We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Simulating the response of Mercury's neutral sodium exosphere to a X-class solar flare.
- Authors
Werner, Anita Linnéa Elisabeth; Leblanc, François; Chaufray, Jean-Yves; Modolo, Ronan
- Abstract
Mercury exhibits a tenuous and nearly collisionless surface-bounded exosphere, whichdemonstrates large variations over the span of a single orbit around the Sun. The sodiumcontent has been shown to be especially variable, with global asymmetries betweendawn/dusk and north/south. These are accompanied by more rapid changes on atime-scale of a few Earth hours. The weak magnetic field, tenuous atmosphere and closedistance from the Sun makes Mercury more susceptible to solar transients than otherterrestrial planets. For this reason, the short-term variations in the sodium emissionhave been linked to coronal mass ejections (CMEs) or even solar flares. In thisfirst work, we simulate the response of Mercury’s exosphere to a X-class solarflare.We will employ the Exospheric Global Model (EGM), a 3-D parallelized Monte Carlo model,to simulate Mercury’s neutral sodium exosphere. In this model, a representative number oftest-particles (∼107) are followed as they move on ballistic (collisionless) trajectories insidethe exosphere. These particles can escape from the exosphere, stick to the surface or bere-ejected through one of three processes: thermal desorption, photo-stimulateddesorption and solar wind sputtering. With reference to solar flares, we expect amomentaneous increase in the solar photon flux. The release of neutral sodium from thesurface through photo-stimulated desorption (PSD) should follow this trend. Byintroducing a step increase in the photon flux we can mimic this effect and determine howquickly the system reacts to a typical variation of the solar flux induced by a X-classflare. From the minimum response time we can establish whether solar flares arecapable of inducing short-term changes in the exospheric sodium emission thatcould be observable from Earth, by MESSENGER or BepiColombo instruments.
- Subjects
SOLAR flares; CORONAL mass ejections; SODIUM compounds; SOLAR oscillations; MERCURY; SOLAR magnetic fields; PHOTON flux; SOLAR wind
- Publication
Geophysical Research Abstracts, 2019, Vol 21, p1
- ISSN
1029-7006
- Publication type
Article