Adrift Upon a Salinity-Stratified Sea: A View of Upper-Ocean Processes in the Bay of Bengal During the Southwest Monsoon

Lucas, Andrew J and Nash, Jonathan D and Pinkel, Robert and MacKinnon, Jennifer A and Tandon, Amit and Mahadevan, Amala and Omand, Melissa M and Freilich, Mara and Sengupta, Debasis and Ravichandran, M and Le Boyer, Arnaud (2016) Adrift Upon a Salinity-Stratified Sea: A View of Upper-Ocean Processes in the Bay of Bengal During the Southwest Monsoon. In: OCEANOGRAPHY, 29 (2, SI). pp. 134-145.

PDF Oce_29-2_134_2016.pdf - Published Version Restricted to Registered users only Download (2MB) | Request a copy

Abstract

The structure and variability of upper-ocean properties in the Bay of Bengal (BoB) modulate air-sea interactions, which profoundly influence the pattern and intensity of monsoonal precipitation across the Indian subcontinent. In turn, the bay receives a massive amount of freshwater through river input at its boundaries and from heavy local rainfall, leading to a salinity-stratified surface ocean and shallow mixed layers. Small-scale oceanographic processes that drive variability in near-surface BoB waters complicate the tight coupling between ocean and atmosphere implicit in this seasonal feedback. Unraveling these ocean dynamics and their impact on air-sea interactions is critical to improving the forecasting of intraseasonal variability in the southwest monsoon. To that end, we deployed a wave-powered, rapidly profiling system capable of measuring the structure and variability of the upper 100 m of the BoB. The evolution of upper-ocean structure along the trajectory of the instrument's roughly two-week drift, along with direct estimates of vertical fluxes of salt and heat, permit assessment of the contributions of various phenomena to temporal and spatial variability in the surface mixed layer depth. Further, these observations suggest that the particular ``barrier-layer'' stratification found in the BoB may decrease the influence of the wind on mixing processes in the interior, thus isolating the upper ocean from the interior below, and tightening its coupling to the atmosphere above.

Item Type:	Journal Article
Publication:	OCEANOGRAPHY
Additional Information:	Copy right for this article belongs to the OCEANOGRAPHY SOC, P.O. BOX 1931, ROCKVILLE, MD USA
Department/Centre:	Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited:	08 Oct 2016 06:43
Last Modified:	08 Oct 2016 06:43
URI:	http://eprints.iisc.ac.in/id/eprint/54711

Actions (login required)

View Item