Analysis of lightning strokes associated with sprites observed by ISUAL in the vicinity of North America

• Published in: TAO : Terrestrial, atmospheric, and oceanic sciences Vol. 28; no. 4; pp. 583 - 595
• Main Authors: Lu, Gaopeng, Cummer, Steven A., Chen, Alfred B., Lyu, Fanchao, Li, Dongshuai, Liu, Fei, Hsu, Rue-Ron, Su, Han-Tzong
• Format: Journal Article
• Language: English
• Published: Taiwan 中華民國地球科學學會 01-08-2017; Chinese Geoscience Union (Taiwan); Springer
• Subjects: Broadband; Coastal zone; Ground-based observation; Lightning; Lightning strokes; Morphology; Oceans; Population (statistical); Sprites; Surveying; Thunderstorms; Tropical climate; North America; Impulse charge moment change (iCMC); Negative sprite; Cloud-to-ground (CG) lightning stroke; Space observation
• ISSN: 1017-0839; 2311-7680
• DOI: 10.3319/TAO.2017.03.31.01

We examined the broadband (＜ 1 Hz to 30 kHz) lightning sferics associated with 395 sprites observed near North America by the Imager of Sprites and Upper Atmospheric Lightning (ISUAL) onboard the FORMOSAT-2 satellite in a 12-year period from 2004 - 2015. Our analysis indicates that the ISUAL dataset contains a significant fraction (69, or ~18%) of negative sprites, which were predominantly (＞ 80%) observed over oceanic and coastal thunderstorms mostly in tropical areas. The mean and median of impulse charge moment change (iCMC) associated with positive (negative) sprites are +346 C km (-709 C km) and +280 C km (-649 C km), respectively. The morphology and parent lightning properties (e.g., typically with high peak currents ＞ -80 kA and large iCMCs ＞ -300 C km) of negative sprites observed by the ISUAL are generally consistent with that documented in ground-based observations, but the ISUAL dataset does imply that sprites are sometimes produced by negative strokes with sub-critical iCMCs (less than -300 C km). Consequently, the future survey of global occurrence of sprites is desired to be based on complementary ground and space-borne observations.