Role of longitudinal activity complexes for solar and stellar dynamos
arXiv:1211.2990 · doi:10.1017/S1743921313002457
Abstract
In this paper we first discuss observational evidence of longitudinal concentrations of magnetic activity in the Sun and rapidly rotating late-type stars with outer convective envelopes. Scenarios arising from the idea of rotationally influenced anisotropic convective turbulence being the key physical process generating these structures are then presented and discussed - such effects include the turbulent dynamo mechanism, negative effective magnetic pressure instability (NEMPI) and hydrodynamical vortex instability. Finally, we discuss non-axisymmetric stellar mean-field dynamo models, the results obtained with them, and compare those with the observational information gathered up so far. We also present results from a pure alpha-squared mean-field dynamo model, which show that time-dependent behavior of the dynamo solutions can occur both in the form of an azimuthal dynamo wave and/or oscillatory behavior related to the alternating energy levels of the active longitudes.
12 pages, 6 figures, to appear in the IAUS 294 proceedings
References in corpus (10)
- Magnetic Cycles in a Convective Dynamo Simulation of a Young Solar-type Star
- Penumbral structure and outflows in simulated sunspots
- Cyclic magnetic activity due to turbulent convection in spherical wedge geometry
- Rapidly Rotating Suns and Active Nests of Convection
- On the Formation of Active Regions
- Magnetic fluctuations and formation of large-scale inhomogeneous magnetic structures in a turbulent convection
- Fermi LAT study of cosmic-rays and the interstellar medium in nearby molecular clouds
- Magnetic field topology of the RS CVn star II Pegasi
- Flip-flops of FK Comae Berenices
- Kinematic frames and "active longitudes": does the Sun have a face?