Estimating of the total atmospheric precipitable water vapor amount from the Chinese new generation polar orbit FengYun meteorological satellite (FY-3) data

The total atmospheric precipitable water vapor amount (TWV) is a key variable for the study of the Earth´s climate. This paper develops an algorithm to estimate the TWV over clear skies from the Medium Resolution Spectral Imager (MERSI) data in the near-IR channels. The MODTRAN 4 code is used to simulate the top of the atmospheric radiances for the MERSI channels. The results show that the proposed algorithm is suitable to estimate TWV form the absorbing channel centered at 0.940 μm and the atmospheric window channels centered at 0.865 μm and centered at 1.030 μm by the radiances over the clear pixels, with relative differences in the range of 10%-15%.