Decadal‐Scale Variability in the Surface Flow of the Gulf of Maine Coastal Current: The Impact of Changing Climate Conditions on Coastal Circulation

Abstract

The Gulf of Maine (GOM) is one of the most productive and ecologically important marine environments on the planet. The Gulf of Maine Coastal Current (GMCC), which stretches along the western side of the GOM from the Bay of Fundy to Cape Cod, plays an important role in supporting this productivity by transporting nutrients, larvae and dinoflagellates southwestward along the Canadian and New England coastlines. Climate change has led to alterations in GOM ecosystems in recent years: GOM water temperatures have warmed and distributions of marine species have shifted. However, the impacts of the changing climate on the circulation within the GOM, including the path and velocity of the GMCC, have remained unclear. Here, we examine data collected by satellite tracked surface drifters and velocity data collected by the NERACOOS buoy array in order to investigate inter‐decadal changes to the flow of the GMCC. We find that over inter‐decadal timescales, the alongshore surface flow of the GMCC has slowed, particularly in the region southwest of Penobscot Bay. The slowdown observed in the GMCC surface flow is most likely attributed to a local strengthening of the southwesterly winds over the time period of interest.