 |
| Titel |
Optical, radar, and magnetic observations of magnetosheath plasma capture during a positive IMF Bz impulse |
| VerfasserIn |
V. Safargaleev, A. Kozlovsky, T. Sergienko, T. K. Yeoman, M. Uspensky, D. M. Wright, H. Nilsson, T. Turunen, A. Kotikov |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 26, no. 3 ; Nr. 26, no. 3 (2008-03-26), S.517-531 |
| Datensatznummer |
250016041
|
| Publikation (Nr.) |
 copernicus.org/angeo-26-517-2008.pdf |
|
|
|
|
|
| Zusammenfassung |
| We present a multi-instrument study of the ionospheric response to a
northward turning of the IMF. The observations were made in the near-noon
(11:00 MLT) sector on Svalbard (at 75° MLAT). The data set includes auroral
observations, ionospheric flows obtained from the EISCAT and CUTLASS radars,
the spectral width of the HF radar backscatter, particle precipitation and
plasma flow data from the DMSP F13 satellite, and Pc1 frequency band
pulsations observed by induction magnetometers. Careful collocation of all
the observations has been made with the HF radar backscatter located by a
ray-tracing procedure utilizing the elevation angle of arrival of the
signals and an ionospheric plasma density profile. Prior to IMF turning
northward, three auroral arcs were observed at the poleward boundary of the
closed llbl, inside the llbl, and in the equatorward part of the llbl, respectively. The
northward IMF turning was accompanied by enhanced HF radar returns with a
broad Doppler spectrum collocated with the arcs. The auroral arcs shifted
poleward whereas the backscatter region moved in the opposite direction,
which is consistent, respectively, with reconnection beyond the cusp and the
capturing of magnetosheath plasma during northward IMF. Locally, magnetic
noise enhancement in the Pc1 frequency band occurred simultaneously with the
anomalous radar backscatter, and the absence of such signals at more remote
magnetic observatories indicates a local generation of the Pc1 turbulence,
which is collocated with the radar backscatter. Finally, we discuss possible
interpretation errors which may be caused by limited observational data. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|