The role of stratification in the spring ice edge bloom in the Bering Sea: a numerical model

Abstract

Marginal ice edge zones are unique frontal systems with air-ice-sea interfaces. Phytoplankton blooms which occur along the edge of some melting ice packs in the spring, appear to be related to melt water driven density stratification. In this thesis a numerical model of a marginal ice edge zone is constructed. The wind driven circulation and spring phytoplankton bloom at the Bering Sea ice edge are simulated as functions of air-ice-sea-biology interaction. It was found that as long as the ice was allowed to melt, blooms occur regardless of wind direction. However, because of the compactness dependent melt scheme invoked, the faster the ice advects out from the pack, the faster the water column stratifies. The speed and the area of the bloom depend on the rate and extent of stratification. The model data compare favorably with field data.