@article{zeng_li_he_yin_2015, title={Clustering of Loop Current patterns based on the satellite-observed sea surface height and self-organizing map}, volume={6}, ISSN={["2150-7058"]}, DOI={10.1080/2150704x.2014.998347}, abstractNote={The self-organizing map is used to investigate variations of the Loop Current (LC) in the Gulf of Mexico from 1992 to 2013 based on satellite-observed sea surface height data. It is found that LC variations can be characterized by three spatial patterns: normal, extension and retraction. The corresponding temporal variations confirm that LC eddy shedding generally occurs during the transition from the extension to retraction patterns. On the weekly time scale, the wind stress curl (WSC) in the Caribbean Sea has a major influence on LC eddy shedding. The increase of Caribbean WSC from June to November favours more frequent LC eddy shedding during that period. On the interannual time scale, there is also a potential linkage between the frequency of LC eddy shedding and El Niño activities.}, number={1}, journal={REMOTE SENSING LETTERS}, publisher={Informa UK Limited}, author={Zeng, Xiangming and Li, Yizhen and He, Ruoying and Yin, Yuqi}, year={2015}, pages={11–19} }
 @article{zeng_li_he_2015, title={Predictability of the Loop Current Variation and Eddy Shedding Process in the Gulf of Mexico Using an Artificial Neural Network Approach}, volume={32}, ISSN={["1520-0426"]}, DOI={10.1175/jtech-d-14-00176.1}, abstractNote={Abstract}, number={5}, journal={JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY}, publisher={American Meteorological Society}, author={Zeng, Xiangming and Li, Yizhen and He, Ruoying}, year={2015}, month={May}, pages={1098–1111} }
 @article{li_he_chen_mcgillicuddy_2015, title={Variational data assimilative modeling of the Gulf of Maine in spring and summer 2010}, volume={120}, ISSN={["2169-9291"]}, DOI={10.1002/2014jc010492}, abstractNote={Abstract}, number={5}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS}, author={Li, Yizhen and He, Ruoying and Chen, Ke and McGillicuddy, Dennis J.}, year={2015}, month={May}, pages={3522–3541} }
 @article{li_he_manning_2014, title={Coastal connectivity in the Gulf of Maine in spring and summer of 2004-2009}, volume={103}, ISSN={["1879-0100"]}, DOI={10.1016/j.dsr2.2013.01.037}, abstractNote={Coastal ocean connectivity associated with the Gulf of Maine (GOM) surface flows in spring and summer seasons of 2004–2009 is studied using surface numerical particle tracking based on realistic regional ocean circulation hindcast solutions. Seven initial particle release sites are selected in key gulf regions often affected by harmful algal (Alexandrium fundyense) blooms, including Massachusetts Bay, the western GOM coastal area, the eastern GOM coastal area, the Bay of Fundy, Wilkinson Basin, the Jordan Basin, and a region seaward of Penobscot Bay. Surface particles are released every 5 days between February 1st and August 1st in each year, and the variability in their trajectories on interannual time scales is quantified by Lagrangian probability density function calculations. Coastal connectivity is further quantified using a connectivity matrix, identifying source and destination functions. Our results suggest that the interannual variability in coastal connectivity has strong impact on the spatial distribution of A. fundyense blooms in each year.}, journal={DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY}, author={Li, Yizhen and He, Ruoying and Manning, James P.}, year={2014}, month={May}, pages={199–209} }
 @article{li_he_mcgillicuddy_2014, title={Seasonal and interannual variability in Gulf of Maine hydrodynamics: 2002-2011}, volume={103}, ISSN={["1879-0100"]}, DOI={10.1016/j.dsr2.2013.03.001}, abstractNote={In situ observations including long-term moored meteorological and oceanographic measurements and multi-year gulf-wide ship survey data are used to quantify interannual variability of surface wind, river runoff, and hydrographic conditions in the Gulf of Maine during summers 2002-2011. The cumulative upwelling index shows that upwelling (downwelling)-favorable wind conditions were most persistent in 2010 (2005) over the 10-year study period. River discharge was highest in 2005; peak runoff occurred in early April in 2010 as opposed to late April to middle May in other years. Moored time series show that coastal water temperature was 0.5-2 °C warmer than average in summer 2010, and about 2 °C colder than average in 2004. Coastal salinity in April 2010 was the lowest in the 10-year study period. Both moored Acoustic Doppler Current Profiler (ADCP) current measurements and dynamic height/geostrophic velocity calculations based on gulf-wide ship survey data show May-June 2010 had one of the weakest alongshore transports in the western Gulf of Maine during the 10-year study period, likely associated with intrusions of warm slope water and fresher-than-usual Scotian Shelf water. Comparisons of coastal currents to the Paralytic Shellfish Poisoning (PSP) closure maps resulting from A. fundyense blooms suggest a linkage between alongshore transport and the downstream extent of toxicity.