Solar type I noise storms and newly emerging magnetic flux
Abstract
A new model of solar type I radio bursts is presented based on the assumption that newly emerging magnetic flux can become, on occasion, weakly super-Alfvenic and thus capable of driving weak collisionless shocks in the front of the flux as it emerges. Using the assumption that the collisionless shock is maintained near marginal stability with respect to various collisionless flute like instabilities, we compute the microturbulence level of lower hybrid waves excited by the shock. It is then argued that these obliquely propagating lower hybrid waves are capable of accelerating electrons in the wake of the weak shock. These accelerated electrons are then utilized to excite upper hybrid waves via a loss-cone instability. The resulting mode coupling between lower hybrid and upper hybrid waves is then suggested as a radiation mechanism for the type I bursts.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- January 1982
- Bibcode:
- 1982A&A...105..221S
- Keywords:
-
- Magnetic Flux;
- Noise Storms;
- Shock Wave Propagation;
- Solar Magnetic Field;
- Solar Radio Bursts;
- Stellar Models;
- Collisionless Plasmas;
- Electron Acceleration;
- Free Energy;
- Magnetic Field Configurations;
- Magnetohydrodynamic Stability;
- Magnetohydrodynamic Waves;
- Propagation Modes;
- Stochastic Processes;
- Solar Physics