Estimation of Autumnal Cooling and Driven circulations in a Large Estuary

Amin Ilia1, James O'Donnell2 and Grant McCardell1, (1)University of Connecticut, Marine Sciences, Groton, CT, United States, (2)University of Connecticut, Connecticut Institute for Resilience and Climate Adaptation, Groton, CT, United States
Long Island Sound (LIS) is a large estuary in the Middle Atlantic Bight of the eastern United States that is separated from the Atlantic Ocean by Long Island, New York. Seasonal variations in solar insolation impact water circulation and biological processes in LIS. Water in LIS warms from February until October and begins to cool in the fall. Ship surveys shows that the vertical temperature structure become uniform during this season. It has been proposed that this is a consequence of static instability that occurs during periods of cold air temperatures. However, there have been no observations that resolve these cooling periods. We report glider measurements of the vertical structure of water properties in LIS. The temperature data is used to compute the rate of change of the heat content. We also estimate the surface heat fluxes at the surface using buoy observations and WRF model data. In addition, we implement FVCOM to simulate the circulations driven by surface heat loss. Lateral cooling from shallow water to deeper region of the sound are estimated. We found that WRF couldn't accurately estimate the latent and sensible heat fluxes, therefore, we modify them by observed data in order to improve our circulation model.