Energetic particle dynamics in Mercury's magnetosphere. Issue 5 (13th May 2013)

• Record Type: Journal Article
• Authors: Walsh, B. M.; Ryou, A. S.; Sibeck, D. G.; Alexeev, I. I.
• Is Part Of: Journal of geophysical research. Volume 118:Issue 5(2013:May)
• Page Start: 1992
• Page End: 1999
• Publication Date: 2013-05-13
• Subjects: Mercury -- energetic particles; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1002/jgra.50266
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract : [1] We investigate the drift paths of energetic particles in Mercury's magnetosphere by tracing their motion through a model magnetic field. Test particle simulations solving the full Lorentz force show a quasi‐trapped energetic particle population that gradient and curvature drift around the planet via "Shabansky" orbits, passing though high latitudes in the compressed dayside by equatorial latitudes on the nightside. Due to their large gyroradii, energetic H + and Na + ions will typically collide with the planet or the magnetopause and will not be able to complete a full drift orbit. These simulations provide direct comparison for recent spacecraft measurements from MESSENGER . Mercury's offset dipole results in an asymmetric loss cone and therefore an asymmetry in particle precipitation with more particles precipitating in the southern hemisphere. Since the planet lacks an atmosphere, precipitating particles will collide directly with the surface of the planet. The incident charged particles can kick up neutrals from the surface and have implications for the formation of the exosphere and weathering of the surface. Key Points: Energetic electrons may be trapped on Mercury Mercury's offset dipole causes asymmetric particle precipitation