Thermohaline structure of the Antarctic Surface Water/Winter Water in the Indian sector of the Southern Ocean

Abstract

Upper-layer thermohaline structure in the Antarctic Zone between 20° and 120°E has been described and interpreted for its underlying physics, based on two recent summer hydrographic sections along 30° and 62°E, together with historical hydrographic data available in the study area. Spatial property distributions of the surface mixed layer and subsurface temperature minimum layer or Winter Water are closely correlated with the seasonal warming and cooling, wind intensity, seasonal sea ice advance and retreat, and the general circulation in the study area. The Prydz Bay area exhibits the most saline, dense, deep Winter Water and appears as the site with the highest potential for the local formation of deep water of the whole study area, although its circumpolar impact is known to be minor. There is strong evidence that the summertime freshwater input in the Enderby Basin comes mostly from the eastward advection of meltwater originating from the Weddell Basin, along the northern limb of the Weddell Gyre.