Correlation of Asian dust with chlorophyll and primary productivity in the coastal seas of China during the period from 1998 to 2008

Abstract

[1] Satellite chlorophyll a (Chl a) concentrations and estimated primary production in the coastal seas of China were correlated with Asian dust events during 1998–2008. Dust events were identified using two approaches, i.e., historical record and satellite aerosol index (AI). Severe and very severe dust events correlated well and positively with Chl a concentrations and primary production in the south Yellow Sea and East China Sea, but it was not statistically significant in the Bohai Sea and the north Yellow Sea. In the south Yellow Sea, Chl a concentration and primary production increased and eventually bloomed 1–21 days after the occurrence of the 16 out of 22 dust storms. Granger causality test showed that AI, photosynthetically available radiation (PAR) and sea surface temperature (SST) did Granger cause primary production in the Yellow Sea, suggesting that past values of the above three variables contain statistically meaningful information about current values of primary production. A stepwise multiple linear regression was used to examine the relative importance of the three factors. PAR and SST accounted for most of the variability of primary production in the north Yellow Sea, while AI was not quite as useful. In the south Yellow Sea, PAR and AI accounted for most of the variability of primary production for all storms; in addition, spring algae blooms were due to dust particles transported in the 5 km) dusts, originated mainly from the Taklimakan Desert, Mongolia, and/or west of Inner Mongolia, had no impact.