Improvement On The Daily Photosynthetically Available Radiation Product Of SeaWiFS

Problems with Daily Photosynthetically Available Radiation (PAR) product of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) are pointed out in this thesis, and two methods are used to improve the accuracy of the PAR product. With the standard algorithm, clouds detection only depends on instantaneous SeaWiFS data, which will apparently bring errors to the Daily PAR product. Here, time series of clouds statistic information multi-sensors are applied to improve the accuracy.Daily time series of clouds statistic information are acquired from sea surface temperature (SST) data using Moderate Resolution Imaging Spectroradiometer (MODIS) and Advanced Very High Resolution Radiometer (AVHRR) with high frequency of passing, the statistic distribution of the existence of clouds are also given between sunrise and sunset. Clouds statistic information is taken as a parameter to calculate Daily PAR and then is applied to the retrieval algorithm and the results respectively. A field PAR data collected by buoys located in 25.01N, 80.38W is used to analyze and compare the two methods. The results show that both specific reprocessing methods of Daily PAR data using clouds statistic information are effective, and the derived results are close to each other.