ON THE CAUSE OF SOLAR-LIKE EQUATORWARD MIGRATION IN GLOBAL CONVECTIVE DYNAMO SIMULATIONS

Journal Article · Thu Nov 20 00:00:00 EST 2014 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/796/1/L12· OSTI ID:22364509

Warnecke, Jörn ^[1]; Käpylä, Petri J.; Käpylä, Maarit J. ^[2]; Brandenburg, Axel ^[3]

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1. Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany)
2. ReSoLVE Centre of Excellence, Department of Information and Computer Science, Aalto University, P.O. Box 15400, FI-00 076 Aalto (Finland)
3. NORDITA, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-10691 Stockholm (Sweden)

We present results from four convectively driven stellar dynamo simulations in spherical wedge geometry. All of these simulations produce cyclic and migrating mean magnetic fields. Through detailed comparisons, we show that the migration direction can be explained by an αΩ dynamo wave following the Parker-Yoshimura rule. We conclude that the equatorward migration in this and previous work is due to a positive (negative) α effect in the northern (southern) hemisphere and a negative radial gradient of Ω outside the inner tangent cylinder of these models. This idea is supported by a strong correlation between negative radial shear and toroidal field strength in the region of equatorward propagation.

• OSTI ID: 22364509
• Journal Information: Astrophysical Journal Letters, Vol. 796, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COMPARATIVE EVALUATIONS
CONVECTION
CORRELATIONS
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
ROTATION
SHEAR
SOUTHERN HEMISPHERE
SPHERICAL CONFIGURATION
STAR MODELS
STARS
STELLAR ATMOSPHERES
SUN
TURBULENCE