On Alfvén waves in the solar breeze
| Autor: | N. L. Isaeva, L. M. B. C. Campos |
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| Rok vydání: | 2003 |
| Předmět: | |
| Zdroj: | Physics of Plasmas. 10:2486-2500 |
| ISSN: | 1089-7674 1070-664X |
| DOI: | 10.1063/1.1565336 |
| Popis: | The application to the solar wind motivates the consideration of Alfven waves in a radial background magnetic field and radial mean flow, in two cases, viz., with velocity and magnetic field perturbations along parallels, or also with perturbations along meridians, combined in the radial components of vorticity and electric current. In both cases the same second-order Alfven wave equation is obtained; it has, in general, two singularities. If the mean flow velocity is taken to be a power of radial distance, with exponent other than zero or unity, there is a transition layer. In general there is a second singularity, viz., a critical layer, where the Alfven speed equals the mean flow velocity. There is one exceptional case in which the critical layer does not exist, namely a homogeneous medium, for which the mean flow velocity decays on the inverse square of the radial distance, and then Alfven speed also decays in the same way, so that their ratio is a constant, leading to two possibilities: (i) the ratio... |
| Databáze: | OpenAIRE |
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