Variability of the water properties in NAFO Subareas 5 and 6 during the 1990s

The variability in temperature and salinity of the waters on the northeast USA continental shelf and the Gulf of Maine during the 1990s is presented and compared to that during a previous period (1978–87). A general freshening of the surface waters in the Gulf of Maine and of the shelf waters in the Middle Atlantic Bight is documented. An increase in the inflow to the Gulf of Maine of cool, low salinity surface water from the Scotian Shelf during the 1990s was responsible for the freshening. Wintertime warming of the shelf waters in the southern part of the region was noted. The deep waters of the western Gulf of Maine also exhibited a warming during the 1990s. This warming is believed due to reduced winter convective cooling, caused at least in part, by the freshening of the surface layer which increased the stratification that inhibited convection