Electron Energetics in the Martian Ionosphere: Model Comparisons with MAVEN Data
Tuesday, 15 December 2015
Poster Hall (Moscone South)
A large part of the solar extreme ultraviolet and soft X-ray radiation absorbed in planetary upper atmospheres appears as photoelectrons and some of the energy ends up heating thermal electrons and increasing the electron temperature. Photoelectrons are important for the heating related to plasma temperatures, ionization and airglow production in planetary atmospheres. Measured electron fluxes provide insight into sources and sinks of energy in the Martian upper atmosphere. Suprathermal electron fluxes measured by the SWEA (Solar Wind Electron Analyzer) instrument onboard the MAVEN (Mars Atmosphere and Volatile EvolutioN) are providing insight into sources and sinks of energy in the Martian upper atmosphere. A two-stream electron transport code was used to interpret these observations including Auger electrons associated with K-shell ionization of carbon, oxygen and nitrogen. External electron fluxes from the Martian magnetosheath or tail, are also included. Electron and ion temperatures are found from numerical solutions of the energy equations and comparisons are made with the electron temperature measured by the MAVEN Langmuir Probe (e.g., Ergun et al., 2015). The overall implications of the plasma energetics for the Martian ionosphere will be discussed.