Figure above: Schematic representation of the major current systems (modified after Schott et al., 2009) in the Indian Ocean for January (left panel) and July (right panel), overlaid on chlorophyll (shaded in mg m-3) climatology. Abbreviations are as follows: Agulhas Current (AC), West India Coastal Current (WICC), East India Coastal Current (EICC), Sri Lanka Dome (SLD), South Equatorial Current (SEC), South Equatorial Countercurrent (SECC), Northeast Madagascar Current and Southeast Madagascar Current (NEMC and SEMC), East African Coastal Current (EACC), Somali Current (SC), Southern Gyre (SG) and Great Whirl (GW), Northeast Monsoon Current (NMC), South Java Current (SJC), Indonesian Throughflow (ITF), East Gyral Current (EGC), Leeuwin Current (LC), and Southwest Monsoon Current (SMC).
Authors: P.N. Vinayachandran, Yukio Masumoto, Michael J. Roberts, Jenny A. Huggett, Issufo Halo, Abhisek Chatterjee, Prakash Amol, Garuda V. M. Gupta, Arvind Singh, Arnab Mukherjee, Satya Prakash, Lynnath E. Beckley, Eric Jorden Raes, and Raleigh Hood
This paper reviews the phenomena of upwelling in the Indian Ocean, from the tip of Africa to the southern tip of the west coast of Australia. The topics covered relate to observed features of upwelling, governing processes, and the impacts on the marine ecosystem. Several new results that emerged from programs such as the Eastern Indian Ocean Upwelling Research Initiative (EIOURI), Western Indian Ocean Upwelling Research Initiative (EIOURI), coastal ADCP mooring network along the Indian coastline are highlights of the synthesis. The review identifies the considerable gap in our understanding of the space–time variability in upwelling in almost all the regions, due to the lack of systematic long-term data sets with sufficient resolution and coverage. The processes that drive upwelling are complicated and a quantitative account of the governing mechanisms are yet to be obtained for most upwelling systems. The review calls for a combined effort that includes systematic observations and focussed model studies to address the outstanding issues. This review is a contribution from the Science Theme-2 of the Second International Indian Ocean Expedition (IIOE-2).
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