Comparative analysis of atmospheric vertical structure before and after heavy rainfall in mountain and plain

Two heavy rainfall events are analyzed based on the hourly rainfall data at Shennongjia airport meteorological station from 11:00 BT on 23 June to 08:00 BT on 24 June 2016 and Xianning meteorological station from 04:00 on July 3 to 01:00 on July 4, 2016, vertical profiles of water vapor density, liquid water, relative humidity and temperature with high resolution from ground to 10 km, and integrated water vapor, path-integrated cloud liquid water and cloud base data, . The differences of atmospheric vertical structure between Shennongjia in mountainous area and Xianning in plain before and after the rainstorm are obvious. The precipitable water and path-integrated cloud liquid water in Shennongjia are lower than those in Xiannin. The water vapor density, liquid water content and temperature at all altitudes above Shennongjia airport meteorological station are also lower than thoae at the corresponding altitudes above Xianning. The relative humidity in the mixing layer at Shennongjia is slightly higher than that at Xianning. Shennongjia is located in the mountainous area, where the external water vapor supply is not sufficient, and the formation of precipitation mainly depends on the condensation of local water vapor. Due to the high elevation of the mountainous area, the atmospheric temperature in Shennongjia is relatively low, and the temperature and humidity conditions are better for ice nucleation and growth than those in Xianning, which makes Shennongjia produce rainstorm even when the water vapor supply is insufficient. Xianning has sufficient water vapor supply, which can be replenished in time after condensation. Although the humidity condition in the mixing layer in Xianning is not as good as that in Shennongjia, and the growth of ice crystals is relatively weak, the process of riming process in the mixing layer and the coagulation of cloud and rain drops in the melting layer play important roles in the precipitation process. Before the onset of precipitation, because of the topographic effect, air lifting at Shennongjia is stronger than that in Xianning, while the atmospheric uplift in Xianning was more significant after the precipitation begans, showing obvious convective characteristics.