Atmospheric Loss Exploration via Mechanisms of Energetic Mass Ejection
Abstract
Loss of atmospheric atoms from an Earth-sized planet requires an amount of energy per atom comparable to atomic ionization potentials (1-10 eV) and hence implies a plasma state, with all the electrodynamic implications thereof, including ambipolar potential. An atmosphere hot enough to escape from Earth must necessarily be in a plasma state. Classical photoionization processes clearly are not the full story in creation of that plasma, once hot auroral electrons come into play. And when new ions are produced in regions of strong plasma flow relative to neutrals from which the ions are created, interesting ion pickup plasma physics will ensue and play an important role in plasma heating to produce outflows. Established plasma diagnostic methods such as Langmuir probes, ion drift meters, and retarding potential analyzers, have not been able of observe the kinetic physics that heats and accelerates the bulk while creating transverse hot tails. Screening of parts of the VDF by spacecraft floating potentials has impeded our progress in understanding outflows. Experience from the MMS mission pointedly illustrates the need for full VDF observations at cadence high enough to resolve spatial structures. Methods for achieving this in the ionospheric context exist and will be described briefly.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFMSA42B..02M
- Keywords:
-
- 2427 Ionosphere/atmosphere interactions;
- IONOSPHERE;
- 2431 Ionosphere/magnetosphere interactions;
- IONOSPHERE;
- 2455 Particle precipitation;
- IONOSPHERE;
- 7807 Charged particle motion and acceleration;
- SPACE PLASMA PHYSICS