Angular momentum transport and dynamo-effect in stratified, weakly magnetic disks

Details Angular momentum transport and dynamo-effect in stratified, weakly magnetic disks Angular momentum transport and dynamo-effect in stratified, weakly magnetic disks

Apr 2000

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000a%26a...356.1141z&link_type=abstract

Astronomy and Astrophysics, v.356, p.1141-1148 (2000)

Astronomy and Astrophysics

Astrophysics

32

Magnetohydrodynamics (Mhd), Instabilities, Turbulence, Magnetic Fields

Scientific paper

The magnetic shear instability is reviewed numerically in the local box approximation for a Kepler disk. Special emphasis is laid on the relation between the viscosity-alpha and dynamo-alpha in case a mean magnetic field is generated. Self-sustaining `turbulence' is initiated by the instability which acts simultaneously as dynamo and efficient outward transporter for angular momentum. The Shakura-Sunyaev parameter alpha_SS is estimated to ~ 1.5* 10-2 for an adiabatic disk model, and the contribution from the Maxwell stress dominates over that of the Reynolds stress by a factor of 4. In case of stress-free, normal-vec {B} vertical boundary conditions, a non-zero mean magnetic field mainly oriented in azimuthal direction is generated. This mean field turns out time-dependent in a quasi-periodic manner. Box resonance oscillations in the horizontal velocities for a limited time lead to an enhanced, violently fluctuating Reynolds stress associated with a reduced magnetic activity. The resulting (dynamo-) alpha -effect is negative in the upper disk plane and positive in the lower disk plane, it is small and highly noisy.

Affiliated with

Also associated with

No associations

Rating

Angular momentum transport and dynamo-effect in stratified, weakly magnetic disks 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 Angular momentum transport and dynamo-effect in stratified, weakly magnetic disks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Angular momentum transport and dynamo-effect in stratified, weakly magnetic disks will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-748161