Quantifying the size and duration of a microburst-producing chorus region on 5 December 2017

Abstract

Many competing processes contribute to the dynamic formation and depletion of the Earth's radiation belts, including radial transport, local wave acceleration, particle loss to the magnetopause, particle precipitation into the atmosphere, and others (see review by Ripoll et al., 2020;Thorne, 2010). These competing mechanisms typically occur simultaneously and are energy dependent; understanding the importance of each is fundamental to radiation belt physics.Electron microbursts are impulsive (<1 s) injections of energetic (few keV to >MeV) electrons into the atmosphere that may represent a major loss source from the radiation belt during storm main phase and recovery (Millan & Thorne, 2007). Microburst electron precipitation was first observed in the 1960s by balloon measurements of bremsstrahlung X-rays produced by precipitating electrons as they enter Earth's atmosphere (K. A.