Electron Precipitation and Joule Heating in the Auroral Ionosphere: Measurements from the Dissipation Sounding Rocket

Electron precipitation into the upper atmosphere provides an energy source to the high-latitude thermosphere-ionosphere system. By ionizing neutral particles, energetic electron precipitation also increases the conductivity of the ionosphere, thereby increasing the Joule heating rate. To study the effect on the neutral atmosphere from Joule heating and other energy inputs, the Dissipation sounding rocket mission was launched on November 8th, 2023 from Poker Flat, Alaska into an active aurora. An electrostatic analyzer (ESA) was included in the instrument suite to measure the electron distributions above and within the aurora at altitudes between 150 and 320 km. These measurements were used to calculate the downwards energy flux from the precipitating electrons and as an input into the GLobal airglOW (GLOW) model, an electron transport model. The Pedersen conductivity profile output from the GLOW model is combined with the in situ electric field measurements to estimate the vertical profile of the Joule heating rate. The energy input into the thermosphere-ionosphere system from precipitating energetic electrons and from Joule heating are compared and discussed, as well as the impact of neutral winds on the observed Joule heating rate, all within the context provided from ground-based observations.