Variability in the vertical structure of precipitation in Sichuan and Chongqing based on 2004-2014 space-borne observations

This study presents a statistical analysis of the variability of vertical precipitation structure in the eastern downstream region of the Tibetan Plateau (TP) based on measurements by the precipitation radar (PR) onboard the National Aeronautics and Space Administration (NASA)'s Tropical Rainfall Measuring Mission (TRMM) satellite. Data over an 11-year time span (Jan 2004-Dec 2014) are analyzed. The results reveal the seasonal and spatial variability of the storm height, the freezing level, and the bright-band for different types of precipitation as well as the characteristics of intensity-related and type-related vertical profiles of reflectivity (VPR). Major findings are as follows. Precipitation types greatly impact the VPR in terms of their different microphysical and dynamical processes. About 90% of the bright-band peak reflectivity of stratiform precipitation are less than 32 dBz, and 50% of the maximum reflectivity of convective precipitation exceed 35 dBz. The intensity of surface rainfall rate also depends on the shape of the VPR. For stratiform precipitation, ice-snow aggregation is faster during moderate and heavy rainfall than that in light rainfall. Both surface heating and terrain impact the VPR shapes and their respective rain region slopes by changing the updrafts, which may affect the ratio of collision-coalescence as well as the low-level evaporation. Overall, the findings indicate that the developed representative Ku-band VPR can be used to improve surface precipitation estimates in regions with complex terrain, where ground-based radar has limited visibility at low levels.