Publications: paper No 25

Solar wind and magnetospheric ion impact on Mercury's surface

Esa Kallio and Pekka Janhunen
Finnish Meteorological Institute, Helsinki, Finland

Geophys. Res. Letters., Vol 30, No 17, 1877, doi:10.1029/2003GL01742, 2003

abstract The impact of the solar wind protons on the surface of Mercury is studied by a global hybrid model. In the three-dimensional self-consistent quasi-neutral hybrid (ions are particles, electrons are a fluid) model ions can hit the surface of the planet. The response of the impact to several solar wind conditions is studied by analyzing four upstream cases: pure northward interplanetary magnetic field (IMF), pure southward IMF, the Parker spiral IMF, and atypically high solar wind speed. Three different high impact regions on the surface can be identified: (1) "auroral" impact on the equatorward side of the open/closed field line boundary, (2) "cusp" impact on the dayside in the noon midnight meridian plane, and (3) "nose" impact around the subsolar point when the solar wind dynamic pressure is high. The particle flux also has North-South and dawn-dusk asymmetries.

 Article (560 kB pdf file)