, i.e., food. Current policies combine an inadequate science covering a very disparate range of activities in a complex industry with social and political overlays. Moreover, agricultural emissions derive from both area and point sources. In the United States, agricultural emissions play an important role in several atmospherically mediated processes of environmental and public health concerns. These atmospheric processes affect local and regional environmental quality, including odor, particulate matter (PM) exposure, eutrophication, acidification, exposure to toxics, climate, and pathogens. Agricultural emissions also contribute to the global problems caused by greenhouse gas emissions. Agricultural emissions are variable in space and time and in how they interact within the various processes and media affected. Most important in the U.S. are ammonia (where agriculture accounts for ∼90% of total emissions), reduced sulfur (unquantified), PM2.5 (∼16%), PM10 (∼18%), methane (∼29%), nitrous oxide (∼72%), and odor and emissions of pathogens (both unquantified). Agriculture also consumes fossil fuels for fertilizer production and farm operations, thus emitting carbon dioxide (CO2), oxides of nitrogen (NOx), sulfur oxides (SOx), and particulates. Current research priorities include the quantification of point and nonpoint sources, the biosphere−atmosphere exchange of ammonia, reduced sulfur compounds, volatile organic compounds, greenhouse gases, odor and pathogens, the quantification of landscape processes, and the primary and secondary emissions of PM. Given the serious concerns raised regarding the amount and the impacts of agricultural air emissions, policies must be pursued and regulations must be enacted in order to make real progress in reducing these emissions and their associated environmental impacts. DA - 2009/6/15/ PY - 2009/6/15/ DO - 10.1021/es8024403 VL - 43 IS - 12 SP - 4234-4240 SN - 1520-5851 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-67449119222&partnerID=MN8TOARS ER - TY - JOUR TI - Diel vertical migration thresholds of Karenia brevis (Dinophyceae) AU - Schaeffer, Blake A. AU - Kamykowski, Daniel AU - Sinclair, Geoff AU - McKay, Laurie AU - Milligan, Edward J. T2 - HARMFUL ALGAE AB - Light and nutrient availability change throughout dinoflagellate diel vertical migration (DVM) and/or with sub-population location in the water column along the west Florida shelf. Typically, the vertical depth of the shelf is greater than the distance a sub-population can vertically migrate during a diel cycle, limiting the ability of a sub-population to photosynthetically fix carbon toward the surface and access nutrients sub-surface. This project investigated changes of Karenia brevis (C.C. Davis) G. Hansen et Moestrup intracellular carbon, nitrogen, internal nitrate (iNO3), free amino acid (FAA), and total lipid concentrations in high-light, nitrate-replete (960 μmol quanta m−2 s−1, 80 μM NO3), and high-light, nitrate-reduced (960 μmol quanta m−2 s−1, <5 μM NO3) mesocosms. The nitrate-reduced mesocosm had a slowed cell division rate when compared to the nitrate-replete mesocosm. Minimum intracellular carbon, nitrogen, iNO3, FAA, and total lipid concentrations during the largest surface sub-population aggregations led to the conclusion that daughter cells resulting from cell division received unequal shares of the parental resources and that this inequality influenced migration behavior. Nutrient reduced daughter cells were more strongly influenced by light and phototaxis for carbon production than their replete same cell division sister cells during vertical migration thus rapidly increasing the fulfillment of constituents through photosynthesis. Vertical migration was consistent with an optimization scheme based on threshold limits through utilization or formation of photosynthate. We propose a simplified conceptual model describing how K. brevis is transported along the benthos of the west Florida shelf from off-shore to on-shore. Dynamic carbon thresholds are also suggested for future DVM modeling efforts on K. brevis populations transported between nitrogen replete and nitrogen reduced environmental conditions. DA - 2009/6// PY - 2009/6// DO - 10.1016/j.hal.2009.01.002 VL - 8 IS - 5 SP - 692-698 SN - 1878-1470 KW - Carbon KW - Diel vertical migration KW - Dinoflagellate KW - Karenia brevis KW - Nitrogen ER - TY - JOUR TI - Deep-sea benthic diversity linked to seasonality of pelagic productivity AU - Corliss, B. H. AU - Brown, C. W. AU - Sun, X. AU - Showers, W. J. T2 - DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS AB - Latitudinal gradients in biodiversity are found in both terrestrial and marine environments, but little agreement exists on the mechanisms or ecological causes creating these patterns. Marine biodiversity patterns have been particularly challenging to document, because of the lack of appropriate data sets from ocean basins. We document latitudinal patterns of North Atlantic deep-sea benthic foraminifera and show that seasonality of primary productivity, as estimated from SeaWiFS satellite imagery, has a significant effect on diversity indices, with generally lower values of H(S), species ♯, and species equitability found with high seasonality between 40 and 60°N. High foraminiferal diversity is not found in areas with phytodetritus deposition in the North Atlantic basin, which indicates that patch dynamics, biological disturbance, and sediment heterogeneity resulting from phytodetritus deposits do not create high deep-sea foraminiferal diversity. Annual resource stability, reflecting the timing of organic carbon flux and the mode of sedimentation, accounts for the benthic foraminiferal patterns found in this study and is an important variable structuring the deep-sea benthic foraminiferal community. DA - 2009/5// PY - 2009/5// DO - 10.1016/j.dsr.2008.12.009 VL - 56 IS - 5 SP - 835-841 SN - 1879-0119 KW - Deep-sea diversity KW - Benthos KW - Foraminifera KW - Seasonality ER - TY - JOUR TI - Conservative cascade interpolation on the sphere: An intercomparison of various non-oscillatory reconstructions AU - Norman, Matthew R. AU - Semazzi, Fredrick H. M. AU - Nair, Ramachandran D. T2 - QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY AB - Abstract Various new polynomial and non‐polynomial approximations to a subgrid distribution have been adapted for use in the conservative cascade scheme (CCS) and applied to conservative grid‐to‐grid interpolation on a latitude‐‐longitude grid. These approximations include the following: piecewise parabolic method (PPM), piecewise hyperbolic method (PHM), piecewise double hyperbolic method (PDHM), power‐limited piecewise parabolic method (P‐PPM), piecewise rational method (PRM), third‐order weighted essentially non‐oscillatory (WENO23), fifth‐order weighted essentially non‐oscillatory (WENO35), and a modified piecewise parabolic method (M‐PPM). A series of test cases are performed in which initial gridded data are interpolated between T 42 and 2° grids and compared against analytical values. Four initial data profiles are used: smooth harmonic, high‐frequency harmonic, quasi‐polar vortex data and slotted cylinder data. In general, PDHM (WENO35) had the lowest error norms of the three‐(five‐)cell stencil methods. Quite often, M‐PPM gave accuracy comparable to WENO35 at significantly lower cost. Monotonicity violations generally only occurred when interpolating to a finer grid with a maximum violation of 1.8% of the data range. Copyright © 2009 Royal Meteorological Society DA - 2009/4// PY - 2009/4// DO - 10.1002/qj.402 VL - 135 IS - 640 SP - 795-805 SN - 1477-870X KW - non-oscillatory KW - conservative interpolation KW - conservative cascade scheme KW - WENO KW - spherical ER - TY - JOUR TI - Combined phylogenetic analysis of a new North American fossil species confirms widespread Eocene distribution for stem rollers (Aves, Coracii) AU - Clarke, Julia A. AU - Ksepka, Daniel T. AU - Smith, N. Adam AU - Norell, Mark A. T2 - ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY AB - We report a nearly complete skeleton of a new species of stem roller (Aves, Coracii) from the early Eocene Green River Formation of North America. The new species is most closely related to two species-depauperate lineages, Coraciidae (rollers) and Brachypteraciidae (ground rollers), that form a monophyletic crown clade (Coracioidea) with an exclusively Old World extant distribution. Phylogenetic analysis utilizing a matrix of 133 morphological characters and sequence data from three genes (RAG-1, c-myc, and ND2) identifies the new species as a stem member of the Coracii more closely related to the crown clade than the only previously identified New World taxon, Primobucco mcgrewi. The phylogenetic placement of the new species and Primobucco mcgrewi indicates a widespread northern hemisphere distribution in the Eocene with subsequent restriction to Africa, Madagascar, Australia, and temperate to tropical parts of Europe and Asia. It provides evidence of further ecological diversity in early stem Coracii and convergence on crown morphologies. The new species contributes to mounting evidence that extant distributions for major avian subclades may be of comparatively recent origin. Further late Palaeogene sampling is needed to elucidate potential drivers for shifting avian distributions and disappearance of Coracii from North America. DA - 2009/11// PY - 2009/11// DO - 10.1111/j.1096-3642.2009.00550.x VL - 157 IS - 3 SP - 586-611 SN - 1096-3642 KW - avian evolution KW - biogeography KW - Cenozoic KW - combined analysis KW - Green River Formation KW - phylogeny ER - TY - JOUR TI - Biomolecular Characterization and Protein Sequences of the Campanian Hadrosaur B. canadensis AU - Schweitzer, Mary H. AU - Zheng, Wenxia AU - Organ, Chris L. AU - Avci, Recep AU - Suo, Zhiyong AU - Freimark, Lisa M. AU - Lebleu, Valerie S. AU - Duncan, Michael B. AU - Heiden, Matthew G. Vander AU - Neveu, John M. AU - Lane, William S. AU - Cottrell, John S. AU - Horner, John R. AU - Cantley, Lewis C. AU - Kalluri, Raghu AU - Asara, John M. T2 - SCIENCE AB - Molecular preservation in non-avian dinosaurs is controversial. We present multiple lines of evidence that endogenous proteinaceous material is preserved in bone fragments and soft tissues from an 80-million-year-old Campanian hadrosaur, Brachylophosaurus canadensis [Museum of the Rockies (MOR) 2598]. Microstructural and immunological data are consistent with preservation of multiple bone matrix and vessel proteins, and phylogenetic analyses of Brachylophosaurus collagen sequenced by mass spectrometry robustly support the bird-dinosaur clade, consistent with an endogenous source for these collagen peptides. These data complement earlier results from Tyrannosaurus rex (MOR 1125) and confirm that molecular preservation in Cretaceous dinosaurs is not a unique event. DA - 2009/5/1/ PY - 2009/5/1/ DO - 10.1126/science.1165069 VL - 324 IS - 5927 SP - 626-631 SN - 1095-9203 ER - TY - JOUR TI - A new physically-based quantification of marine isoprene and primary organic aerosol emissions AU - Gantt, B. AU - Meskhidze, N. AU - Kamykowski, D. T2 - ATMOSPHERIC CHEMISTRY AND PHYSICS AB - Abstract. The global marine sources of organic carbon (OC) are estimated here using a physically-based parameterization for the emission of marine isoprene and primary organic matter. The marine isoprene emission model incorporates new physical parameters such as light sensitivity of phytoplankton isoprene production and dynamic euphotic depth to simulate hourly marine isoprene emissions totaling 0.92 Tg C yr−1. Sensitivity studies using different schemes for the euphotic zone depth and ocean phytoplankton speciation produce the upper and the lower range of marine-isoprene emissions of 0.31 to 1.09 Tg C yr−1, respectively. Established relationships between sea spray fractionation of water-insoluble organic carbon (WIOC) and chlorophyll-a concentration are used to estimate the total primary sources of marine sub- and super-micron OC of 2.9 and 19.4 Tg C yr−1, respectively. The consistent spatial and temporal resolution of the two emission types allow us, for the first time, to explore the relative contributions of sub- and super-micron organic matter and marine isoprene-derived secondary organic aerosol (SOA) to the total OC fraction of marine aerosol. Using a fixed 3% mass yield for the conversion of isoprene to SOA, our emission simulations show minor (<0.2%) contribution of marine isoprene to the total marine source of OC on a global scale. However, our model calculations also indicate that over the tropical oceanic regions (30° S to 30° N), marine isoprene SOA may contribute over 30% of the total monthly-averaged sub-micron OC fraction of marine aerosol. The estimated contribution of marine isoprene SOA to hourly-averaged sub-micron marine OC emission is even higher, approaching 50% over the vast regions of the oceans during the midday hours when isoprene emissions are highest. As it is widely believed that sub-micron OC has the potential to influence the cloud droplet activation of marine aerosols, our findings suggest that marine isoprene SOA could play critical role in modulating properties of shallow marine clouds and influencing the climate. DA - 2009/// PY - 2009/// DO - 10.5194/acp-9-4915-2009 VL - 9 IS - 14 SP - 4915-4927 SN - 1680-7324 ER - TY - JOUR TI - 40Ar/39Ar Thermochronology of Late- and Postorogenic Extension in the Caledonides of North-Central Norway AU - Steltenpohl, Mark G. AU - Carter, Brad T. AU - Andresen, Arild AU - Zeltner, Daniel L. T2 - JOURNAL OF GEOLOGY AB - We report 40Ar/39Ar mineral cooling data that elucidate the timing and style of Devonian late‐orogenic extensional collapse and Permian‐Triassic postorogenic continental rifting in the north‐central Norwegian Caledonides. 