Nnadih, OKosch, MMlynarczyk, J2022-07-202022-07-202021Nnadih, Ogechukwu & Kosch, Mike & Mlynarczyk, Janusz. (2021). Estimating the electron energy and the strength of the electric field within sprites using ground-based optical data observed over South African storms. Journal of Atmospheric and Solar-Terrestrial Physics. 225. 105760. 10.1016/j.jastp.2021.105760.1364-682610.1016/j.jastp.2021.105760http://hdl.handle.net/10566/7619We present a new simplified method to estimate the characteristic electron energy and electric field within a mesospheric transient luminous event using ground-based calibrated and filtered optical data. We assume non-relativistic motion, a Maxwell-Boltzmann distribution, a model of the electron-neutral collision frequency, elastic electron collisions, that the collisional excitation cross-section can be assigned to a single value, and that each electron-neutral collision produces one photon on average. Example observations of carrot sprites over South Africa give estimated electron energy of 4.6–4.9 ± 0.03 eV, which compares favourably with previous similar results using more sophisticated methods. Ideally, two wavelengths should be observed simultaneously but we show a good estimate is possible with only the bright N2(1 PG) red emission.enLightning dischargesSprites electron energyMesosphereThunderstormsSolar-TerrestrialAtmospheric PhysicsArticle