Physical Process Influencing the Ecosystem of the Indian Sector of Southern Ocean-An Overview

  • N Anilkumar National Centre for Antarctic and Ocean Research (NCAOR), Earth System Science Organisation (ESSO), Healand Sada, Vasco-da-Gama, Goa 403 804
  • P Sabu National Centre for Antarctic and Ocean Research (NCAOR), Earth System Science Organisation (ESSO), Healand Sada, Vasco-da-Gama, Goa 403 804

Abstract

The Antarctic Circumpolar Current (ACC) is the key current system in the Southern Ocean (SO) which connects three major oceans. The eastward flowing ACC in the Indian sector of SO (IOSO) influences by the southwest Indian ridge and Weddell gyre which results a southward shift of the core of ACC. This brings warm water to the coastal Antarctica and may cause glacier/sea-ice melting and further warming and freshening of bottom water masses. Additionally eddies in IOSO are the principal mechanism which transfer heat, salt, and carbon poleward across the zonal ACC and contribute to the mixing of water masses. The southward intrusions of Subtropical Surface Water as well as the upward movement of Antarctic Intermediate Water are attributed to the influence of anticyclonic and cyclonic eddies respectively. Presence of upwelling in the coastal waters of Antarctica (Prydz Bay), increased sea ice extant and subsequent enhanced melting in positive Southern Annular Mode (SAM) events causes high chlorophyll a in the coastal waters as well as south of Polar Front
during austral summer, which perhaps makes the IOSO a potential site for CO2 sink. Further, the bottom waters from this region may bring the dissolved CO2 which is getting ventilated in subtropics. However detailed investigations covering seasons are required to be implemented using Models and Observations (Both satellite and in-situ) for a better understanding about the IOSO ecosystem and it’s links to Tropical Ocean.

Published
2017-05-05