SINCE LIGHTNING PRODUCTION IS CLOSELY TIED TO THE DYNAMICS AND CONVECTIVE VIGOR OF THE PARENT THUNDERSTORM TOTAL LIGHTNING OBSERVATIONS CAN BE USEFUL FOR DIAGNOSING CONVECTIVE AND ELECTRICAL PROCESSES THEREIN. THE DEPLOYMENT OF A LIGHTNING IMAGING SENSOR (LIS) ON THE INTERNATIONAL SPACE STATION WILL PROVIDE A ROBUST DATASET FOR EXAMINING TOTAL LIGHTNING ACTIVITY IN THUNDERSTORMS ACROSS THE GLOBE AS A DIRECT SUCCESSOR TO THE LIS ON THE TROPICAL RAINFALL MEASUREMENT MISSION (TRMM) SATELLITE. WE PROPOSE TO EXAMINE HOW LIGHTNING ACTIVITY AND FLASH PROPERTIES MEASURED BY LIS RELATE TO THE CONVECTIVE INTENSITY AND CONVECTIVE MODE OF THE PARENT THUNDERSTORM. THIS STUDY WILL BEGIN BY LEVERAGING THE COINCIDENT LIGHTNING AND THUNDERSTORM OBSERVATIONS OVER THE TROPICS IN THE TRMM/LIS DATASET TO ESTABLISH AND/OR BUILD UPON RELATIONSHIPS BETWEEN THE CONVECTIVE INTENSITY AND MORPHOLOGY OF THUNDERSTORMS AND THE FREQUENCY LOCATION AND PROPERTIES OF THE LIGHTNING THEY PRODUCE. WE WILL THEN APPLY THESE RELATIONSHIPS TO THE ISS/LIS DATASET TO CHARACTERIZE THUNDERSTORMS IN THE TROPICS AS WELL AS THOSE IN THE MIDTO HIGH-LATITUDES. THE IMPLICATIONS OF REGIONAL AS WELL AS DIURNAL AND SEASONAL VARIATIONS IN ISS/LIS FLASH PROPERTIES FOR THUNDERSTORM STRUCTURE AND LIGHTNING PHYSICS WILL BE ASSESSED. WE ARE PARTICULARLY INTERESTED IN WHAT ISS/LIS HAS TO TELL US BEYOND FLASH RATES. FOR EXAMPLE GROUP-LEVEL LIS OBSERVATIONS CAN BE USED TO DIFFERENTIATE BETWEEN FLASHES THAT REMAIN STATIONARY OVER THE COURSE OF THEIR DURATION AND THOSE THAT PROPAGATE ACROSS SIGNIFICANT HORIZONTAL DISTANCES AS THEY EVOLVE. FLASHES OF THE LATTER CLASSIFICATION TYPICALLY OCCUR IN STRATIFORM REGIONS OF CONVECTIVE SYSTEMS AND ARE UP TO THREE-TIMES MORE FREQUENT OVER THE SUBTROPICAL OCEANS THAN THE GLOBAL AVERAGE OF 12%. AS THE ISS/LIS WILL EXTEND THE TRMM/LIS RECORD BEYOND THE TROPICS IT WILL BE AN IDEAL PLATFORM TO EXPLORE THE PROPERTIES OF LIGHTNING FLASHES IN THESE REGIONS AND MAKE CONNECTIONS WITH THUNDERSTORM INTENSITY DYNAMICS AND MICROPHYSICS. A MAJOR GOAL OF THIS STUDY WILL BE TO LAY THE GROUNDWORK FOR NEW GEOSTATIONARY LIGHTNING IMAGER (GLM) SCIENCE AND APPLICATIONS. THE INSIGHTS PROVIDED BY TRMM/LIS AND ISS/LIS WILL BE DIRECTLY APPLICABLE TO GLM WHICH WILL PROVIDE A CONTINUOUS TEMPORAL PERSPECTIVE ON THE EVOLUTION OF STORM SYSTEMS AND THE FLASHES THEY PRODUCE.