Role of longitudinal activity complexes for solar and stellar dynamos
2012 (English)In: Proc. Int. Astron. Union, 2012, no S294, 175-186 p.Conference paper (Refereed)
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 α2 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.
Place, publisher, year, edition, pages
2012. no S294, 175-186 p.
, Proceedings of the International Astronomical Union, ISSN 1743-9213 ; 8
MHD, Stars: magnetic fields, Sun: magnetic fields, turbulence
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:kth:diva-128630DOI: 10.1017/S1743921313002457ScopusID: 2-s2.0-84880515495ISBN: 9781107033832OAI: oai:DiVA.org:kth-128630DiVA: diva2:653143
Symposium International Astronomical Union 2012
QC 201310032013-10-032013-09-162013-10-03Bibliographically approved