}, journal={DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY}, author={Li, Yizhen and He, Ruoying and McGillicuddy, Dennis J., Jr.}, year={2014}, month={May}, pages={210–222} }
 @article{yuqi_xiaopei_yizhen_xiangming_2014, title={Seasonal variability of Kuroshio intrusion northeast of Taiwan Island as revealed by self-organizing map}, volume={32}, ISSN={["1993-5005"]}, DOI={10.1007/s00343-015-4017-x}, number={6}, journal={CHINESE JOURNAL OF OCEANOLOGY AND LIMNOLOGY}, author={Yuqi, Yin and Xiaopei, Lin and Yizhen, Li and Xiangming, Zeng}, year={2014}, month={Nov}, pages={1435–1442} }
 @article{li_he_2014, title={Spatial and temporal variability of SST and ocean color in the Gulf of Maine based on cloud-free SST and chlorophyll reconstructions in 2003-2012}, volume={144}, ISSN={["1879-0704"]}, DOI={10.1016/j.rse.2014.01.019}, abstractNote={The spatial and temporal variability of sea surface temperature (SST) and Chlorophyll-a (Chl-a) in the Gulf of Maine (GOM) is examined using daily, cloud-free Data INterpolating Empirical Orthogonal Function (DINEOF) reconstructions during 2003–2012. The utility of the DINEOF SST and Chl-a is demonstrated through direct comparisons with buoy- and ship-based observations. EOF analyses of cloud-free products are further used to quantify the SST and Chl-a variability on seasonal to inter-annual timescales. The first mode of SST is dominated by an annual cycle in response to net surface heat flux, with SST lagging surface flux by ~ 57 days. The second mode of SST underscores interactions between GOM, the Scotian Shelf, and the slope sea in response to the basin scale atmospheric forcing represented by the North Atlantic Oscillation. The third mode correlates well with the evolution of Scotian Shelf-slope frontal displacement. The first EOF mode of Chl-a is dominated by a winter–spring bloom and a fall bloom, with a spatial distribution modified by the tidal mixing that facilitates nutrient delivery from the deep ocean. The second EOF mode is likely associated with a winter bloom in the warm slope sea, where the low-frequency variations of second modes of SST and Chl-a are in phase, suggesting a possible coupling between physical and biological responses to atmospheric forcing. The third mode of the Chl-a is likely associated with freshening events associated with advection of the Scotian Shelf Water, which enhance stratifications in the eastern GOM.}, journal={REMOTE SENSING OF ENVIRONMENT}, publisher={Elsevier BV}, author={Li, Yizhen and He, Ruoying}, year={2014}, month={Mar}, pages={98–108} }
 @article{young_he_emlet_li_qian_arellano_van gaest_bennett_wolf_smart_et al._2012, title={Dispersal of Deep-Sea Larvae from the Intra-American Seas: Simulations of Trajectories using Ocean Models}, volume={52}, ISSN={["1557-7023"]}, DOI={10.1093/icb/ics090}, abstractNote={Using data on ocean circulation with a Lagrangian larval transport model, we modeled the potential dispersal distances for seven species of bathyal invertebrates whose durations of larval life have been estimated from laboratory rearing, MOCNESS plankton sampling, spawning times, and recruitment. Species associated with methane seeps in the Gulf of Mexico and/or Barbados included the bivalve "Bathymodiolus" childressi, the gastropod Bathynerita naticoidea, the siboglinid polychaete tube worm Lamellibrachia luymesi, and the asteroid Sclerasterias tanneri. Non-seep species included the echinoids Cidaris blakei and Stylocidaris lineata from sedimented slopes in the Bahamas and the wood-dwelling sipunculan Phascolosoma turnerae, found in Barbados, the Bahamas, and the Gulf of Mexico. Durations of the planktonic larval stages ranged from 3 weeks in lecithotrophic tubeworms to more than 2 years in planktotrophic starfish. Planktotrophic sipunculan larvae from the northern Gulf of Mexico were capable of reaching the mid-Atlantic off Newfoundland, a distance of more than 3000 km, during a 7- to 14-month drifting period, but the proportion retained in the Gulf of Mexico varied significantly among years. Larvae drifting in the upper water column often had longer median dispersal distances than larvae drifting for the same amount of time below the permanent thermocline, although the shapes of the distance-frequency curves varied with depth only in the species with the longest larval trajectories. Even species drifting for >2 years did not cross the ocean in the North Atlantic Drift.}, number={4}, journal={INTEGRATIVE AND COMPARATIVE BIOLOGY}, author={Young, Craig M. and He, Ruoying and Emlet, Richard B. and Li, Yizhen and Qian, Hui and Arellano, Shawn M. and Van Gaest, Ahna and Bennett, Kathleen C. and Wolf, Maya and Smart, Tracey I. and et al.}, year={2012}, month={Oct}, pages={483–496} }
