 |
| Titel |
A new view on drivers of magnetopause locations |
| VerfasserIn |
Zdenek Nemecek, Jana Safrankova, Ramon E. Lopez, Stefan Dusik, Libor Nouzak, Lubomir Prech, Jiri Simunek, Jih-Hong Shue |
| Konferenz |
EGU General Assembly 2016
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250123695
|
| Publikation (Nr.) |
 EGU/EGU2016-2991.pdf |
|
|
|
|
|
| Zusammenfassung |
| The magnetopause location is generally believed to be determined by the solar wind
dynamic pressure and by the sign and value of the interplanetary magnetic field
vertical (Bz) component. The contribution of other parameters is usually considered
to be minor or negligible near the equatorial plane. Recent papers have shown a
magnetopause expansion during intervals of a nearly radial IMF but our ability to predict
the magnetopause location under steady or slowly changing upstream conditions
remains rather weak even if the effect of the radial magnetic field is considered.
We present a statistical study based on more than 10.000 magnetopause crossings
identified in the THEMIS data in course of the last half of the solar cycle. The observed
magnetopause locations are compared with empirical magnetopause models and the
sources of differences between observations and model predictions are analyzed.
This analysis reveals that the magnetopause location depends on the solar activity
being more compressed during the solar maximum because a dependence on the
upstream dynamic pressure is stronger than usually expected. Furthermore, we
have found that, beside the solar wind dynamic pressure and vertical magnetic
field component, the solar wind speed and ionospheric conductivity (F10.7 index is
used as a proxy) are important physical quantities controlling this compression. |
|
|
|
|
|
|