Chromospheric and coronal Alfvénic oscillations in non-vertical magnetic fields

✍ Scribed by Steven J. Schwartz; Paul S. Cally; Nicole Bel

• Publisher: Springer
• Year: 1984
• Tongue: English
• Weight: 790 KB
• Volume: 92
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00157237

✦ Synopsis

We generalize previous studies of Alfv6nic oscillations in the solar atmosphere to geometries in which the background magnetic field is not parallel to the gravitational acceleration. A uniform but inclined field produces only subtle changes in the mathematics, and virtually no changes to the coronal energy flux, over previous vertical field studies. We show that simple, two-layer rnodels agree remarkably well with more sophisticated, multi-layer calculations. In addition, we derive several useful and accurate analytic results with which we highlight many features and parameter dependences. We also study a model with a spreading field geometry. For low magnetic fields (~-10 G) the corona still appears WKB to the oscillations and we do not find any significant deviations from the uniform field calculations. This is not the case for higher magnetic fields in active regions (~-3000 G) where we confirm previous results which suggest an order of magnitude increase in the coronal flux.Again, we derive useful analytic approximations.