Mesoscale circulation along the Sakhalin Island eastern coast

TL;DR

This study analyzes the seasonal and interannual variability of mesoscale cyclones and anticyclones along Sakhalin Island's eastern coast, revealing their formation mechanisms and ecological impacts using satellite and oceanographic data.

Contribution

It provides new insights into the formation processes and seasonal patterns of mesoscale circulation along Sakhalin Island's coast based on long-term observational data.

Findings

Cyclones occur mainly in summer due to coastal upwelling.

Anticyclones form in colder seasons from river inflow and wind patterns.

Cyclones enhance biological productivity in summer.

Abstract

The seasonal and interannual variability of mesoscale circulation along the eastern coast of the Sakhalin Island in the Okhotsk Sea is investigated using AVISO velocity field and oceanographic data for the period from 1993 to 2016. It is found that mesoscale cyclones with the horizontal dimension of about 100 km occur there predominantly during summer, whereas anticyclones occur predominantly during fall and winter. The cyclones are generated due to the coastal upwelling forced by northward winds and the positive wind stress curl along the Sakhalin coast. The anticyclones are formed due to an inflow of low-salinity Amur-River waters from the Sakhalin Gulf intensified by southward winds and the negative wind stress curl in the cold season. The mesoscale cyclones support the high biological productivity at the eastern Sakhalin shelf in July - August.