Abstract
Sprites are mesospheric optical emissions that are mostly produced by large, positive cloud-to-ground lightning discharges. Sprites appear in different morphologies such as carrot, jellyfish and column, and are typically in the altitude range of ~40–100 km above the Earth’s surface. Sprites are a subset of transient luminous events and they contribute to the global electric circuit. South Africa has large convective thunderstorms, which typically occur in the summer months of every year. Peak current, time and geographical position of lightning strokes were obtained from the South African Weather Service. Sprite observations were recorded in South Africa for the first time on 11 January 2016 from Sutherland in the Northern Cape using a night-vision television camera from the South African National Space Agency’s Optical Space Research laboratory. We report the first estimates of the top altitude, and the altitude of maximum brightness, of 48 sprites over South Africa. We found that the average top altitude and the altitude of maximum brightness of sprites are approximately 84.3 km and 69 km, respectively, which is consistent with estimates made elsewhere. We also found a moderately high positive and a weak positive correlation between the top altitude and the altitude of maximum brightness, respectively, of sprites and the lightning stroke charge moment change.
 Significance:
 
 We present the first altitude estimation of sprites observed over Africa.
 The altitude of sprites observed over South Africa is in agreement with observations made elsewhere.
 There is a positive correlation between the top altitude of sprites and the parent lightning charge moment change.
 Sprite maximum brightness is observed near the stratopause.
Highlights
Sprites are optical phenomena generated by the electric field in the mesosphere, almost exclusively during positive cloud-to-ground (+CG) lightning flashes with a high peak current and a high charge moment change (CMC)
We report the first estimates of the top altitude, and the altitude of maximum brightness, of 48 sprites over South Africa
From the South African Weather Service (SAWS) lightning data, all observed sprite events were produced by +CG lightning strikes with a peak current magnitude varying from 11 kA to 191 kA.[12]
Summary
Sprites are optical phenomena generated by the electric field in the mesosphere, almost exclusively during positive cloud-to-ground (+CG) lightning flashes with a high peak current and a high charge moment change (CMC). Sprites play a role in the global electric circuit.1-3The optical signature of sprite events typically lasts for about 1–10 ms.[2] some sprite events can last for more than 10 ms, especially in the case of dancing sprites and column sprites which are not very bright.[4,5] Sprites are the most familiar type of transient luminous events (TLEs), which are short-lived gas breakdown phenomena that occur well above the altitudes of normal lightning and storm clouds, typically ~40–100 km. Sprites consist of many streamers, which are typically measure 60–200 m in horizontal length.[1]
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