CYCLIC MAGNETIC ACTIVITY DUE TO TURBULENT CONVECTION IN SPHERICAL WEDGE GEOMETRY

Journal Article · Fri Aug 10 00:00:00 EDT 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/755/1/L22· OSTI ID:22047607

Kaepylae, Petri J; Mantere, Maarit J ^[1]; Brandenburg, Axel ^[2]

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1. Physics Department, Gustaf Haellstroemin katu 2a, P.O. Box 64, FI-00014 University of Helsinki (Finland)
2. NORDITA, Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-10691 Stockholm (Sweden)

We report on simulations of turbulent, rotating, stratified, magnetohydrodynamic convection in spherical wedge geometry. An initially small-scale, random, weak-amplitude magnetic field is amplified by several orders of magnitude in the course of the simulation to form oscillatory large-scale fields in the saturated state of the dynamo. The differential rotation is solar-like (fast equator), but neither coherent meridional poleward circulation nor near-surface shear layer develop in these runs. In addition to a poleward branch of magnetic activity beyond 50 Degree-Sign latitude, we find for the first time a pronounced equatorward branch at around 20 Degree-Sign latitude, reminiscent of the solar cycle.

• OSTI ID: 22047607
• Journal Information: Astrophysical Journal Letters, Vol. 755, 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
ASTROPHYSICS
CONVECTION
LAYERS
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
RANDOMNESS
ROTATION
SHEAR
SOLAR CYCLE
SPHERICAL CONFIGURATION
SURFACES
TURBULENCE