Vertical structures of abrupt heavy rainfall events over southwest China with complex topography detected by dual‐frequency precipitation radar of global precipitation measurement satellite

Abstract

Southwest China is with complex topography including basins, mountains, hills and plains, where abrupt heavy rainfall events (AHREs) occur frequently and are difficult to quantitatively estimate due to limited ground‐based observations. Using the data of ground rain gauges and GPM dual‐frequency precipitation radar during April to September in 2014–2020, this study investigates vertical structures of AHREs over southwest China. Both mass‐weighted mean diameter (Dm) and reflectivity (Ze) of AHREs increase rapidly in ice‐phase process but slowly in liquid‐phase process. For convective rainfall of AHREs, abundant water vapour and strong atmospheric convective motion cause higher Dm and Ze but lower generalized intercept parameter (dBNw) than those for stratiform rainfall. Moreover, ice‐phase process is active while liquid‐phase process is weak in the mountains, but the situation is opposite in the plains, which results in large‐size and low‐concentration raindrops in the mountains while small‐size and high‐concentration raindrops in the plains. Furthermore, statistical models of vertical profile of reflectivity (VPR) indicate that VPR patterns are affected by surface rain intensity and present different trends around the 0°C level between stratiform and convective rainfalls. In addition, higher rain top height in the mountains is conducive to ice‐phase process while lower terrain height in the plains is favourable for liquid‐phase process. Therefore, the VPR pattern depends on rain type, terrain and rainfall intensity, and its fine model is beneficial for understanding microphysical process of AHREs and improving quantitative precipitation estimation by ground‐based radars.

Regional discrepancies in the microphysical attributes of summer season rainfall over Taiwan using GPM DPR

“…While exploring the warm rain microphysical processes (collision-coalescence, breakup, and evaporation), previous researchers adopted the combined information of radar reflectivity and differential radar reflectivity over a 3 km layer depth from 3.5 km to 0.5 km 50 . Owing to the unavailability of differential radar reflectivity in the GPM DPR and the direct relation of differential reflectivity with the mass-weighted mean diameter, the GPM DPR Z and D m values below the melting www.nature.com/scientificreports/ layer are used to understand the warm rain microphysical process 13,49,51,52 . Considering the susceptibility of the warm rain region on zero degrees isotherm, which varies with the geographic area, different height levels for the warm layer depth were adopted in the literature 13,49,51 .…”

“…Owing to the unavailability of differential radar reflectivity in the GPM DPR and the direct relation of differential reflectivity with the mass-weighted mean diameter, the GPM DPR Z and D m values below the melting www.nature.com/scientificreports/ layer are used to understand the warm rain microphysical process 13,49,51,52 . Considering the susceptibility of the warm rain region on zero degrees isotherm, which varies with the geographic area, different height levels for the warm layer depth were adopted in the literature 13,49,51 . Since the melting layers in summer over Taiwan are well above the 3 km height level (Fig.…”

“…Mitigation and assessment of heavy rainfall events dictate to progress the precipitation estimation algorithms and cloud modeling simulations based on the enhanced understanding of cloud and rain microphysical process [11][12][13][14][15][16] . Such goals in Taiwan can be achieved with the aid of precipitation measurement instruments like disdrometers and radars.…”

Predicting Summer Precipitation Anomalies in the Yunnan–Guizhou Plateau Using Spring Sea-Surface Temperature Anomalies

“…The region experiences alternating winter and summer monsoons, leading to diverse climate characteristics [3]. The spatial distribution of precipitation in the Yunnan-Guizhou Plateau exhibits significant regional differences, which are closely related to its distinctive topographical and climatic characteristics [4,5]. In this region, precipitation exhibits significant seasonality.…”