 @article{mcgillicuddy_townsend_he_keafer_kleindinst_li_manning_mountain_thomas_anderson_2011, title={Suppression of the 2010 Alexandrium fundyense bloom by changes in physical, biological, and chemical properties of the Gulf of Maine}, volume={56}, ISSN={["0024-3590"]}, DOI={10.4319/lo.2011.56.6.2411}, abstractNote={For the period 2005–2009, the abundance of resting cysts in bottom sediments from the preceding autumn was a first‐order predictor of the overall severity of spring–summer blooms of Alexandrium fundyense in the western Gulf of Maine and southern New England. Cyst abundance off mid‐coast Maine was significantly higher in autumn 2009 than it was preceding a major regional bloom in 2005. A seasonal ensemble forecast was computed using a range of forcing conditions for the period 2004–2009, suggesting that a large bloom was likely in the western Gulf of Maine in 2010. This did not materialize, perhaps because environmental conditions in spring–summer 2010 were not favorable for growth of A. fundyense. Water mass anomalies indicate a regional‐scale change in circulation with direct influence on A. fundyense's niche. Specifically, near‐surface waters were warmer, fresher, more stratified, and had lower nutrients than during the period of observations used to construct the ensemble forecast. Moreover, a weaker‐than‐normal coastal current lessened A. fundyense transport into the western Gulf of Maine and Massachusetts Bay. Satellite ocean color observations indicate the 2010 spring phytoplankton bloom was more intense than usual. Early season nutrient depletion may have caused a temporal mismatch with A. fundyense's endogenous clock that regulates the timing of cyst germination. These findings highlight the difficulties of ecological forecasting in a changing oceanographic environment, and underscore the need for a sustained observational network to drive such forecasts.}, number={6}, journal={LIMNOLOGY AND OCEANOGRAPHY}, author={McGillicuddy, D. J., Jr. and Townsend, D. W. and He, R. and Keafer, B. A. and Kleindinst, J. L. and Li, Y. and Manning, J. P. and Mountain, D. G. and Thomas, M. A. and Anderson, D. M.}, year={2011}, month={Nov}, pages={2411–2426} }
 @article{li_he_mcgillicuddy_anderson_keafer_2009, title={Investigation of the 2006 Alexandrium fundyense bloom in the Gulf of Maine: In-situ observations and numerical modeling}, volume={29}, ISSN={["1873-6955"]}, DOI={10.1016/j.csr.2009.07.012}, abstractNote={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.}, number={17}, journal={CONTINENTAL SHELF RESEARCH}, publisher={Elsevier BV}, author={Li, Yizhen and He, Ruoying and McGillicuddy, Dennis J., Jr. and Anderson, Donald M. and Keafer, Bruce A.}, year={2009}, month={Sep}, pages={2069–2082} }
 @article{li_willits_2008, title={An experimental evaluation of thermal stratification in a fan-ventilated greenhouse}, volume={51}, DOI={10.13031/2013.25237}, abstractNote={Experiments were performed to investigate air velocity and vertical air temperature distributions in a fan-ventilated greenhouse. The effects of ventilation rate and canopy size on the allocation of airflow between canopy and non-canopy areas were examined. The data suggested that the ratio of the air velocity within the canopy to the mean velocity of the entire greenhouse cross-section depended on not only the area ratio of canopy to greenhouse cross-section, but also ventilation rate. The ratio of canopy air velocity to greenhouse average velocity decreased if ventilation rate increased. The effects of outside solar radiation, ventilation rate, evaporative cooling pads, and presence of a canopy on the vertical air temperature variations were also investigated. The vertical air temperature variation increased approximately linearly with solar radiation. Use of an evaporative pad increased the temperature variation. Increasing ventilation rate resulted in reduced air temperature variation. The presence of a canopy modified the vertical temperature distribution and reduced temperature variations as well.}, number={4}, journal={Transactions of the ASABE}, author={Li, S. and Willits, D. H.}, year={2008}, pages={1443–1448} }
