Results of the Caspian Sea satellite survey: internal wave climate

Abstract

Results of satellite observations of surface manifestations of internal waves in the Caspian Sea are presented. Our work produced data on a spatial and temporal variability of internal waves of non-tidal origin via their surface manifestations. By using high-resolution satellite data, we were able to get a clear picture of generation, propagation and interaction of internal wave packets and significantly broadened our insights on the physics and geography of internal waves in the World Ocean. The large amount of the data available allowed us to make some generalizations and obtain statistically significant results on a spatial and temporal variability of various internal wave surface manifestations in satellite images. We discovered numerous diverse instances of internal wave manifestations in satellite images of the Caspian Sea. We further demonstrated that this observed diversity of internal wave behavior is due to a diversity of their generation mechanisms and indicates the complexity of the dynamic environment in the region. We put together a detailed map of spatial distribution of surface manifestations of the internal waves in the Caspian Sea. We revealed a seasonal and inter-annual variability of wave activity, identified main regions of the internal wave localization for each season and revealed causes of a spatial inhomogenity of internal wave packet manifestations. Possible factors leading to the generation of non-tidal internal waves are determined on the basis of joint analysis of available satellite remote sensing data of the sea surface in microwave, visible (VIS) and infra-red (IR) ranges complemented by contact measurements.