Observations of Transient Luminous Events from Greece

Abstract

Transient Luminous Events (TLEs) are rare electrical discharges occurring in the middle and upper atmosphere above thunderstorms. The results of systematic observations of TLEs in a region that includes Greece and its surrounding area during a 2-year period (September 2020–September 2022) are presented. This study provides a first insight about the frequency, the spatiotemporal distribution, and the variety of these events in that region. In total, 1632 TLEs were observed during these 2 years. Of these, 95.5% were red sprites. Most events occurred over the Ionian Sea, the southern Adriatic Sea, and western Greece. The most favorable period for TLEs in Greece and its surrounding area is from October to February. Noteworthy were two prolific nights, 15–16 October 2020 and 4–5 December 2021, over mesoscale convective systems at the Ionian Sea and the southeastern Aegean Sea, respectively, when hundreds of these events were observed. Observations of this kind are of great significance, not only because they are the first-ever conducted in the aforementioned region but also due to the fact that these events seem to exhibit a relatively high frequency of appearance there.

Keywords

• transient luminous events
• atmospheric electricity
• red sprites