Characteristics of SpatialTemporal Distribution of Tornadoes in China
Based on “the Handbook of China Meteorological Disasters” published in 2008 and other relevant documents for period 1961-2010, spatialtemporal distribution characteristics of significant tornadoes (EF2 or greater) are analyzed according to the “Enhanced Fujita Scale”. And based on “the Annual Report of China Meteorological Disasters” which began to be published from the year 2005, spatialtemporal distribution characteristics of EF1 or greater tornadoes are investigated. The main results show there are total 165 significant tornadoes recorded in China during the 50 year period from 1961 to 2010, including 145 EF2, 16 EF3 and 4 EF4 tornadoes, with average 3.3 significant tornadoes each year. Most of the tornadoes occur in plain area, with higher frequency in Jianghuai Plain, South China, Northeast China Plain and the North China Plain. The highest frequency of tornadoes is during the period 1986-1990. Then, it starts to decline. Most of significant tornadoes occur in spring and summer (from April to August) which account for 87% of the total. The peak frequency of tornado genesis in the diurnal variation is from 12:00 to 20:00 local time. The 165 significant tornadoes killed at least 1772 people and wounded more than 31700.During the 10 year period from 2004-2013, according to “the Annual Report of China Meteorological Disasters” from 2005 to 2014, there are 121 EF1, 19 EF2 and 3 EF3 tornadoes recorded and their spatial distribution is similar to those of the significant tornadoes from 1961 to 2010. Furthermore, at least there are 570 EF0 tornadoes during the same period. With the data, we can infer roughly there is about at least 85 tornadoes and 21 EF1 or greater tornadoes seen in China on average each year, less than the tenth of the tornado occurring frequency in the United States.