Interplanetary magnetic field properties and variability near Mercury's orbit

James, M. K., Imber, S. M., Bunce, E. J., Yeoman, T. K., Lockwood, M. ORCID: https://orcid.org/0000-0002-7397-2172, Owens, M. J. ORCID: https://orcid.org/0000-0003-2061-2453 and Slavin, J. A. (2017) Interplanetary magnetic field properties and variability near Mercury's orbit. Journal of Geophysical Research: Space Physics, 122 (8). pp. 7907-7924. ISSN 21699380 doi: 10.1002/2017JA024435

Abstract/Summary

The first extensive study of interplanetary magnetic field (IMF) characteristics and stability at Mercury is undertaken using MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) magnetometer data. Variations in IMF and solar wind conditions have a direct and rapid effect upon Mercury's highly dynamic magnetosphere; hence, understanding of the time scales over which these variations occur is crucial because they determine the duration of magnetospheric states. We characterize typical distributions of IMF field strength, clock angle, and cone angle throughout the duration of MESSENGER's mission. Clock and cone angle distributions collected during the first Earth year of the mission indicate that there was a significant north-south asymmetry in the location of the heliospheric current sheet during this period. The stability of IMF magnitude, clock angle, cone angle, and IMF Bz polarity is quantified for the entire mission. Changes in IMF Bz polarity and magnitude are found to be less likely for higher initial field magnitudes. Stability in IMF conditions is also found to be higher at aphelion (heliocentric distance r ∼ 0.31 AU) than at perihelion (r ∼ 0.47 AU).

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/72499
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	American Geophysical Union
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