南海1998—2002年初级生产力的遥感估算及其时空演化机制

Estimation of primary production of South China Sea from 1998 to 2002 by remote sensing and its spatio-temporal variation mechanism

基于SeaWiFS资料得到1998—2002年海洋叶绿素浓度值以及海表温度(SST)数据和其它海洋数据,通过VGPM模型最终反演得到南海1998—2002年逐月初级生产力分布图以及季节分布图,发现在这5年内南海海域初级生产力年平均值变化不大,仅略有差异,1998年的年平均初级生产力要比其它几年的年平均初级生产力小一些;而南海海域初级生产力的季节变化则很明显,冬季要比其它几个季节高得多,而夏季最低。不同季节控制南海海域初级生产力的主导因素各不相同,主要是叶绿素浓度的分布、营养盐的分布、温度条件等,不同海区又略有不同。

The South China Sea （SCS） is the largest marginal sea in southeast Asia. Some researches of oceanic primary production （（）PP） have been conducted in some areas of SCS, but very few studies have been carried out in the whole SCS. The monthly and seasonal OPP from 1998 to 2002 and their spatial distributions in the whole SCS were investigated by analyzing SeaWiFS-derived chlorophyll-a （Chl-a）content, NOAA-AVHRR-derived sea surface temperature （SST）and other oceanographic data, and the vertically generalized production model （VGPM） was employed to calculate the OPP of the SCS. The results showed evident seasonal variations of OPP, SST and sea surface wind in the whole SCS, and revealed that the OPP peak value occured in winter （23.2 gC. m 2 ）and the lowest value in summer （18.0 gC· m^-2）. In summer, the SST was so high that a number of phytoplankton could＇t survive in the surface, so the average primary production was the lowest. In winter, the strong wind and high nutrient concentration were the main impetus to phytoplankton, therefore, the OPP in winter was the highest. To the whole SCS, nutrient and SST were the important factors influencing primary production.