40Ar/39Ar mineral cooling ages from ductile extensional shear zones that have either excised or reactivated Caledonian thrust faults along the western flanks of two major basement domes indicate that late‐orogenic extensional deformation in this region occurred during the Early (ca. 409–388 Ma) and Late Devonian (ca. 371–355 Ma). These extensional pulses are consistent with events recently identified by workers investigating areas to the south of our study area. The timing and style of the Early Devonian event supports the northern continuation of the Devonian orogen‐parallel, scoop‐shaped extensional deformation documented in the central Norwegian Caledonides. Late Devonian extension, on the other hand, was orogen‐orthogonal. This Late Devonian event is similar in timing and kinematics to the extension documented in the Lofoten Archipelago due west of our study area. 40Ar/39Ar data on K‐feldspar samples from brittle extensional faults of the Vestfjord‐Vanna fault complex, which opened the major NNE‐SSW‐trending Vestfjord basin, document two pulses of E‐W‐directed postorogenic continental rifting. The first pulse of extension occurred during the Early Permian, at ca. 272 Ma, and the other during the Middle Triassic, at ca. 236 Ma. The Early Permian faults are upper‐crustal features found in the hanging wall of the Lofoten metamorphic core complex, the result of rifting the Lofoten block from the Norwegian mainland during the initial opening of the Vestfjord basin. Middle Triassic faulting occurred because of continued movement along the Vestfjord‐Vanna fault complex during further development of the Vestfjord basin. The timing and kinematics of development of the Vestfjord basin have similarities with those of major basins submerged along and exposed on the continental margins of Norway and Greenland, respectively. Permian‐Triassic extension, long recognized throughout eastern Greenland, is evidently more pronounced along the Norwegian continental margin than was previously thought. We interpret this event as marking the transition from Devonian‐Carboniferous extensional collapse to continental rifting sensu stricto, preceding the Eocene opening of the nascent Norwegian‐Greenlandian Sea. DA - 2009/7// PY - 2009/7// DO - 10.1086/599217 VL - 117 IS - 4 SP - 399-414 SN - 1537-5269 ER - TY - JOUR TI - Use of long-term data and multivariate ordination techniques to identify environmental factors governing estuarine phytoplankton species dynamics AU - Rothenberger, Meghan B. AU - Burkholder, JoAnn M. AU - Wentworth, Thomas R. T2 - LIMNOLOGY AND OCEANOGRAPHY AB - A continuous, 13‐yr record of environmental data and phytoplankton species and assemblage structure in the mesohaline Neuse River Estuary (biweekly, April‐October; monthly, November‐March) was used to evaluate phytoplankton assemblage responses to changing environmental conditions. Ordination techniques including nonmetric multidimensional scaling, indicator species analysis, and BIO‐ENV software were used to investigate potential environmental predictors of phytoplankton assemblage patterns under chronic eutrophication. Phytoplankton assemblages were strongly related to temperature and total nitrogen : total phosphorus ratios, with expected seasonal changes in species composition. Interannual changes in river discharge influenced whether phytoplankton assemblages were dominated by diatoms and phototrophic flagellates or by mixotrophic and heterotrophic dinoflagellates. Increasing ammonium concentrations also have been an important influence on phytoplankton assemblages. Raphidophytes (including the potentially toxic species Heterosigma akashiwo ), haptophytes, chlorophytes, and the bloom‐forming dinoflagellate Heterocapsa rotundata have increased in more recent years (2000–2006), concomitant with increasing ammonium concentrations. Abundance of the potentially toxic dinoflagellates Prorocentrum minimum and the grouping Pfiesteria spp., “pfiesteria‐like” dinoflagellates, and Karlodinium veneficum remained stationary over time and rarely exceeded 103 cells mL −1 . Abundance of P. minimum was positively related to dissolved organic nitrogen and suspended solids concentrations, whereas the highest abundance of the grouping Pfiesteria spp., “pfiesteria‐like” dinoflagellates, and K. veneficum occurred during summer and fall, related to high total phosphorus concentrations, temperature, and salinity. Overall, this study provides new species‐level insights to advance understanding about anthropogenic influences on phytoplankton assemblages. The data suggest an increasingly important role of ammonium in controlling phytoplankton assemblage structure, including increased abundance of some harmful species, in eutrophic estuaries. DA - 2009/11// PY - 2009/11// DO - 10.4319/lo.2009.54.6.2107 VL - 54 IS - 6 SP - 2107-2127 SN - 1939-5590 ER - TY - JOUR TI - Tropical instability wave interactions within the Galapagos Archipelago AU - Sweet, W. V. AU - Morrison, J. M. AU - Liu, Y. AU - Kamykowski, D. AU - Schaeffer, B. A. AU - Xie, L. AU - Banks, S. T2 - DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS AB - Abstract The effects of tropical instability waves (TIW) within the eastern equatorial Pacific during the boreal fall of 2005 were observed in multiple data sets. The TIW cause oscillations of the sea surface temperature (SST), meridional currents ( V ), and 20 °C isotherm (thermocline). A particularly strong 3-wave packet of ∼15-day period TIW passed through the Galapagos Archipelago in Sep and Oct 2005 and their effects were recorded by moored near-surface sensors. Repeat Argo profiles in the archipelago showed that the large temperature (>5 °C) oscillations that occurred were associated with a vertical adjustment within the water column. Numerical simulations report strong oscillations and upwelling magnitudes of ∼5.0 m d −1 near the Tropical Atmosphere Ocean (TAO) buoy at 0°, 95°W and in the Archipelago at 92°W and 90°W. A significant biological response to the TIW passage was observed within the archipelago. Chlorophyll a measured by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) increased by >30% above 1998–2007 mean concentrations within the central archipelago. The increases coincide with coldest temperatures and the much larger increases within the archipelago as compared to those of 95°W indicate that TIW induced upwelling over the island platform itself brought more iron-enriched upwelling waters into the euphotic zone. DA - 2009/8// PY - 2009/8// DO - 10.1016/j.dsr.2009.02.005 VL - 56 IS - 8 SP - 1217-1229 SN - 1879-0119 KW - Tropical instability waves KW - Upwelling KW - Eastern equatorial pacific KW - Galapagos KW - Chlorophyll ER - TY - JOUR TI - The effects of interdune vegetation changes on eolian dune field evolution: a numerical-modeling case study at Jockey's Ridge, North Carolina, USA AU - Pelletier, Jon D. AU - Mitasova, Helena AU - Harmon, Russell S. AU - Overton, Margery T2 - EARTH SURFACE PROCESSES AND LANDFORMS AB - Abstract Changes in vegetation cover within dune fields can play a major role in how dune fields evolve. To better understand the linkage between dune field evolution and interdune vegetation changes, we modified Werner's ( Geology , 23, 1995: 1107–1110) dune field evolution model to account for the stabilizing effects of vegetation. Model results indicate that changes in the density of interdune vegetation strongly influence subsequent trends in the height and area of eolian dunes. We applied the model to interpreting the recent evolution of Jockey's Ridge, North Carolina, where repeat LiDAR surveys and historical aerial photographs and maps provide an unusually detailed record of recent dune field evolution. In the absence of interdune vegetation, the model predicts that dunes at Jockey's Ridge evolve towards taller, more closely‐spaced, barchanoid dunes, with smaller dunes generally migrating faster than larger dunes. Conversely, the establishment of interdune vegetation causes dunes to evolve towards shorter, more widely‐spaced, parabolic forms. These results provide a basis for understanding the increase in dune height at Jockey's Ridge during the early part of the twentieth century, when interdune vegetation was sparse, followed by the decrease in dune height and establishment of parabolic forms from 1953‐present when interdune vegetation density increased. These results provide a conceptual model that may be applicable at other sites with increasing interdune vegetation cover, and they illustrate the power of using numerical modeling to model decadal variations in eolian dune field evolution. We also describe model results designed to test the relative efficacy of alternative strategies for mitigating dune migration and deflation. Installing sand‐trapping fences and/or promoting vegetation growth on the stoss sides of dunes are found to be the most effective strategies for limiting dune advance, but these strategies must be weighed against the desire of many park visitors to maintain the natural state of the dunes. Copyright © 2009 John Wiley & Sons, Ltd. DA - 2009/7// PY - 2009/7// DO - 10.1002/esp.1809 VL - 34 IS - 9 SP - 1245-1254 SN - 1096-9837 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-69749085481&partnerID=MN8TOARS KW - eolian dunes KW - numerical modeling KW - biogeomorphology ER - TY - JOUR TI - The Role of Momentum Transport in the Motion of a Quasi-Idealized Mesoscale Convective System AU - Mahoney, Kelly M. AU - Lackmann, Gary M. AU - Parker, Matthew D. T2 - MONTHLY WEATHER REVIEW AB - Abstract Momentum transport is examined in a simulated midlatitude mesoscale convective system (MCS) to investigate its contribution to MCS motion. Momentum budgets are computed using model output to quantify the role of specific processes in determining the low-level wind field in the system’s surface-based cold pool. Results show that toward the leading convective line of the MCS and near the leading edge of the cold pool, the momentum field is most strongly determined by the vertical advection of the storm-induced perturbation wind. Across the middle rear of the system, the wind field is largely a product of the pressure gradient acceleration and, to a lesser extent, the vertical advection of the background environmental (i.e., base state) wind. The relative magnitudes of the vertical advection terms in an Eulerian momentum budget suggest that, for gust-front-driven systems, downward momentum transport by the MCS is a significant driver of MCS motion and potentially severe surface winds. Results further illustrate that the contribution of momentum transport to MCS speed occurs mainly via the enhancement of the cold pool propagation speed as higher-momentum air from aloft is transported into the surface-based cold pool. DA - 2009/10// PY - 2009/10// DO - 10.1175/2009MWR2895.1 VL - 137 IS - 10 SP - 3316-3338 SN - 1520-0493 ER - TY - JOUR TI - TAXONOMIC REVISON OF THE BASAL NEORNITHISCHIAN TAXA THESCELOSAURUS AND BUGENASAURA AU - Boyd, Clint A. AU - Brown, Caleb Marshall AU - Scheetz, Rodney D. AU - Clarke, Julia A. T2 - JOURNAL OF VERTEBRATE PALEONTOLOGY AB - ABSTRACT Considerable controversy surrounds the taxonomy and phylogenetic relationships of Maastrichtian basal neornithischian taxa from North America. Discovery of previously unrecognized cranial material from the paratype specimen of Thescelosaurus neglectus (USNM 7758), along with the examination of two new specimens that preserve nearly complete skulls and mandibles, allows for reevaluation of specimens previously referred to Thescelosaurus that preserve cranial material, including the holotypes of Bugenasaura infernalis (SDSM 7210) and Parksosaurus warreni (ROM 804). A phylogenetic analysis was conducted that included as terminals the holotypes of B. infernalis and P. warreni, the type series of T. neglectus, and six specimens previously referred to Thescelosaurus. This analysis is the first to recover a clade containing all basal neornithischian taxa from the Cretaceous of North America, within which P. warreni is recovered as the sister taxon to a Thescelosaurus clade whose monophyly is supported by five cranial autapomorphies. The results of this analysis support: (1) the synonymization of Bugenasaura with Thescelosaurus; (2) the removal of ROM 804 from Thescelosaurus; and (3) the validity of Thescelosaurus garbanii and its referral to Thescelosaurus despite its fragmentary nature. Currently, Parksosaurus and Thescelosaurus are the only basal neor-nithischian taxa definitively known from Maastrichtian age sediments of North America, while other basal neornithischian taxa proposed to demonstrate fossorial behavior (i.e., Orodromeus, Oryctodromeus, and Zephyrosaurus) are known from Campanian and older sediments. This temporal segregation may support previous hypotheses of an environmental or ecological shift during the latest Cretaceous in North America. DA - 2009/9/12/ PY - 2009/9/12/ DO - 10.1671/039.029.0328 VL - 29 IS - 3 SP - 758-770 SN - 1937-2809 ER - TY - JOUR TI - Systematic along-axis tidal triggering of microearthquakes observed at 9 degrees 50 ' N East Pacific Rise AU - Stroup, D. F. AU - Tolstoy, M. AU - Crone, T. J. AU - Malinverno, A. AU - Bohnenstiehl, D. R. AU - Waldhauser, F. T2 - GEOPHYSICAL RESEARCH LETTERS AB - Hydrothermal fluid circulation at mid‐ocean ridges facilitates the exchange of heat and chemicals between the oceans and the solid Earth, and supports chemosynthetic microbial and macro‐faunal communities. The structure and evolution of newly formed oceanic crust plays a dominant role in controlling the character and longevity of hydrothermal systems; however, direct measurements of subsurface processes remain technologically challenging to obtain. Previous studies have shown that tidally‐induced stresses within the subseafloor modulate both fluid flow and microearthquake origin times. In this study, we observe systematic along‐axis variations between peak microearthquake activity and maximum predicted tidal extension beneath the hydrothermal vent site at 9°50′N East Pacific Rise. We interpret this systematic triggering to result from pore‐pressure perturbations propagating laterally through the hydrothermal system. Based on our observations and a one‐dimensional pore pressure perturbation model, we estimate bulk permeability at ∼10 −13 to 10 −12 m 2 within layer 2B over a calculated diffusive lengthscale of 2.0 km. DA - 2009/9/22/ PY - 2009/9/22/ DO - 10.1029/2009gl039493 VL - 36 SP - SN - 1944-8007 ER - TY - JOUR TI - Photoreactivity of chromophoric dissolved organic matter transported by the Mackenzie River to the Beaufort Sea AU - Osburn, Christopher L. AU - Retamal, Leira AU - Vincent, Warwick F. T2 - Marine Chemistry AB - The photoreactivity of chromophoric dissolved organic matter (CDOM) transported to Arctic shelf environments by rivers has only recently been studied and its quantitative role in Arctic shelf biogeochemistry has received little attention. Sunlight exposure experiments were performed on CDOM collected over a three year period (2002 to 2004) from river, estuary, shelf, and gulf regions of the Western Canadian Arctic. Decreases in CDOM absorption, synchronous fluorescence (SF), and dissolved organic carbon (DOC) concentration were followed after 3 days of exposure, and in two experiments, six optical cutoff filters were used to incrementally remove ultraviolet radiation incident on the samples. Apparent quantum yields for CDOM photobleaching (AQYble) and for DOC photomineralization (AQYmin) were computed, as were two AQY spectra (ϕble and ϕmin) for the Mackenzie River and a sample from the Mackenzie Shelf. The photoreactivity of Mackenzie River CDOM was highest after break-up and peak discharge and lowest in late summer. The half-lives of CDOM and DOC were estimated at 3.7 days and 4.8 days, respectively, when Mackenzie River water was exposed to full sunlight. Photobleaching of Mackenzie River CDOM fluorescence after most UV-B wavelengths were removed increased the correlation between the river and offshore waters in the Beaufort Sea. When light attenuation from particle- and CDOM-rich river water was considered for the Mackenzie Shelf, our photodegradation models estimated around 10% loss of absorption and < 1% DOC loss, suggesting that sunlight exposure does not substantially degrade CDOM on Arctic shelves. DA - 2009/6// PY - 2009/6// DO - 10.1016/j.marchem.2009.05.003 VL - 115 IS - 1-2 SP - 10-20 J2 - Marine Chemistry LA - en OP - SN - 0304-4203 UR - http://dx.doi.org/10.1016/j.marchem.2009.05.003 DB - Crossref KW - Chromophoric dissolved organic matter KW - Dissolved organic carbon KW - Photodegradation KW - Mackenzie River KW - Arctic Ocean ER - TY - JOUR TI - Influence of Environmental Humidity on Tropical Cyclone Size AU - Hill, Kevin A. AU - Lackmann, Gary M. T2 - MONTHLY WEATHER REVIEW AB - Abstract Observations demonstrate that the radius of maximum winds in tropical cyclones (TCs) can vary by an order of magnitude; similar size differences are evident in other spatial measures of the wind field as well as in cloud and precipitation fields. Many TC impacts are related to storm size, yet the physical mechanisms that determine TC size are not well understood and have received limited research attention. Presented here is a hypothesis suggesting that one factor controlling TC size is the environmental relative humidity, to which the intensity and coverage of precipitation occurring outside the TC core is strongly sensitive. From a potential vorticity (PV) perspective, the lateral extent of the TC wind field is linked to the size and strength of the associated cyclonic PV anomalies. Latent heat release in outer rainbands can result in the diabatic lateral expansion of the cyclonic PV distribution and balanced wind field. Results of idealized numerical experiments are consistent with the hypothesized sensitivity of TC size to environmental humidity. Simulated TCs in dry environments exhibit reduced precipitation outside the TC core, a narrower PV distribution, and reduced lateral extension of the wind field relative to storms in more moist environments. The generation of diabatic PV in spiral bands is critical to lateral wind field expansion in the outer portion of numerically simulated tropical cyclones. Breaking vortex Rossby waves in the eyewall lead to an expansion of the eye and the weakening of inner-core PV gradients in the moist environment simulation. Feedback mechanisms involving surface fluxes and the efficiency of diabatic PV production with an expanding cyclonic wind field are discussed. DA - 2009/10// PY - 2009/10// DO - 10.1175/2009MWR2679.1 VL - 137 IS - 10 SP - 3294-3315 SN - 1520-0493 ER - TY - JOUR TI - Early Ordovician rifting of Avalonia and birth of the Rheic Ocean: U-Pb detrital zircon constraints from Newfoundland AU - Pollock, Jeffrey C. AU - Hibbard, James P. AU - Sylvester, Paul J. T2 - JOURNAL OF THE GEOLOGICAL SOCIETY AB - Abstract: Avalonia is the largest accreted crustal block in the Appalachian orogen and comprises a collection of late Neoproterozoic volcano-sedimentary sequences that are overlain by a Palaeozoic platformal sedimentary succession. Detrital zircons from the Conception Group are dominated by 570–620 Ma ages and contain a significant component generated by erosion of coeval igneous arc-volcanic rocks. Overlying samples from the Cuckold and Crown Hill formations are dominated by Neoproterozoic populations with ages between 600 and 650 Ma and are interpreted to be derived from the underlying calc-alkaline arc-plutonic rocks. Early Palaeozoic platform units are dominated by c . 