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Seasonal Evolution of Oceanic Upper Layer Processes in the Northern Bay of Bengal Following a Single Argo Float
Author(s) -
Shee Abhijit,
Sil Sourav,
Gangopadhyay Avijit,
Gawarkiewicz Glen,
Ravichandran M.
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl082078
Subject(s) - argo , mixed layer , bay , climatology , shortwave radiation , atmospheric sciences , temperature salinity diagrams , geology , downwelling , environmental science , geostrophic wind , surface layer , oceanography , upwelling , salinity , radiation , layer (electronics) , materials science , physics , quantum mechanics , composite material
Seasonal evolution of the barrier layer (BL) and temperature inversion in the northern Bay of Bengal and their role on the mixed layer temperature (MLT) is examined using observations from a single Argo during December 2013 to July 2017. During fall, low salinity at surface generates BL in this region. It thickens to almost 80 m in winter enhanced by deepening of isothermal layer depth due to remote forcing. During winter, surface cooling lowers near‐surface temperature, and thus, the subsurface BL experiences a significant temperature inversion (~2.5 °C ). This temperature inversion diffuses to distribute heat within ML and surface heating begins deep penetration of shortwave radiation through ML during spring. Hence, the ML becomes thermally well stratified, resulting in the warmest MLT. The Monin‐Obukhov length attains its highest value during summer indicating wind dominance in the ML. During spring and fall, upper ocean gains heat allowing buoyancy to dominate over wind mixing.