English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Theoretical models for the solar dynamo range from simple low-dimensional``toy models'' to complex 3D-MHD simulations. Here we mainly discussappproaches that are motivated and guided by solar (and stellar) observations.We give a brief overview of the evolution of solar dynamo models since 1950s,focussing upon the development of the Babcock-Leighton approach between itsintroduction in the 1960s and its revival in the 1990s after being longovershadowed by mean-field turbulent dynamo theory. We summarize observationsand simple theoretical deliberations that demonstrate the crucial role of thesurface fields in the dynamo process and and give quantitative analyses of thegeneration and loss of toroidal flux in the convection zone as well as of theproduction of poloidal field resulting from flux emergence at the surface.Furthermore, we discuss possible nonlinearities in the dynamo process suggestedby observational results and present models for the long-term variability ofsolar activity motivated by observations of magnetically active stars and theinherent randomness of the dynamo process.

Observationally guided models for the solar dynamo and the role of the surface field