Modulation of chlorophyll concentration by downwelling Rossby waves during the winter monsoon in the southeastern Arabian Sea

Amol, P and Bemal, S and Shankar, D and Jain, V and Thushara, V and Vijith, V and Vinayachandran, PN (2020) Modulation of chlorophyll concentration by downwelling Rossby waves during the winter monsoon in the southeastern Arabian Sea. In: Progress in Oceanography, 186 .

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Abstract

Signatures of Rossby waves that are evident in satellite ocean colour data in the southeastern Arabian Sea (SEAS) are more prominent during the winter than the summer monsoon. During the winter, the sea level is high, and the conditions are less conducive for the injection of nutrients through the eddy-pumping mechanism. In this study, we use satellite observations and a physical-ecosystem model to examine the role of horizontal advection associated with Rossby waves in enhancing chlorophyll concentration in the SEAS. Zonal advection dominates over meridional advection, and its effect is more prominent in the south of Indian subcontinent and west of the Maldives. Except along the coast and around the islands, the vertical processes are weak and do not lead to a substantial increase in chlorophyll. Model simulations show that the currents associated with the Rossby wave also transport nutrients and other physicochemical properties of water along the path of the wave. The advected water decreases the concentration of Arabian Sea High Salinity water mass and replenishes the oxygen in the oxygen minimum zone in the SEAS. © 2020 Elsevier Ltd

Item Type:	Journal Article
Publication:	Progress in Oceanography
Publisher:	Elsevier Ltd
Additional Information:	copy right for this article belongs to Elsevier Ltd
Keywords:	Advection; Atmospheric thermodynamics; Chlorophyll; Nutrients; Ocean currents; Oxygen; Physicochemical properties; Sea level, Chlorophyll concentration; Horizontal advection; Indian subcontinents; Model simulation; Oxygen minimum zone; Pumping mechanism; Satellite observations; Southeastern arabian seas, Mechanical waves, downwelling; island; monsoon; oxygen minimum layer; physicochemical property; Rossby wave; satellite data; sea level change; seasonal variation; water mass; winter, Arabian Sea; Indian Ocean; Maldives
Department/Centre:	Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited:	18 Nov 2020 07:21
Last Modified:	18 Nov 2020 07:21
URI:	http://eprints.iisc.ac.in/id/eprint/65852

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