Correlation between lightning types

The spatial correlation of cloud-to-ground (CG), intracloud (IC), and narrow-bipolar event (NBE) lightning was investigated. Lightning data were collected for a two-month period in Florida. Separate analyses were performed for lightning over land and lightning over water. Space-time cells were defined, and lightning flash density was computed on each cell for the three lightning types. Correlation coefficients were computed for each of the three pairs of lightning types: CG-IC, IC-NBE, and CG-NBE. The CG-IC lightning pair was correlated most strongly. Best fit curves were also produced for each pair of lightning densities. These were second order polynomial fits in log space. These fits displayed curvature on log-log axes, signifying that the relative fractions of lightning types vary with storm intensity. The land/water separation did not have a strong effect on the relationships.