3-5 



General Patterns of Circulation in Long Island Sound 



The waters of New Haven Harbor ultimately flush into Long 



2 

 Island Sound, which covers more than 2400 km and whose circulation 



patterns have been well characterized by the Long Island Sound Regional 



Study (197 3) . The following is a brief summary from that report. 



Circulation patterns in Long Island Sound and adjacent estu- 

 aries are controlled by tides, fresh water inflow, winds and other 

 weather conditions , bottom topography and salinity and temperature 

 gradients. The circulation pattern influences the chemical composition 

 of the water and the sediment distribution within the basin. In gen- 

 eral, the tidal range increases to the west, while current velocities 

 decrease. The circulation pattern in the Long Island tidal basin shows 

 an exchange of water at the eastern end with a net outward flow of 

 surface water to Block Island Sound and an influx of more dense bottom 

 water from Block Island Sound. In western Long Island Sound, surface 

 fresh water moves eastward into the Sound from the East River, while 

 Sound bottom water flows westward into the East River. In central Long 

 Island Sound, the tidal current patterns flow in an elliptical counter- 

 clockwise direction. Upwelling occurs in the central Sound, resulting 

 in decreased transport in bottom layers . Upwelling has been reported 

 along the Connecticut shore between New Haven and Old Saybrook and in 

 coastal Long Island between Mattituck Inlet and Orient Point (Hollman 

 and Sandberg, 1972 in Long Island Sound Regional Study, 1973) . Tidal 

 currents run parallel to the shoreline under the influence of coastal 

 topography . 



Climatology 



The Long Island Sound climate has also been described in some 

 detail in the Long Island Sound Regional Study (1973) . The four sea- 

 sons, consistent monthly precipitation, localized temperature changes, 

 and the moderating maritime influence of Long Island Sound air masses 



