Near-surface salinity and stratification in the north Bay of Bengal from moored observations

Sengupta, Debasis and Raj, Bharath GN and Ravichandran, M and Lekha, Sree J and Papa, Fabrice (2016) Near-surface salinity and stratification in the north Bay of Bengal from moored observations. In: GEOPHYSICAL RESEARCH LETTERS, 43 (9). pp. 4448-4456.

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Abstract

A thin layer of fresh water from summer monsoon rain and river runoff in the Bay of Bengal (BoB) has profound influence on air-sea interaction across the south Asian region, but the mechanisms that sustain the low-salinity layer are as yet unknown. Using the first long time series of high-frequency observations from a mooring in the north BoB and satellite salinity data, we show that fresh water from major rivers is transported by large-scale flow and eddies, and shallow salinity stratification persists from summer through the following winter. The moored observations show frequent 0.2-1.2 psu salinity jumps with time scales of 10 min to days, due to O(1-10) km submesoscale salinity fronts moving past the mooring. In winter, satellite sea surface temperature shows 10km wide filaments of cool water, in line with moored data. Rapid salinity and temperature changes at the mooring are highly coherent, suggesting slumping of salinity-dominated fronts. Based on these observations, we propose that submesoscale fronts may be one of the important drivers for the persistent fresh layer in the north BoB.

Item Type:	Journal Article
Publication:	GEOPHYSICAL RESEARCH LETTERS
Publisher:	AMER GEOPHYSICAL UNION
Department/Centre:	Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences Division of Mechanical Sciences > Civil Engineering
Date Deposited:	17 Aug 2016 04:36
Last Modified:	17 Aug 2016 04:36
URI:	http://eprints.iisc.ac.in/id/eprint/54281

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