Spatiotemporal variability of satellite-derived colored dissolved and detrital organic materials in the South China Sea from 1997–2007

The dominant spatial patterns and temporal variations of colored dissolved and detrital materials in the South China Sea were presented by Sea-viewing Wide Field-of-view Sensor derived data from September 1997 to December 2007. Seasonal and interannual variations of colored materials in the South China Sea were discussed for the first time. Results showed that high values of these materials were mainly within the regions with large mixing and large-scale upwelling induced by a seasonally reversing monsoon (e.g. Gulf of Tonkin and northwest of Luzon Island in winter, southeast of Vietnam in summer, etc.) and in coastal regions, particularly in the estuaries of the rivers in summer (e.g. Pearl River and Mekong River). By contrast, low values were observed in the regions of downwelling (northwest of Luzon Island in summer) and deep basin regions in the South China Sea all throughout the year. This variability is highly correlated with that of chlorophyll a, except for at some costal regions, e.g. the Pearl River estuary, where the colored materials seldom co-vary with chlorophyll-a over an established threshold. High concentration of colored material will reduce photo-biological processes at these regions in some months. The main South China Sea is still below the critical value, when comparing with the thresholds of the seasonal colored material concentrations in the Sea. Such conclusions may be useful for the management of the South China Sea environments.