Seasonal evolution of hydrographic fields in the central Middle Atlantic Bight from glider observations

Abstract

The first sustained glider observations in the Middle Atlantic Bight are used to describe the seasonal evolution of hydrographic fields off New Jersey. Near-surface temperatures respond to the seasonal cycle of surface heating, while waters at depth are primarily influenced by advection of cold waters from the north in the cold-pool during spring/ summer, and warming due to mixing during fall. The thermocline thickness increases in the offshore direction. Salinity presents seasonal variability due to river discharge and wind variations, with low-salinity waters spanning ∼100 km across the shelf from May to September in a ∼10 m thick surface layer. Stratification intensifies from April/May to late summer, especially within 80 km from the coast. The pycnocline deepens in the water column during late summer, while the passage of storms during fall rapidly reduces the stratification. The glider high-resolution observations allowed for unprecedented detailed characterization of the spatial scales of variability. Copyright 2008 by the American Geophysical Union.