Determination of the influence of wind on the Keweenaw Current in the LakeSuperior basin as identified by Advanced Very High Resolution Radiometer (AVHRR) imagery

The Keweenaw Current is a warm coastal current in Lake Superior that flows northeastward along the northern shore of Michigan's Keweenaw peninsula. Th is study focuses on the fate of the current at the tip of the Keweenaw Peni nsula. Results of this study suggest that the path of the current beyond th e peninsula is primarily controlled by wind. In this study, eleven surface temperature maps derived from Advanced Very H igh Resolution Radiometric (AVHRR) data using computer assisted image proce ssing techniques were used to identify the Keweenaw Current. Wind data from two moored data buoys, a Coastal Marine Automated Network (CMAN) fixed buo y, and three airport weather stations, collected on the same day as each of the images and for the two days preceding the image date, are used to dete rmine whether wind direction and speed influence the path of the Keweenaw C urrent past the tip of the peninsula. In nine images the current's path is similar to the surface Ekman transport direction predicted from wind data. All eleven images show a similarity between the current's actual path and a path calculated when net Ekman transport is assumed. Results of this study also show that there may be a possible lag time of one day between a chang e in wind direction and the current's adjustment to that change.