Precision test and analysis of MERRA-2 vapor products in Qinghai-tibet plateau

MERRA-2 is the latest atmospheric reanalysis data, and the grid water vapor products provided by it have high temporal and spatial resolution, but there is still no literature to evaluate the applicability of MERRA-2 water vapor products in Qinghai-Tibet Plateau. It is urgent to carry out the applicability analysis of MERRA-2 water vapor products in this region. In this paper, the water vapor vertical profile function of Qinghai-Tibet Plateau is established by using MERRA-2 grid water vapor data and lattice dot height data, and the water vapor value of lattice dot is calculated to nearby sounding station or the Global Navigation Satellite System (GNSS) station by using water vapor vertical profile function, and then the bilinear interpolation method is used to calculate the water vapor interpolation in horizontal direction. Finally, the accuracy analysis is carried out. The results show that the daily average deviation between stations in the plateau area is mostly within 2 mm, and the monthly average deviation is less than 1 mm. While the accuracy of MERRA-2 water vapor products is higher in the middle and north of the plateau and lower in the south.