Variability of the coastal current and nutrient pathways in the eastern Gulf of Maine

Abstract

The eastern Maine coastal current flows southwestward, carrying cold and nutrient-rich waters along the coast from the tidally stirred eastern gulf toward the central and western gulf, where in summer the waters are warmer and more stratified. The current typically turns offshore before reaching Penobscot Bay, near the central coast, at a location determined largely by the distribution of dense slope water in Jordan Basin. The slope water, which enters the gulf as a deep inflow from the Atlantic Ocean, thus plays a major role in determining the intensity, direction and timing of the delivery of nutrients to the interior gulf. In this paper, we use data from two cruises in August 1987 to examine the variability and nutrient transport of the coastal current, especially to show the important physical linkages between the deep slope water, the structure of the coastal current, and its likely significant effect on biological productivity in the gulf.