Record Details

Chlorophyll modulation of mixed layer thermodynamics in a mixed-layer isopycnal general circulation model - An example from Arabian Sea and Equatorial Pacific

DRS at CSIR-National Institute of Oceanography

View Archive Info
 
 
Field Value
 
Title Chlorophyll modulation of mixed layer thermodynamics in a mixed-layer isopycnal general circulation model - An example from Arabian Sea and Equatorial Pacific
 
Creator Nakamoto, S.
PrasannaKumar, S.
Oberhuber, J.M.
Saito, H.
Muneyama, K.
 
Subject chlorophylls
mixed layer
thermodynamics
atmospheric circulation
models
phytoplankton
algal blooms
isopycnics
seasonal variations
 
Description Western Tropical Indian Ocean, Arabian Sea and equatorial Pacific are known to be regions of intense bio-chemical-physical interactions with Arabian sea being largest in seasonal phytoplankton bloom while the equatorial Pacific bloom being perennial and supported by quasi-steady upwelling. Remotely sensed chlorophyll pigment concentrations from the Coastal Zone Color Scanner (CZCS) are used to investigate the chlorophyll modulation of ocean mixed layer thermodynamics in a bulk mixed-layer model, embedded in the ocean isopycnal general circulation model (OPYC). A higher abundance of chlorophyll increases absorption of solar irradiance and heating rate in the upper ocean, resulting in decreasing the mixed layer thickness than they would be under clear waer condition. These changes in the model mixed layer were consistent with Joint Global Ocean Flux Study (JGOFS) observation during the 1994-1995 Arabian Sea experiment and epi-fluorescence microscopy (EFM) on samples collected during Equatorial Pacific Ocean Climate Study (EPOCS) in November, 1988. In the Arabian Sea, as the chlorophyll concentrations peak in August (3mg/m sup(3)) due to summer plankton bloom induced by coastal upwelling, the chlorophyll induced biological heating enhanced the sea surface temperature (SST) by as much as 0.6 degrees C while sub-layer temperature decreases and sub-layer thickness increases. In the equatorial Pacific, modest concentrations of chlorophyll less than 0.3mg/m sup(3) is enough to introduce a meridional differential heating that results in reducing the equatorial mixed layer thickness by more than 20m. The anomalous meridional tilting of the mixed layer bottom enhances off equatorial westward geostrophic currents. Consequently, the equatorial undercurrent transport more water from west to east.
 
Date 2009-01-09T09:15:26Z
2009-01-09T09:15:26Z
2000
 
Type Conference Article
 
Identifier The Fifth Pacific Ocean Remote Sensing Conference (PORSEC), 5-8 December 2000. Proceedings,Vol.1; 505-510p.
http://drs.nio.org/drs/handle/2264/1698
 
Language en
 
Rights Copyright [2000]. 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 NIO, Dona Paula, Goa (India)