Interaction of Mesoscale and Submesoscale Eddies in the Sea of Okhotsk Based on Satellite Data

Abstract

We have investigated the interaction between the mesoscale and submesoscale eddies in the deep Kuril Basin of the Sea of Okhotsk. An analysis of the long-term series of satellite altimetry observations (2000–2011) has demonstrated that the circulation in the Kuril Basin is determined by quasi-stationary mesoscale anticyclonic eddies. Based on the QuikSCAT SeaWind scatterometer satellite data, a negative vorticity wind-stress field exists over the deep part of the Sea of Okhotsk in the warm season, which generates anticyclonic circulation composed of mesoscale eddies. An analysis of the satellite infrared images reveals that submesoscale processes determine the interaction of mesoscale eddies with the waters of the zone of intense tidal mixing on the shelf of the Kuril Islands. Submesoscale cyclonic eddies are formed at the fronts of tidal mixing and near the Bussol Strait located in the central part of the Kuril Islands. Applications of Lagrangian analysis have shown that submesoscale eddies move at the periphery of the northern mesoscale eddy within the advective streamer limited by the transport barriers. The formation and destruction of submesoscale eddies caused by horizontal mixing leads to the injection of cold water rich in nutrients from the zone of intense tidal mixing to the deep Kuril Basin. In the summer period, high concentrations of chlorophyll-a are observed in the upper layer of the northeastern part of the Sea of Okhotsk due to the interaction between submesoscale and mesoscale eddies.