Interannual variability of remotely sensed chlorophyll α during an autumn monsoon transitional period in the Taiwan Strait

The time series of multiple sources of satellite data are used to examine the interannual variability of chlorophyll α concentration (Chl α) and its relation to the physical environment during the autumn monsoon transitional period in the Taiwan Strait (TWS). The satellite data included the Chl α concentration and sea surface temperature (SST) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS)/ Aqua as well as the multi-sensors merged wind products from 2002 to 2012. The results show that the average Chl α concentration of the whole TWS is mainly contributed by the northern TWS. The average Chl α in the northern TWS is 3.6 times that in the southern TWS. The maximum variability of Chl α is located in the frontal regions between the cold Zhe-Min Coastal Water and the strait warm water. The temporal change of Chl α concentration is different in the northern and southern TWS. The changes in the relative strength of the cold and warm water masses is suggested to be the dominant processes in controlling the phytoplankton growth in the northern TWS, while there is wind-induced mixing in the southern TWS. Additionally, La Niña events exhibited complex effects on the interannual variability of Chl α concentration in autumn. The longterm time series of physical and biological observations are especially needed to better understand how the TWS complex ecosystem responds to climate variations.