Observations of the Eastern Maine Coastal Current and its offshore extensions in 1994

Cold surface temperatures, reflecting Scotian Shelf origins and local tidal mixing, serve as a tracer of the Eastern Maine Coastal Current and its off shore extensions, which appear episodically as cold plumes erupting from th e eastern Maine shelf. A cold water plume emanating from the Eastern Maine Coastal Current in May 1994 was investigated using advanced very high resol ution radiometer (AVHRR) imagery, shipboard surveys of physical and biochem ical properties, and satellite-tracked drifters. Evidence is presented that suggests that some of the plume waters were entrained within the cyclonic circulation over Jordan Basin, while the major portion participated in an a nticyclonic eddy at the distal end of the plume. Calculations of the nitrat e transported offshore by the plume show that this feature can episodically export significant quantities of nutrients from the Eastern Maine Coastal Current to offshore regions that are generally nutrient depleted during spr ing-summer. A series of AVHRR images is used to document the seasonal along -shelf progression of the coastal plume separation point. We speculate on p otential causes and consequences of plume separation from the coastal curre nt and suggest that this feature may be an important factor influencing the patterns and overall biological productivity of the eastern Gulf of Maine.