|
Titel |
Low altitude energetic electron lifetimes after enhanced magnetic activity as deduced from SAC-C and DEMETER data |
VerfasserIn |
S. Benck, L. Mazzino, M. Cyamukungu, J. Cabrera, V. Pierrard |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
0992-7689
|
Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 28, no. 3 ; Nr. 28, no. 3 (2010-03-22), S.849-859 |
Datensatznummer |
250016808
|
Publikation (Nr.) |
copernicus.org/angeo-28-849-2010.pdf |
|
|
|
Zusammenfassung |
When flux enhancements of energetic electrons are produced as a consequence
of geomagnetic storm occurrence, they tend to vanish gradually when the
magnetic activity calms down and the fluxes decay to quiet-time levels. We
use SAC-C and DEMETER low altitude observations to estimate the energetic
electron lifetimes (E=0.16–1.4 MeV, L=1.6–5, B=0.22–0.46 G) and compare the
decay rates to those observed at high altitude. While crossing the radiation
belts at high latitude, the SAC-C and DEMETER instruments sample particles
with small equatorial pitch angles (αeq<18° for L>2.5)
whereas the comparison is done with other satellite data measured mainly in
the equatorial plane (for αeq>75°). While in the inner
belt and in the slot region no significant lifetime differences are observed
from the data sets with different αeq, in the outer belt, for
the least energetic electrons (<500 keV), the lifetimes are up to ~3
times larger for the electrons with the equatorial pitch-angle close to the
loss cone than for those mirroring near the equator. The difference
decreases with increasing energy and vanishes for energies of about 1 MeV. |
|
|
Teil von |
|
|
|
|
|
|