Analysis Of Characteristics Of Lightning Disaster Activities In Different Regions Of My Country Using The Very Low Frequency Global Lightning Location Networ

This paper uses the lightning data of the Wordwide Lightning Location System(WWLLN),the fifth generation reanalysis data(ERA-5)of the European Centre for Medium-Range Weather Forecasts,and the digital elevation model(DEM)data of the Shuttle Radar Topography Mission(SRTM)to study lightning in different regions of Chinese Mainland,It is helpful to establish prediction factors for lightning,improve the prediction level of lightning activity,and provide reference for lightning disaster prevention and risk assessment.The results of this article indicate that:(1)Lightning and CAPE,P,CAPE × P and other meteorological factors have good correlation in time and space;A suitably small CIN and a sufficiently large CAPE are most conducive to generating lightning;The higher the CAPE,the more lightning;The smaller the suppression energy,the easier it is for convection to occur and further lightning to occur,but the CIN cannot be too small,as too small a CIN can lead to fewer lightning;A low CIN value is not a sufficient condition for lightning to occur,and the relative humidity also needs to be very high;Lightning activity is concentrated in an environment where RH is between 60% and90%.If RH continues to increase,lightning activity will decrease;Even in high CIN environments,as long as there are certain water vapor and CAPE conditions,there will be a large number of lightning.(2)In the daily cycle,there is a good correspondence between the occurrence time of lightning frequency extremes and altitude.The occurrence time of lightning frequency in low altitude areas such as valleys,basins,and plains is often earlier than in high altitude areas such as mountains,plateaus,and hills;By studying the distribution of lightning,precipitation,and convective effective potential energy at different altitudes over various time periods,it is found that convective activity is more intense in the evening at high altitudes,while convective activity is more intense at night and in the early morning at low altitudes;The daily variation of lightning activity is greater in high altitude areas than in low altitude areas.(3)In places where altitude changes significantly and terrain slopes are large,the number of lightning flashes will be more intensive;In the same area,lightning in high altitude areas mostly occurs in the afternoon and evening,while in adjacent low altitude areas,due to the influence of mesoscale convective systems,lightning often occurs at night or in the early morning;The number of lightning in mountain areas in central and western China mostly increases with the rise of slope,while the number of lightning in mountain areas in eastern China mostly decreases with the rise of slope;From the perspective of mountain trend,the impact of slope on CAPE and precipitation can well reflect the impact of slope on lightning,and the impact of slope on these three variables in arid areas is greater than that in humid areas;The number of lightning flashes in east-west mountain areas tends to increase as the slope increases,while the number of lightning flashes in north-south mountain areas tends to decrease as the slope increases.