Presentation Information
[PEM18-09]Local time and seasonal dependence of occurrence rate for the zero-order mode of tweek atmospherics
*Hiroyo Ohya1, Tohru Araki, Kazuo Shiokawa2, Yoshizumi Miyoshi2, Takashi Kikuchi2 (1.Graduate School of Engineering, Chiba University, 2.Institute for Space-Earth Environmental Research, Nagoya University)
Tweek atmospherics are VLF/ELF electromagnetic waves originated from lightning discharges and propagate in the Earth-ionosphere waveguide for long distances. So far, there are few studies for the zeroth-order mode of the tweeks. The preliminary reverse impulse (PRI) electric field of the geomagnetic sudden commencement (SC) is transmitted by the TM0 mode waves propagating at the speed of light in the Earth-ionosphere waveguide (Kikuchi et al., 1978; Kikuchi and Araki, 1979). In this study, we investigate the local time and seasonal dependence of the tweek zero-order mode to understand the characteristics of the zero-order mode. For statistical analysis, we developed the automatic detection procedure for the zero-order mode. In this session, we will discuss the results for the tweek zero-order mode in detail.
