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Seasonal Variability of Sonic Layer Depth in the Central Arabian Sea  

Bhaskar, TVS Udaya (Indian National Centre for Ocean Information Services)
Swain, Debadatta (Space Physics Laboratory, Vikram Sarabhai Space Centre, ISRO)
Ravichandran, M (Indian National Centre for Ocean Information Services)
Publication Information
Ocean Science Journal / v.43, no.3, 2008 , pp. 147-152 More about this Journal
Abstract
The seasonal variability of sonic layer depth (SLD) in the central Arabian Sea (CAS) (0 to $25^{\circ}N$ and $62-66^{\circ}E$) was studied using the temperature and salinity (T/S) profiles from Argo floats for the years 2002-2006. The atmospheric forcing responsible for the observed changes was explored using the meteorological data from NCEP/NCAR and Quickscat winds. SLD was obtained from sound velocity profiles computed from T/S data. Net heat flux and wind forcing regulated SLD in the CAS. Up-welling and down-welling (Ekman dynamics) associated with the Findlater Jet controlled SLD during the summer monsoon. While in winter monsoon, cooling and convective mixing regulated SLD in the study region. Weak winds, high insolation and positive net heat flux lead to the formation of thin, warm and stratified sonic layer during pre and post summer monsoon periods, respectively.
Keywords
Argo float; sonic layer depth; net heat flux; wind speed; Arabian Sea;
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