The Potential Relationship Between Aeolian Dust Input During Monsoon And The Red Tide In East China Sea

In this research, the numerical diagnosis examination on atmospheric science and the research method of biogeochemistry is associated together.The relationships among red tide, monsoon and the aeolian dust input are investigated based on analyzing Aerosol Index (AI) data from Ozone Monitoring Instrument (OMI) provided by National Aeronautics and Space Administration (NASA), vertical velocity, horizontal flow field data from National Centers for Environmental Prediction (NECP) and red tides in the East China Sea (ECS) data. Elemental composition and chemical speciation in total suspended particulate (TSP) are further studied, which are collected from Hangzhou and Tiantai, Zhejiang Province. On the basis of analysis for the relationships, the major results are summarized as follows:1) The first red tide of ECS often occurs after about 1-3 weeks when summer monsoon in the South China Sea broke out;2) The all of red tide of ECS in 2005 and 2006 are associated with aeolian dust input brought winter monsoon, and their deposition in the areas where red tide occurs.3) The elemental composition in total suspended particulate (TSP) is different from the crustal abundance of Zhejiang, it is speculated that a part of TSP may be brought by winter monsoon.4) The main chemical speciation in sea water of Fe, Mn, Zn, Cu, and Co in TSP is soluble and exchangeable fraction, and carbonates, oxides and reducible pools, showing that these 5 metals in TSP is available for marine biota. The contents of soluble and exchangeable fraction and carbonates, oxides and reducible metals will increase when red tides appear in ECS.5)Fe has the most enriched content in carbonates, oxides and reducible carbonates, oxides and reducible pools based on analyzing the chemical speciation of TSP in sea water. It is guessed that these nutriments consisting of Fe in the cement enwrapping inside crystal was released into sea water.6) Summer monsoon (southerly or southwest wind) in Lower lay (850hPa) provides the hydrodynamic force condition for occurring red tide in ECS. Finally, the model of relationship between monsoon and red tide is given.