Characteristics of different precipitation types and corresponding thermal structures in Northwest China in summer derived from GPM observation, ERA5 and IGRA2

Due to the limitation of remote sensing observation, the research on the three-dimensional precipitation in Northwest China is insufficient. However, the launch of GPM provides convenience for the study of precipitation structures and types in Northwest China. In this work, the spatio-temporal distributions of convective and stratiform precipitation and corresponding thermal structures are analyzed during summer of 2014-2019 in Northwest China based on GPM observations, EAR5 reanalysis and IGRA2 datasets. The result shows that the stratiform precipitation is dominant in Northwest China and four representative sub-regions are divided to further discuss (Tianshan Mountain, Tarim Basin, Qilian Mountain and eastern part of Northwest China). The storm tops of convective precipitation are generally 2-3 km higher than those of stratiform precipitation, and the storm top reaches the maximum in the Tianshan Mountain (16 km) and the lowest in the Tarim Basin (10 km). Moreover, the maximum rain rate of convective precipitation below 4 km occurs in the Tianshan Mountain, while maximum rain rate of stratiform precipitation occurs in the eastern part of Northwest China. The maximum latent heating of both precipitation types occurs at 4-6 km. The peak frequency of convective precipitation mainly appears in the afternoon, whereas the diurnal variation of stratiform precipitation displays a bimodal peak (in the early morning and evening). Furthermore, the intensities of both precipitation types vary with the total column water vapor and follow an approximate quadratic function relationship. The precipitation conversion of convective precipitation and CAPE are obviously larger than those of stratiform precipitation. There is convergence in the lower troposphere and divergence in the upper troposphere, which is favorable to occurrence of precipitation (except for Tarim Basin). Additionally, the positive temperature and humidification are significant in the lower-middle troposphere during process of both precipitation types. This study aims to reveal the features of convective and stratiform precipitation from the perspective of GPM remote sensing observation and provide reference for numerical simulation in arid-semiarid regions.