Lightning Data Analysis of the CMA Network in China

Abstract. Based on analysis and evaluation of the 2009 to 2013 national lightning monitoring data, the average lightning detection station distance is approximately 170 kilometers in China, and the average operational availability (AO) exceeds 90 %. Lightning detection systems use a hybrid location method of direction finding (DF) and the time difference of arrival (TOA). The stations use four localization algorithms, including two-station mixing, three-station mixing, four-station mixing and two-station amplitude. Among them, the four-station method has the highest positioning accuracy, i.e., close to 50 %. The statistical results show that lightning occurrences in China have increased, especially negative cloud-to-ground (−CG) flashes because positive cloud-to-ground (+CG) flashes account for only 5.1 % of the total. In china, most of lightning currents range are in the −60 ~ +60 kA, Lightning current between −10 ~ +10 kA only accounted for small proportion of 0.6 %.The average intensity of positive flashes is 64.2 kA, the average intensity of negative flashes is −40.28 kA. The average +CG intensity is higher than that of −CG flashes, which is consistent with statistical results of other Lightning detection network. Lightning frequency has obvious regional differences across the country; the high density lightning area is mainly distributed in south-central China, the south-central Yangtze River region and the eastern part of southwestern China. Seasonal variation in lightning activity is well defined, with few lightning occurrences in winter and a gradual but significant increase from spring to autumn in the middle and lower reaches of the Yangtze River to the north, south and southwest. The ratio of positive to negative flashes is highest in winter.