Methods That Amalgamate Satellite And Sounding Relative Humidity Data And The Influence Of Amalgamation Relative Humidity Data On Visibility

Contrasting the atmosphereic relative humidity data in January 2013 from sounding and that from MODIS atmosphereic profile product, the conclusion that MODIS relative humidity data is higher than sounding data; Relative humidity data from MODIS in cloudy less than 5% from sounding need to eliminate; Before amalgamation, correcting the systematic error by mean revision is necessary. Direct reduction method and maximum correlation coefficient method were used to fuse the two kinds of relative humidity data. Analyzing the fusion results and using cross check, the results show that:(1) Relative humidity data from direct reduction method is higher than that from sounding when in low relative humidity area and opposite in high humidity area, relative humidity data from maximum correlation coefficient method is close to sounding data in all area; (2) Compared with sounding data, the error of amalgamation result made by direct reduction method is no more than 10% in 850hPa, no more than 12% in 925hPa, no more than 9% in 1000hPa, and the error of amalgamation result made by maximum correlation coefficient method are no more than 4% in all level..Overall, maximum correlation coefficient method is better than direct reduction method.Analysing the 1000hPa fusion relative humidity data in January 2013 detaily, using the fusion humidity data and aerosol concentration data to caculate fusion visibility, and compare with CUACE visibility and MICAPS surface visibility, the result show that:1000hPa fusion humidity data is lower than surface humidity data, the maximum error of the site is less than 8%; The accuracy of two kinds of fusion visibility data is improved, but error still exist; The improvement effect of fusion visibility is closely relate to the accuracy of fusion humidity data; The fusion visibility data caculated by direct reduction method is between the CUACE visibility data and surface visibility data, The fusion visibility data caculated by maximum correlation coefficient method is unstable; the mean square error of visibility reduce 40% by using direct reduction method, and reduce 45% by using the maximum correlation coefficient method.