Lightning flashes recorded in photographs by 2 satellites in the Defense Meteorological Satellite Program (DMSP) are use to calculate flash frequencies for land and ocean regions in 10o latitude belts between 60oS and 60oN for dusk and midnight local times. Data are analyzed for the first week of each month between March 1974 and February 1975. We find that the annual land-ocean ratio of global lightning at dusk ranges from 8 to c20. We estimate an annual global lightning flash frequency from the dusk satellite data to be 123 s-1 with average values of 142 s-1 for the northern summer and 100 s-1 for the southern summer. A similar analysis for the midnight satellite data yields an annual lightning frequency of 96 s-1 with average values of 110 s-1 in the northern summer and 79 s-1 in the southern summer. These flash frequency estimates may be in error by a factor of 2.-from Authors
