华东地区一次积层混合云降水中融化层附近微物理特征分析OA

The microphysical characteristics of the melting layer(ML)play a crucial role in shaping cloud structures and precipitation formation.In this study,the cloud microphysical characteristics near the ML in stratiform precipitation with embedded convection over East China on September 15,2023,are analyzed.The data are collected using an airborne Ka-band precipitation cloud radar(KPR)and a suite of in situ observation instruments onboard a King Air 350 aircraft operated by the Weather Modification Center of the China Meteorological Administration.The results show that above the ML,cloud particles primarily grow through riming and aggregation,with aggregated graupel particles being predominant.As ice-phase particles fall through the ML,they begin to melt,and graupel particles and large ice crystals gradually transform into small liquid droplets.With decreasing altitude,both the radial velocity and spectral width observed by the KPR gradually increase,and particle growth becomes dominated by collision and coalescence.Small droplets subsequently grow into larger ones through this process,ultimately forming precipitation.Fitted particle size distributions indicate that the Gamma distribution provides a good fit to both cloud and precipitation particle spectra.Above the ML,the slopes of the cloud droplet spectra and precipitation particle spectra gradually increase and decrease,respectively,with decreasing altitude.However,below the ML,the slopes of both the cloud droplet and precipitation particle spectra first increase and then decrease with decreasing altitude.