620 Ma zircons with lesser Mesoproterozoic and Palaeoproterozoic zircons. The range of detrital zircon ages is inconsistent with a West African provenance and suggests that Avalonia originated along the Gondwanan margin of the Amazon craton. The influx of Mesoproterozoic and Palaeoproterozoic detritus in the Avalonian platform suggests a major change in tectonic regime. The prominent change in provenance is interpreted to be related to separation of Avalonia from Gondwana during the Early Ordovician opening of the Rheic Ocean. The Redmans Formation is interpreted to represent the rift–drift transition of the Rheic Ocean, which imposes important constraints on the palaeotectonic evolution of Avalonia. Supplementary material: U–Pb isotopic data of LA-ICP-MS analysis of detrital zircons are available at http://www.geolsoc.org.uk/SUP18346. DA - 2009/5// PY - 2009/5// DO - 10.1144/0016-76492008-088 VL - 166 SP - 501-515 SN - 0016-7649 ER - TY - JOUR TI - Development of a Dynamic Pharmacokinetic Model to Estimate Bioconcentration of Xenobiotics in Earthworms AU - Henson-Ramsey, Heather AU - Levine, Jay AU - Kennedy-Stoskopf, Suzanne AU - Taylor, Sharon K. AU - Shea, Damian AU - Stoskopf, Michael K. T2 - ENVIRONMENTAL MODELING & ASSESSMENT DA - 2009/6// PY - 2009/6// DO - 10.1007/s10666-007-9132-4 VL - 14 IS - 3 SP - 411-418 SN - 1573-2967 KW - Pharmacokinetic model KW - Xenobiotic KW - Earthworm KW - Soil ER - TY - JOUR TI - Customization of RegCM3 Regional Climate Model for Eastern Africa and a Tropical Indian Ocean Domain AU - Davis, Neil AU - Bowden, Jared AU - Semazzi, Fredrick AU - Xie, Lian AU - Onol, Baris T2 - JOURNAL OF CLIMATE AB - Abstract Rainfall is a driving factor of climate in the tropics and needs to be properly represented within a climate model. This study customizes the precipitation processes over the tropical regions of eastern Africa and the Indian Ocean using the International Centre for Theoretical Physics (ICTP) Regional Climate Model (RegCM3). The convective schemes of Grell with closures Arakawa–Schubert (Grell–AS)/Fritch–Chappel (Grell–FC) and Massachusetts Institute of Technology–Emanuel (MIT–EMAN) were compared to determine the most realistic spatial distribution of rainfall and partitioning of convective/stratiform rainfall when compared to observations from the Tropical Rainfall Measuring Mission (TRMM). Both Grell–AS and Grell–FC underpredicted convective rainfall rates over land, while over the ocean Grell–FC (Grell–AS) over- (under-) estimates convective rainfall. MIT–EMAN provides the most realistic pardoning and spatial distribution of convective rainfall despite the tendency for overestimating total rainfall. MIT–EMAN was used to further customize the subgrid explicit moisture scheme (SUBEX). Sensitivity tests were performed on the gridbox relative humidity threshold for cloudiness (RHmin) and the autoconversion scale factor (Cacs). An RHmin value of 60% (RHmin-60) reduced the amount of total rainfall over five heterogeneous rainfall regions in eastern Africa, with most of the reduction coming from the convective rainfall. Then, Cacs sensitivity tests improved upon the total rainfall amounts and convective stratiform partitioning compared to RHmin-60. Based upon all sensitivity simulations performed, the combination of the MIT–EMAN convective scheme, RHmin-60, and halving the model default value (0.4) of Cacs provided the most realistic simulation in terms of spatial distribution, convective partition, rainfall totals, and temperature bias when compared to observations. DA - 2009/7// PY - 2009/7// DO - 10.1175/2009JCLI2388.1 VL - 22 IS - 13 SP - 3595-3616 SN - 1520-0442 UR - http://dx.doi.org/10.1175/2009jcli2388.1 ER - TY - JOUR TI - Aging of black carbon in outflow from anthropogenic sources using a mixing state resolved model: 2. Aerosol optical properties and cloud condensation nuclei activities AU - Oshima, N. AU - Koike, M. AU - Zhang, Y. AU - Kondo, Y. T2 - Journal of Geophysical Research AB - The Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution with resolution of a mixing state of black carbon (BC) (referred to as MADRID‐BC hereinafter) has recently been developed to accurately simulate the time evolution of the entire BC mixing state. In this study, we apply MADRID‐BC to evaluate the influence of changes in BC mixing state on aerosol optical properties and cloud condensation nuclei (CCN) activities in air parcels horizontally transported out from an urban area in Japan within the planetary boundary layer (PBL) over the ocean. The evaluation shows that the coatings on BC particles enhance light absorption at a wavelength of 550 nm by 38% in air leaving the source region and by 59% after transport over the ocean for half a day. When the model treats aerosols using the conventional size‐resolved sectional representation that does not resolve BC mixing states, the simulated absorption coefficients and single scattering albedos are greater by 35–44% and smaller by 7–13%, respectively, than those from a simulation that resolves the BC mixing state. These results indicate that it is essential to take into account BC‐free particles in atmospheric models for accurate prediction of aerosol optical properties, because the conventional representation cannot separately treat BC‐containing and BC‐free particles in each size section. The evaluation also shows that BC‐containing particles having 55% and 83% of the BC mass can act as CCN at a supersaturation of 0.05% when they leave the source region and after transport for half a day, respectively. These results suggest the importance of the uplifting of BC particles from the PBL near source regions for their efficient long‐range transport in the free troposphere. Results from comparisons with aerosol optical measurements conducted during various campaigns, such as the Asian Aerosol Characterization Experiment (ACE Asia) and the Indian Ocean Experiment (INDOEX), suggest that MADRID‐BC simulations can capture general features of aerosol optical properties in outflow from anthropogenic sources. DA - 2009/9/19/ PY - 2009/9/19/ DO - 10.1029/2008JD011681 VL - 114 IS - D18 J2 - J. Geophys. Res. LA - en OP - SN - 0148-0227 UR - http://dx.doi.org/10.1029/2008JD011681 DB - Crossref ER - TY - JOUR TI - Wind energy input to the Ekman-Stokes layer: Reply to comment by Jeff A. Polton AU - Liu, B. AU - Wu, K. J. AU - Guan, C. L. T2 - Journal of Oceanography DA - 2009/// PY - 2009/// VL - 65 IS - 5 SP - 669-673 ER - TY - JOUR TI - Variations in temperature and salinity of the surface water above the middle Okinawa Trough during the past 37kyr AU - Yu, Hua AU - Liu, Zhenxia AU - Berné, Serge AU - Jia, Guodong AU - Xiong, Yingqian AU - Dickens, Gerald R. AU - Wei, Gangjian AU - Shi, Xuefa AU - Liu, J.Paul AU - Chen, Fajin T2 - Palaeogeography, Palaeoclimatology, Palaeoecology AB - East China Sea (ECS) is an important climate modulator of East Asia. In the last glacial period, the global sea level, the path and strength of the Kuroshio Current experienced great changes; combined with the variable volume of fresh run-off input, they made the hydrographic situation in the ECS quite different from nowadays. Based on high-resolution alkenone-sea surface temperature (SST) and oxygen isotope composition of planktonic foraminifera Globigerinoides sacculifer we reconstructed paleo-sea surface salinity (SSS) of a long piston core DGKS9604 retrieved from the middle Okinawa Trough of the eastern ECS. The δ18O and SST records display significant variations with global ice volume. Synchrony of the millennial-scale climate events like YD and Heinrich events of core DGKS9604 to the ice core from the northern high latitudes, and the synchroneity of deglacial warming with the Bølling–Allerød warming suggests a strong coupling of the SST variations in the marginal Pacific Ocean to the climate of the North Atlantic, most likely through the Asian monsoon atmospheric circulation. The ECS documents lowest SST (22 °C) at ~ 26 cal kyr BP and ~ 3 °C SST difference between the full glaciation (26 to 19 cal kyr BP) and mid-to-late Holocene (6 cal kyr BP–present). The overall long-term hydrographic variations in the middle Okinawa Trough are controlled by temporal and spatial variations in: (i) the intensity and position of the Kuroshio Current, (ii) intensity of the Asian summer monsoon and (iii) sea-level fluctuations coupled with ECS topography. Saline surface water dominated over the middle Okinawa Trough during early pre-glaciation (37 to 31 cal kyr BP), last deglaciation (19 to 11.6 cal kyr BP), and mid-to-late Holocene (6 cal kyr BP–present), whilst freshened surface water prevailed during the late pre-glaciation (31 to 26 cal kyr BP), full glaciation (26 to 19 cal kyr BP) and early Holocene (11.6 to 6 cal kyr BP). DA - 2009/10// PY - 2009/10// DO - 10.1016/j.palaeo.2009.08.002 VL - 281 IS - 1-2 SP - 154-164 J2 - Palaeogeography, Palaeoclimatology, Palaeoecology LA - en OP - SN - 0031-0182 UR - http://dx.doi.org/10.1016/j.palaeo.2009.08.002 DB - Crossref KW - East China Sea KW - Okinawa Trough KW - Kuroshio Current KW - East Asian monsoon KW - Sea surface temperature KW - Sea surface salinity ER - TY - JOUR TI - Stable oxygen and carbon isotope profiles in an invasive bivalve (Corbicula fluminea) in North Carolina watersheds AU - Bucci, John P. AU - Showers, William J. AU - Genna, Bernie AU - Levine, Jay F. T2 - Geochimica et Cosmochimica Acta AB - The modern invasive bivalve Corbicula fluminea was collected in 2006 from three sites with different land uses located in a North Carolina River Basin. The primary objective was to describe the δ18O and δ13C profiles of C. fluminea shells under various land use conditions. An additional aim was to evaluate whether growth patterns of C. fluminea form seasonally. Annual shell growth patterns were measured from the umbo to the margin and co-varied with estimates of ambient water temperature, corresponding to seasonal variation. The C. fluminea growth patterns as translucent bands (slower growth) appeared to form during winter months and opaque bands (rapid growth) formed during summer. A mixed model analysis (ANOVA) showed a significant site level effect of δ18O and δ13C profiles examined among sites (F = 17.1; p = 0.003). A second model showed a borderline significant site effect among profiles with variability more pronounced at the urban site, Crabtree Creek (p = 0.085). Previous habitat assessment ratings and water chemistry measurements suggested that the urban site was more impacted by storm water runoff. Understanding δ18O and δ13CSHELL profiles and shell growth patterns of the invasive bivalve (C. fluminea) may help establish a framework for using these animals as biomonitors to record water temperature and nutrient pollution. DA - 2009/6// PY - 2009/6// DO - 10.1016/j.gca.2009.03.023 VL - 73 IS - 11 SP - 3234-3247 J2 - Geochimica et Cosmochimica Acta LA - en OP - SN - 0016-7037 UR - http://dx.doi.org/10.1016/j.gca.2009.03.023 DB - Crossref ER - TY - JOUR TI - Spatial and temporal dynamics of coupled groundwater and nitrogen fluxes through a streambed in an agricultural watershed AU - Kennedy, Casey D. AU - Genereux, David P. AU - Corbett, D. Reide AU - Mitasova, Helena T2 - WATER RESOURCES RESEARCH AB - This paper presents results on the spatiotemporal dynamics of the coupled water flux ( v ) and nitrogen fluxes ( f N = v [N], where [N] is the concentration of a dissolved N species) through a streambed in an agricultural watershed in North Carolina. Physical and chemical variables were measured at numerous points in the streambed of a 0.26‐km reach: hydraulic conductivity ( K ) and head gradient ( J ) and the concentrations of NO 3 − and other N species in streambed groundwater, from which water flux ( v = KJ ) and N fluxes (e.g., f NO3 = v [NO 3 − ]) through the streambed were computed, mapped, and integrated in space. The result was a novel set of streambed maps of the linked variables ( K , J , v , and N concentrations and fluxes), showing their spatial variability and how it changed over a year (on the basis of seven bimonthly sets of maps). Mean f NO3 during the study year was 154 mmol m −2 d −1 ; this NO 3 − flux, together with that of dissolved organic nitrogen ( f DON = 17 mmol m −2 d −1 ), accounted for >99% of the total dissolved N flux through the streambed. Repeat measurements at the same locations on the streambed show significant temporal variability in f NO3 , controlled largely by changes in v rather than changes in [NO 3 − ]. One of the clearest and most persistent aspects of spatial variability was lateral variability across the channel from bank to bank. K and v values were greater in the center of the channel; this distribution of K (ultimately a reflection of sediment dynamics in the channel) apparently focuses groundwater discharge toward the center of the channel. The opposite pattern (low values in the center) was found for J , [NO 3 − ], and (to a lesser extent) f NO3 . Overall, f NO3 was characterized by localized zones of high and low values that changed in size and shape over time but remained in basically the same locations (the same was true of K , J , and [NO 3 − ], though less so for v ), with 70% of NO 3 − flux occurring through about 38% of the streambed area. Lateral distributions of the physical hydrologic attributes ( K , J , and v ) were highly symmetrical across the channel, while those of [NO 3 − ] and f NO3 showed higher values on the left than on the right, likely a reflection of different N use on opposite sides of the stream. The streambed‐based approach taken here offers insights concerning the spatial and temporal dynamics of linked water and N fluxes through a streambed and their controls. DA - 2009/9/3/ PY - 2009/9/3/ DO - 10.1029/2008wr007397 VL - 45 IS - 9 SP - SN - 0043-1397 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-72149089873&partnerID=MN8TOARS ER - TY - JOUR TI - Relationships among groundwater age, denitrification, and the coupled groundwater and nitrogen fluxes through a streambed AU - Kennedy, Casey D. AU - Genereux, David P. AU - Corbett, D. Reide AU - Mitasova, Helena