Manifestation of ship wakes in satellite images in periods of intense algae bloom

Abstract

Manifestation of moving ships' wakes in satellite images of the sea surface in conditions of intense algae bloom is discussed. Long-living ship wakes, whose lengths sometimes reach two hundred kilometers, are manifested on radar images in the form of long narrow bright bands of high backscatter. Estimates of spatial and temporal characteristics of such wakes are made. Joint analysis of SAR, VIS and IR satellite data indicated some factors that are likely to cause the occurrence of the wakes. Hypotheses to explain this phenomenon are presented. Remote sensing observations during more than ten years over different parts of the Black, Baltic and Caspian Seas showed that the ship wakes are often subjected to significant shift and deformation under the impact of wind and currents. Comparing the true route of a ship with its wake one can obtain more detailed information about current components.