 |
| Titel |
Statistical study of foreshock cavitons |
| VerfasserIn |
P. Kajdič, X. Blanco-Cano, N. Omidi, K. Meziane, C. T. Russell, J.-A. Sauvaud, I. Dandouras, B. Lavraud |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 31, no. 12 ; Nr. 31, no. 12 (2013-12-06), S.2163-2178 |
| Datensatznummer |
250086159
|
| Publikation (Nr.) |
 copernicus.org/angeo-31-2163-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| In this work we perform a statistical analysis of 92 foreshock cavitons
observed with the Cluster spacecraft 1 during the period 2001–2006. We
analyze time intervals during which the spacecraft was located in the Earth's
foreshock with durations longer than 10 min. Together these amount to
~ 50 days. The cavitons are transient structures in the Earth's
foreshock. Their main signatures in the data include simultaneous depletions
of the magnetic field intensity and plasma density, which are surrounded by a
rim of enhanced values of these two quantities. Cavitons form due to
nonlinear interaction of transverse and compressive ultra-low frequency (ULF)
waves and are therefore always surrounded by intense compressive ULF
fluctuations. They are carried by the solar wind towards the bow shock. This
work represents the first systematic study of a large sample of foreshock
cavitons. We find that cavitons appear for a wide range of solar wind and
interplanetary magnetic field conditions and are therefore a common feature
upstream of Earth's quasi-parallel bow shock with an average occurrence rate of
~ 2 events per day. We also discuss their observational properties in
the context of other known upstream phenomena and show that the cavitons are
a distinct structure in the foreshock. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|