T2 - WATER RESOURCES RESEARCH AB - The relationships among coupled groundwater and nitrogen (N) fluxes, groundwater age, and denitrification were examined for a section of West Bear Creek, an agricultural stream in the coastal plain of North Carolina, United States. Simultaneous streambed measurements of hydraulic conductivity ( K ) and hydraulic head gradient ( J ) and the concentrations of NO 3 − ([NO 3 − ]), dissolved gases, and chlorofluorocarbons in groundwater were interpolated, mapped, and (for water flux v = KJ and nitrate flux f NO3 = v [NO 3 − ]) integrated over the streambed area. Nitrate and dissolved organic N accounted for 92 and 8% of N flux through the streambed, respectively. Streambed maps show a band of greater groundwater age, and lower [NO 3 − ] and f NO3 , running through the center of most of the study reach. Nitrate flux ( f NO3 ) exhibits this “center‐low” pattern even though one of its controlling factors, groundwater flux ( v ), has on average the opposite “center‐high” pattern. An inverse relationship between [NO 3 − ] and age is indicative of fertilizer as the primary source of groundwater NO 3 − . Denitrification reduced mean f NO3 by ∼50%, from 370 mmol m −2 d −1 (what it would have been in the absence of denitrification) to 173 mmol m −2 d −1 (what it actually was). Measurement of both groundwater age and v made possible a new method for estimating flow‐weighted mean groundwater age ( τ FWM ), an important aquifer hydraulic characteristic related to groundwater storage and recharge rate. This method gives τ FWM = 30 years, which, along with the overall distribution of groundwater ages, suggests the possibility of a significant time lag between changes in N fertilizer application rates and NO 3 − flux from groundwater to West Bear Creek. Differences in streambed groundwater chemistry between the left and right sides of the streambed suggest differences in agricultural practices on opposite sides of the stream. DA - 2009/9/3/ PY - 2009/9/3/ DO - 10.1029/2008wr007400 VL - 45 IS - 9 SP - SN - 1944-7973 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-72149099351&partnerID=MN8TOARS ER - TY - JOUR TI - Predicting Atlantic Tropical Cyclone Seasonal Activity in April AU - Keith, Elinor AU - Xie, Lian T2 - WEATHER AND FORECASTING AB - Abstract Seasonal hurricane forecasts are continuing to develop skill, although they are still subject to large uncertainties. This study uses a new methodology of cross-correlating variables against empirical orthogonal functions (EOFs) of the hurricane track density function (HTDF) to select predictors. These predictors are used in a regression model for forecasting seasonal named storm, hurricane, and major hurricane activity in the entire Atlantic, the Caribbean Sea, and the Gulf of Mexico. In addition, a scheme for predicting landfalling tropical systems along the U.S. Gulf of Mexico, southeastern, and northeastern coastlines is developed, but predicting landfalling storms adds an extra layer of uncertainty to an already complex problem, and on the whole these predictions do not perform as well. The model performs well in the basin-wide predictions over the entire Atlantic and Caribbean, with the predictions showing an improvement over climatology and random chance at a 95% confidence level. Over the Gulf of Mexico, only named storms showed that level of predictability. Predicting landfalls proves more difficult, and only the prediction of named storms along the U.S. southeastern and Gulf coasts shows an improvement over random chance at the 95% confidence level. Tropical cyclone activity along the U.S. northeastern coast is found to be unpredictable in this model; with the rarity of events, the model is unstable. DA - 2009/4// PY - 2009/4// DO - 10.1175/2008WAF2222139.1 VL - 24 IS - 2 SP - 436-455 SN - 1520-0434 ER - TY - JOUR TI - Idealized simulation of hydrodynamic characteristics of Lake Victoria that potentially modulate regional climate AU - Anyah, Richard O. AU - Semazzi, Fredrick T2 - INTERNATIONAL JOURNAL OF CLIMATOLOGY AB - Abstract This study explores, through three‐dimensional (3D)‐lake model simulations, the unique thermodynamic and hydrodynamic characteristics of Lake Victoria that can potentially modulate the lake catchment climate. The simulations are mostly based on idealized forcing due to lack of sufficient observed data. A suite of simulations with an elliptic (oval) geometry and prescribed wind speed (surface wind stress), lake–atmosphere temperature difference and vertical temperature profile are performed. The time evolutions of lake temperature as well as the currents (circulation characteristics) at different depths and/or points are analysed to understand the lake's response to certain aspects of surface forcing conditions. Similarities and differences between the features simulated in a typical tropical lake (Lake Victoria) and typical mid‐latitude lake based on the effects of the Coriolis force are also examined. Our simulations revealed a number of unique features in the time and space evolutions and profiles of the lake temperature. Considered at different points on the lake surface, the temperature of both runs with or without effect of Coriolis force equilibrates after almost the same time (between 30 and 40 days). However, there is a conspicuous difference in the vertical temperature profiles of the two runs (cases). For example, the MIDLAT run is characterized by a ‘dome‐shaped’ profile in the bottom layers (40 m and deeper) after 30 days of model integration, in contrast to the VICTORIA case which is nearly isothermal over the full water column. Perhaps one of the most significant outcomes of the present study is that the two‐gyre circulation pattern shown in the VICTORIA case after 30 days of model integration is also present in the simulations with observed lake bathymetry. Even more significant is that our results with a fully coupled regional climate‐3D lake hydrodynamics simulate more realistic evaporation/evapotranspiration and precipitation over the lake surface and immediate environs. Copyright © 2008 Royal Meteorological Society DA - 2009/6/15/ PY - 2009/6/15/ DO - 10.1002/joc.1795 VL - 29 IS - 7 SP - 971-981 SN - 0899-8418 KW - Lake Victoria influence on regional climate KW - Lake Victoria hydrodynamics KW - lake currents KW - time and space evolutions of lake temperatures ER - TY - JOUR TI - Domestic wastewater influent profiling using mitochondrial real-time PCR for source tracking animal contamination AU - Caldwell, Jane M. AU - Levine, Jay F. T2 - Journal of Microbiological Methods AB - Real-time PCR amplifying mammalian and avian mitochondrial DNA (mtDNA) was developed to characterize domestic and light industrial wastewater influent from two municipal wastewater treatment facilities (WWTF) over a 24-week period. Influent samples were assayed with species-specific primers and dual-labeled probes for human, bovine, swine, dog, cat, Canada goose and white-tailed deer to detect and quantify eukaryotic mtDNA contributors to local municipal wastewaters. Human (mean=9.6 x 10(4) copies/ml) and dog (mean=5.3 x 10(2) copies/ml) mtDNA were detected in all 24 samples (12 samples/site). Bovine and swine mtDNA were detected sporadically and at lower levels than human mtDNA, means=3.0 x 10(4) and 9.5 x 10(2) copies/ml, respectively. Domestic cat, Canada goose and white-tailed deer were detected only once in 24 samples. Mitochondrial DNA concentrations were compared to other bacterial, chemical and spectrophotometric parameters. Human mtDNA was positively correlated with ammonia concentration (P=0.01) and initial OD(600) reading (P=0.02) at one WWTF. Bovine mtDNA was positively correlated with biological oxygen demand (BOD) (P=0.02), final DNA concentration (P=0.03), initial and final humic acid concentrations (P=0.01, P=0.01), and final OD(600) (P=0.03) at one WWTF and total suspended solids (TSS) (P=0.04, P=0.09) at both facilities. Fecal coliforms were not positively or negatively correlated with mtDNA concentrations of any species assayed. For source tracking purposes, a combination of human (10(5) copies/ml) and dog mtDNA signal (10(2) copies/ml) could be indicative of municipal domestic wastewater contamination of environmental waters. DA - 2009/4// PY - 2009/4// DO - 10.1016/j.mimet.2008.11.007 VL - 77 IS - 1 SP - 17-22 J2 - Journal of Microbiological Methods LA - en OP - SN - 0167-7012 UR - http://dx.doi.org/10.1016/j.mimet.2008.11.007 DB - Crossref KW - Fecal contaminants KW - Mitochondrial DNA KW - Source tracking KW - Wastewater ER - TY - JOUR TI - Dental microwear in the orthodentine of the Xenarthra (Mammalia) and its use in reconstructing the palaeodiet of extinct taxa: the case study of Nothrotheriops shastensis (Xenarthra, Tardigrada, Nothrotheriidae) AU - Green, Jeremy L. T2 - ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY AB - The utility of orthodentine microwear analysis as a proxy for dietary reconstruction in xenarthrans (tree sloths, armadillos) was quantitatively and statistically accessed via low-magnification stereomicroscopy. Features such as number of scratches and pits, as well as presence of gouges, hypercoarse scratches, > four large pits, > four cross scratches, and fine, mixed or coarse scratch texture were recorded in 255 teeth from 20 extant xenarthran species. Feature patterns are consistent with scar formation through abrasional (tooth–food) and attritional (tooth–tooth) contact. Number of scratches is the most dietary diagnostic microwear variable for xenarthrans, with herbivorous sloths characterized by > ten scratches and nonherbivorous armadillos by < ten scratches. Discriminant function analysis differentiated arboreal folivores (sloths) and frugivore-folivores (sloths) both from each other and from fossorial carnivore-omnivores (armadillos) and insectivores (armadillos). Microwear patterns in carnivore-omnivores and insectivores are difficult to distinguish between; armadillo microwear may reflect a fossorial lifestyle (grit consumption) rather than primary diet. Cabassous centralis is anomalous in its microwear signal relative to all other insectivores. To test the utility of orthodentine microwear analysis as an indicator of palaeodiet in extinct xenarthrans, microwear in the ground sloth Nothrotheriops shastensis was quantitatively and statistically compared to microwear in extant taxa. Microwear patterns in N. shastensis are most comparable to extant folivores based on scratch number and hierarchical cluster analysis. This strongly supports an herbivorous diet for N. shastensis that is corroborated by multiple independent lines of evidence. Thus, orthodentine microwear analysis can be used to reconstruct diet in extinct xenarthrans. DA - 2009/5// PY - 2009/5// DO - 10.1111/j.1096-3642.2008.00486.x VL - 156 IS - 1 SP - 201-222 SN - 0024-4082 KW - armadillos KW - Cingulata KW - dentine KW - diet KW - ecology KW - ground sloths KW - teeth KW - tree sloths ER - TY - JOUR TI - Coastal Erosion Induced by Human Activities: A Northwest Bohai Sea Case Study AU - Xue, Zuo AU - Feng, Aiping AU - Yin, Ping AU - Xia, Dongxing T2 - JOURNAL OF COASTAL RESEARCH AB - Using mooring hydrodynamic observation, cross-shore profiles, and topographic-map and satellite-image comparisons, this study shows dramatic coastal erosion on the Qinhuangdao coast (northeast Bohai Sea, China) between 1986 and 2000, with an average retreat rate of 3.7 m/y. While the retreat rate during 1996–2003 decreased to 1.5 m/y, serious coastal erosion was found around river mouths, such as the Tang, Dai, Yang, Dapu, and Renzaohe Rivers, as well as Qilihai Lagoon, with the maximum of >7.0 m/y. Sediment starvation induced by dams mainly caused this fast coastal retreat. Sediment flux of the Luan River, the dominant fluvial sediment source in the study area, declined to only 9.0% of the levels before the impoundment of two large dams in 1979. Sharply reduced sediment supply disrupted the stability of sediment transport as well as the beaches' self-recovery processes after storm surges. Coastal erosion was further intensified by coastal engineering and tourism activities. DA - 2009/5// PY - 2009/5// DO - 10.2112/07-0959.1 VL - 25 IS - 3 SP - 723-733 SN - 0749-0208 KW - Luan River KW - coastal retreat KW - sediment transport KW - Qinhuangdao coast ER - TY - JOUR TI - Chemical and isotopic signature of old groundwater and magmatic solutes in a Costa Rican rain forest: Evidence from carbon, helium, and chlorine AU - Genereux, David P. AU - Webb, Mathew AU - Solomon, D. Kip T2 - WATER RESOURCES RESEARCH AB - C, He, and Cl concentrations and isotopes in groundwater and surface water in a lowland Costa Rican rain forest are consistent with the mixing of two distinct groundwaters: (1) high‐solute bedrock groundwater representing interbasin groundwater flow (IGF) into the rain forest and (2) low‐solute local groundwater recharged in the lowlands. In bedrock groundwater, high δ 13 C (−4.89‰), low 14 C (7.98 pM), high R/R A for He (6.88), and low 36 Cl/Cl (17 × 10 −15 ) suggest that elevated tracer concentrations are derived from magmatic outgassing and/or weathering of volcanic rock beneath nearby Volcan Barva. In local groundwater, the magmatic signature is absent, and data suggest atmospheric sources for He and Cl and a biogenic soil gas CO 2 source for dissolved inorganic carbon. Dating of 14 C suggests that the age of bedrock groundwater is 2400–4000 years (most likely at the lower end of the range). Local groundwater has 14 C > 100 pM, indicating the presence of “bomb carbon” and thus ages less than ∼55 years. Overall, data are consistent with a conceptual hydrologic model originally proposed on the basis of water budget and major ion data: (1) large variation in solute concentrations can be explained by mixing of the two distinct groundwaters, (2) bedrock groundwater is much older than local groundwater, (3) elevated solute concentrations in bedrock groundwater are derived from volcanic fluids and/or rock, and (4) local groundwater has not interacted with volcanic rock. Tracers with different capabilities converge on the same hydrologic interpretation. Also, transport of magmatic CO 2 into the lowland rain forest via IGF seems to be significant relative to other large ecosystem‐level carbon fluxes. DA - 2009/8/11/ PY - 2009/8/11/ DO - 10.1029/2008wr007630 VL - 45 SP - SN - 1944-7973 ER - TY - JOUR TI - Broadband calibration of the R/V Marcus G. Langseth four-string seismic sources AU - Tolstoy, M. AU - Diebold, J. AU - Doermann, L. AU - Nooner, S. AU - Webb, S. C. AU - Bohnenstiehl, D. R. AU - Crone, T. J. AU - Holmes, R. C. T2 - GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS AB - The R/V Marcus G. Langseth is the first 3‐D seismic vessel operated by the U.S. academic community. With up to a four‐string, 36‐element source and four 6‐km‐long solid state hydrophone arrays, this vessel promises significant new insights into Earth science processes. The potential impact of anthropogenic sound sources on marine life is an important topic to the marine seismic community. To ensure that operations fully comply with existing and future marine mammal permitting requirements, a calibration experiment was conducted in the Gulf of Mexico in 2007–2008. Results are presented from deep (∼1.6 km) and shallow (∼50 m) water sites, obtained using the full 36‐element (6600 cubic inches) seismic source. This array configuration will require the largest safety radii, and the deep and shallow sites provide two contrasting operational environments. Results show that safety radii and the offset between root‐mean‐square and sound exposure level measurements were highly dependent on water depth. DA - 2009/8/15/ PY - 2009/8/15/ DO - 10.1029/2009gc002451 VL - 10 SP - SN - 1525-2027 KW - calibration KW - Langseth KW - seismic ER - TY - JOUR TI - AFFINITIES