Influence of the Interaction Between Typhoons and Oceanic Mesoscale Eddies on Phytoplankton Blooms: INFLUENCE OF TYPHOONS AND OCEANIC EDDIES ON PHYTOPLANKTON

Phytoplankton blooms induced by the interaction between typhoons and oceanic mesoscale eddies in the South China Sea were investigated using the composite averaging method based on cyclone-centric coordinates from nine years (2002-2010) of satellite observations. Increases in the chlorophyll (Chl) concentration following the passage of a typhoon differed greatly among the pre-existing cyclonic eddy (PCE), pre-existing anticyclonic eddy (PACE) and non-eddy (NE) ocean conditions (with Chl increases of approximately 35%, 6% and 12%, respectively), but the magnitude of sea surface temperature (SST) cooling was similar under the three conditions (approximate to 1 degrees C). Under the same level of SST decreases, the greater increase in the Chl concentration in the PCE condition was attributed to the longer persistence of both SST cooling and nutrient input caused by the typhoon-strengthened PCE (associated with upwelling), which stopped the re-warming of the typhoon-induced cold water.