Siphon Flows in Isolated Magnetic Flux Tubes. III. The Equilibrium Path of the Flux-Tube Arch
Abstract
It is shown how to calculate the equilibrium path of a thin magnetic flux tube in a stratified, nonmagnetic atmosphere when the flux tube contains a steady siphon flow. The equilbrium path of a static thin flux tube in an infinite stratified atmosphere generally takes the form of a symmetric arch of finite width, with the flux tube becoming vertical at either end of the arch. A siphon flow within the flux tube increases the curvature of the arched equilibrium path in order that the net magnetic tension force can balance the inertial force of the flow, which tries to straighten the flux tube. Thus, a siphon flow reduces the width of the arched equilibrium path, with faster flows producing narrower arches. The effect of the siphon flow on the equilibrium path is generally greater for flux tubes of weaker magnetic field strength. Examples of the equilibrium are shown for both isothemal and adiabatic siphon flows in thin flux tubes in an isothermal external atmosphere.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 1990
- DOI:
- 10.1086/169086
- Bibcode:
- 1990ApJ...359..550T
- Keywords:
-
- Magnetic Flux;
- Solar Atmosphere;
- Solar Magnetic Field;
- Adiabatic Conditions;
- Differential Equations;
- Field Strength;
- Sunspots;
- Solar Physics;
- HYDROMAGNETICS;
- PLASMAS;
- SUN: ATMOSPHERIC MOTIONS;
- SUN: MAGNETIC FIELDS;
- SUN: SUNSPOTS