Study On Atmospheric Water Vapor Retrieved From Satellite Remote Sensing Data

The atmospheric water vapor has extremely important effect on the whole world climaticchanges, it is not only the necessary condition of make cloud and rain, but also the link of thetransmission of material and energy in the system of the sea-atmosphere and the earth-atmosphere. But the lack of precisely, stable and long-term water vapor data still is the mainreason that restricts thorough research on water vapor affection in climate system. Since halfcentury, the international balloon meteorological sounding network has been carrying on the watervapor survey continuously. But because the observation instrument changes and lacks theeffective correction, these meteorological sounding data is still unable to be used in the climatemodel. At the same time, because of the data from meteorological sounding is scattered, it must beinserted spatial data before being used in the climate model. But the method "use plot insteadpolygon" can cause big error in the model simulation result. And we can solve the problem byusing the characteristic of water vapor remote sensing inversion surface shape distribution.Based on the above research background, the atmospheric water vapor retrieval has beentaken as the center and the methods of satellite remote sensing retrieve atmospheric water vaporhas been discussed from the theory and the practice this article. Firstly, the basic rationale ofsatellite remote sensing retrieve atmospheric water vapor has been introduced and the atmospherebasic physical process has been described, and the atmospheric radiation transmission model hasbeen introduced by the example of 6s model. At the same time, the mechanism of the atmosphericwater vapor absorption action and the atmospheric water vapor absorption transmissibility modelhas been discussed. Secondly, the analyses of atmospheric water vapor research technique duringthe late several dozen years have been carried on. Then the split-window water vapor retrievealgorithm based on the MODIS data has been inferred from the similar analysis of AVHRR data 4,5 channels and the MODIS data 31 and 32 channels by using of the confirmed theory and thepractice in view of AVHRR massively split-window algorithm principle and the formula obtainedfrom overseas. And the MODIS near-infrared wave band water vapor retrieve algorithm, namelytwo channels and three channels ratios has also been inferred, too. Finally, these two methodshave been used in the actual MODIS data. The feasibility analysis to split-windowcovariance-variance water vapor retrieve algorithm has been carried out, and the principle ofnear-infrared two channels with three channels water vapor retrieve calculated has been applied tothe concrete MODIS data in this process. Then the procedure of the retrieve has been shown. Andthe result attained reflects the rule of actual water vapor distributed. So the effect obtained fromthe experiment is very well.