Dynamics of the solar atmosphere: Spicules and fibrils
Numerical and analytical studies of MHD waves on magnetic flux tubes are applied to problems of the solar atmosphere. In particular, theoretical analysis of the chromospheric features known as spicules and fibrils are undertaken. The thesis consists of three principal segments: 1. A preexisting spicule model is extended and developed. In the model, a series of rebound shocks propagating on a vertical magnetic flux tube results in chromospheric material with spicule-like properties below a raised transition region. The model emphasize dynamic motions and shock heating, but excludes radiative and ionization losses. 2. An analytical study is performed using linearized MHD equations to demonstrate that spicules may act as resonance cavities for MHD Alfven waves propagating along a vertical magnetic flux tube. When the resonances are excited, large amounts of wave energy from the photosphere and lower chromosphere can propagate into the spicule. This may result in the observed heating, fading, and twisting motions of spicules. 3. The spicule model used in (1.) is applied to a magnetic field geometry that is vertical through the photosphere and chromosphere, turns horizontal in the low corona, and eventually turns vertical again and extends into the outer corona.
- Research Organization:
- New Hampshire Univ., Durham, NH (USA). Dept. of Chemistry
- OSTI ID:
- 5598029
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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