Small negative cloud‐to‐ground lightning reports at the NASA Kennedy Space Center and Air Force Eastern Range

Abstract

The NASA Kennedy Space Center (KSC) and Air Force Eastern Range (ER) use data from two cloud‐to‐ground (CG) lightning detection networks, the Cloud‐to‐Ground Lightning Surveillance System (CGLSS) and the U.S. National Lightning Detection Network™ (NLDN), and a volumetric lightning mapping array, the Lightning Detection and Ranging (LDAR) system, to monitor and characterize lightning that is potentially hazardous to launch or ground operations. Data obtained from these systems during June–August 2006 have been examined to check the classification of small, negative CGLSS reports that have an estimated peak current, ∣Ip∣ less than 7 kA, and to determine the smallest values of Ip that are produced by first strokes, by subsequent strokes that create a new ground contact (NGC), and by subsequent strokes that remain in a preexisting channel (PEC). The results show that within 20 km of the KSC‐ER, 21% of the low‐amplitude negative CGLSS reports were produced by first strokes, with a minimum Ip of −2.9 kA; 31% were by NGCs, with a minimum Ip of −2.0 kA; and 14% were by PECs, with a minimum Ip of −2.2 kA. The remaining 34% were produced by cloud pulses or lightning events that we were not able to classify.