 |
| Titel |
Thermospheric mass density variations during geomagnetic storms and a prediction model based on the merging electric field |
| VerfasserIn |
R. Liu, H. Lühr, E. Doornbos, S.-Y. Ma |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 28, no. 9 ; Nr. 28, no. 9 (2010-09-03), S.1633-1645 |
| Datensatznummer |
250016877
|
| Publikation (Nr.) |
 copernicus.org/angeo-28-1633-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| With the help of four years (2002–2005) of CHAMP accelerometer data we have
investigated the dependence of low and mid latitude thermospheric density on
the merging electric field, Em, during major magnetic storms. Altogether
30 intensive storm events (Dstmin<−100 nT) are chosen for a statistical
study. In order to achieve a good correlation Em is preconditioned.
Contrary to general opinion, Em has to be applied without saturation
effect in order to obtain good results for magnetic storms of all activity
levels. The memory effect of the thermosphere is accounted for by a weighted
integration of Em over the past 3 h. In addition, a lag time of the
mass density response to solar wind input of 0 to 4.5 h depending on latitude
and local time is considered. A linear model using the preconditioned
Em as main controlling parameter for predicting mass density
changes during magnetic storms is developed: ρ=0.5 Em +
ρamb, where ρamb is based on the mean density during the quiet
day before the storm. We show that this simple relation predicts all
storm-induced mass density variations at CHAMP altitude fairly well
especially if orbital averages are considered. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|