The Structure and Dissipation of Forced Current Sheets in the Solar Atmosphere
Abstract
The equilibrium structure and magnetic-reconnection (MR) processes in current sheets produced by global MHD forces are investigated theoretically, considering the case (complementary to that studied by Parker, 1979 and 1983) where the magnetic field near the sheet lies on good flux surfaces, with substantial accumulation of magnetic stress. The derivation and application of the model, based on the approximate MHD equations developed by Strauss (1976) for tokamak plasmas, are presented in detail. Three main stages of MR are characterized: a linear sheet-tearing mode which grows more rapidly than the magnetic-tearing mode for diffuse profiles, acceleration of MR by small shear-flow-driven MHD fluctuations acting as an anomalous resistivity, and rapid MR in a broad turbulent layer. This mechanism is shown to provide the rapid current dissipation required by some models of solar flares and coronal heating.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1987
- DOI:
- 10.1086/165340
- Bibcode:
- 1987ApJ...317..900C
- Keywords:
-
- Current Sheets;
- Energy Dissipation;
- Magnetohydrodynamics;
- Solar Atmosphere;
- Solar Corona;
- Solar Flares;
- Flow Stability;
- Magnetic Field Reconnection;
- Shear Flow;
- Solar Physics;
- HYDROMAGNETICS;
- SUN: ATMOSPHERE;
- SUN: CORONA;
- SUN: FLARES