Satellite measurements of global lightning

The satellite‐borne NASA/MSFC Optical Transient Detector provides global distributions of lightning and lightning‐stroke radiance. Measurements made during the first year of its operation show that lightning activity is particularly pronounced over the tropics, much greater over land than over the oceans, and exhibits great seasonal variability. The values of lightning‐stroke radiance tend to be greater over the oceans, less when lightning activity is high, and greater in the northern hemisphere winter than summer.