FY-4A LMI Observed Lightning Activity in Super Typhoon Mangkhut(2018)in Comparison with WWLLN Data

摘要

Using lightning observations from the Fengyun-4A Lightning Mapping Imager(FY-4A LMI),best-track data from the Shanghai Typhoon Institute,bright temperature(TBB)data from Himawari-8 satellite,and composite reflectivity(CR)data from the South China radar network,we investigate the spatiotemporal distribution of lightning activity and convective evolution during the landfall of Super Typhoon Mangkhut,the strongest landing typhoon in China in2018.Three stages of active total lightning are observed,and differences of lightning characteristics between the inner core and the outer rainbands are present.The onset of inner-core lightning outbreak is about 4 h ahead of the maximum intensity of the storm,providing indicative information on the change of typhoon intensity.Lightning rates in the outer rainbands increase rapidly 12 h before the landfall,and lightning activity is mainly confined in the outer rainbands after the landfall.A good correlation in hourly variation is shown between lightning rates from the LMI and TBBs from the satellite.The averaged TBB within the inner core reaches its minimum(–80℃)when the innercore lightning outbreak occurs,indicating the occurrence and enhancement of deep convection there.Lightning locations observed by the LMI has a good spatial correspondence with regions of low TBBs and high CRs,revealing the monitoring capability of the LMI to lightning activity and deep convection in landing typhoons.Comparisons between the World Wide Lightning Location Network(WWLLN)and the LMI reveal that the spatial distribution,temporal evolution,and radial pattern of lightning activity in Mangkhut observed by the two systems are consistent.Furthermore,due to the detection capability of total lightning,the LMI has advantages in revealing the higher ratio of intra-cloud lightning within the inner core in typhoon.The continuous and real-time observation ofFY-4ALMI provides an unprecedented platform for monitoring total lightning and deep convection in landing typhoons in China,which will promote the generation of new research and applications in the future.