OF PALAEOSPIZA BELLA AND THE PHYLOGENY AND BIOGEOGRAPHY OF MOUSEBIRDS (COLIIFORMES) AU - Ksepka, Daniel T. AU - Clarke, Julia A. T2 - AUK AB - Palaeospiza bella was described as an oscine songbird in the late 19th century. The late Eocene age of the holotype specimen would make it the oldest Northern Hemisphere record of the Passeriformes. However, few recent workers have accepted the placement of P. bella within Passeriformes, and the higher relationships of this fossil have remained controversial. We show that P. bella is a member of the Coliiformes (mousebirds) and represents the latest North American occurrence of a clade with an exclusively African extant distribution. Coliiformes are now known from the latest Paleocene to the approach of the Eocene-Oligocene boundary in North America. We present a redescription of P. bella and a new phylogenetic analysis of fossil and living Coliiformes based on a matrix including 49 characters and 18 ingroup taxa. The results of this analysis place P. bella in Colii, the clade comprising taxa more closely related to Coliidae (crown mousebirds) than to the extinct Sandcoleidae. The oldest stem-group Coliiformes are late Paleocene (about 56.2–56.6 Ma) in age. However, no fossil taxon can be confidently placed within the crown clade Coliidae at present. Phylogenetic results imply that a minimum of three mousebird dispersals from Europe to North America occurred during the Early Cenozoic. Review of the early Eocene fossil Eocolius walkeri from the London Clay shows that this taxon lacks convincing coliiform synapomorphies and should be removed from the clade. DA - 2009/4// PY - 2009/4// DO - 10.1525/auk.2009.07178 VL - 126 IS - 2 SP - 245-259 SN - 1938-4254 KW - Coliidae KW - Coliiformes KW - Florissant Formation KW - fossil KW - mousebird KW - Palaeospiza bella KW - phylogeny ER - TY - JOUR TI - US GODAE global ocean prediction with the Hybrid Coordinate Ocean Model (HYCOM) AU - Chassignet, E. P. AU - Hurlburt, H. E. AU - Metzger, E. J. AU - Smedstad, O. M. AU - Cummings, J. A. AU - Halliwell, G. R. AU - Bleck, R. AU - Baraille, R. AU - Wallcraft, A. J. AU - Lozano, C. AU - Tolman, H. L. AU - Srinivasan, A. AU - Hankin, S. AU - Cornillon, P. AU - Weisberg, R. AU - Barth, A. AU - He, Ruoying T2 - Oceanography DA - 2009/// PY - 2009/// DO - 10.5670/oceanog.2009 VL - 22 IS - 2 SP - 64–75 ER - TY - JOUR TI - Long-Term Effects of Changing Land Use Practices on Surface Water Quality in a Coastal River and Lagoonal Estuary AU - Rothenberger, Meghan B. AU - Burkholder, JoAnn M. AU - Brownie, Cavell T2 - ENVIRONMENTAL MANAGEMENT DA - 2009/9// PY - 2009/9// DO - 10.1007/s00267-009-9330-8 VL - 44 IS - 3 SP - 505-523 SN - 1432-1009 KW - Agriculture KW - Estuary KW - Eutrophication KW - Land use KW - Longitudinal regression models KW - Urban KW - Watershed ER - TY - JOUR TI - Implications of Beaver Castor canadensis and Trout Introductions on Native Fish in the Cape Horn Biosphere Reserve, Chile AU - Moorman, Michelle C. AU - Eggleston, David B. AU - Anderson, Christopher B. AU - Mansilla, Andres AU - Szejner, Paul T2 - TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY AB - Abstract Invasive species threaten global biodiversity, but multiple invasions make predicting the impacts difficult because of potential synergistic effects. We examined the impact of introduced beaver Castor canadensis , brook trout Salvelinus fontinalis , and rainbow trout Oncorhynchus mykiss on native stream fishes in the Cape Horn Biosphere Reserve, Chile. The combined effects of introduced species on the structure of the native freshwater fish community were quantified by electrofishing 28 stream reaches within four riparian habitat types (forest, grassland, shrubland, and beaver‐affected habitat) in 23 watersheds and by measuring related habitat variables (water velocity, substrate type, depth, and the percentage of pools). Three native stream fish species (puye Galaxias maculatus [also known as inanga], Aplochiton taeniatus , and A. zebra ) were found along with brook trout and rainbow trout, but puye was the only native species that was common and widespread. The reaches affected by beaver impoundments had significantly higher puye densities than all other reaches in this study. These results are comparable to those reported for other streams in southern Chile. The presence of trout reduced the abundance of puye, but only in beaver‐affected areas; all three natural riparian habitat types had uniformly low puye abundance and were unaffected by the presence or absence of trout. The data suggest that one invasive species, the beaver, enhanced puye habitat and thereby increased the abundance of that species, which, in turn, helped moderate the negative impacts of invasive trout. DA - 2009/3// PY - 2009/3// DO - 10.1577/T08-081.1 VL - 138 IS - 2 SP - 306-313 SN - 1548-8659 ER - TY - JOUR TI - Environmental Ingredients for Supercells and Tornadoes within Hurricane Ivan AU - Baker, Adam K. AU - Parker, Matthew D. AU - Eastin, Matthew D. T2 - WEATHER AND FORECASTING AB - Abstract Hurricane Ivan (2004) was a prolific producer of tornadoes as it made landfall on the U.S. Gulf Coast. Prior researchers have revealed that the tornadic cells within tropical cyclone (TC) rainbands are often supercellular in character. The present study investigates the utility of several common midlatitude, continental supercell and tornado diagnostic tools when applied to Hurricane Ivan’s tornado episode. The environment within Hurricane Ivan was favorable for storm rotation. While well offshore, the bands of Hurricane Ivan possessed embedded cells with mesocyclones of moderate intensity. A dual-Doppler analysis reveals that the updrafts of these cells were highly helical in the lower troposphere, suggesting significant ingestion of streamwise environmental vorticity. These coherent cells were long lived and could be tracked for multiple hours. As the supercells over the Gulf of Mexico approached the coast during Ivan’s landfall, rapid increases in midlevel vorticity and vertically integrated liquid (VIL) occurred. Based on compiled severe weather reports, these increases in storm intensity appear often to have immediately preceded tornadogenesis. The local environment for supercells in Ivan’s interior is evaluated through the use of 62 soundings from the operational land-based network and from research flights. There were substantial differences in the thermodynamic profiles and wind profiles at differing ranges from Ivan’s center, from quadrant to quadrant of Ivan’s circulation, and between land and sea. The most optimal environment for supercells and tornadoes occurred in the most interior section of Ivan’s right-front quadrant, with conditions being even more favorable over land than over the sea. For contrast, comparable values are presented for Hurricane Jeanne (2004), which was similar to Ivan in several respects, but was not a prolific tornado producer at landfall. Although both storms provided environments with comparable shallow—and deep—layer vertical wind shear, the Ivan environment had notably more CAPE, likely due to a prominent dry air intrusion. This increase in CAPE was reflected in substantial increases in common operational forecasting composite indices. The results suggest that the conventionally assessed ingredients for midlatitude continental supercells and tornadoes can be readily applied to discriminate among TC tornado episodes. DA - 2009/2// PY - 2009/2// DO - 10.1175/2008WAF2222146.1 VL - 24 IS - 1 SP - 223-244 SN - 1520-0434 ER - TY - JOUR TI - Do Blue Crab Spawning Sanctuaries in North Carolina Protect the Spawning Stock? AU - Eggleston, David B. AU - Bell, Geoffrey W. AU - Searcy, Steven P. T2 - TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY AB - Abstract Spawning sanctuaries located at the five major inlets to Pamlico Sound, North Carolina, as well as various harvest controls, have not been adequate to protect the spawning stock of the blue crab Callinectes sapidus . We conducted an extensive trawl survey within Pamlico and Croatan sounds as well as five inlet spawning sanctuaries during 2002 to quantify the spatiotemporal use of spawning sanctuaries by mature female blue crabs and to identify potential migration corridors to spawning grounds. The abundance of mature females was highest along the northwestern portion of Pamlico Sound, suggesting this is an important staging area for females before their seaward migration; however, there was no clear evidence of specific migration corridors. Mature female abundance was no different inside inlet sanctuary boundaries versus 1‐2 km outside sanctuary boundaries, and sanctuaries only protect 44.9% and 0.7% of the current local inlet and Pamlico Sound‐wide spawning populations, respectively, of mature female blue crabs. In general, the abundance of mature female blue crabs was higher at inlets located to the extreme north or south in Pamlico Sound than at inlets located in the central portion of the sound. The results from this study suggest that the particular geometry and placement of inlet spawning sanctuaries are not adequate to protect the North Carolina blue crab spawning stock, and other management options should be considered, such as (1) a double sanctuary and migration corridor system located in northern and southern portions of Croatan and Pamlico sounds coupled with either (2) reduction of fishery effort on females or (3) seasonal closures. DA - 2009/5// PY - 2009/5// DO - 10.1577/T08-070.1 VL - 138 IS - 3 SP - 581-592 SN - 1548-8659 ER - TY - JOUR TI - Coupling winds to ocean surface currents over the global ocean AU - Deng, Zengan AU - Xie, Lian AU - Liu, Bin AU - Wu, Kejian AU - Zhao, Dongliang AU - Yu, Ting T2 - OCEAN MODELLING AB - A Wind stress–Current Coupled System (WCCS) consisting of the HYbrid Coordinate Ocean Model (HYCOM) and an improved wind stress algorithm based on Donelan et al. [Donelan, W.M., Drennan, Katsaros, K.B., 1997. The air–sea momentum flux in mixed wind sea and swell conditions. J. Phys. Oceanogr. 27, 2087–2099] is developed by using the Earth System Modeling Framework (ESMF). The WCCS is applied to the global ocean to study the interactions between the wind stress and the ocean surface currents. In this study, the ocean surface current velocity is taken into consideration in the wind stress calculation and air–sea heat flux calculation. The wind stress that contains the effect of ocean surface current velocity will be used to force the HYCOM. The results indicate that the ocean surface velocity exerts an important influence on the wind stress, which, in turn, significantly affects the global ocean surface currents, air–sea heat fluxes, and the thickness of ocean surface boundary layer. Comparison with the TOGA TAO buoy data, the sea surface temperature from the wind–current coupled simulation showed noticeable improvement over the stand-alone HYCOM simulation. DA - 2009/// PY - 2009/// DO - 10.1016/j.ocemod.2009.05.003 VL - 29 IS - 4 SP - 261-268 SN - 1463-5011 KW - Wind-Current Coupled System KW - HYCOM KW - Wind stress KW - Heat flux KW - Ocean surface boundary layer KW - ESMF KW - Ocean current ER - TY - JOUR TI - Chlorophyll a in Arctic sediments implies long persistence of algal pigments AU - Pirtle-Levy, Rebecca AU - Grebmeier, Jacqueline M. AU - Cooper, Lee W. AU - Larsen, Ingvar L. T2 - DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY AB - Sediment cores were collected from the shelf, slope, and basin of the Bering, Chukchi, and Beaufort Seas during May–June (under ice cover) and July–August (largely ice-free) 2004. Measurements of chlorophyll a (chl a), total organic carbon (TOC), and C/N ratios were made in surface and some subsurface core increments. Surface sediment chl a decreased with increasing water depth. Significant positive correlations were found between chl a and TOC and chl a and C/N ratios in the basin (>2000 m), but there were significant negative correlations between chl a and C/N ratios on the shelf (⩽200 m). Chl a values generally declined in down-core profiles, but in some deeper slope and basin cores, measurable inventories of subsurface chl a were present at depth. In some cases, these subsurface chlorophyll inventories coincident with peak activities of the anthropogenic radionuclide 137Cs were detected, which had maximal deposition following the atmospheric nuclear weapons testing era in the 1960s. A sedimentation rate independently determined for one of these cores using 210Pb was consistent with the depths of subsurface 137Cs peaks in slope sediments reflecting steady, relatively undisturbed deposition over a several-decade period. The depth of penetration of 137Cs in some continental slope sediments, together with detectable chl a, suggests that chl a can be buried in some of these deeper-water sediments under cold conditions for decadal periods in the absence of deposit feeders. Because organic deposition from the water column is episodic at high latitudes and concentrated following the spring bloom, these buried sources of organic materials, whether on the shelf or in deeper basin sediments, may ultimately be important for benthic invertebrates that could utilize this food source during times of the year when primary production flux from the overlying water column is reduced. DA - 2009/8/1/ PY - 2009/8/1/ DO - 10.1016/j.dsr2.2008.10.022 VL - 56 IS - 17 SP - 1326-1338 SN - 1879-0100 KW - Chlorophyll KW - Sediments KW - Benthic infauna KW - Cesium-137 KW - Arctic KW - Bering Sea ER - TY - JOUR TI - Broken gears in the avian molecular clock: New phylogenetic analyses support stem galliform status for Gallinuloides wyomingensis and rallid affinities for Amitabha urbsinterdictensis AU - Ksepka, D. T. T2 - Cladistics DA - 2009/// PY - 2009/// VL - 25 IS - 2 SP - 173-197 ER - TY - JOUR TI - Bimolecular Rate Constant Determination for the Reaction of Hydroxyl Radicals with Domoic and Kainic Acid in Aqueous Solution AU - Jones, Kimberly G. AU - Cooper, William J. AU - Mezyk, Stephen P. T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - Bimolecular rate constants for the hydroxyl radical, ·OH, reaction with domoic acid, kainic acid, and several model compounds were determined using electron pulse radiolysis and transient absorption spectroscopy. These oxidation rate constants were determined as (9.22 ± 0.60) × 109 M−1 s−1 and (2.46 ± 0.19) × 109 M−1 s−1, for domoic acid and kainic acid, respectively. Model compound rate constant measurements suggested that the conjugated double bond of the C4 substituent of domoic acid, and the double bond in kainic acid, were the preferential initial site of ·OH reaction, which would destroy the conjugation and/or molecular conformation of these toxins. These reaction rate constants were also used to determine potential persistence in natural water systems, however the calculated half-life for domoic acid of ∼34 days implies that significant photodegradation via ·OH reaction mechanisms is unlikely. DA - 2009/9/1/ PY - 2009/9/1/ DO - 10.1021/es901128c VL - 43 IS - 17 SP - 6764-6768 SN - 1520-5851 ER - TY - JOUR TI - A COLLABORATIVE APPROACH TO STUDY NORTHWEST FLOW SNOW IN THE SOUTHERN APPALACHIANS AU - Keighton, Steve AU - Lee, Laurence AU - Holloway, Blair AU - Hotz, David AU - Zubrick, Steven AU - Hovis, Jeffrey AU - Votaw, Gary AU - Perry, L. Baker AU - Lackmann, Gary AU - Yuter, Sandra E. AU - Konrad, Charles AU - Miller, Douglas AU - Etherton, Brian T2 - BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY AB - Upslope-enhanced snowfall events during periods of northwesterly flow in the southern Appalachians have been recognized as a significant winter forecasting problem for some time. However, only in recent years has this problem received noteworthy attention by both the academic and operational communities. The complex meteorology of these events includes