Interannual Variability in the South Shetland Island system

Abstract

The objective is make a analisys of both spatial and temporal of sea superficial temperature (SST) variability on area between 61-64ºS and 55-64ºW. Region around South Shetland Island, covering the Drake Passage to north and Bransfield Straits to Routh. From satellite data of SST obtained from remote sensing system calls Advanced Microwave Scanning Radiometer (AMRS-E). This system is a combined product between both infrared sensor (high spatial resolutions, but can not see through clouds) and microwave sensor (capability to see through clouds, but have low spatial resolution). With this system the work is based in a 0.25x0.25 degree grid, with this resolution the mesoescalar structures can be analyzed and this spatial resolution is similar with our Project (CLOUPLING Project). The data base is from 2006 to 2010 and with this data we make SST distributions in both whole region and different temporal periods (Days, months, annuals and years stations) allowing us a caracterization of series temporal SST in all year not only southern summer, because the remote sensing system not limited for the formation of the winter ice how happen with the oceanographic cruises From this study are obtained the most high SST records in south summer (>2.5ºC) and the largest seasonal variations, while the lowest records are located in the south winter (<-1ºC) and homogeneous distribution of SST. demonstrating a variability in temperature at 3°C. On the other hand, summer (December-April) its the best period for study the superficial mesoescalar structures, because in this time period the principal structures are visible in superficie, whereas in winter, rise to the surface homogeneity not presents any superficial structure visible Despite the above, the frontal structures surrounding the South Shetland Islands are dominant structures in the system. this is shown in the graphic representation of the average total of superficial sea temperature, where surface structures are both dominant and are located parallel to the archipelago of the South Shetland Islands. This spatial variation can be explained by the dynamics that exist around the South Shetland Islands: - the north of archipelago (Drake Passage) has features circumpolar because the system is dominated by the Antarctic Circumpolar Current. - the south of the archipelago (Bransfield Strait) is influenced by the presence of two water mass: Transitonal Zonal water with Bellinghausen influence (TBW) and Transitonal Zonal water with Weddell Sea influence (TWW) This set determines the characteristics of the different hydrographic fronts in the area, its extent and intensity, and justifies the observed spatial variability. From 2006, when I make my profesional practice in the antarctic chilean institut, I start my antarctic adventure, participated in several Antarctic latinoamerican Congress, I did my master research in Spain and actually I’m PhD(c) in Oceanography physical in the south shetland island, through the project called Physical-biological coupling around South Shetland Islands (Antarctica) at the mesoscale range (COUPLING), awarded by the Ministry of Research of the Spanish government. Our research line is make a model exchange heat between atmosphere-ocean, but first we need make a good description about the system around the south shetland island both time and spacing.