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Southern B ay of B engal currents and salinity intrusions during the northeast monsoon
Author(s) -
Wijesekera H. W.,
Jensen T. G.,
Jarosz E.,
Teague W. J.,
Metzger E. J.,
Wang D. W.,
Jinadasa S. U. P.,
Arulananthan K.,
Centurioni L. R.,
Fernando H. J. S.
Publication year - 2015
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2015jc010744
Subject(s) - hydrography , oceanography , monsoon , geology , salinity , bay , climatology , bengal , drifter , equator , subsurface flow , forcing (mathematics) , boundary current , current (fluid) , ocean current , latitude , lagrangian , physics , geotechnical engineering , geodesy , groundwater , mathematical physics
Shipboard velocity and hydrographic profiles collected in December 2013 along with drifter observations, satellite altimetry, global ocean nowcast/forecast products, and coupled model simulations were used to examine the circulation in the southern Bay of Bengal as part of ongoing international research efforts in the region. The observations captured the southward flowing East India Coastal Current (EICC) off southeast India and east of Sri Lanka. The EICC was approximately 100 km wide, with speeds exceeding 1 m s −1 in the upper 75 m. East of the EICC, a subsurface‐intensified 300 km‐wide, northward current was observed, with maximum speeds as high as 1 m s −1 between 50 m and 75 m. The EICC moved low‐salinity water out of the bay and the subsurface northward flow carried high‐salinity water into the bay during typical northeast monsoon conditions during a time period when the central equatorial Indian Ocean was experiencing a westerly wind burst related to the Madden‐Julian Oscillation (MJO) event. While the northward subsurface high‐salinity flow has previously been observed during the southwest monsoon, it was observed during the northeast monsoon. The observations are consistent with northward high‐salinity subsurface flow in numerical model solutions. The analysis suggests that direct forcing along the equator may play a significant role for high‐salinity intrusions east of Sri Lanka.