| Satellite data is used in conjunction with other data sets to study two ocean margin phenomena. The seasonal cycle and interannual behavior of the Northeast Water (NEW) Polynya is described using a series of daily total ice concentrations derived from passive microwave satellite observations (1978-1994). The total ice-free area on the shelf northeast of Greenland is used as an indication of the summer opening of the NEW Polynya which lasts from the beginning of May to the end of September. The summer maximum total water area (TW) ranges from a minimum 59,000 (in 1992) to a maximum of 120,000 km{dollar}sp2{dollar} (in 1985) and the date of maximum opening from the beginning of July to the end of September. Monthly averages of surface meteorological parameters are analyzed to explain the TW variations. The heat budget, for the pentad March 1985-February 1990, explains 86% of the observed variance in TW. Utilizing this relationship and the TW for the summers of 1992 and 1993, the potential amount of melt water agreed with that derived from hydrographic observations. The effect of the Gulf Stream lateral fluctuations and meandering on both sea-level and current regime in the slope region off the southern Middle Atlantic Bight is investigated in the spatial and temporal domains. The dynamical forcing of the GS on the slope region is represented in terms of a triangular area defined by the shelf break, the 73{dollar}spcirc{dollar}W meridian and the GS front, based on satellite-derived thermal information. For the same time period, the flow response to this forcing is quantified in terms of diabathic and parabathic current fields derived from satellite altimeter data. The sea-level adjustment along the 750m depth contour has its concavity directed upward (downward) for GS close (far) from the shelf, implying recirculation. In the parabathic direction flow to the southwest is found to correspond to periods when the GS is far from the shelf, and vice versa. In the spectral domain current velocity is most coherent with the rate of change of area at a period of 24 days, which corresponds to the fastest-growing GS meanders. |
