Global lightning distributions at dawn and dusk

Abstract

Global lightning distributions for the period August 1977 to June 1978 have been obtained from lightning sensors on Defense Meteorological Satellite Program (DMSP) flights 2 and 3. Seasonally averaged trigger rates are calculated for 10°×10° cells on the earth, an area roughly equal to the resolution limit of the sensors. These data indicate that 37% of global lightning activity originates over the oceans at dawn, and this fraction drops to 15% at dusk. The seasonally averaged mean global lightning flash rate varies by about 10% through the year, with an absolute value within the range of 40–120 flashes per second.