Concerning Channel Base Current Functions for Lightning Studies

Analysis of channel base current functions with specific reference to new channel base current (NCBC) function is reported. The main concern has been of adjusting the maximum time rate of change of lightning current (di/dt)_max along with time to crest t_m. A new ratio (maximum time rate of change of lightning current (di/dt)_max by average time rate of change of lightning current (di/dt)_avg) has been defined. The critical numerical value for this ratio is identified as 1.7 for NCBC function. The performance of NCBC function is compared with Heidler´s function in the wave front region.