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| Titel |
Prediction of the Dst index with magnetic field observations in the inner
heliosphere |
| VerfasserIn |
Manuel Kubicka, Christian Möstl, Tanja Rollett, Peter Boakes, Li Feng, Jonathan Eastwood |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250127800
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| Publikation (Nr.) |
 EGU/EGU2016-7712.pdf |
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| Zusammenfassung |
| The prediction of the effects of interplanetary coronal mass ejections (ICMEs) on Earth
strongly depends on knowledge of the properties of the interplanetary magnetic field (IMF),
especially it’s southward component (Bz), acting as a main driver for geomagnetic
storms.
We are using data from a spacecraft located in the inner heliosphere, Venus Express
(VEX) at 0.72 AU and will provide a proof-of-concept for predicting an ICMEs arrival time
and speed at 1AU, the ICMEs Bz component at Earth and the resulting Dst index by only
using data measured by VEX.
To forecast the Dst index, the two well established Dst models from Burton et al. (1975)
and O’Brien & McPherron (2000) are used. In combination with a drag based model (Vršnak
et al. 2013) and the WSA/ENLIL model the ICMEs arrival speed at Earth is obtained.
Additionally, a power law (Leitner et al. 2007) is used to scale the magnetic field from 0.72 to
1 AU.
Investigation of an ICME in June 2012 shows already promising results for the
Dst index (predicted: -96 nT ± 17nT, observed: -86 nT), as well as for the arrival
speed (predicted: 531 km s−1± 23 kms−1, observed: 490 kms−1± 30 kms−1) and
timing (∼6h ± 1h late of true arrival) . An advantage of this method is the high
prediction lead time of ∼21 hours compared only ∼40-60 minutes, using an L1 located
spacecraft.
To further investigate the feasibility of this method, data from any spacecraft temporarily
located between Sun and Earth can be used. It is possible to extend this method to arbitrary
spacecraft alignments and also to apply it to data from Helios or future space missions like
Solar Orbiter and Solar Probe Plus. The techniques we develop could be routinely applied to
a mission that forms an artificial Lagrange point along the Sun-Earth line, e.g. for a
Sunjammer or Heliostorm mission. |
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