The optical power radiated by lightning return strokes

During 1981 the optical signals radiated by Florida lightning were recorded in correlation with wideband electric field signatures. Measurements of the initial linear slopes of the signals produced by return strokes in the 0.4- to 1.1-μm wavelength interval indicate that the space-and-time-averaged radiance emitted during the early phase of first strokes averages about 1.3±1.2×106 W/m and that subsequent strokes produce about 3.9±4.9 × 105 W/m, values that are in reasonably good agreement with those obtained in 1980 by Guo and Krider (1982) who used a different detector at longer ranges. The average peak radiance in subsequent return strokes near the ground is estimated to be in the range from about 6×105 W/m to 1×106 W/m.