Precipitation, microphysical and environmental characteristics for shallow and deep clouds over Yangtze-Huaihe River Basin

Abstract

The precipitation, microphysical, and environmental characteristics of shallow and deep precipitation clouds (SPCs and DPCs) are investigated over the Yangtze-Huaihe River during the summers from 2014 to 2021, using the observational data from dual-frequency precipitation radar (DPR) on board Global Precipitation Mission and the reanalysis data. DPCs (SPCs) are mainly associated with convective (stratiform) precipitation, contributing approximately 2% ∼ 15% (20% ∼ 40%) to the total precipitation events, while contributing only around 0.05–0.15% (below 0.05%) to the total rainfall. Compared to SPCs, the rain hydrometeors for DPCs are mainly composed of lower concentrations of larger-sized hydrometeors near the surface, showing larger mass-weighted mean diameter (Dm: 1.0 to 3.0 mm) and lower generalized intercept parameter (Nw: 20 to 40 dBNw) at 2 km in altitude. Below the melting layer, the Dm, reflectivity, and rain rate of DPCs decrease rapidly as the decreasing altitude, reflecting the breakup or the evaporation of liquid hydrometeors, while those of SPCs rapidly increase, indicating vigorous processes of collision and coalescence. DPCs tend to occur in environmental conditions with increased convective available potential energy (CAPE) and higher surface air temperatures, but drier low-level humidity, compared to SPCs. Furthermore, the DPCs tend to occur in the environment with more significant updraft (≥5 m s−1) in comparison with SPCs. Especially at 4 km and 10 km in altitude, the updraft fractions could reach 45% and 38%, respectively. These results may provide an observational reference for the microphysical parameterization in numeric models for the vertical development of storms.