Satellite observations of regular eddies in bays of the Shantar Archipelago, Sea of Okhotsk

Abstract

Eddies with diameters of 4–40 km are formed near headlands running out into the sea in bays of the Shantar Archipelago. Such eddies play an important part in the dispersion of ice and plankton. The formation of these eddies is studied based on satellite and marine observations. To construct velocity vectors, images from the Aqua and Terra satellites were used (the data of channel 1 of the MODIS radiometer with a spatial resolution of 250 m). The measurements of currents were made by sequential satellite images with an interval of about 100 min. Large ice floes were chosen to determine currents by satellite data. Vectors of ice displacement were constructed and their velocities were calculated for each pair of images. The flow convergence is estimated using these data. The marine observations include direct observations of currents and CTD data. The observations of currents were obtained with electromagnetic meters mounted on anchored buoys. The results of direct observations point to tidal currents as the main mechanism for the formation of short-lived but regular convergence regions associated with headland eddies.