The Winter And Autumn Distribution Characteristics Of Some Chemical Components Of The Suspended Particulate Matter And Their Influence Factors In The Yellow And East China Seas

The eastern continental shelf seas of China have special regional characteristics and hydrodynamic conditions. Suspended particulate matter (SPM) and sediment in the East China Sea and the Yellow Sea comprise terrestrial, autogenous and biogenic materials. Analysis of the chemical components of suspended particulate matter can be used to get essential information about the source-sink of the materials. In order to know the chemical component characteristics of SPM, some chemical components of suspended particulate matter in winter and autumn in the Yellow and East China Seas were studied.Field observations were carried out from January to February 2007 (winter) and in November 2007 (autumn) by the R.V. Dongfanghong 2. Surface water was collected and SPM samples were obtained by filtration performance. Some major chemical compositions of SPM, including particulate organic carbon, calcium carbonate and particulate biogenic silica, were analyzed. Particulate organic carbon was determined by a CHN analyzer after eliminating inorganic carbon. Calcium carbonate and particulate biogenic silica were extracted sequentially with a chemical leaching method. The leaching solutions were analyzed for Ca2+ and dissolved Si to obtain calcium carbonate and biogenic silica contents. The main results are shown as following:(1) The content of SPM, particulate calcium carbonate, particulate organic carbon and particulate biogenic silica in surface seawater ranged 0.2～117.8 mg/L, 0.0008～7.6 mg/L, 8.7～1036μg/L, 0.16～8.07μmol/L and averaged to 9.8 mg/L, 0.6 mg/L, 101μg/L, 1.4μmol/L, respectively, in winter. The max content of SPM in surface seawater appeared in the north side out of the Changjiang Estuary, and the highest content of calcium carbonate was found in the southwest of the Cheju Island. The max content of POC appeared in the north side out of Changjiang Estuary and decreased from the coast area to the shelf. The distribution of particulate biogenic silica had the same trend as that of POC.(2) The content of SPM, particulate calcium carbonate, particulate organic carbon and particulate biogenic silica in surface seawater ranged 0.1～68.6 mg/L, 0.002～4.0 mg/L, 11～280μg/L, 0.1～7.0μmol/L and averaged to 5.3 mg/L, 0.4 mg/L, 75μg/L, 1.3μmol/L, respectively, in autumn. The contents of SPM, particulate calcium carbonate, POC and biogenic silica in surface seawater were high in the north side out of Changjiang Estuary and decreased from the coast to the shelf.(3) Calcium carbonate in the SPM of the surface seawater was mainly derived from terrestrial input. POC was derived from both terrestrial and autogenous input. Biogenic silica was affected by the biological production of siliceous organisms and varied spatially and seasonally.