Dynamics of the Cusp at Mercury's Magnetosphere

0477971 - ÚFA 2018 BE eng A - Abstract
Schriver, D. - Trávníček, Pavel M. - Hellinger, P. - Richard, R. L. - Perkins, D. - Raines, J.M.
Dynamics of the Cusp at Mercury's Magnetosphere.
Papers from URSI: XXXIInd General Assembly and Scientific Symposium (URSI GASS). Ghent: URSI, 2017. H37-3.
[URSI General Assembly and Scientific Symposium (URSI GASS) 2017 /32./. 19.08.2017-26.08.2017, Montreal]
Institutional support: RVO:68378289
Keywords : planetary magnetosphere * foreshock * bow shock * magnetosheath * thermalized plasma * MESSENGER spacecraft * Mercur
Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

When the solar wind with its interplanetary magnetic field (IMF) interacts with a planetary magnetosphere, a foreshock forms upstream of the bow shock, an upstream magnetosheath consisting of thermalized plasma is created between the bow shock and the magnetopause, and a funnel shaped magnetic cusp extending down to the planet forms at high northern and southern latitudes on the dayside. The foreshock location, thickness of the magnetosheath and location of the northern and southern cusps depends on the solar wind pressure, IMF orientation and properties of the planet’s internal magnetic field. Global kinetic simulations of the solar wind interaction with Mercury's intrinsic magnetic field have been carried out in close coordination with data from the MESSENGER spacecraft during its 4 year orbital mission to examine the formation and dynamics of the various dayside structures for different solar wind conditions. Unique aspects of Mercury’s magnetosphere include the intrinsic planetary magnetic dipole being shifted directly to the north by ~ 450 km (with no tilt), the lack of an atmosphere or ionosphere, and the presence of heavy ions (primarily sodium ions) of planetary origin that mass load the plasma. Ion and electron transport, acceleration and precipitation loss will be examined in the dayside and cusp regions in Mercury’s magnetosphere. Charged particle precipitation onto Mercury’s surface, which over long time periods can result in space weathering of the surface, will be calculated. In particular, precipitation of energetic plasma in the cusp can affect water ice deposits trapped in permanently shadowed craters at high northern latitudes, leading to a thin layer of darkened organic material covering the ice ( M. L. Delitsky, D. A. Paige, M. A. Siegler, E. R. Harju, D. Schriver, R. E. Johnson, and P. M. Travnicek, “Ices on Mercury: Chemistry of volatiles in permanently cold areas of Mercury’s north polar region”, Icarus, 281, January 2017, pp. 19-31).
Permanent Link: http://hdl.handle.net/11104/0274210