The Modulation of Solar Wind Hydrogen Deposition in the Martian Ionosphere by Foreshock Phenomena
Abstract
The Hydrogen in Mars' atmosphere extends far out into space. This Hydrogen can interact with particles emitted by and flowing away from the Sun (known as "solar wind protons"), to produce what are known as "energetic neutral atoms", or ENAs. At Mars, ENAs are essentially just Hydrogen atoms, produced far ahead and in front of the planet, that will barrel into the dayside Martian atmosphere. During "normal" conditions at Mars, space in front of the planet is relatively calm, and these ENAs are produced at a constant rate there; they subsequently stream into the dayside atmosphere in a steady fashion. There are times, however, when space in front of Mars is highly disturbed. During such times, ENAs are produced at highly variable rates, meaning that they stream into the dayside atmosphere in a stop-start fashion. Although the total number of ENAs that stream into the atmosphere is small compared to the total number of atoms already present there, these ENAs can still deposit energy into the atmosphere and are an important indicator of whether space in front of Mars is calm or disturbed.
- Publication:
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EPSC-DPS Joint Meeting 2019
- Pub Date:
- September 2019
- Bibcode:
- 2019EPSC...13..150F