Illustration of Cowling channel coupling to the shear Alfven wave
| Autor: | Heikki Vanhamäki, Akimasa Yoshikawa, Ryoichi Fujii, Olaf Amm |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Physics
010504 meteorology & atmospheric sciences Geophysics Conductivity Polarization (waves) 7. Clean energy 01 natural sciences Alfvén wave Space and Planetary Science Ionospheric convection Quantum electrodynamics Electric field 0103 physical sciences Perpendicular Cowling 010303 astronomy & astrophysics 0105 earth and related environmental sciences Channel coupling |
| Zdroj: | Journal of Geophysical Research: Space Physics. 118:6405-6415 |
| ISSN: | 2169-9380 |
| DOI: | 10.1002/jgra.50513 |
| Popis: | [1] Decomposition of horizontally extended current system into components in the polarization processes and extraction of Cowling channel defined in the companion paper embedded in the total current system are numerically demonstrated. We successfully visualize the background and polarization components in the magnetosphere-ionosphere coupling process by using the proposed theoretical framework. As a fundamental response, the polarization charge produced by the Pedersen current divergence has a role to cancel and intensify the ambient background electric field inside and outside the high-conductivity band, respectively. In contrast, the polarization charge produced by the Hall current divergence has a role to rotate the electric field from the background electric field, which causes a meandering of ionospheric convection flow along the boundary of a high-conductivity band. The Hall and Pedersen currents are always perpendicular to each other. They never close each other when conductances are homogeneous, but they can do that at the conductivity gradient region. This is the reason why a Hall polarization charge is induced and a resultant Cowling channel is formed. |
| Databáze: | OpenAIRE |
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