Effects of mesoscale eddies on the flow of the Alaskan Stream

Abstract

Using a high‐resolution, pan‐Arctic ice‐ocean model forced with realistic atmospheric data, we examine the mean transport and temporal and spatial variability within the Alaskan Stream. Model results are analyzed and compared with observations, including satellite altimetry and CTD measurements. The mean net transport of the Alaskan Stream is found to be between 34 and 44 Sv, intensifying downstream. Mesoscale eddies are found to periodically move along the path of the Alaskan Stream and alter the mean position of the typically westward‐flowing current. However, the strength of the current is not reduced as an anticyclonic eddy passes a point along the path. Instead, there appears to be an offshore (or southward) shift in the current velocity core. Stationary measurement instruments may not be able to detect this shift in position over the slope if their southernmost location does not coincide with the current shift due to an eddy. This may result in recording of a weakened or sometimes reversed flow. Finally, we examine and demonstrate that modeled eddies within the Alaskan Stream have dominant effect on northward transport and variability through the eastern and central Aleutian Island passes.