Analysis of Sprite Activity in Middle Latitudes

Sprite activity in the middle latitudes of the Northern Hemisphere is analyzed, with the example of the territory of Russia, aiming to facilitate the planning of observational campaigns in the region. The global model previously proposed by the authors is applied, using data from the WWLLN lightning detection network for 2015–2021. It is shown that the total number of sprites per year varies widely, from 394 in 2019 to 2354 in 2015. The most intense sprite activity almost always occurs in July, but in some years, there may be a shift to June (2015) and August (2021). The highest frequency of sprite initiation is observed in the Krasnodar Territory, Altai, and the Far East. Altai shows a high intensity of sprite activity every year, which is caused by the relief and underlying surface, while Krasnodar Territory and the Far East demonstrate sprites developed by incoming convective systems, which leads to high year-to-year variability

Transient Luminous Events in the Lower Part of the Atmosphere Originated in the Peripheral Regions of a Thunderstorm

We present and discuss transient luminous events (TLEs) in the lower atmosphere, observed during large disturbances of the near-surface electric fields (NSEF) and coinciding with large enhancements of the particle fluxes (thunderstorm ground enhancements—TGEs). Despite large distances from the strongest electric field region, the maximum energy of TGE particles on 22 and 25 May 2018 reaches ≈40 MeV. Thus, the accelerating electric field reaches ≈2.0 keV/cm far from the zone of the strong lightning activity on the periphery of the storm. Light glows appearing simultaneously in the skies may be due to the local charge rearrangement generating a small illuminating discharge without initiating the lightning flash. This type of charge rearrangement does not lower the potential difference in the cloud, allowing the electron accelerator to operate and send particle fluxes in the direction of the earth’s surface

Transient Luminous Events in the Lower Part of the Atmosphere Originated in the Peripheral Regions of a Thunderstorm

We present and discuss transient luminous events (TLEs) in the lower atmosphere, observed during large disturbances of the near-surface electric fields (NSEF) and coinciding with large enhancements of the particle fluxes (thunderstorm ground enhancements—TGEs). Despite large distances from the strongest electric field region, the maximum energy of TGE particles on 22 and 25 May 2018 reaches ≈40 MeV. Thus, the accelerating electric field reaches ≈2.0 keV/cm far from the zone of the strong lightning activity on the periphery of the storm. Light glows appearing simultaneously in the skies may be due to the local charge rearrangement generating a small illuminating discharge without initiating the lightning flash. This type of charge rearrangement does not lower the potential difference in the cloud, allowing the electron accelerator to operate and send particle fluxes in the direction of the earth’s surface