On the origin of solar wind. Alfvén waves induced jump of coronal temperature |
| |
Authors: | T M Mishonov M V Stoev Y G Maneva |
| |
Institution: | (1) Department of Theoretical Physics, Faculty of Physics, University of Sofia St. Clement of Ohrid, 5 J. Bourchier Boulevard, 1164 Sofia, Bulgaria |
| |
Abstract: | Absorption of Alfvén waves is considered to be the main mechanism of
heating in the solar corona. It is concluded that the sharp increase
of the plasma temperature by two orders of magnitude is related to a
self-induced opacity with respect to Alfvén waves. The maximal
frequency for propagation of Alfvén waves is determined by the
strongly temperature dependent kinematic viscosity. In such a way
the temperature jump is due to absorption of high frequency Alfvén
waves in a narrow layer above the solar surface. It is calculated
the power per unit area dissipated in this layer due to damping of
Alfvén waves that blows up the plasma and gives birth to the
solar wind. A model short wave-length (WKB) evaluation takes into
account the 1/f2 frequency dependence of the transversal magnetic
field and velocity spectral densities. Such spectral densities agree
with old magnetometric data taken by Voyager 1 and recent
theoretical calculations in the framework of Langevin-Burgers MHD.
The presented theory predicts existence of intensive high frequency
MHD Alfvén waves in the cold layer beneath the corona. It is
briefly discussed how this statement can be checked experimentally.
It is demonstrated that the magnitude of the Alfvén waves
generating random noise and the solar wind velocity can be expressed
only in terms of satellite experimental data. It is advocated that
investigation of properties of the solar surface as a random driver by
optical methods is an important task for future solar physics. |
| |
Keywords: | 52 35 Bj Magnetohydrodynamic waves (e g Alfven waves) 52 50 Sw Plasma heating by microwaves ECR LH collisional heating 96 60 P- Corona 94 30 cq MHD waves plasma waves and instabilities |
本文献已被 SpringerLink 等数据库收录! |