Climatic Structure of the Dynamic and Temperature Fronts in the Scotia Sea and the Adjacent Water Areas

• Main Authors: Yu.V. Artamonov, E.A. Skripaleva, N.V. Nikolsky
• Format: Article in Journal/Newspaper
• Language: English
• Published: Federal State Budget Scientific Institution «Marine Hydrophysical Institute of RAS» 2022
• Subjects: scotia sea; drake passage; weddell sea; sea surface temperature; satellite altimetry; temperature horizontal gradients; geostrophic currents; bottom topography; Oceanography; GC1-1581; Antarctic; Drake Passage; Falkland Plateau; Scotia Sea; Shackleton; Shackleton Ridge; South Shetland Islands; The Antarctic; Weddell; Weddell Sea; Antarc*; Antarctica; Tierra del Fuego
• Online Access: https://doaj.org/article/2c814a6889ed406fb265f84d88078bf4

Purpose. The aim of the work is to clarify the spatial structure of the climatic dynamic fronts (geostrophic current jets) and to estimate the relationship between their position and that of the large-scale temperature fronts on the surface of the Scotia Sea and the adjacent water areas in the southwestern part of the Atlantic sector of Antarctica. Methods and Results. The daily averaged data arrays of the CMEMS (1993–2017) and NOAA OI SST (1982–2017) reanalysis at the regular 0.25° grid were used. The CMEMS reanalysis contains the sea surface geostrophic velocity values, the NOAA OI SST reanalysis – the sea surface temperature ones which were reduced to the climatic form through their averaging for each month of the corresponding periods. Position of the current jets and the temperature fronts was determined using the maximums of the geostrophic velocity components and the extremes of the temperature horizontal gradients. The updated scheme of the average long-term position of dynamic fronts was constructed. It shows that in the areas of the most pronounced bottom topography inhomogeneities (the northern boundary of the Falkland Plateau and the Tierra del Fuego shelf, the boundaries of the Falkland Islands shelf and the Birdwood Bank, the Shackleton Ridge and the South Shetland Islands shelf), the fronts do not change their latitudinal position during a year. It is revealed that in most of the water area, the temperature horizontal gradient extremes (temperature fronts) correspond to the geostrophic velocity maximums (dynamic fronts). The Northern and Central Branches of the Antarctic Circumpolar Current are most clearly manifested in the temperature field. In general, in the water area under study, the average annual latitudinal position of the Subantarctic and Antarctic Polar Fronts is displaced to the south relative to the position of the Northern and Central branches jets of the Antarctic Circumpolar Current by 0.25–0.5° and 0.25–1°, respectively. Conclusions. It is shown that, being influenced by the ...