 @article{li_willits_2008, title={Comparing low-pressure and high-pressure fogging systems in naturally ventilated greenhouses}, volume={101}, ISSN={["1537-5129"]}, DOI={10.1016/j.biosystemseng.2008.06.004}, abstractNote={The cooling performance of a low-pressure (405 kPa working pressure) and a high-pressure fogging system (6.89 MPa) was evaluated. Experiments were conducted in two empty, naturally ventilated greenhouses under summer conditions for a period of about two months. One greenhouse was used as the treatment greenhouse (fogged house) and another was used as the control house (un-fogged house). Cooling efficiency was defined by the ratio of the temperature difference between the un-fogged and fogged greenhouses to the difference between the temperature in un-fogged house and the wet-bulb temperature in the fogged greenhouse. Evaporation efficiency was defined as the ratio of fog evaporation rate to spray rate. Cooling efficiency and evaporation efficiency were compared for the low-pressure and high-pressure systems after accounting for differences in weather conditions under which the two systems were operated. It is suggested that on average evaporation efficiency for the high-pressure system was at least 64% greater than the low-pressure system; cooling efficiency for the high-pressure system was at least 28% greater than for the low-pressure system.}, number={1}, journal={BIOSYSTEMS ENGINEERING}, author={Li, S. and Willits, D. H.}, year={2008}, month={Sep}, pages={69–77} }
 @article{li_willits_2008, title={Modeling thermal stratification in fan-ventilated greenhouses}, volume={51}, DOI={10.13031/2013.25307}, abstractNote={A two-dimensional thermal model was developed to investigate the thermal stratification in fan-ventilated greenhouses. Model inputs include outside weather (air temperature, humidity, and solar radiation), geometric parameters of crop rows and leaf area index, greenhouse ground and roof temperatures, ventilation rate, and operation of evaporative cooling pads. Comparing predictions with observed data indicated that the air temperature and relative humidity were modeled at acceptable accuracies, with air temperature underpredicted by 1.3°C and relative humidity overpredicted by 9%, on average for a planted greenhouse. For an unplanted greenhouse, the air temperature was predicted with an absolute error of 0.7°C, while for relative humidity the absolute error was 3%. Vertical temperature variation, defined as maximum temperature minus minimum temperature at approximately the central location of greenhouse, was predicted with an absolute error of 0.1°C and a relative absolute error of 10% for the planted greenhouse, while for an unplanted greenhouse it was 0.6°C for the absolute error and 12% for the relative absolute error. Simulations with the model suggest that increasing ventilation rate reduced the vertical temperature gradient. Increased ventilation reduced air temperature more at the top than the bottom of the greenhouse. Greater air temperature variation was produced when using evaporative pad cooling than not. Air temperature was reduced more at the bottom than at the top with evaporative pad cooling. The presence of a canopy altered the vertical air temperature distribution and reduced the temperature variation. A sample simulation showed that on a typical summer day at Raleigh, North Carolina, the presence of a canopy row with a height of 1.75 m occupying 69% of the ground area reduced the air temperature variation from 11.5°C to 1.8°C in a fan-ventilated greenhouse operating with a ventilation rate of 0.087 m3 m-2 s-1 and using evaporative pad cooling. The peak air temperature generally occurred at the top of canopy or somewhat below the canopy top. This finding may have some significance in establishing the location of temperature control sensors in future control systems.}, number={5}, journal={Transactions of the ASABE}, author={Li, S. and Willits, D. H.}, year={2008}, pages={1735–1746} }
 @article{cowen_chen_morales_li_levine_tong_carlton_huff_1988, title={Descriptive analysis of diagnostic test results of quarantined pigs and cattle imported into the People's Republic of China from the United States}, volume={84}, journal={Acta Veterinaria Scandinavica}, author={Cowen, P. and Chen, B. and Morales, R. A. and Li, S. and Levine, J. F. and Tong, K. and Carlton, T. L. and Huff, D. R.}, year={1988}, pages={271–273} }