Global Transients in ultraviolet and red-infrared ranges from data of the "Universitetsky-Tatiana-2" satellite

TL;DR

This study analyzes global transient luminous events detected in ultraviolet and red-infrared ranges from the Universitetsky-Tatiana-2 satellite, revealing their distribution, possible high-altitude origins, and potential long-distance influence of thunderstorms.

Contribution

It provides the first comprehensive global distribution data of transient luminous events in UV and IR ranges from satellite observations, highlighting their high-altitude origin and occurrence outside thunderstorm areas.

Findings

Events are uniformly distributed over latitudes and longitudes for lower photon counts.

High photon count events concentrate near the equator above continents.

Transients can occur thousands of kilometers away from thunderstorms, suggesting long-distance atmospheric influence.

Abstract

Detectors of fast flashes (duration of 1-128 ms) in near ultraviolet (240-400 nm) and red-infrared (>610 nm) ranges on board the "Universitetsky-Tatiana-2" satellite have measured transient luminous events global distribution. Events with number of photons 10^20-5{\cdot}10^21 radiated in the atmosphere are uniformly distributed over latitudes and longitudes. Events with number of photons more than 5{\cdot}10^21 are concentrated near the equator above continents. Measured ratio of photons number radiated in red-IR range to photons number radiated in UV related to excitation of nitrogen molecular indicates a high altitude (>50 km) of the atmospheric electric discharges responsible for the observed transients. Series of every minute transients (from 3 to 16 transients in the series) were observed. The detection of transients out of thunderstorm area, in cloudless region- sometimes thousands km away of thunderstorms is remarkable. The obtained data allow us to assume that transient events are not only consequences of lightning in event-by-event way but they are the result of "long distance" influence of thunderstorm electric activity causing breakdowns in the upper atmosphere (at altitudes >50 km).