significant topographic influences, as well as a linkage between the upstream Great Lakes and resultant southern Appalachian snowfall. A unique collaborative team has recently formed, working toward the goals of improving the physical understanding of the mechanisms at work in these events and developing more accurate forecasts and more detailed climatologies. The literature shows only limited attention to this problem through the 1990s. However, with modernization of the National Weather Service (NWS) in the mid-1990s came opportunities to bring more attention to new or poorly understood forecast problems. These opportunities included the establishment of new forecast offices, often collocated with universities, the deployment of the Weather Surveillance Radar-1988 Doppler (WSR-88D) network, expansion of the surface observational network in both space and time, improved access to sophisticated numerical models, and growth of the spotter and cooperative observer networks. A collaborative team, consisting of faculty from five universities and meteorologists from six NWS forecast offices, has established an ongoing, structured dialogue to help advance the understanding and improve the forecasting of these events. The team utilizes a variety of communication strategies to discuss emerging research findings, review recent events, and share data and ideas. The ultimate goal is to continue fostering working relationships among research and operational meteorologists, climatologists, and students, all with a common motivation of continually improving forecasts and understanding of this important phenomenon. This group may serve as a model for other collaborative efforts between the research and operational communities interested in a common forecast problem. DA - 2009/7// PY - 2009/7// DO - 10.1175/2009BAMS2591.1 VL - 90 IS - 7 SP - 979-991 SN - 0003-0007 ER - TY - JOUR TI - The Florida red tide dinoflagellate Karenia brevis: New insights into cellular and molecular processes underlying bloom dynamics AU - Van Dolah, Frances M. AU - Lidie, Kristy B. AU - Monroe, Emily A. AU - Bhattacharya, Debashish AU - Campbell, Lisa AU - Doucette, Gregory J. AU - Kamykowski, Daniel T2 - HARMFUL ALGAE AB - The dinoflagellate Karenia brevis is responsible for nearly annual red tides in the Gulf of Mexico that cause extensive marine mortalities and human illness due to the production of brevetoxins. Although the mechanisms regulating its bloom dynamics and toxicity have received considerable attention, investigation into these processes at the cellular and molecular level has only begun in earnest during the past decade. This review provides an overview of the recent advances in our understanding of the cellular and molecular biology on K. brevis. Several molecular resources developed for K. brevis, including cDNA and genomic DNA libraries, DNA microarrays, metagenomic libraries, and probes for population genetics, have revolutionized our ability to investigate fundamental questions about K. brevis biology. Two cellular processes have received particular attention, the vegetative cell cycle and vertical migration behavior, which are of key importance due to their roles in the development of both surface populations that constitute blooms and subsurface cell aggregations that may serve to initiate them. High throughput sequencing of cDNA libraries has provided the first glimpse of the gene repertoire in K. brevis, with approximately 12,000 unique genes identified to date. Phylogenomic analysis of these genes has revealed a high rate of horizontal gene transfer in K. brevis, which has resulted in a chimeric chloroplast through the selective retention of genes of red, green, and haptophyte origin, whose adaptive significance is not yet clear. Gene expression studies using DNA microarrays have demonstrated a prevalence of post-transcriptional gene regulation in K. brevis and led to the discovery of an unusual spliced leader trans-splicing mechanism. Among the trans-spliced gene transcripts are type I polyketide synthases (PKSs), implicated in brevetoxin biosynthesis, which are unique among type I PKSs in that each transcript encodes an individual catalytic domain, suggesting a novel gene structure in this dinoflagellate. Clone libraries of 16S ribosomal DNA sequences developed from bloom waters have unveiled the temporal and spatial complexity of the microbial soup that coexists with K. brevis and its active involvement in both bloom growth and termination processes. Finally, the development and application of population genetic markers has revealed a surprisingly high genetic diversity in K. brevis blooms, long assumed to consist of essentially clonal populations. With these foundations in place, our understanding of K. brevis bloom dynamics is likely to grow exponentially in the next few years. DA - 2009/3// PY - 2009/3// DO - 10.1016/j.hal.2008.11.004 VL - 8 IS - 4 SP - 562-572 SN - 1878-1470 KW - Bacterial-algal interactions KW - Cell cycle KW - Dinoflagellate KW - Florida red tide KW - Genome KW - Harmful algal bloom KW - Horizontal gene transfer KW - Karenia brevis KW - Population genetics KW - Vertical migration ER - TY - JOUR TI - Isotopic evidence for dead fish maintenance of Florida red tides, with implications for coastal fisheries over both source regions of the West Florida shelf and within downstream waters of the South Atlantic Bight AU - Walsh, J. J. AU - Weisberg, R. H. AU - Lenes, J. M. AU - Chen, F. R. AU - Dieterle, D. A. AU - Zheng, L. AU - Carder, K. L. AU - Vargo, G. A. AU - Havens, J. A. AU - Peebles, E. AU - Hollander, D. J. AU - He, R. AU - Heil, C. A. AU - Mahmoudi, B. AU - Landsberg, J. H. T2 - PROGRESS IN OCEANOGRAPHY AB - Toxic Florida red tides of the dinoflagellate Karenia brevis have downstream consequences of 500–1000 km spatial extent. Fish stocks, shellfish beds, and harmful algal blooms of similar species occupy the same continental shelf waters of the southeastern United States, amounting to economic losses of more than 25 million dollars in some years. Under the aegis of the Center for Prediction of Red tides, we are now developing coupled biophysical models of the conditions that lead to red tides and impacted coastal fisheries, from the Florida Panhandle to Cape Hatteras. Here, a nitrogen isotope budget of the coastal food web of the West Florida shelf (WFS) and the downstream South Atlantic Bight (SAB) reaffirms that diazotrophs are the initial nutrient source for onset of red tides and now identifies clupeid fish as the major recycled nutrient source for their maintenance. The recent isotope budget of WFS and SAB coastal waters during 1998–2001 indicates that since prehistoric times of Timacua Indian settlements along the Georgia coast during 1075, ∼50% of the nutrients required for large red tides of >1 μg chl l−1 of K. brevis have been derived from nitrogen-fixers, with the other half from decomposing dead sardines and herrings. During 2001, >90% of the harvest of WFS clupeids was by large ichthyotoxic red tides of >10 μg chl l−1 of K. brevis, rather than by fishermen. After onset of the usual red tides in summer of 2006 and 2007, the simulated subsequent fall exports of Florida red tides in September 2007 to North Carolina shelf waters replicate observations of just ∼1 μg chl l−1 on the WFS that year. In contrast, the earlier red tides of >10 μg chl l−1 left behind off West Florida during 2006, with less physical export, are instead 10-fold larger than those of 2007. Earlier, 55 fish kills were associated with these coastal red tides during September 2006, between Tampa and Naples. Yet, only six fish kills were reported there in September 2007. With little export of red tides and their fish prey during the former year, the computed larger nutrient-sated, fish-fed growth rates of the model’s dinoflagellates also replicate satellite-observed daily increments of K. brevis during fall maintenance in 2006, compared to simulated smaller fish-starved growth rates of decanted red tides during fall 2007. During the last few decades, K. brevis has remained a “prudent predator” of some clupeids, i.e. Spanish sardine, whereas humans have now overfished other Florida stocks of both thread herring and Atlantic shad. Thus, future operational forecasts of the land falls and durations of Florida red tides, from Louisiana to North Carolina, as well as prudent management of regional fisheries of the southeastern United States, require consideration of negelected fish losses, at intermediate trophic levels, to algal predators. Some clupeids are harvested by K. brevis, but these fish are separately supported by a longer parallel diatom-based food chain of calanoid copepods, feeding the zooplanktivores and thence other piscivore fish predators, while intersecting the shorter food chain of just diazotrophs and red tide dinoflagellates, poorly grazed in turn by harpactacoid copepods. The distinct phytoplankton functional groups, different herbivores, as well as zoophagous and piscivore fishes, must all be formulated as explicit state variables of the next set of complex ecological models, cued by satellite data and driven by nested circulation models, within an ecosystem-based management paradigm of commercial and sport harvests of biotic marine resources at higher trophic levels of the WFS and SAB. DA - 2009/// PY - 2009/// DO - 10.1016/j.pocean.2008.12.005 VL - 80 IS - 1-2 SP - 51-73 SN - 0079-6611 KW - Harmful algal blooms KW - Models KW - Coastal fisheries KW - Isotope budget ER - TY - JOUR TI - Effects of wind waves of the Pacific westerly on the eastern Pacific wave transport AU - Deng, Z. A. AU - Wu, K. J. AU - Zhao, D. L. AU - Yu, T. T2 - Acta Oceanologica Sinica DA - 2009/// PY - 2009/// VL - 28 IS - 1 SP - 83-88 ER - TY - JOUR TI - Geochemistry of four tropical montane watersheds, Central Panama AU - Harmon, Russell S. AU - Lyons, W. Berry AU - Long, David T. AU - Ogden, Fred L. AU - Mitasova, Helena AU - Gardner, Christopher B. AU - Welch, Kathleen A. AU - Witherow, Rebecca A. T2 - APPLIED GEOCHEMISTRY AB - The major element chemistry was determined for surface waters from four watersheds in Central Panama during the 2005 dry season to ascertain geochemical patterns resulting from differing geology and human influences as well to estimate chemical denudation rates for this montane region of tropical rain forest. The Upper Rio Chagres (580 km2), Rio Pequini (281 km2) and Rio Cuango (175 km2) watersheds are formed on a geologically mixed terrain that consists of strongly hydrothermally altered andesite and volumetrically subordinate mafic-intermediate volcanic rocks and felsic intrusive lithologies, whereas the Rio Pacora watershed (374 km2) is developed largely on gabbroic and dioritic lithologies. The headwater areas of all four river basins lie in pristine tropical rainforest, with the Rio Cuango, Rio Pequini and Rio Pacora subject to varying degrees of different land uses in their middle to lower reaches. Values of pH for the four watersheds are near neutral to slightly alkaline (7.0–8.5), DO saturation is high (typically >90%) and dissolved solute contents of the rivers and tributary streams are low (SPC = 130 ± 31 μS/cm), documenting the overall pristine quality of the waters in all four basins. Cluster analysis, supported by a comparison of elemental variations, indicates a broad geochemical similarity of rivers and streams in the four watersheds, but also reveals subtle differences that can be attributed to lithologic control rather than anthropogenic influences. Low-order streams in the Pacora watershed have distinctly higher TDS values plus silica and Ca2+ concentrations than those forming in the mixed lithology terrain. Streams and rivers developed on mafic terrain are also slightly more enriched in total dissolved cations (TZ+) and HCO3-, relative to silica, than streams and rivers developed in the mixed lithology terrain. Potassium concentrations are uniformly low, and like Mg2+ and Na+, are similar in both terrains. Calcium/Mg ratios for all watersheds are lower than the world river average, indicating the importance of the weathering of Mg-rich minerals. The Ca/Na, HCO3/Na and Mg/Na ratios for the Rio Pacora streams and rivers fall within the mid-range of what has been observed globally for other streams/rivers draining mafic rocks. The chemical weathering rate calculated is 108 tons/km2/a, which is about 40% of the physical denudation rate for the Upper Rio Chagres watershed of 275–289 tons/km2/a. The results of this study document that both chemical and physical erosion rates within tropical montane watersheds in central Panama are significant in a global context. DA - 2009/4// PY - 2009/4// DO - 10.1016/j.apgeochem.2008.12.014 VL - 24 IS - 4 SP - 624-640 SN - 0883-2927 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-62849118013&partnerID=MN8TOARS ER - TY - JOUR TI - Variability of Graupel and Snow Observed in Tropical Oceanic Convection by Aircraft during TRMM KWAJEX AU - Sukovich, Ellen M. AU - Kingsmill, David E. AU - Yuter, Sandra E. T2 - JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY AB - Abstract Empirical characterization of graupel and snow in precipitating tropical convective clouds is important for refining satellite precipitation retrieval algorithms and cloud-resolving and radiative transfer models. Microphysics data for this analysis were collected by the University of North Dakota (UND) Citation and the National Aeronautics and Space Agency (NASA) DC-8 aircraft during the Tropical Rainfall Measuring Mission (TRMM) Kwajalein Experiment (KWAJEX) in the western tropical Pacific Ocean. An ice particle identification algorithm was applied to two-dimensional optical array probe data for the purpose of identifying ice particle ensembles dominated by graupel or snow particles. These ensembles were accumulated along 1-km flight segments at temperatures below 0°C. A third category, mixed graupel/snow, has characteristics between those of the predominately graupel and snow ensembles and can be used either in combination with the other two categories or separately. Snow particle ensembles compose 80% of UND Citation and 98% of NASA DC-8 ensemble data. For the UND Citation, graupel ensembles compose ∼5% of the total with mixed graupel/snow ensembles composing ∼15%. There were no graupel ensembles in the NASA DC-8 data, which were collected primarily at temperatures &lt;−35°C. Particles too small to classify (&lt;150-μm maximum dimension) compose 56% of UND Citation and 64% of NASA DC-8 particle images. Nearly all these “tiny” particles occur coincident with particles &gt;∼150 μm. Combining data from both aircraft, snow and mixed graupel/snow ensembles were evident over the full range of subfreezing temperatures (from 0° to −65°C) sampled by the aircraft. In contrast, graupel ensembles were present primarily at temperatures &gt;−10°C. Accurate graupel identification was further supported by all graupel ensembles observed either coincident with or within a 10-km horizontal distance of radar-identified convective precipitation structures. DA - 2009/2// PY - 2009/2// DO - 10.1175/2008JAMC1940.1 VL - 48 IS - 2 SP - 185-198 SN - 1558-8432 ER - TY - JOUR TI - Raster-Based Analysis of Coastal Terrain Dynamics from Multitemporal Lidar Data AU - Mitasova, Helena AU - Overton, Margery F. AU - Recalde, Juan Jose AU - Bernstein, David J. AU - Freeman, Christopher W. T2 - JOURNAL OF COASTAL RESEARCH AB - Multitemporal sets of lidar data provide a unique opportunity to analyze and quantify changes in topography in rapidly evolving landscapes. Methodology for geospatial analyses of lidar data time series was developed to investigate patterns of coastal terrain evolution, including the beach and dune systems. The diverse lidar-point data density, noise, and systematic errors were first quantified, and the results were