Solar wind forcing at Mercury: WSA-ENLIL model results
Article first published online: 31 JAN 2013
©2012. American Geophysical Union. All Rights Reserved.
Journal of Geophysical Research: Space Physics
Volume 118, Issue 1, pages 45–57, January 2013
How to Cite
2013), Solar wind forcing at Mercury: WSA-ENLIL model results, J. Geophys. Res. Space Physics, 118, 45–57, doi:10.1029/2012JA018064., et al. (
- Issue published online: 5 MAR 2013
- Article first published online: 31 JAN 2013
- Manuscript Accepted: 2 DEC 2012
- Manuscript Revised: 5 NOV 2012
- Manuscript Received: 27 JUN 2012
- Carnegie Institution of Washington. Grant Number: NASW-00002
- The Johns Hopkins University Applied Physics Laboratory. Grant Number: NAS5-97271
 Analysis and interpretation of observations from the MESSENGER spacecraft in orbit about Mercury require knowledge of solar wind “forcing” parameters. We have utilized the Wang-Sheeley-Arge (WSA)-ENLIL solar wind modeling tool in order to calculate the values of interplanetary magnetic field (IMF) strength (B), solar wind velocity (V) and density (n), ram pressure (~nV2), cross-magnetosphere electric field (V × B), Alfvén Mach number (MA), and other derived quantities of relevance for solar wind-magnetosphere interactions. We have compared upstream MESSENGER IMF and solar wind measurements to see how well the ENLIL model results compare. Such parameters as solar wind dynamic pressure are key for determining the Mercury magnetopause standoff distance, for example. We also use the relatively high-time-resolution B-field data from MESSENGER to estimate the strength of the product of the solar wind speed and southward IMF strength (Bs) at Mercury. This product VBs is the electric field that drives many magnetospheric dynamical processes and can be compared with the occurrence of energetic particle bursts within the Mercury magnetosphere. This quantity also serves as input to the global magnetohydrodynamic and kinetic magnetosphere models that are being used to explore magnetospheric and exospheric processes at Mercury. Moreover, this modeling can help assess near-real-time magnetospheric behavior for MESSENGER or other mission analysis and/or ground-based observational campaigns. We demonstrate that this solar wind forcing tool is a crucial step toward bringing heliospheric science expertise to bear on planetary exploration programs.