The Study Of Lighting And Radar Data Fitting Algorithm In Northeast

In recent years,a large number of research of the relationship between weather radar reflectivity and lightning location data has been made at home and abroad,and some conclusions have been drawn.But these conclusions are not widely used in the daily meteorological business.So the lightning and radar data are fused to study the application of radar data on lightning warning by using the radar and lightning database in northeast from CMA.The purpose is to propose an algorithm that can be applied to daily business work.The data of radar reflectivity and lightning in Shenyang and Harbin are analyzed.It is found that the average of the radar reflectivity in the previous time period(6min)is significantly correlated with the lightning number of the time period.According to the different correlation coefficients between the average of radar reflectivity and the number of lightning of the minimum time period(6min,30min),the quadratic fitting relation of day correlation coefficient at 0.4,0.6 and 0.8 is obtained respectively,and the data are verified.The results show that the average value of the radar reflectance calculated by the correlation formula can be consistent with the theoretical value,and the relative error can be controlled within a reasonable range.Although the fitting relation of different regions is different,the cross correlation function is consistent with the waveform of autocorrelation function.It notes that the relevance is consistent in the same time shift.This provides a strong theoretical basis for the establishment of operational application algorithms.The business algorithm is initially proposed.According to the climate characteristics,a number of central stations are established throughout the country to store the fitting coefficients.The coefficients are updated based on real-time data to enable more accurate correlation analysis of the region.Many scholars in the past have shown that the correspondence of occurrence of lightning,echo intensity and echo top is good.Based on the sounding data,lightning location data and radar echo data in Harbin,the recognition effect of nine identification indicators is analyzed.A rule of recognition effect is proposed by counting the lightning location data and the radar volume reflectance data of 20 thunderstorms,and the identification indicator is validated.So the best indicator of lightning strikes in Harbin is being drawn by using radar data: Radar echo reflectivity is above 40 dBZ,and the top of the echo reaches a height of-10 °.Thebusiness algorithms that can be widely used are proposed: First,the stacking height of-10 ° is determined from the sounding data;Search for the echo intensity which can consistent with lightning forecast index in this height;Do lightning warning work.