Synoptical monitoring of thermic fronts on the sea surface of the Southern Ocean

The methodology of synoptical monitoring of Southern Ocean fronts based on observations during the seasonal maritime operations for supply Russian Antarcticstations is offered. Thecontinuous registrations of the variability of horizontal gradients sea surface layer temperature (SSLT) in situ, and horizontal gradients sea surface temperature (SST) from satellite infrared (IR) data are used, they were taken on board of research vessel in real-time. This makes possible a detailed definition of the horizontal gradients of thermic characteristicsand extent of the frontalzones by continuous data on SSLT from vessel’s automatic meteorological station, with simultaneous GPS-registration of their spatial location, on one side; and a precise definition of the geographical position of frontal zones of SST from satellite by the very high resolution IR-images of the ocean surface, on the other. Such data obtained during regular meridional voyages of research-supply vessels of the Russian Antarctic expedition between Africa and Antarctica, allow more confident than before judge the presence (or absence) of trends in interannual changes in the latitudinal location of the main fronts in the Southern Ocean, as evidence of the manifestations of global warming in the surface layer waters. In the period 2009–2015 interannual seasonal positions of major climatic fronts on the surface of the Indian Ocean sector of the Southern Ocean pronounced tendency to shift to the north or south is not revealed. The meandering processes of the main fronts and associated vortices formation in the area of the Antarctic Circumpolar Current, both create horizontal movements of water with vorticity of different signs. This leads to movements upward or downward in the photic layer of the sea, and increases or reduces the concentration of nutrients in it, thereby affecting the rate of growth of phytoplankton which is the basis of the primary productivity of the ocean