THIS PROPOSED RESEARCH WILL EXPLORE LIGHTNING-ENVIRONMENT RELATIONSHIPS ACROSS THE GLOBE USING TRMM AND ISS LIS OBSERVATIONS AND MERRA2 ENVIRONMENTAL FIELDS. ENVIRONMENTAL VARIABLES OF PARTICULAR INTEREST ARE CAPE COLUMN HUMIDITY AND OMEGA AT 500 MB BUT OTHER FIELDS SUCH AS WIND SHEAR WILL BE ANALYZED TO QUANTIFY THE ENVIRONMENTS MOST CONDUCIVE TO LIGHTNING OCCURRENCE AND INTENSITY FOR LAND AND OCEAN REGIONS IN THE TROPICS INTO THE MIDLATITUDES AND FOR TIME SCALES RANGING FROM DIURNAL TO INTERANNUAL. RADAR DATA FROM THE TRMM AND GPM SATELLITES WILL BE FURTHER USED TO UNDERSTAND THE ENVIRONMENTAL CONDITIONS AND VARIATIONS THAT PROMOTE LIGHTNING PRODUCTION. FOR EXAMPLE WE POSTULATE THAT CONVECTIVE RAIN INTENSITY IN MODEST-CAPE MODEST-HUMIDITY ENVIRONMENTS IS BEST CORRELATED TO MODERATE LIGHTNING PRODUCTION BUT THAT EXTREME LIGHTNING PRODUCTION IS MORE LIKELY TO OCCUR IN MODEST-CAPE HIGH-HUMIDITY ENVIRONMENTS WITH LARGE STRATIFORM RAIN REGIONS. FINALLY A SUITE OF CMIP5 GCMS WILL BE ASSESSED FOR THEIR ABILITY TO SIMULATE THE ENVIRONMENTAL CONDITIONS THAT ARE MOST CLOSELY ASSOCIATED TO LIGHTNING PRODUCTION IN OUR CURRENT CLIMATE AND THE CHANGES THE MODELS FORECAST IN FUTURE CLIMATE SCENARIOS. AN IDEAL END RESULT WOULD BE AN UNDERSTANDING OF WHAT ENVIRONMENTAL CONDITIONS CONTRIBUTE MOST STRONGLY TO LIGHTNING ONSET AND FLASH RATE INCREASE HOW THESE CONDITIONS VARY BETWEEN IMPORTANT REGIONS IN THE GLOBAL CIRCULATION AND WHAT THESE CONDITIONS ARE FOR EXTREME LIGHTNING OCCURRENCE.