The impact of Asian dust events on the chlorophyll a in the Yellow Sea: a preliminary analysis based on remote sensing

摘要

Asian dust often occurring in the spring can be transported to the China Sea, even far to the North Pacific region. In this process, the dust deposition brings some nutrients and microelements into ocean and can affect the marine ecosystem significantly, such as the phytoplankton populations. In this study, we firstly analyze the monthly variations of chlorophyll a (Chla) concentrations and aerosol optical thickness (AOT), and then consider three major dust storm events during April 2006 to study their impact on the chlorophyll concentrations along the track of the dust storm using satellite observations over the Yellow Sea, including AOT and the Chla from Modis, composited sea surface temperature (SST) from TRMM / TMI and AMSR-E, and sea surface winds (SSW) from Quikscat. The central of North Yellow Sea ( 38-39°N,123-124°E ) and South Yellow Sea ( 35-37°N , 123-125°E ) are regions where Chla blooming frequently during dust events. The Chla usually up to 5-12mg/m~3 and the max value even greater than 30 mg/m~3. Without high wind speed and suitable temperature, dust deposition could also cause chlorophyll concentrations increased, but its impact region is limited and intensity is small in the Yellow Sea. Due to the AOT usually overflow or failure over dust regions, the high AOT can denote dust event. In the future, the dust aerosol optical thickness and other properties need to be estimated for further study on the ocean biogeochemical response to Asian dust events.