Observations from a Yakutat eddy in the northern Gulf of Alaska

Abstract

The impingement of deep basin eddies on the shelf in the Gulf of Alaska has been implicated as an important mechanism for cross-shelf exchange. The influence of eddies on biological processes has been confirmed with data from the Sea-viewing Wide Field-of-view Sensor showing elevated chlorophyll associated with eddies. Altimetry data suggest that an eddy formed in the winter of 2003 near Yakutat, Alaska, and propagated along the shelf break, reaching the head of the gulf by spring. This eddy was sampled during May and September of 2003. The eddy core water was warm, salty, and high in nitrate relative to basin water of the same density but was similar to historical water properties from the shelf near Yakutat. This suggests a shelf origin for the eddy core water. Copyright 2005 by the American Geophysical Union.