Record Details

Biophysical processes in the Indian Ocean

DRS at CSIR-National Institute of Oceanography

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Title Biophysical processes in the Indian Ocean
 
Creator McCreary, J.P.
Murtugudde, R.
Vialard, J.
Vinayachandran, P.N.
Wiggert, J.D.
Hood, R.R.
Shankar, D.
Shetye, S.R.
 
Subject physical processes
biological activity
Indian Ocean
subsurface circulations
 
Description Basic physical processes that impact biological activity in the Indian Ocean (IO), namely, near-surface processes (upwelling, entrainment, detrainment, and advection) and subsurface circulations (shallow overturning cells and subthermocline currents), are reviewed. In the Arabian Sea, there are upwelling blooms during the southwest monsoon (SWM) along Somalia, Oman, and the west coast of India. In the central Arabian Sea, the overall SWM (northeast monsoon; NEM) blooms appear to be a series of entrainment (detrainment) blooms forced by intraseasonal winds. In the western Bay of Bengal, a prominent NEM bloom results from the entrainment of a preexisting deep chlorophyll maximum (DCM). South of Sri Lanka, the SWM bloom is caused by coastal upwelling and Ekman suction, and is swept into the Bay of Bengal by the Southwest Monsoon Current. In the tropical, South IO (5-20 degrees S), there is a weak, surface bloom during boreal summer when new production is enhanced by nutrient entrainment; the surface bloom is even weaker (or absent) during boreal winter because the mixed layer is thinner, the thermocline is deeper, and hence, nutrient entrainment weaker. At intraseasonal timescales, blooms are associated with wind events and Rossby waves/eddies, and they can be generated by both new production and entrainment of a preexisting DCM. During the 1997/1998 El Nino Southern Oscillation/IO zonal dipole event, there was an upwelling bloom near Sumatra/Java in fall 1997, a much deeper DCM and weaker surface bloom along 5-10 degrees S in spring 1998, and a weaker bloom in the Arabian Sea during the SWM of 1998.
 
Date 2009-12-22T09:59:59Z
2009-12-22T09:59:59Z
2009
 
Type Book Chapter
 
Identifier In "Indian Ocean biogeochemical processes and ecological variability. eds. by: Wiggert, J.D.; Hood, R.R.; Naqvi, S.W.A.; Brink, K.H.; Smith, S.L.", 9-32p.
no
http://drs.nio.org/drs/handle/2264/3515
 
Language en
 
Rights Copyright [2009] AGU. All efforts have been made to respect the copyright to the best of our knowledge. Inadvertent omissions, if brought to our notice, stand for correction and withdrawal of document from this repository.
 
Publisher American Geophysical Union