HR: 0800h
AN: OS51A-1291    [Abstracts]
TI: Size Dependent 4D Structures of Phyto- and Zooplankton Biomasses due to Advective Processes in the Kuroshio Region
AU: * Komatsu, K
EM: kosei@affrc.go.jp
AU: Watanabe, T
EM: wattom@fra.affrc.go.jp
AB: Temporal and spatial variations of plankton biomasses were calculated by a three-dimensional ecosystem model with focus on size dependent effects of advective processes in the frontal region of the Kuroshio and the Kuroshio Extension in the western North Pacific. The model consists of a lower trophic-level model with 11 compartments based on NEMURO coupled with an eddy-resolving physical model assimilated to satellite altimetry, and it was driven by a surface forcing from January 1997 through April 2004. Downstream of the Kuroshio, high concentration region of phyto- and zooplankton was distributed along the northern edge of the front, where variation of the biomass was controlled primarily by advective processes due to the stream. Moreover local maxima were formed in convergence zones located downstream (upstream) of the meander ridge (trough), as observed. On the other hand, in the fringe areas of the Kuroshio the variation was affected mainly by in situ biological growth. Consequently in the frontal region, a small difference in initial growth rate between small and large-sized plankton induced a large difference in their biomass, coupled with advective process due to convergence and divergence, cross-frontal current and eddy-stream interaction.
DE: 4815 Ecosystems, structure and dynamics
DE: 4842 Modeling
DE: 4855 Plankton
DE: 4520 Eddies and mesoscale processes
DE: 4528 Fronts and jets
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting