Particulate Organic Carbon Flux In The East China Sea Model

The research of this paper is a part of tudy on the Key Process of Ocean Flux in the East China Sea supported by National Science Fund Committee. The contents of POC(Particulate Organic Carbon) are determined and the distribution characteristics of POC and the factors affecting the distribution are studied through the cruise of East China Sea in July, 1998. The apparent flux of POC was calculated through the modeling calculation. Based on the data of POC contents in the suspended matter, phytoplankton and surface sediments at some stations of Section 1 and Section PN, the resuspension ratios and net fluxes of POC of these stations are studied. Therefore, a quantitative understanding of the net vertical flux of POC is obtained in the East China Sea. The characteristics of POC distribution in the East China Sea showed that: (1) there is an obvious area of high POC content, and the decrease of POC content along with the increase of distance from the shore indicates the influence of runoff of Changjiang River; (2) there is also a high POC area centered in (320N, 1250E -125.5 0E) surface layer and the concentration decreases along with depth, but the concentration begins to increase under 25m depth and form another high POC area at the bottom. We think that the surface high POC area was controlled by the production of phytoplankton and the bottom high POC area was induced by the up-welling near this area; (3) the contents of POC show a good positive correlation with the content of TSM at stations of Section 1 and Section PN. The apparent vertical fluxes were obtained at six stations by modeling calculation, and the fluxes range from 12.43 mg m2 d?to 148.23 mg m2 d4 The maximum of POC is at the layer of lOin of Station 107(320N, 1250E); and the minimum is at the bottom layer of Station 11 1(3200.O8N 125059.57). The resuspension ratios of five stations are obtained through the quantitative modeling calculation in the East China Sea and the result showed that: (1) the resuspension ratios of surface layers range from 47.4% to 79.18%, and the resuspension ratios of bottom layers range from 72.75% to 96.96%; (2) the maximum the resuspension ratios was at the bottom layer of Station 106 (320N, 1 24030) , and the minimum was at the surface layer of Station 102 (320N, 122030) Based on the data of apparent vertical flux of POC and resuspension ratios at some stations, the net vertical flux of POC at six stations was calculated. The result showed that the maximum of net vertical flux of POC with 117.4 was at the layer of lOin of Station 107(320N, 1250E), the minimum of net vertical flux of POC with 0.79 mgCm2 day was at the bottom layer of Station 111(3200.08, 125059.57). Integrating the data obtained above, we estimated that the average sedimentation flux of POC was about 6.55 mgCm2 day 2.39g&m2...