177 citations · 2.4k across the 68 of their papers we have counts for
3 papers · 1 filter
Magnetic flux concentrations from turbulent stratified convection
P. J. Käpylä, A. Brandenburg, N. Kleeorin +2
(abridged) Context: The mechanisms that cause the formation of sunspots are still unclear. Aims: We study the self-organisation of initially uniform sub-equipartition magnetic fiel…
Multiple dynamo modes as a mechanism for long-term solar activity variations
Maarit J. Käpylä, Petri J. Käpylä, Nigul Olspert +4
Solar magnetic activity shows both smooth secular changes, such as the Grand Modern Maximum, and quite abrupt drops that are denoted as Grand Minima. Direct numerical simulations (…
Influence of a coronal envelope as a free boundary to global convective dynamo simulations
Jörn Warnecke, Petri J. Käpylä, Maarit J. Käpylä +1
We explore the effects of an outer stably stratified coronal envelope on rotating turbulent convection, differential rotation, and large-scale dynamo action in spherical wedge mode…