Compact intracloud discharges: New classification of field waveforms and identification by lightning locating systems

Autor: Brígida Ramati Pereira da Rocha, Vladimir A. Rakov, Adonis F. R. Leal
Rok vydání: 2019
Předmět:
Zdroj: Electric Power Systems Research. 173:251-262
ISSN: 0378-7796
DOI: 10.1016/j.epsr.2019.04.016
Popis: We analyzed wideband electric field waveforms of 1022 compact intracloud discharges (CIDs) that transported negative charge upward and were recorded in 2016 by the Lightning Detection and Waveform Storage System (LDWSS) operating at the Lightning Observatory in Gainesville (LOG), Florida. According to the NLDN, all the examined events occurred within 500 km of the LOG. CIDs, which are the strongest natural producers of HF-VHF radiation on Earth may represent a serious threat to airborne vehicles. They were distinguished from other lightning processes using their characteristic features in both the time-domain waveform and the frequency spectrum. Eleven types of CID electric field waveshapes were identified, seven of which have not been reported as separate types before. More than half of the observed CIDs showed pronounced ringing on the opposite-polarity overshoot of their bipolar electric field waveforms, which is indicative of a bouncing wave process. Two major lightning locating systems (NLDN and ENTLN) each reported most of our CIDs as CGs (essentially all as +CGs). The percentage of misclassified CIDs was higher for higher-intensity events: for peak current ranges of 0–20 kA, 20–50 kA, and ≥ 50 kA NLDN misclassified 10%, 97%, and 100% of CIDs, respectively. The corresponding percentages for ENTLN were 2%, 63%, and 100%.
Databáze: OpenAIRE
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