What drives the increased phytoplankton biomass in the Arabian Sea?

Prasanna Kumar, S and Roshin, P Raj and Narvekar, Jayu and Dinesh Kumar, P K and Vivekanandan, E (2010) What drives the increased phytoplankton biomass in the Arabian Sea? Current Science, 99 (1). pp. 101-106.


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    The seasonal variability of phytoplankton biomass in the Arabian Sea, though a well researched topic, its inter-annual variability is less explored and understood. Analysis of the satellite-derived chlorophyll pigment concentration in the Arabian Sea during 1997–2007 showed a weak increasing trend. Contrary to the earlier hypothesis, our analysis showed that this increased phytoplankton biomass was not driven by the strengthening winds during summer monsoon. In fact, the basin-averaged chlorophyll concentrations during summer monsoon tend to decline, whereas those in September–October and during the winter monsoon showed an increasing trend. Based on the analysis of wind and aerosol optical thickness data, we attribute the increased phytoplankton biomass during September–October to dust-induced iron fertilization when there is sufficient buildup of nitrate in the upper ocean. During winter, the enhanced evaporative cooling under the strengthening winds led to the increased convective mixing. Subsequent supply of subsurface nutrients to the euphotic zone coupled with the increased dust delivery support the observed increase in phytoplankton biomass during winter.

    Item Type: Article
    Uncontrolled Keywords: Aerosol optical thickness; chlorophyll pigment concentration; iron fertilization; monsoon wind; nutrients; upwelling
    Subjects: Marine Biology > Phytoplanktons
    Divisions: CMFRI-Madras (Chennai)
    Depositing User: Users 171 not found.
    Date Deposited: 10 Nov 2010 11:30
    Last Modified: 09 Sep 2015 15:36
    URI: http://eprints.cmfri.org.in/id/eprint/6205

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