A practical algorithm of atmospheric correction for turbid coastal and inland waters is provided. The presentalgorithm uses the property that the water-leaving radiance at 412 nm increases very little with the increas...A practical algorithm of atmospheric correction for turbid coastal and inland waters is provided. The presentalgorithm uses the property that the water-leaving radiance at 412 nm increases very little with the increasing of waterturbidity. Thus, in very turbid coastal and inland waters, the radiance at 412 nm can be used to estimate the aerosolscattering radiance at 865 nm. The performance of the new algorithm is validated with simulation for several cases. Itis found that the retrieved remotely sensed reflectance is usually with error less than 10% for the first six bands ofSeaWiFS. This new algorithm is also tested under various atmospheric conditions in the Changjiang River Estuaryand the Hangzhou Bay where the sediment concentration is very high and the standard SeaWiFS atmosphericcorrection algorithm creates a mask due to atmospheric correction failure. The result proves the efficiency of thissimple algorithm in reducing the errors of the water-leaving radiance retrieving using SeaWiFS satellite data.展开更多
The monthly mean suspended sediment concentration in the upper layer of the East China Seas was derived from the retrieval of the monthly binned SeaWiFS Level 3 data during 1998 to 2006. The seasonal variation and spa...The monthly mean suspended sediment concentration in the upper layer of the East China Seas was derived from the retrieval of the monthly binned SeaWiFS Level 3 data during 1998 to 2006. The seasonal variation and spatial distribution of the suspended sediment concentration in the study area were investigated. It was found that the suspended sediment distribution presents apparent spatial characteristics and seasonal variations, which are mainly affected by the resuspension and transportation of the suspended sediment in the study area. The concentration of suspended sediment is high inshore and low offshore, and river mouths are generally high concentration areas. The suspended sediment covers a much wider area in winter than in summer, and for the same site the concentration is generally higher in winter. In the Yellow and East China Seas the suspended sediment spreads farther to the open sea in winter than in summer, and May and October are the transitional periods of the extension. Winds, waves, currents, thermocline, halocline, pycnocline as well as bottom sediment feature and distribution in the study area are important influencing factors for the distribution pattern. If the 10rag L^-1 contour line is taken as an indicator, it appears that the transportation of suspended sediment can hardly reach 124^o00＇E in summer or 126^o00＇E in winter, which is due to the obstruction of the Taiwan Warm Current and the Kuroshio Current in the southern Yellow Sea and the East China Sea.展开更多
基金This study was supported by the National“863”Project of China under contract No.2002AA639490 and No.2002AA639220.
文摘A practical algorithm of atmospheric correction for turbid coastal and inland waters is provided. The presentalgorithm uses the property that the water-leaving radiance at 412 nm increases very little with the increasing of waterturbidity. Thus, in very turbid coastal and inland waters, the radiance at 412 nm can be used to estimate the aerosolscattering radiance at 865 nm. The performance of the new algorithm is validated with simulation for several cases. Itis found that the retrieved remotely sensed reflectance is usually with error less than 10% for the first six bands ofSeaWiFS. This new algorithm is also tested under various atmospheric conditions in the Changjiang River Estuaryand the Hangzhou Bay where the sediment concentration is very high and the standard SeaWiFS atmosphericcorrection algorithm creates a mask due to atmospheric correction failure. The result proves the efficiency of thissimple algorithm in reducing the errors of the water-leaving radiance retrieving using SeaWiFS satellite data.
基金the National Key Basic Research Science Foundation (973 Project)‘Marine Physical Variations in Eastern Marginal Seas of China and Their Environmental Impacts’ (2005CB422303)the Program for New Century Excellent Talents in University (NCET-05-0592)
文摘The monthly mean suspended sediment concentration in the upper layer of the East China Seas was derived from the retrieval of the monthly binned SeaWiFS Level 3 data during 1998 to 2006. The seasonal variation and spatial distribution of the suspended sediment concentration in the study area were investigated. It was found that the suspended sediment distribution presents apparent spatial characteristics and seasonal variations, which are mainly affected by the resuspension and transportation of the suspended sediment in the study area. The concentration of suspended sediment is high inshore and low offshore, and river mouths are generally high concentration areas. The suspended sediment covers a much wider area in winter than in summer, and for the same site the concentration is generally higher in winter. In the Yellow and East China Seas the suspended sediment spreads farther to the open sea in winter than in summer, and May and October are the transitional periods of the extension. Winds, waves, currents, thermocline, halocline, pycnocline as well as bottom sediment feature and distribution in the study area are important influencing factors for the distribution pattern. If the 10rag L^-1 contour line is taken as an indicator, it appears that the transportation of suspended sediment can hardly reach 124^o00＇E in summer or 126^o00＇E in winter, which is due to the obstruction of the Taiwan Warm Current and the Kuroshio Current in the southern Yellow Sea and the East China Sea.
