A Discussion of the New M-component Engineering Model From Azadifar et al. by Simultaneous Measurements in Rocket-Triggered Lightning

A discussion of the new M-component engineering model proposed by Azadifar et al. (2019) is presented. The M-component electric fields were measured at both close distance of 78 m and far multiple-station distances ranging 69 km −126 km in rocket-triggered lightning. Both the fast microsecond-scale pulse and the following slow millisecond-scale pulse are reproduced in the new engineering model. The electrostatic field component produced by the return-stroke like process along the branch among the new engineering model contributes to weaken the positive overshoot of the close M-component electric field. The modified new engineering model considering an exponential current decay along the grounded channel in the study allows a more satisfactory performance of reproducing full M-component electric fields than that of the model from Azadifar et al .