Influence of Rainfall Over Eastern Arabian Sea on Its Salinity

Behara, Ambica and Vinayachandran, P N and Shankar, D (2019) Influence of Rainfall Over Eastern Arabian Sea on Its Salinity. In: JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 124 (7). pp. 5003-5020.

PDF jou_geo_res_oce_124-7_5003_2019.pdf - Published Version Restricted to Registered users only Download (21MB) | Request a copy

Abstract

The west coast of India and the adjoining eastern Arabian Sea (EAS) is one of the high rainfall zones of Indian summer monsoon. The summer monsoon rainfall in this region is about 1,036km(3), which is comparable to the annual runoff of the Ganga-Brahmaputra river system. We have investigated the impact of EAS rainfall and Bay of Bengal (BoB) low-salinity water on the Arabian Sea salinity with a suite of experiments using an ocean general circulation model. The sea surface salinity (SSS) of EAS decreases progressively from June to September by 0.5 to 1psu. A numerical experiment that isolates the effect of EAS rainfall suggests that this SSS decrease is largely due to local rainfall over the EAS. The spatial pattern of SSS decrease, however, is influenced by the prevailing West India Coastal Current. The role of low-salinity water originating in the BoB on reducing the EAS salinity has also been examined. In the South Eastern Arabian Sea, during winter, the SSS decreases by about 1.5psu. This freshening is caused by rainfall during the early winter in the southwestern BoB between 6 degrees N and 15 degrees N. Neither rainfall to the north of 15 degrees N nor river runoff into the BoB contributes much to the South Eastern Arabian Sea freshening during winter.

Item Type:	Journal Article
Publication:	JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
Publisher:	AMER GEOPHYSICAL UNION
Additional Information:	copyright for this article belongs to AMER GEOPHYSICAL UNION
Keywords:	eastern Arabian Sea rainfall; sea surface salinity; Southern Bay of Bengal rainfall; Bay of Bengal rivers; salinity budget; West India Coastal Current
Department/Centre:	Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited:	17 Sep 2019 06:59
Last Modified:	17 Sep 2019 06:59
URI:	http://eprints.iisc.ac.in/id/eprint/63568

Actions (login required)

View Item