Greifswald 2009 – scientific programme
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EP: Fachverband Extraterrestrische Physik
EP 9: Sun III and Heliophysics I
EP 9.9: Talk
Wednesday, April 1, 2009, 16:00–16:15, Zahnklinik
Perpendicular Transport in the Inner Heliosphere — •Florian Lampa and May-Britt Kallenrode — University of Osnabrueck, Department of Physics, Barbarastraße 7, 49076 Osnabrueck, Germany
In previous studies, transport of solar energetic particles in the inner heliosphere has been regarded as one dimensional along the archimedian field spiral; any perpendicular transport is neglected. We have extended Ruffolo’s equation of focused transport for solar energetic particles to accommodate perpendicular transport in the plane of ecliptic. Numerically, this additional term is solved with the implicit and stable Laasonen scheme. For typical ratios κ⊥/κ|| between 0.02 and 0.1 at 1 AU as suggested in non linear guiding center theory and a scaling of κ⊥ with r2 as suggested from the random walk of field lines we find that (a) azimuthal spread over some ten degrees occurs within a few hours, (b) the variation of maximum intensities with longitude is comparable to the ones inferred from multi-spacecraft observations, and (c) on a given field line intensity- and anisotropy-time profiles are modified such that fits with the 2D transport model give different combinations of injection profiles and mean free paths.
Implications for the interpretation of intensity and anisotropy time profiles observed in interplanetary space and consequences for our understanding of particle propagation and acceleration in space will be discussed. We will also address the question whether and how the modeling of flux dropouts and propagation channels is possible in the presence of perpendicular diffusion as the ultimate leveler.