Difference analysis of raindrop size distribution characteristics in Meiyu and typhoon types of short-term heavy rainfall in summer in Jiangsu Prov-ince
Accurate understanding of microphysical characteristics of short-term heavy rainfall is crucial to im-prove the monitoring and warning capabilities of severe convective weather such as short-term heavy rainfall and accurate understanding of raindrop size distribution(DSD)characteristics of short-term heavy rainfall is also the key to improve the forecasting and early warning capabilities of it.Currently there are still few studies on DSD statistical characteristics of short-term heavy rainfall.Most studies either focus on the rainstrom process under the influence of a certain weather system or contrastive studies on different weather types.Studies on the DSD charac-teristics of short-term heavy rainfall under the influence of different weather systems are rare.Furthermore,most of the research is based on the observations of a single station or several stations,so the results have some limitations due to the local site observations.In this paper,based on automatic weather station data and disdrometer data dur-ing 2019-2020 in summer in Jiangsu Province,the short-term heavy rainfall is divided into four types:Meiyu 20,Meiyu 50,Typhoon 20 and Typhoon 50 according to different weather types(Meiyu and typhoon)and differ-ent rainfall intensities(20-50 and＞50 mm·h-1).The different DSD characteristics in different types of short-term heavy rainfall with different intensity is further analyzed to deepen the understanding of the differences of microphysical characteristics of the different types of short-term heavy rainfall.Statistical results show that the av-erage raindrop particle size(number concentration)of Meiyu-type short-term heavy rainfall(SHR)is obviously higher(lower)than that of typhoon-type SHR on the whole.The contribution of small raindrops(diameter≤ 2 mm)to typhoon-type SHR is significantly more than that to Meiyu-type SHR.Furthermore,with the increase of rainfall intensity,the large raindrop number concentration and the average raindrop particle size of Meiyu-type SHR with intensity over 50 mm·h-1 increased significantly compared with Meiyu-type SHR with intensity be-tween 20 and 50 mm·h-1.Similarly,the number concentration of typhoon-type SHR with intensity over 50 mm·h-1 increased significantly but the growth of particle size is not obvious compared with typhoon-type SHR with in-tensity between 20 and 50 mm·h-1.Therefore,the typhoon-type SHR with different intensities is mainly contrib-uted by high concentration of small particle size raindrops,while the extreme Meiyu-type SHR is contributed by larger raindrops,and the DSD characteristics are more complex.Similar observation conclusions are also obtained through typical case study.It shows that the DSD of Meiyu-type SHR is more obvious than that of typhoon-type SHR.
short-term heavy rainfallraindrop size distributionMeiyutyphoonJiangsu
万方数据
维普
