Caspian Sea surface circulation variability inferred from satellite altimeter and sea surface temperature

Abstract

Multiyear (1993-2007) satellite-derived Sea Level Anomaly (SLA), Sea Surface Temperature (SST), and model-derived mean dynamic topography were used together to analyze climatological and interannual variations of the Caspian Sea surface circulation. Constructed geostrophic currents are in good agreement with the known circulation features of the Caspian Sea, obtained from models and verified by some drifter observations. It is shown that the climatological surface circulation of the Middle Caspian Sea (MCS) is dominated by a basin-wide cyclonic circulation in winter, switching to an anticyclonic circulation in summer. A dipole pattern (an anticyclonic eddy near 39.5°N and a cyclonic one near 38°N) exist in the Southern Caspian Sea (SCS) (stronger from September to January). Evaluation of the multiyear geostrophic velocities shows that the Caspian Sea surface circulation exhibits strong interannual variations, with the location and intensity of the circulation patterns changing from one year to another. Key Points Ocean model derived field was combined with the satellite-derived observations The surface circulation characteristics of the Caspian Sea is investigated Interannual variability of the surface circulation of the Caspian is examined © 2014. American Geophysical Union. All Rights Reserved.