Eddy-induced cross-shelf phytoplankton transport along the downwelling coast off Western Australia  

作　　者：FENG Ming 

机构地区：[1]CSIRO Marine ＆ Atmospheric Research, Floreat, Western Australia, Australia

出　　处：《热带海洋学报》2009年第5期6-10,共5页Journal of Tropical Oceanography

基　　金：supported by Strategic Research Fund for Marine Environment

摘　　要：Along the downwelling coast off Western Australia, late-austral-autumn/early-austral-winter chlorophyll a blooms are observed on the continental shelf south of the Shark Bay (26° S). The late-austral-autumn/early-austral-winter blooms are in phase with seasonal strengthening of the Leeuwin Current and its eddy field. From satellite altimeter and ocean color data , anticyclonic eddies are found to entrain the high phytoplankton biomass waters from the shelf and transport them offshore into the oligotrophic, subtropical marine environment. The late-austral-autumn/early-austral-winter blooms are highly linked with enhanced horizontal mixing by mesoscale eddies in the region, as derived from the finite-size Lyapunov exponent (FSLE) of the surface geostrophic flow field obtained from satellite altimeter data. The pathways of cross-shelf exchanges, which are mostly driven by the mesoscale eddies, are revealed with coalescing of the FSLE of the surface geostrophic flow field and the satellite chlorophyll a images.Along the downwelling coast off Western Australia, late-austral-autumn/early-austral-winter chlorophyll a blooms are observed on the continental shelf south of the Shark Bay （26°S）. The late-austral-autumn/early-austral-winter blooms are in phase with seasonal strengthening of the Leeuwin Current and its eddy field. From satellite altimeter and ocean color data, anticyclonic eddies are found to entrain the high phytoplankton biomass waters from the shelf and transport them offshore into the oligotrophic, subtropical marine environment. The late-austral-autumn/early-austral-winter blooms are highly linked with enhanced horizontal mixing by mesoscale eddies in the region, as derived from the finite-size Lyapunov exponent （FSLE） of the surface geostrophic flow field obtained from satellite ahimeter data. The pathways of cross-shelf exchanges, which are mostly driven by the mesoscale eddies, are revealed with coalescing of the FSLE of the surface geostrophic flow field and the satellite chlorophyll a images.

关 键 词：下降流 漩涡 澳大利亚 叶绿素 浮游植物 

分 类 号：P731[天文地球—海洋科学]