Based on national ground-based lightning detection data,the detection effect of FY-4A LMI in the eastern Zhejiang region is evaluated.High spatiotemporal resolution non-modal variable data of LMI is used to improve the accuracy and timeliness of lightning monitoring and warning in convective weather processes.By comparing the lightning detection data of strong convective weather processes in the eastern Zhejiang region,the significance test of lightning landing point and cloud top brightness temperature,as well as weather process validation,showed that the Event products detected by LMI mainly occurred in the strong echo area,with echo intensity above 35 dBZ and cloud top height of 8～10 km.The ratio of detection quantity to ground lightning detection quantity is 0.16～0.45,with an average of 0.323.In terms of spatial distribution,considering only the location of the flash landing point,the LMI high flash density area is more southeast in the same period.LMI has a good detection effect on cloud flashes,with cloud flashes oc-curring more than 45 minutes earlier than ground flashes in time.It has an advantage in monitoring and warning of primary convection and weak convection.The detection efficiency at night is significantly better than during the day,and there is a good correlation between hourly changes in high flash density areas and TBB brightness temperature.More than 90％of flash signals are located in the range below 230 K(＜-40 ℃),and have passed the significance test based on single population t-values.Overall,there is a slight deviation in the detection efficiency and lightning location of LMI in the eastern Zhejiang region,but it can compensate for the limitations of radar observation and ground-based lightning positioning systems in terms of spatiotemporal resolution.It can provide a longer lead time(over 45 minutes)for lightning mo-nitoring and warning,and provide assistance for scientific defense against natural disasters such as light-ning.
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万方数据