 |
| Titel |
Substorm onset location and dipole tilt angle |
| VerfasserIn |
J. Wanliss |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 24, no. 2 ; Nr. 24, no. 2 (2006-03-23), S.577-588 |
| Datensatznummer |
250015496
|
| Publikation (Nr.) |
 copernicus.org/angeo-24-577-2006.pdf |
|
|
|
|
|
| Zusammenfassung |
| From an initial data set of over 200 substorms we have studied a subset of
30 magnetospheric substorms close to magnetic midnight to investigate, in a
statistical fashion, the source region of the auroral arc that brightens at
the onset of expansive phase. This arc is usually identified as the
ionospheric signature of the expansive phase onset that occurs in the
magnetotail. All the substorm onsets were identified via ground-based
magnetometer and photometer data from the CANOPUS array. Various Tsyganenko
global magnetic field models were used to map magnetic field lines from the
location of the onset arc out to its greatest radial distance in the
magnetotail. The results appear to favour the current disruption model of
substorms since the average onset location has an average of 14.1 Earth radii
(RE) and is therefore more consistent with theories that place the onset location
in the inner magnetotail. For the narrow range of tilts available our
modeling indicates the parameter that appears to strongly influence the
location of the substorm onset is the dipole tilt angle; as tilt becomes
less negative onsets occur further downtail. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|