Book contents
- Frontmatter
- Dedication
- Contents
- Preface
- 1 General Principles
- 2 Waves in a Uniform Medium
- 3 Magnetically Structured Atmospheres
- 4 Surface Waves
- 5 Magnetic Slabs
- 6 Magnetic Flux Tubes
- 7 The Twisted Magnetic Flux Tube
- 8 Connection Formulas
- 9 Gravitational Effects
- 10 Thin Flux Tubes: The Sausage Mode
- 11 Thin Flux Tubes: The Kink Mode
- 12 Damping
- 13 Nonlinear Aspects
- 14 Solar Applications of MHD Wave Theory
- References
- Index
10 - Thin Flux Tubes: The Sausage Mode
Published online by Cambridge University Press: 15 July 2019
- Frontmatter
- Dedication
- Contents
- Preface
- 1 General Principles
- 2 Waves in a Uniform Medium
- 3 Magnetically Structured Atmospheres
- 4 Surface Waves
- 5 Magnetic Slabs
- 6 Magnetic Flux Tubes
- 7 The Twisted Magnetic Flux Tube
- 8 Connection Formulas
- 9 Gravitational Effects
- 10 Thin Flux Tubes: The Sausage Mode
- 11 Thin Flux Tubes: The Kink Mode
- 12 Damping
- 13 Nonlinear Aspects
- 14 Solar Applications of MHD Wave Theory
- References
- Index
Summary
The thin tube theory for a sausage wave is developed from first principles and shown to lead to the Klein-Gordon equation. The equations that hold when gravity is negligible are explored and the dispersion relation obtained and compared with earlier results. The effects of stratification are explored in detail, with contributing terms to the cutoff frequency explored for various cases ranging from a rigid and straight tube to a diverging elastic tube of the shape expected for a thin flux tube. The cutoff frequency is illustrated for a range of conditions likely to arise in the solar atmosphere. The role of cutoff for coronal loops is explored.
- Type
- Chapter
- Information
- MHD Waves in the Solar Atmosphere , pp. 281 - 310Publisher: Cambridge University PressPrint publication year: 2019