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| Titel |
Modelling cosmic ray intensities along the Ulysses trajectory |
| VerfasserIn |
D. C. Ndiitwani, S. E. S. Ferreira, M. S. Potgieter, B. Heber |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 23, no. 3 ; Nr. 23, no. 3 (2005-03-30), S.1061-1070 |
| Datensatznummer |
250015201
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| Publikation (Nr.) |
 copernicus.org/angeo-23-1061-2005.pdf |
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| Zusammenfassung |
| Time dependent cosmic ray modulation in the inner heliosphere is studied by
comparing results from a 2-D, time-dependent cosmic ray transport
model with Ulysses observations. A compound approach, which combines the
effects of the global changes in the heliospheric magnetic field magnitude
with drifts to establish a realistic time-dependence, in the diffusion and
drift coefficients, are used. We show that this model results in realistic
cosmic ray modulation from the Ulysses launch (1990) until recently (2004) when
compared to 2.5-GV electron and proton and 1.2-GV electron and Helium
observations from this spacecraft. This approach is also applied to compute
radial gradients present in 2.5-GV cosmic ray electron and protons in the
inner heliosphere. The observed latitude dependence for both positive and
negative charged particles during both the fast latitude scan periods,
corresponding to different solar activity conditions, could also be
realistically computed. For this an additional reduction in particle drifts
(compared to diffusion) toward solar maximum is needed. This results in
a realistic charge-sign dependent modulation at solar maximum and the model is
also applied to predict charge-sign dependent modulation up to the next
expected solar minimum. |
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