Activity Characteristics of CG Lightning in Hainan Island under the lnfluence of Southwest Low Pressure Trough

The spatial and temporal distribution characteristics of the occurrence probability of CG lightning under the influence of southwest low pressure trough were analyzed using the data of weather classification and lightning location from 2010 to 2018 over Hainan Island.The results are as follows:CG lightning mainly appeared from April to September; the monthly distribution curve of the occurrence probability of CG lightning shows a bimodal characteristic, the main peak is in August and the second peak is in May; the monthly distribution curve of the occurrence probability of CG lightning at 00-12 BT is different from that of the whole day, it is mainly characterized by monthly rise; the time period distribution curve of the occurrence probability and the number of CG lightning show single peak characteristics, both peaks occurred between 15 and 18 BT, except for 12-21 BT, the occurrence probability and number of CG lightning at other time periods are very low, the probability of occurrence and the number of CG lightning are slightly higher in the later stage of the control process than in the earlier stage; for 00 to 12 BT, the occurrence probability center of CG lightning was distributed in the southeast coast, the central value of probability is below 5%, the probability center of CG lightning is distributed in the north of inland from 12 to 21 BT, the probability center moves from the middle of Baisha to the east of Chengmai, the direction of movement is from southwest to northeast, the probability center reaches a maximum of 40% in the south of Chengmai; the occurrence probability of CG lightning in each period from July to September is higher than that in April to June, the peak number of CG lightning in July to September is fewer than that in April to June, the both of the spatial distribution of the probability center of CG lightning in each time period is completely consistent.