Southern Ocean Science Plan

The Southern Ocean (SO) is the source and sink for several intermediate and deep water masses of the world oceans. Compared to the corresponding northern latitudes, SO is devoid of land mass and this in turn results in the high surface wind speeds. In addition, a weather front located typically in the mid-latitudes separates Antarctic and Polar air masses from Tropical air masses known as Polar front, which acts as a trigger for mid-latitude cyclones. The higher amount of the vertical transfer of the momentum from the horizontal winds leads to deeper mixed layers. Also, wind driven currents and fronts in SO aid in the formation of latitudinally separated zones with distinct physical and biological features. These properties makes the SO a potential site for sink of atmospheric carbon dioxide.

SO is also a High-Nutrient Low Chlorophyll (HN-LC) regime due to lack of bioavailability of Fe to support primary production. Such regimes are known to have complex food-web structure including highly active microbial loop that complements the low-iron paradigm. Despite its importance in global climate system and its role in various biogeochemical cycles, adequate information and understanding of the processes and response of SO to climate change are lacking, especially in the Indian Ocean sector of Southern Ocean. In view of the importance of the Indian Ocean sector of SO in global scenario, a research plan for SO was developed focussing on [1] dynamics of the formation and distribution of water masses, [2] ocean currents and sea ice, [3] relationship between oceanic and atmospheric circulation systems, [4] Vertical structure of temperature, humidity and dynamics of the SO troposphere, [5] Aerosol characteristics and long range transport, [6] physical basis for biological productivity, [7] assessment of the distribution, sources and sinks of carbon and [8] deciphering paleoclimatic records through integrated sedimentological,      micropaleontological and geochemical studies.

To address the above mentioned research plan, major scientific investigations in the areas of biogeochemistry, atmospheric sciences, physical oceanography, geological and geophysics are being carried out.