Study on Summer Precipitation in Chengdu Based on MRR and 2DVD

The study of raindrop spectrum distribution (DSD) and precipitation microphysical parameters is beneficial to deepen people's understanding of precipitation microphysical process and is of great significance to improve the level of weather manipulation. Chengdu plain is located in the east of the Qinghai-Tibet plateau, plenty of studies have found that plain underlying surface conditions due to the basin topography as well as the southwest vortex and southwest vortex, the influence of such factors result in Chengdu area is easy to appear the summer rain and night continuous precipitation phenomenon, this kind of phenomenon of vertical structure change and precipitation physical evolution characteristics in-depth research for the further understanding and the understanding the formation mechanism of rainstorm, regional estimates of precipitation and weather modification is of great significance, but regional precipitation provides research foundation for the research of meteorological workers. In this paper, the precipitation data of MRR and 2DVD(Two Dimensional Video Disdrometer) in atmospheric observation field of Chengdu university of information engineering from 20 18 to 2019 are selected to study the vertical distribution and evolution process of raindrop spectra in different types of precipitation processes, and the main results are as follows: (1) In stratiform cloud precipitation, the concentration of small drops decreases with height, while the concentration of medium drops and large drops changes little with height. When less than 150m, 2DVD has a high consistency with MRR average raindrop spectral concentration. In convective cloud precipitation, the concentration of small particles (<; 1.5mm) changes obviously with the height, and the impact and growth between raindrops is strong. The concentration of medium and large drops(1.5mm<; D<; 5.3mm) increases with the decrease of height, and there is a process of impact and growth. (2) The accumulated rainfall measured by MRR is on the whole higher than that measured by 2DVD, but the trend consistency of the two observations is very high. The average deviation of rain intensity is 3.2mm/h, and the average deviation of rain intensity of MRR 210m is very close to that of raindrop spectrometer, with an average deviation of 2.8mm/h. The correlation coefficient of rain intensity between the two elevation layers and 2DVD is 0.86.