Preliminary Analysis On The Structures Of Radar Precipitation Echo And The Features Of Lightning In Thunderstorms Over Beijing In Summer

In this paper the structures of radar echo and the spatial-temporal characteristics of the lightning activities in three strong thunderstorm and precipitation weather cases were detailed analyzed,mainly using the Very-short-range Interactive Prediction System(VIPS) data(Including data of Doppler Radar,Wind Profile Radar, Lightning Detection System and Automatic Weather Station) in summer from Beijing Meteorological Bureau.It is aimed to provide some new understandings of the relationship between the spatial-temporal characteristics of the lightning and the structures of radar echo and be used as references for the local rainstorm and thunderstorm in weather nowcasting.The results are summarized as:(1) This paper first studies the spatial-temporal distribution features of the precipitation and lightning,including the spatial distribution of the precipitation and the lightning and the time relationship between rainfall rate and lightning frequency. The analysis indicates that there are some differences between them in the different thunderstorm or even in the same.For the time relationship of the rainfall rate and the flash rate,the research shows that the peak of the rainfall rate is ahead or behind the peak of the flash rate.The first appear time of Intra-Cloud flashes(IC) is generally 5～15 minutes before the Cloud-to-Ground(CG) flashes,namely IC has an ahead time comparing with the CG.Based on this point,IC possesses an important reference value and guidance to weather disasters Information Alarm Publishing, especially for the CG.(2) Further research on the spatial-temporal distribution features of the lightning and its relationship with radar,atmospheric stratification,and wind structure.The analysis shows that more than 70%of the total flashes happened in areas where radar composite reflectivity(CR) was larger than 40 dBZ in the heavy thunderstorm and rainstorm cells.When the maximum reflectivity values exceeded 60 dBZ,the probability of IC occurred in strong radar echo may approach 90%.The study between IC and the vertical radar echo profile indicates that the heights of the IC often occurs above 6km,and the altitudes of peak flash rate are between 8 and 11km. The Analysis of the atmospheric stratification demonstrates that around the height of 6km corresponding to the temperature range from-5℃to -10℃and at height of 8～11km the temperature range is between -20℃and-40℃where is the peak of IC frequency appeared.The horizontal and vertical distribution of lightning track may indicate the altitude and lifting of the center of lightning activity.Automatic Weather Station wind field Combined with radar reflectivity can timely discovery of the Characteristics of Surface wind,it has the important directive significance to display the Trigger and Evolution of the Severe Weather.The high time resolution data of Wind Profile Radar can reflect the structure of the atmospheric wind field,such as low-level jet and Vertical Wind Shear etc.