| Strong thunderstorm in atmosphere is not only along with heavy rainfall,high wind and hailstone, but also with severely impair to the safety of people, electronic system, aerospace system, electric transmission line and forest. By analyzing the location data of three-dimensional total lightning, the activity routines of lightning are grasped,which can enhance the knowledge of physical process in thunder cloud and offer reference for lightning protection and disaster reduction.By combining the location data of three-dimensional total lightning, radar data and meteorological data, the spatial and temporal distribution characteristic of lightning frequency, lightning intensity and altitude of total lightning, intracloud lightning(IC), cloud-to-ground lightning(CG) are analyzed. In addition, the total lightning active character of single cell, severe cell and squall line are analyzed. The function of total lightning data in hailstone warning and the total lightning character in hailstorm are studied based on 4σ algorithm through hailstorm cases. The main conclusions are as follow.The frequency of IC mainly focuses from 14:00 to 20:00.Most of IC are prone to occur in summer. High value region of IC density is Xuzhou, Changzhou and the boundary between Changzhou and Wuxi. Middle value region of IC density is Nanjing and Suzhou. Low value region of IC density is north and center of Jiangsu; The height of IC mainly distributes at 3-10km, account for 98.68% of total IC. The IC frequency at 5-6km is at most and the maximum of IC height is 17.75km; the spatial and temporal distribution and density distribution of total lightning, CG are according to IC. The monthly variation of proportional of positive CG frequency is opposite to CG frequency. The month that has high CG frequency has low proportional of positive CG frequency on the contrary. The hourly, monthly variation of the value of IC/CG has negative correlation to total lightning frequency. The lightning current intensity mainly distributes in 0-40kA regardless of total lightning, IC, CG. Comparing with total lightning and CG, IC frequency distributes less in 0-10kA. Comparing with negative IC, positive IC distributes more in high lightning current intensity(>100kA) and low lightning current intensity(<20kA). The lightning current intensity in south of Jiangsu is higher than north of Jiangsu.The analysis of squall line process shows that the descending, ascending of IC ratio can indicate the reinforcing, receding of thunderstorm in the process of the squall line. Charge Structure in thunderstorm cloud is inferred as tripole charge structure by combining the change of introcloud activity and sounding data. Lightning density in the convective region is far higher than in the stratiform region. Comparing with positive cloud-to-ground lightning, negative cloud-to-ground lightning focus on the severe convection region of radar echoes. The location of IC is more random and easy to happen in weak echoes region and stratiform region. There is a high correlation between the occurrence of lightning and cloud top height. The occurrence of IC is consistent with the development of strong echo region in profile of reflectivity factor. Compare process of single cell, super cell and squall line, result shows that the first time of the cloud top’s height higher than the -20℃ layer is in advance of first IC. IC mainly distribute in 3-8 km. The corresponding temper layer of height which the maximum IC frequency appears in is all 0℃ to-10℃. Lightning mainly appear in strong echo area and nearby area which has great echo intensity gradient. Comparing with cloud-to-ground lightning, IC focuses on the weak echo area and area with no radar echo.3 processes all have convergence in the middle-low classes and divergence in high level. The atmosphere in the process of severe cell and squall line are more unstable. The process of single cell and squall line is mainly with negative lightning. The process of severe cell is mainly with positive lightning and echo pendency.The function of total lightning data in hailstone warning are studied based on 4a algorithm. The results show that the peak of 30dBZ echo top height and cloud top height occur before hailstone happening. The happening of 30dBZ echo top height and cloud top height can be index to hailstone warning. Comparing to cloud top height,30dBZ echo top height has more correlation to total lightning frequency. Higher proportion of positive lightning is corresponding to longer duration and bigger hailstone diameter. Higher proportion of negative lightning is corresponding to shorter duration and smaller hailstone diameter.4σ algorithm in hailstone warning has great effect by using the location data of three-dimensional total lightning in 3 hailstorm. The average warning time is 43min. Comparing with two-dimensional CG lightning, the location data of three-dimensional total lightning has better effect.The analysis of character of total lightning and radar in different thunderstorm case shows that the location data of three-dimensional total lightning has great indicative function to thunder warning and the identification of severe convection weather. |
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