Global lightning distributions for the period August 1977 to June 1978 have been obtained from lightning sensors on Defense Meteorological Satellite Program (DMSP) flight 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. |