HR: 0800h
AN: OS51A-1290    [Abstracts]
TI: Dust Transport to the Surface of the Arabian Sea Followed by Phytoplankton Biomass Increase
AU: Gieskes, W W
EM: W.W.C.Gieskes@biol.rug.nl
AF: Wim Klaassen, Marine Biology University of Groningen PO Box 14, Haren, 9750 AA Netherlands
AU: * Klaassen, W
EM: W.Klaassen@biol.rug.nl
AF: Wim Klaassen, Marine Biology University of Groningen PO Box 14, Haren, 9750 AA Netherlands
AB: Oligotrophic open-ocean regions, including the Arabian Sea during the NE Monsoon, are characterized by low phytoplankton abundance near the surface. Here we report significant increases in micro-algal biomass in the Arabian Sea just a few days after aeolian transport of desert dust to that area. The result is based on weekly averaged remote sensing images of aerosol optical depth and chlorophyll concentrations obtained with the MODIS instrument. Enhanced phytoplankton concentrations were found after four out of five dust events during the two seasons of observations. A similar effect was not observed in images obtained in other regions of the globe in the same period (the Mediterranean; the northern Atlantic). This may be due to the fact that in those areas dust deposition is much more continuous than in the Indian Ocean region we focused on. The stimulation of micro-algal growth may have been direct by enrichment with nutrients associated with dust particles, or indirect by a positive effect of these particles on microbial mineralization of organic matter. This is the first time that the link between desert dust storms and chlorophyll increase has been established repeatedly in a time series of observations.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0312 Air/sea constituent fluxes (3339, 4504)
DE: 0315 Biosphere/atmosphere interactions
DE: 0933 Remote sensing
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting