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| Titel |
MESSENGER Observations of Magnetotail Dynamics at Mercury |
| VerfasserIn |
J. A. Slavin, S. M. Imber, G. A. DiBraccio, T. Sundberg, S. A. Boardsen, B. J. Anderson, H. Korth, D. N. Baker, R. L. McNutt, S. C. Solomon |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250061770
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| Zusammenfassung |
| MESSENGER magnetic field observations taken in Mercury’s magnetotail at distances of ~
2 to 4 RM (where RMis Mercury’s radius or 2440 km) frequently include tail loading and
unloading events, traveling compression regions (TCRs) in the lobes, and plasmoid ejection
in the plasma sheet. During these loading–unloading events, the magnitude of the lobe
magnetic field can increase and then decrease by up to a factor of ~2, as observed during
MESSENGER’s third flyby. The duration of these events is usually ~1–3 min, but in some
case they can last for as long as ~ 10 min. The transition from loading to unloading is often
marked by one or more TCRs signaling the onset of magnetic reconnection in the cross-tail
current sheet and the ejection of plasmoids. When MESSENGER crosses the plasma
sheet at ~ 3 RM downstream of Mercury during the orbital phase of the mission,
plasmoids are frequently present in the magnetic field measurements, especially when
the interplanetary magnetic field has been southward. These plasmoids can occur
singly, in groups of several events, or in quasi-periodic series with durations as
long at ~ 10 min and with individual plasmoids separated by ~ 5–10 s. These
phenomena at Mercury are qualitatively similar to dynamic events observed during
terrestrial magnetospheric substorms and continuous dissipation events, albeit on
time scales of seconds to minutes compared with tens of minutes to hours at Earth. |
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