Roles of the EMP and QE field in the generation of columniform sprites

In order to elucidate the electrodynamic coupling process between sprites and their causative cloud-to-ground lightning discharges, we investigated 38 columniform sprite events observed in the wintertime sprite campaigns in Japan. By analyzing the data of sprite images, transient Schumann resonance waveforms and the JLDN/LPATS lightning detection network systems, we found that the number of columns in each sprite event was proportional to the peak current intensity of positive cloud-to-ground lightning discharges (+ CGs) while the average vertical length of columns was proportional to the charge moment of the causative + CGs. Based on these results, we suggest that electromagnetic pulses (EMPs) radiated from + CGs contribute to the formation of seeds for sprite streamers while the QE field contribute to the development of the streamers from the seeds.