Seasonal thermally induced structural front in a Basin with horizontal and vertical salinity stratification

The goal of the work presented was to reveal specific features of the thermal bar formation in brackish basins with an essential horizontal and vertical salinity gradient. Influence of the vertical salinity gradient is discussed on an example of the Baltic wintry conditions; the horizontal salinity gradients are considered in the Vistula lagoon and the Baltic Sea. On the basis of an available field and remote sensing data obtained in the river Pregel mouth, the Vistula lagoon and the Baltic Sea we analyzed the thermal bar structure, formation and propagation. In particular, we have arranged the dates in spring and in autumn, when water in the hydrological system of the river Pregel - the Vistula lagoon - the Baltic Sea reaches the temperature of maximum density (depending on water salinity). An average speed of the thermal bar propagation in the given system is estimated and compared with ones observed for lakes. Peculiarity of the structural front formation and propagation in the Baltic are discused.