used to compute a consistent series of high-resolution digital elevation models using spline-based approximation with optimized parameters. Raster-based statistical analysis was applied to the elevation-model time series to derive maps representing multiyear trends in spatial patterns of elevation change, to quantify dynamics at each cell using standard deviation maps, and to extract the core surface below which the elevation has never decreased. The methodology was applied to a North Carolina barrier island that was mapped by a sequence of 13 lidar surveys during the past decade, using several different lidar systems. Assessment of vertical differences between the lidar data sets using stable structures such as a road, was shown to be essential for correct quantification of coastal terrain change and its pattern. The analysis revealed the highly dynamic nature of foredunes, the trend toward inland sand transport, and the impact of anthropogenic sand disposal on that trend. DA - 2009/3// PY - 2009/3// DO - 10.2112/07-0976.1 VL - 25 IS - 2 SP - 507-514 SN - 1551-5036 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-66449138133&partnerID=MN8TOARS KW - Coastal change KW - systematic error KW - barrier island KW - North Carolina KW - GRASS GIS ER - TY - JOUR TI - Modeling intercontinental air pollution transport over the trans-Pacific region in 2001 using the Community Multiscale Air Quality modeling system AU - Wang, Kai AU - Zhang, Yang AU - Jang, Carey AU - Phillips, Sharon AU - Wang, Binyu T2 - Journal of Geophysical Research AB - The Community Multiscale Air Quality modeling system is used to study the intercontinental transport of air pollution across the Pacific region. Baseline simulations are conducted for January, April, July, and October 2001 at a 108 km horizontal grid resolution. A sensitivity simulation is conducted for April 2001 to study the impact of Asian anthropogenic emissions on the United States's air quality. Process analysis is conducted to study pollutant formation and transport and to quantify the relative contributions of atmospheric processes to ozone (O 3 ) and fine particulate matter (PM 2.5 ). Model simulations are evaluated with available surface, aircraft, and satellite observations. Simulated meteorology basically captures the synoptic pattern, but precipitation amounts are significantly underpredicted. Most of the PM 2.5 components are overestimated over the United States and most gases are underestimated over east Asia. Simulated NO 2 and CO columns agree well with satellite observations. Aerosol optical depths and tropospheric O 3 residuals are underpredicted, especially in July. The simulated horizontal fluxes and process analyses show that the transport in the lower free troposphere followed by a large‐scale subsidence over the United States provides a major Asian pollution export pathway for most pollutants, while the transport in the planetary boundary layer also plays an important role, especially for CO, O 3 , PM 2.5 , and SO 4 2− . The background concentrations of O 3 and SO 4 2− in the western United States can increase by ∼1 ppb (∼2.5%) and 0.4 μ g m −3 (∼20%) in monthly average, up to 2.5 ppb and 1.0 μ g m −3 in daily average, respectively, due to the Asian emissions in April. DA - 2009/2/27/ PY - 2009/2/27/ DO - 10.1029/2008JD010807 VL - 114 IS - D4 J2 - J. Geophys. Res. LA - en OP - SN - 0148-0227 UR - http://dx.doi.org/10.1029/2008JD010807 DB - Crossref ER - TY - JOUR TI - Internal solitary waves induced by flow over a ridge: With applications to the northern South China Sea AU - Shaw, Ping-Tung AU - Ko, Dong Shan AU - Chao, Shenn-Yu T2 - JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS AB - The generation of internal solitary waves by barotropic tides over a ridge is studied in a nonhydrostatic numerical model under idealized oceanographic settings. The experiments examine the effects of ridge width, barotropic tidal strength, and stratification on wave generation. The barotropic tidal flow produces internal wave beams emitting from the ridge top if the slope of the ridge exceeds a critical value equal to the slope of the wave beam. Reflection and refraction of a wave beam in an upper ocean waveguide associated with a strong shallow thermocline produce horizontally propagating internal tides. When the local Froude number over a ridge is not small, lee waves generated on the ridge convert enough energy from the barotropic tides to the internal tides to form tidal bores and solitary waves. Increasing stratification at ridge depths enhances the generation of internal waves, particularly at the diurnal periods. In the Luzon Strait, the slope of the wave beam decreases in spring and summer as stratification at the ridge depths increases, favoring the generation of internal tides. Without the presence of a strong shallow thermocline, internal solitary waves are not observed east of the Luzon Strait. In the northern South China Sea, internal solitary waves are likely observed from April to July when a strong shallow thermocline is present. A deep mixed layer in winter suppresses the production of internal solitary waves. DA - 2009/2/24/ PY - 2009/2/24/ DO - 10.1029/2008jc005007 VL - 114 SP - SN - 2169-9291 ER - TY - JOUR TI - Increases in the longwave photobleaching of chromophoric dissolved organic matter in coastal waters AU - Osburn, Christopher L. AU - Daniel W. O'Sullivan, AU - Boyd, Thomas J. T2 - LIMNOLOGY AND OCEANOGRAPHY AB - Salinity effects on the photobleaching of chromophoric dissolved organic matter (CDOM) due to coastal mixing were investigated through a comparative study of surrogate and surface-water CDOM. Suwannee River humic acid (SRHA) and ultrafiltered river dissolved organic matter (UDOM) added to mixtures of river and seawater permeates (<1 kDa) that varied in salinity from 0 to 33 to mimic coastal mixing. Surface-water CDOM was collected from the Chesapeake Bay in January, June, and September 2002. Shortwave CDOM absorption loss (e.g., 280 nm) did not change with salinity; however, longwave CDOM absorption loss (e.g., 440 nm) often decreased by 10% to 40% with salinity. Apparent quantum yields for average absorption loss from 280 to 550 nm (ϕavg) increased with salinity for both surrogate and surface-water CDOM, providing evidence for an effect of salinity independent of light absorption among different samples. Further, hydrogen peroxide photoproduction from UDOM increased from 15 to 368 nmol L−1 h−1 with salinity, even though pH values were circumneutral. A kinetic model demonstrated that, at circumneutral pH and iron concentrations expected for the Chesapeake Bay, photo-Fenton chemistry could not explain the increase in hydrogen peroxide production quantum yields (ϕhp) with salinity. Using ϕavg for the SRHA and UDOM surrogates, a model of the change in surface-water CDOM photoreactivity in the Chesapeake Bay as a function of salinity suggested additional CDOM inputs for the lower Chesapeake Bay. Because estuarine mixing increases photobleaching of longwave CDOM absorption, the modeling of absorption coefficients above 400 nm may underestimate dissolved organic matter in coastal waters. DA - 2009/1// PY - 2009/1// DO - 10.4319/lo.2009.54.1.0145 VL - 54 IS - 1 SP - 145-159 SN - 1939-5590 ER - TY - JOUR TI - Export of reactive nitrogen from coal-fired power plants in the U.S.: Estimates from a plume-in-grid modeling study AU - Vijayaraghavan, Krish AU - Zhang, Yang AU - Seigneur, Christian AU - Karamchandani, Prakash AU - Snell, Hilary E. T2 - Journal of Geophysical Research AB - The export of reactive nitrogen (nitrogen oxides and their oxidation products, collectively referred to as NO y ) from coal‐fired power plants in the U.S. to the rest of the world could have a significant global contribution to ozone. Traditional Eulerian gridded air quality models cannot characterize accurately the chemistry and transport of plumes from elevated point sources such as power plant stacks. A state‐of‐the‐science plume‐in‐grid (PinG) air quality model, a reactive plume model embedded in an Eulerian gridded model, is used to estimate the export of NO y from 25 large coal‐fired power plants in the U.S. (in terms of NO x and SO 2 emissions) in July 2001 to the global atmosphere. The PinG model used is the Community Multiscale Air Quality Model with Advanced Plume Treatment (CMAQ‐APT). A benchmark simulation with only the gridded model, CMAQ, is also conducted for comparison purposes. The simulations with and without advanced plume treatment show differences in the calculated export of NO y from the 25 plants considered reflecting the effect of using a detailed and explicit treatment of plume transport and chemistry. The advanced plume treatment results in 31% greater simulated export of NO y compared to the purely grid‐based modeling approach. The export efficiency of NO y (the fraction of NO y emitted that is exported) is predicted to be 21% without APT and 27% with APT. When considering only export through the eastern boundary across the Atlantic, CMAQ‐APT predicts that the export efficiency is 24% and that 2% of NO y is exported as NO x , 49% as inorganic nitrate, and 25% as PAN. These results are in reasonably good agreement with an analysis reported in the literature of aircraft measurements over the North Atlantic. DA - 2009/2/27/ PY - 2009/2/27/ DO - 10.1029/2008JD010432 VL - 114 IS - D4 J2 - J. Geophys. Res. LA - en OP - SN - 0148-0227 UR - http://dx.doi.org/10.1029/2008JD010432 DB - Crossref ER - TY - JOUR TI - Development and Evaluation of a Coupled Photosynthesis-Based Gas Exchange Evapotranspiration Model (GEM) for Mesoscale Weather Forecasting Applications AU - Niyogi, Dev AU - Alapaty, Kiran AU - Raman, Sethu AU - Chen, Fei T2 - JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY AB - Abstract Current land surface schemes used for mesoscale weather forecast models use the Jarvis-type stomatal resistance formulations for representing the vegetation transpiration processes. The Jarvis scheme, however, despite its robustness, needs significant tuning of the hypothetical minimum-stomatal resistance term to simulate surface energy balances. In this study, the authors show that the Jarvis-type stomatal resistance/transpiration model can be efficiently replaced in a coupled land–atmosphere model with a photosynthesis-based scheme and still achieve dynamically consistent results. To demonstrate this transformative potential, the authors developed and coupled a photosynthesis, gas exchange–based surface evapotranspiration model (GEM) as a land surface scheme for mesoscale weather forecasting model applications. The GEM was dynamically coupled with a prognostic soil moisture–soil temperature model and an atmospheric boundary layer (ABL) model. This coupled system was then validated over different natural surfaces including temperate C4 vegetation (prairie grass and corn field) and C3 vegetation (soybean, fallow, and hardwood forest) under contrasting surface conditions (such as different soil moisture and leaf area index). Results indicated that the coupled model was able to realistically simulate the surface fluxes and the boundary layer characteristics over different landscapes. The surface energy fluxes, particularly for latent heat, are typically within 10%–20% of the observations without any tuning of the biophysical–vegetation characteristics, and the response to the changes in the surface characteristics is consistent with observations and theory. This result shows that photosynthesis-based transpiration/stomatal resistance models such as GEM, despite various complexities, can be applied for mesoscale weather forecasting applications. Future efforts for understanding the different scaling parameterizations and for correcting errors for low soil moisture and/or wilting vegetation conditions are necessary to improve model performance. Results from this study suggest that the GEM approach using the photosynthesis-based soil vegetation atmosphere transfer (SVAT) scheme is thus superior to the Jarvis-based approaches. Currently GEM is being implemented within the Noah land surface model for the community Weather Research and Forecasting (WRF) Advanced Research Version Modeling System (ARW) and the NCAR high-resolution land data assimilation system (HRLDAS), and validation is under way. DA - 2009/2// PY - 2009/2// DO - 10.1175/2008JAMC1662.1 VL - 48 IS - 2 SP - 349-368 SN - 1558-8432 ER - TY - JOUR TI - Axenic Culture of the Heterotrophic Dinoflagellate Pfiesteria shumwayae in a Semi-Defined Medium AU - Skelton, Hayley M. AU - Burkholder, Joann M. AU - Parrow, Matthew W. T2 - JOURNAL OF EUKARYOTIC MICROBIOLOGY AB - A semi-defined, biphasic culture medium was developed that supported the axenic growth of three strains of the heterotrophic dinoflagellate Pfiesteria shumwayae. Maximum cell yields and division rates in the semi-defined medium ranged from 0.1 x 10(5) to 4.0 x 10(5) cells/ml and 0.5 to 1.7 divisions/day, respectively, and depended on the concentration of the major components in the medium as well as the P. shumwayae strain. The medium contained high concentrations of certain dissolved and particulate organic compounds, including amino acids and lipids. Pfiesteria shumwayae flagellated cells were attracted to insoluble lipids present in the medium and appeared to feed on the lipid particles, suggesting that phagocytosis may be required for growth in axenic culture. Development of a semi-defined medium represents significant progress toward a completely defined axenic culture medium and subsequent determination of the biochemical requirements of P. shumwayae, needed to advance understanding of the nutritional ecology of this species. Further, this medium provides an economical, simplified method for generating high cell densities of P. shumwayae in axenic culture that will facilitate controlled investigations on the physiology and biochemistry of this heterotrophic dinoflagellate. DA - 2009/// PY - 2009/// DO - 10.1111/j.1550-7408.2008.00368.x VL - 56 IS - 1 SP - 73-82 SN - 1550-7408 KW - Biochemical requirements KW - cultivation KW - nutrition KW - phagotrophy KW - protist ER - TY - JOUR TI - The early-warning effects of assimilation of the observations over the large-scale slope of the "World Roof" on its downstream weather forecasting AU - ShiQiu, Peng AU - XiangDe, Xu AU - XiaoHui, Shi AU - DongXiao, Wang AU - YuXiang, Zhu AU - JingJiao, Pu T2 - CHINESE SCIENCE BULLETIN DA - 2009/2// PY - 2009/2// DO - 10.1007/s11434-008-0560-6 VL - 54 IS - 4 SP - 706-710 SN - 1861-9541 KW - AWS data KW - 3DVAR KW - Qinghai-Xizang Plateau KW - snow storm KW - numerical simulation ER - TY - JOUR TI - LIPID CLASS, CAROTENOID, AND TOXIN DYNAMICS OF KARENIA BREVIS (DINOPHYCEAE) DURING DIEL VERTICAL MIGRATION AU - Schaeffer, Blake A. AU - Kamykowski, Daniel AU - McKay, Laurie AU - Sinclair, Geoff AU - Milligan, Edward T2 - JOURNAL OF PHYCOLOGY AB - The internal lipid, carotenoid, and toxin concentrations of Karenia brevis (C. C. Davis) Gert Hansen and Moestrup are influenced by its ability to use ambient light and nutrients for growth and reproduction. This study investigated changes in K. brevis toxicity, lipid class, and carotenoid concentrations in low‐light, nitrate‐replete (250 μmol quanta · m −2 · s −1 , 80 μM NO 3 ); high‐light, nitrate‐replete (960 μmol quanta · m −2 · s −1 , 80 μM NO 3 ); and high‐light, nitrate‐reduced (960 μmol quanta · m −2 · s −1 , <5 μM NO 3 ) mesocosms. Reverse‐phase HPLC quantified the epoxidation state (EPS) of the xanthophyll‐cycle pigments diadinoxanthin and diatoxanthin, and a Chromarod Iatroscan thin layer chromatography/flame ionization detection (TLC/FID) system quantified changes in lipid class concentrations. EPS did not exceed 0.20 in the low‐light mesocosm, but increased to 0.65 in the high‐light mesocosms. Triacylglycerol and