Winter Circulation in the Western Gulf of Maine: Part 2. Current and Pressure Observations

Abstract The wintertime circulation in the western Gulf of Maine has been studied with a moored current, temperature and pressure array which was deployed from November 1974 to January 1975. These observations have been interpreted with three additional data sets: coastal sea level records, Portland Lightship meteorological data, and offshore hydrographic transect data which describe the evolution of the density field on weekly time scales. The observed mean currents are consistent with the idea of a cyclonic Gulf of Maine gyre. The subtidal current fluctuations were coherent in the vertical at each mooring but incoherent between the moorings which were separated by about 50 km in both the alongshore and offshore direction. Furthermore, the currents showed only weak coherence with the winds. The pressure field was highly coherent over the whole Gulf of Maine. Therefore, estimates of the pressure gradient vector inside and outside the 100 m isobath were made using coastal subsurface and bottom pressure rec...