Analysis on the Spatio-temporal Distribution Features of Cloud-to-ground Lightning in Hubei Province During 2006-2007

Based on the cloud-to-ground lightning data collected by the lightning detection and location system composed of 13 lightning detectors from March 2006 to February 2008, the daily and monthly lightning variation are studied to analyze the spatio-temporal distribution features of cloud-to-ground Lightning in Hubei, as well as lightning intensity, polarity and density. The results are showed as follows: the percentage of negative lightning to total lightning number is 96.3% with the average lightning intensity of 32.33 kA, the percentage of positive lightning is 3.7% with the average intensity of 42.24 kA; daily variation of lightning frequency shows obviously single peak and single valley, its maximum value appears during 3-4 PM., the minimum value appears in 9-10 AM.. The number of the lightning appearing from April to August is 96.7% of the annual total; the lightning appears most frequently in July and August; the intensity of positive and negative lightning is mainly concentrated in 10~45 kA, about 80% of the lightning intensity is not more than 45 kA. The number of the lightning whose intensity being less than 100 kA accounts for 98.6% of the total; the lightning density distribution has obvious regional difference, one high density area of lightning is southeast Hubei including Jiayu, Xianning, Huangshi, Ezhou. Another area is in west Hubei including Yuan-an, Yichuang, Zhijiang, the two areas are both in the regions conjoining the mountains with hilly or plain.