monogalactosyldiacylglycerol (MGDG) were the largest lipid classes consisting of 9.3% to 48.7% and 37.3% to 69.7% of total lipid, respectively. Both lipid classes also experienced the greatest concentration changes in high‐light experiments. K. brevis increased EPS and toxin concentrations while decreasing its lipid concentrations under high light. K. brevis may mobilize its toxins into the surrounding environment by reducing lipid concentrations, such as sterols, limiting competition, or toxins are released because lipids are decreased in high light, reducing any protective mechanism against their own toxins. DA - 2009/2// PY - 2009/2// DO - 10.1111/j.1529-8817.2008.00627.x VL - 45 IS - 1 SP - 154-163 SN - 1529-8817 KW - behavior KW - brevetoxins KW - dinoflagellate KW - epoxidation state KW - lipids ER - TY - JOUR TI - Growth Dynamics and Morphology of Oleic Acid Vapor-Deposited on a Silica Surface AU - Garland, Eva R. AU - Lee, Amy D. AU - Baer, Tomas AU - Clarke, Laura I. T2 - JOURNAL OF PHYSICAL CHEMISTRY C AB - The vapor deposition of oleic acid onto silica surfaces at 25% relative humidity and temperatures ranging from 60 to 80 °C is found to proceed in three stages: (I) rapid formation of monolayer-high islands of approximately 100 nm diameter on timescales of a few minutes; (II) relatively little growth over timescales of tens to hundreds of minutes; and (III) a linear increase in apparent thickness as a function of time, characterized by the formation of multilayer islands on time scales of thousands of minutes. The rate of growth in region III is faster at higher temperatures. This growth process is analyzed in the context of the transition from two-dimensional to three-dimensional island growth at submonolayer coverage observed for metal vapor deposition on oxide surfaces. At a relative humidity of 94%, with several layers of water molecules present on the silica surface, the oleic acid wets the surface rather than forming discrete islands. DA - 2009/2/12/ PY - 2009/2/12/ DO - 10.1021/jp8068514 VL - 113 IS - 6 SP - 2141-2148 SN - 1932-7447 ER - TY - JOUR TI - Analysis of Idealized Tropical Cyclone Simulations Using the Weather Research and Forecasting Model: Sensitivity to Turbulence Parameterization and Grid Spacing AU - Hill, Kevin A. AU - Lackmann, Gary M. T2 - MONTHLY WEATHER REVIEW AB - Abstract The Weather Research and Forecasting Advanced Research Model (WRF-ARW) was used to perform idealized tropical cyclone (TC) simulations, with domains of 36-, 12-, and 4-km horizontal grid spacing. Tests were conducted to determine the sensitivity of TC intensity to the available surface layer (SL) and planetary boundary layer (PBL) parameterizations, including the Yonsei University (YSU) and Mellor–Yamada–Janjic (MYJ) schemes, and to horizontal grid spacing. Simulations were run until a quasi-steady TC intensity was attained. Differences in minimum central pressure (Pmin) of up to 35 hPa and maximum 10-m wind (V10max) differences of up to 30 m s−1 were present between a convection-resolving nested domain with 4-km grid spacing and a parent domain with cumulus parameterization and 36-km grid spacing. Simulations using 4-km grid spacing are the most intense, with the maximum intensity falling close to empirical estimates of maximum TC intensity. Sensitivity to SL and PBL parameterization also exists, most notably in simulations with 4-km grid spacing, where the maximum intensity varied by up to ∼10 m s−1 (V10max) or ∼13 hPa (Pmin). Values of surface latent heat flux (LHFLX) are larger in MYJ than in YSU at the same wind speeds, and the differences increase with wind speed, approaching 1000 W m−2 at wind speeds in excess of 55 m s−1. This difference was traced to a larger exchange coefficient for moisture, CQ, in the MYJ scheme. The exchange coefficients for sensible heat (Cθ) and momentum (CD) varied by &lt;7% between the SL schemes at the same wind speeds. The ratio Cθ/CD varied by &lt;5% between the schemes, whereas CQ/CD was up to 100% larger in MYJ, and the latter is theorized to contribute to the differences in simulated maximum intensity. Differences in PBL scheme mixing also likely played a role in the model sensitivity. Observations of the exchange coefficients, published elsewhere and limited to wind speeds &lt;30 m s−1, suggest that CQ is too large in the MYJ SL scheme, whereas YSU incorporates values more consistent with observations. The exchange coefficient for momentum increases linearly with wind speed in both schemes, whereas observations suggest that the value of CD becomes quasi-steady beyond some critical wind speed (∼30 m s−1). DA - 2009/2// PY - 2009/2// DO - 10.1175/2008MWR2220.1 VL - 137 IS - 2 SP - 745-765 SN - 1520-0493 ER - TY - JOUR TI - Vegetation exposure to ozone over the continental United States: Assessment of exposure indices by the Eta-CMAQ air quality forecast model AU - Tong, Daniel Q. AU - Mathur, Rohit AU - Kang, Daiwen AU - Yu, Shaocai AU - Schere, Kenneth L. AU - Pouliot, George T2 - ATMOSPHERIC ENVIRONMENT AB - The main use of air quality forecast (AQF) models is to predict ozone (O3) exceedances of the primary O3 standard for informing the public of potential health concerns. This study presents the first evaluation of the performance of the Eta-CMAQ air quality forecast model to predict a variety of widely used seasonal mean and cumulative O3 exposure indices associated with vegetation using the U.S. AIRNow O3 observations. These exposure indices include two concentration-based O3 indices, M7 and M12 (the seasonal means of daytime 7-h and 12-h O3 concentrations, respectively), and three cumulative exposure-based indices, SUM06 (the sum of all hourly O3 concentrations ≥ 0.06 ppm), W126 (hourly concentrations weighed by a sigmoidal weighting function), and AOT40 (O3 concentrations accumulated over a threshold of 40 ppb during daylight hours). During a three-month simulation (July–September 2005), the model over predicted the M7 and M12 values by 8–9 ppb, or a NMB value of 19% and a NME value of 21%. The model predicts a central belt of high O3 extending from Southern California to Middle Atlantic where the seasonal means, M7 and M12 (the seasonal means of daytime 7-h and 12-h O3 concentrations), are higher than 50 ppbv. In contrast, the model is less capable of reproducing the observed cumulative indices. For AOT40, SUM06 and W126, the NMB and NME values are two- to three-fold of that for M7, M12 or peak 8-h O3 concentrations. The AOT40 values range from 2 to 33 ppm h by the model and from 1 to 40 ppm h by the monitors. There is a significantly higher AOT40 value experienced in the United States in comparison to Europe. The domain-wide mean SUM06 value is 14.4 ppm h, which is about 30% higher than W126, and 40% higher than AOT40 calculated from the same 3-month hourly O3 data. This suggests that SUM06 and W126 represent a more stringent standard than AOT40 if either the SUM06 or the W126 was used as a secondary O3 standard. Although CMAQ considerably over predicts SUM06 and W126 values at the low end, the model under predicts the extreme high exposure values (>50 ppm h). Most of these extreme high values are found at inland California sites. Based on our analysis, further improvement of the model is needed to better capture cumulative exposure indices. DA - 2009/1// PY - 2009/1// DO - 10.1016/j.atmosenv.2008.09.084 VL - 43 IS - 3 SP - 724-733 SN - 1873-2844 KW - Vegetation exposure KW - Ozone (O-3) KW - CMAQ KW - Air quality forecast KW - Crop KW - Regional air quality KW - Exposure index KW - Air quality standard ER - TY - JOUR TI - Diorite Segregations in Gabbro: Geochemical Characteristics and Conditions for Origin Assessed at Diorite-Gabbro Contacts AU - Fodor, R. V. T2 - JOURNAL OF GEOLOGY AB - Silicic segregation veins in the Basement Sill, Dry Valleys, Antarctica, represent fracture-filling liquids differentiated from mid-Jurassic Ferrar tholeiitic basalt magmas. Geochemical and mineralogical characterizations for several of these veins and for their host gabbros within centimeters of sharp contacts with the veins provide information about silicic liquid produced from basalt in closed systems. The Basement Sill silicic veins are coarse- to pegmatite-textured diorites (∼60 wt% SiO2; 1.6%–2.6% MgO) composed of Fe-rich clinopyroxene (cpx; Fs20-60) and orthopyroxene (and pigeonite), ∼An50-60 plagioclase, and ∼20–30 vol% mesostases of micrographic quartz + alkali feldspar (∼Or80-90). The host gabbros (52–54 wt% SiO2; 5.5%–9.2% MgO) within ∼2 cm of veins contain pyroxene and feldspar with compositions that range from overlapping those in the diorite veins to those closer to characteristic of gabbro (e.g., cpx ∼Fs20; ∼An60-80) but unlike the more primitive mineral compositions representing the Basement Sill as a whole (e.g., ∼Fs15). The gabbros also contain interstitial micrographic quartz + alkali feldspar. Evolved minerals and quartz + alkali feldspar in gabbro at vein contacts are signatures consistent with evolved interstitial liquids having migrated through the sill’s solidification zones to fill fractures formed by sag/collapse of roof-side solidification zones. MELTS software crystallization (at fO2 FMQ) of the sill magma (marginal chill zone as proxy), mass balance by linear regression, and Rayleigh fractionation all show that diorite forms after ∼72% at ∼1070°C but that it only generally resembles the diorite veins. Compositions that more fully resemble the actual segregations appear to require more than fractional crystallization, such as dioritic liquids admixed with up to ∼10% of the minerals in assemblages they crystallize. That is, evolved interstitial liquids produced from ∼70%–75% crystallization (e.g., SiO2∼60–65 wt%) over a volume of solidification zone framework and purged into fractures to crystallize “dioritic” pyroxene and plagioclase can produce varying diorite compositions and modes from place to place by admixing, a liquid-crystal process reasonable to expect for liquids purged into fractures. DA - 2009/3// PY - 2009/3// DO - 10.1086/596506 VL - 117 IS - 2 SP - 109-125 SN - 0022-1376 ER - TY - JOUR TI - Characterizing the South Atlantic Bight seasonal variability and cold-water event in 2003 using a daily cloud-free SST and chlorophyll analysis AU - Miles, Travis N. AU - He, Ruoying AU - Li, Mingkui T2 - Geophysical Research Letters AB - Concurrent MODIS sea surface temperature (SST) and chlorophyll‐a (Chl‐a) data are used with a new technique: Data Interpolating Empirical Orthogonal Function (DINEOF) method to produce daily, 4‐km, cloud‐free SST and Chl‐a analyses for the South Atlantic Bight in 2003. Comparisons between SST analysis and in situ buoy temperature demonstrate the utility of DINEOF. To quantify linkages between surface wind, SST, and Chl‐a variations, Empirical Orthogonal Function (EOF) analysis is applied to North American Regional Reanalysis winds, and cloud‐free DINEOF SST and Chl‐a analyses. Wind EOF modes highlight upwelling winds from June to September. While the first SST mode represents seasonal heat flux variations, the second SST mode shows a direct response to upwelling winds with an abrupt drop in SST. The top two Chl‐a EOF modes show less connection with wind. More subsurface Chl‐a and nutrient observations are needed to quantify its relation with surface wind. DA - 2009/1// PY - 2009/1// DO - 10.1029/2008GL036396 VL - 36 IS - 2 SP - n/a-n/a J2 - Geophys. Res. Lett. LA - en OP - SN - 0094-8276 UR - http://dx.doi.org/10.1029/2008GL036396 DB - Crossref ER - TY - JOUR TI - Late Quaternary fluvial terraces of the Romagna and Marche Apennines, Italy: Climatic, lithologic, and tectonic controls on terrace genesis in an active orogen AU - Wegmann, Karl W. AU - Pazzaglia, Frank J. T2 - QUATERNARY SCIENCE REVIEWS AB - We synthesize a new fluvial terrace chronostratigraphy of the Bidente and Musone Rivers cast within a broader European framework, which forms the basis of a terrace genesis and river incision model for the northern Apennines, Italy. Our model, supported by terrace long profiles, correlation to Po foreland sediments, 15 new radiocarbon dates, and published numeric and relative stratigraphic ages, highlights how drainage basin substrate drives concurrent formation of strath terraces in the Bidente basin and fill terraces in the Musone basin. Quaternary climate change paces the formative geomorphic processes through unsteady discharges of water and sediment. In the weathering-limited setting represented by the Bidente basin, siliciclastic detritus carves broad strath surfaces during glacial climates that are preserved as terraces as the river incises during the transition to an interglacial climate. In contrast, the transport-limited and carbonate detritus dominated Musone basin sees valleys deeply buried by aggradation during glacial climates followed by river incision during the transition to an interglacial climate. Incision of these rivers over the past ∼1 million years has been both unsteady and non-uniform. These and all Po-Adriatic draining rivers are proximal to a base level defined by mean sea level and have little room for increasing their longitudinal profile concavities through incision, particularly in their lower reaches despite periodic glacio-eustatic drawdowns. As a result, the observed incision is best explained by rock uplift associated with active local fault or fold growth embedded in the actively thickening and uplifting Apennine foreland. DA - 2009/1// PY - 2009/1// DO - 10.1016/j.quascirev.2008.10.006 VL - 28 IS - 1-2 SP - 137-165 SN - 1873-457X UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-57749180160&partnerID=MN8TOARS ER - TY - JOUR TI - Acidic processing of mineral dust iron by anthropogenic compounds over the north Pacific Ocean AU - Solmon, F. AU - Chuang, P. Y. AU - Meskhidze, N. AU - Chen, Y. T2 - JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES AB - Atmospheric processing of mineral aerosol by anthropogenic pollutants may be an important process by which insoluble iron can be transformed into soluble forms and become available to oceanic biota. Observations of the soluble iron fraction in atmospheric aerosol exhibit large variability, which is poorly represented in models. In this study, we implemented a dust iron dissolution scheme in a global chemistry transport model (GEOS‐Chem). The model is applied over the North Pacific Ocean during April 2001, a period when concentrations of dust and pollution within the east Asia outflow were high. Simulated fields of many key chemical constituents compare reasonably well with available observations, although some discrepancies are identified and discussed. In our simulations, the production of soluble iron varies temporally and regionally depending on pollution‐to‐dust ratio, primarily due to strong buffering by calcite. Overall, we show that the chemical processing mechanism produces significant amounts of dissolved iron reaching and being deposited in remote regions of the Pacific basin, with some seasonal variability. Simulated enhancements in particulate soluble iron fraction range from 0.5% to 6%, which is consistent with the observations. According to our simulations, ∼30% to 70% of particulate soluble iron over the North Pacific Ocean basin can be attributed to atmospheric processing. On the basis of April 2001 monthly simulations, sensitivity tests suggest that doubling SO 2 emissions can induce a significant increase (13% on average, up to 40% during specific events) in dissolved iron production and deposition to the remote Pacific. We roughly estimate that half of the primary productivity induced by iron deposition in a north Pacific high‐nutrient low‐chlorophyll region is due to soluble iron derived from anthropogenic chemical processing of Asian aerosol. DA - 2009/1/24/ PY - 2009/1/24/ DO - 10.1029/2008jd010417 VL - 114 SP - SN - 2169-8996 ER -