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| Titel |
A Reexamination of Latitudinal Limits of Substorm-Produced Energetic Electron Precipitation |
| VerfasserIn |
Kathy Cresswell-Moorcock, Craig Rodger, Antti Kero, Andrew Collier, Mark Clilverd, Ingemar Häggström, Timo Pitkänen, Ian Whittaker |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250090323
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| Publikation (Nr.) |
 EGU/EGU2014-4551.pdf |
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| Zusammenfassung |
| The primary sources of energetic electron precipitation (EEP) which affect altitudes
30keV) are expected to be from the radiation belts, and during substorms. EEP
from the radiation belts should be restricted to locations between L=1.5-8, while substorm
produced EEP is expected to range from L=4-9.5 during quiet geomagnetic conditions.
Therefore, one would not expect any significant D-region impact due to electron precipitation
at geomagnetic latitudes beyond about L=10. In this study we report on large unexpectedly
high latitude D-region ionization enhancements, detected by an incoherent scatter radar at
L-16, which appear to be caused by electron precipitation from substorms. We go
on to reexamine the latitudinal limits of substorm produced EEP using data from
multiple low-Earth orbiting spacecraft, and demonstrate that the precipitation stretches
many hundreds of kilometers polewards of the previously suggested limits. We find
that a typical substorm will produce significant EEP over the IGRF L-shell range
L=4.6(±0.2)-14.5(±1.2), peaking at L=6-7. However, there is significant variability from
event to event; in contrast to the median case, the strongest 25% of substorms have
significant EEP in the range spaning L=4.1(±0.1)-20.7(±2.2), while the weakest 25%
of substorms have significant EEP in the range spaning L=5.5(±0.1)-10.1(±0.7). |
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