CLOSE OBSERVATIONS OF FORKED AND UPWARD-ILLUMINATION RETURN STROKES AT THE KENNEDY SPACE CENTER/CAPE CANAVERAL AIR FORCE STATION
A total of 232 well-resolved multiple ground contact flashes were recorded via high-speed video at the Kennedy Space Center (KSC)/Cape Canaveral Air Force Station (CCAFS) during 2014 and 2015. Of these 232 flashes, 58 flashes exhibited at least one clear instance of either forked or upward illumination (UI) return strokes.
Characteristics of these 58 flashes are examined via close-range high-speed video recordings and time correlated rate of change of electric field (dE/dt) measurements. The dataset of forked strokes is subdivided into three separate classifications depending on inter-stroke interval and branching altitude. Interstroke intervals and distance separations between first and subsequent ground attachment points are evaluated for all classes of forked strokes and for UI strokes. The detection efficiency and peak current reporting of the National Lightning Detection Network (NLDN) is evaluated for all classes of forked strokes and for UI strokes.