Abstract. Much work has been done on Corotating Interaction Regions (CIRs), see e.g. Balogh et al. (1999). Apart from the actual impact of CIRs on the solar wind plasma environment, the influence of CIRs on energetic particle populations has been of special interest. In this paper we study the influence of a CIR on the propagation of Jovian electrons to a spacecraft located at 1 AU. Recent modelling in this field has been concentrated on the local influence of CIRs on the electron flux at distances greater than 1 AU. This is due to the fact that modelling on larger spatial scales thus reaching closer to the Sun requires a 3D numerical model which also includes an energy and time dependence of the intensities. With our recently developed numerical model we were able to fulfil these requirements. We show the results of the calculated influence of CIRs on the Jovian and Galactic electron intensity at 1 AU, compared to data taken by the IMP 8 spacecraft, and discuss the implications for the CIR effects on the transport of energetic electrons.Key words. cosmic rays -turbulence -shock waves -convection -diffusion -methods: numerical
MotivationThe research concerned with the influence of Corotating Interaction Regions (CIRs) on the continuous flux of energetic electrons, i.e. of Jovian and Galactic origin can formally be split into two fields. First, very interesting results can be obtained by a direct analysis of the data recorded by various spacecraft. Since, usually, only the data recorded on one spacecraft is available, such analysis is confined to the space regions close to the spacecraft. For an analysis of a non-local effect of CIRs one has to apply models to take into account the transport of the particles. These models constitute the second of these fields. According to the region of interest, models considering the transport of Jovian electrons are applicable to different spatial regions. For example the analytical model by Chenette et al. (1974) is only applicable in the vicinity of the Jovian source.In contrast, considering the huge database provided by many spacecraft at 1 AU as well as in the outer heliospheree.g. the IMP 8 probe recorded data throughout more than two solar cycles without major data gaps -a model for the influence of CIRs on large-scale electron transport would be desirable. For this, one needs to solve the Parker equation (Parker 1965) considering three spatial dimensions:Here f (r, P, t) is the electron distribution function depending on rigidity P (this is defined as P = pc |q| with p the momentum, c the speed of light and q the charge of the particle. This is for Send offprint requests to: R. Kissmann, e-mail: rk@tp4.rub.de electrons with energies above 6 MeV, as under consideration here, nearly equivalent to the energy of the particle), position r and time t. Additionally, u represents the solar wind velocity,κ is the diffusion tensor and Q represents any sources. Now, the first term on the right-hand side represents the diffusion of the particles, followed by the term representing c...