First ground-based observations of sprites over southern Africa
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Date
2018
Journal Title
Journal ISSN
Volume Title
Publisher
Academy of Science of South Africa
Abstract
Sprites are the optical signatures of electrical discharges in the mesosphere triggered by large lightning
strikes associated with thunderstorms. Since their discovery in the late 1980s, sprites have been
observed extensively around the world, although very few observations of sprites from Africa have been
documented in the literature. In this paper, we report the first ground-based recorded observations of
sprites from South Africa. In 2 out of the 22 nights of observations (11 January and 2 February 2016),
about 100 sprite elements were recorded from Sutherland in the Northern Cape, comprising different
morphologies (carrot (55%), carrot/column (11%), unclassified (21%), column (13%)). The sprites were
triggered by positive cloud-to-ground lightning strikes, which had an average peak value of ~74 kA and
were observed at distances from ~400 km to 800 km. The estimated charge moment change of the
lightning discharges associated with these events was in agreement with the threshold for dielectric
breakdown of the mesosphere and correlates well with the observed sprite brightness.
Description
Keywords
Sprites, South Africa, Northern Cape, Cloud-to-ground lightning strikes
Citation
Nnadih, S. et al. (2018). First ground-based observations of sprites over southern Africa. South African Journal of Science, 114(9/10): Art. #4272, 6 pages.