Plasma streams in the Hermean dayside magnetosphere: Solar wind injection through the reconnection region. (March 2016)

• Record Type: Journal Article
• Authors: Varela, J.; Pantellini, F.; Moncuquet, M.
• Is Part Of: Planetary and space science. Volume 122(2016)
• Page Start: 46
• Page End: 52
• Publication Date: 2016-03
• Subjects: Plasma physics -- Solar wind -- Hermean magnetosphere; Space sciences -- Periodicals; Atmosphere, Upper -- Periodicals; Sciences spatiales -- Périodiques; Haute atmosphère -- Périodiques; 523
• DOI: 10.1016/j.pss.2016.01.008
• Languages: English
• ISSNs: 0032-0633

Abstract

Abstract: The aim of this research is to simulate the interaction of the solar wind with the magnetic field of Mercury and to study the particle fluxes between the magnetosheath and the planet surface. We simulate the magnetosphere structure using the open source MHD code PLUTO in spherical geometry with a multipolar expansion of the Hermean magnetic field (Anderson et al., 2010 ). We perform two simulations with realistic solar wind parameters to study the properties of a plasma stream originated in the reconnection region between the interplanetary and the Hermean magnetic field. The plasma precipitates along the open magnetic field lines to the planet surface showing a fast expansion, rarefaction and cooling. The plasma stream is correlated with a flattening of the magnetic field observed by MESSENGER due to the adjacency of the reconnection region where the solar wind is injected into the inner magnetosphere. Highlights: The simulations show a plasma stream that links the Hermean magnetosheath with the planet surface at both Hemispheres. The plasma stream is originated in the reconnection region between the interplanetary and the Hermean magnetic fields. The plasma streams are strongly affected by the location of the reconnection regions and by the asymmetries of the Hermean magnetosphere. The plasma streams are correlated with the regions of the strongest inflows, mass deposition and particle sputtering on the planet surface. The results are compatible with the observations of protons precipitation from the magnetosheath along the Hermean cusp.