The Propagation Effect of NBEs by Using FDTD Model and Compare with Ground-based Measurements at Different Distances
Abstract
Narrow bipolar events (NBEs) (sometimes called Narrow bipolar pulses (NBPs) or impact intracloud discharges (CIDs)) are energetic intracloud discharges characterized by typical narrow bipolar electromagnetic waveforms identified from ground based VLF/LF observations. Recent results show that, due to a large amount of high frequency components for the narrow features of NBEs, the peak amplitude, the zero-crossing time, the FWHM, and the time derivatives of NBEs were significantly distorted by propagation effects over the finitely conducting ground. However, the propagation effect of the electromagnetic fields of NBEs at distant distance will not only depend on the effective ground conductivity, but also the geometry of the earth-ionosphere waveguide (EIWG), the Earth magnetic field and the effective ionospheric conductivity profile. In this study, we will investigate the propagation effect of NBEs by using our full-wave FDTD approach. The simulated results are validated by comparing with the ground-based measurements at different distances in China. Moreover, we assess the accuracy of the simplified ray-theory model to account for the error in the evaluation of the height of the NBE source and the virtual reflection height of the ionosphere due to the propagation effects in EIWG.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMAE31B3115L
- Keywords:
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- 3304 Atmospheric electricity;
- ATMOSPHERIC PROCESSES;
- 3324 Lightning;
- ATMOSPHERIC PROCESSES;
- 3394 Instruments and techniques;
- ATMOSPHERIC PROCESSES