Gravitational damping of Alfven waves in stellar atmospheres and winds

Details Gravitational damping of Alfven waves in stellar atmospheres and winds Gravitational damping of Alfven waves in stellar atmospheres and winds

Aug 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994apj...430..814k&link_type=abstract

The Astrophysical Journal, vol. 430, no. 2, pt. 1, p. 814-823

Astronomy and Astrophysics

Astrophysics

23

Energy Dissipation, Gravitational Effects, Magnetohydrodynamic Waves, Stellar Atmospheres, Stellar Coronas, Stellar Mass Ejection, Stellar Winds, Wave Propagation, Astronomical Models, Astrophysics, Ion Temperature, Plasma Heating, Stellar Gravitation, Wave Attenuation

Scientific paper

We consider how gravity affects the propagation of Alfven waves in a stellar atmosphere. We show that when the ion gyrofrequency exceeds the collision rate, the waves are absorbed at a rate proportional to the gravitational acceleration g. Estimates show that this mechanism can readily account for the observed energy losses in the solar chromosphere. The mechanism predicts that the pressure at the top of the chromosphere PTc should scale with g as PTc proportional to gdelta, where delta approximately equals 2/3; this is close to empirical results which suggest delta approximately equals 0.6. Gravitational damping leads to deposition of energy at a rate proportional to the mass of the particles. Hence, heavier ion are heated more effectively than protons. This is consistent with the observed proportionality between ion temperature and mass in the solar wind. Gravitational damping causes the local g to be effectively decreased by an amount proportional to the wave energy. This feature affects the acceleration of the solar wind. Gravitational damping may also lead to self-regulation of the damping of Alfven waves in stellar winds: this is relevant in the context of slow massive winds in cool giants.

Affiliated with

Also associated with

No associations

Rating

Gravitational damping of Alfven waves in stellar atmospheres and winds does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Gravitational damping of Alfven waves in stellar atmospheres and winds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gravitational damping of Alfven waves in stellar atmospheres and winds will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1494266