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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The relative importance of the helicity and cross-helicity electromotivedynamo effects for self-sustained magnetic field generation by chaotic thermalconvection in rotating spherical shells is investigated as a function of shellthickness. Two distinct branches of dynamo solutions are found to coexist indirect numerical simulations for shell aspect ratios between 0.25 and 0.6 - amean-field dipolar regime and a fluctuating dipolar regime. The propertiescharacterising the coexisting dynamo attractors are compared and contrasted,including differences in temporal behavior and spatial structures of both themagnetic field and rotating thermal convection. The helicity $\alpha$-effectand the cross-helicity $\gamma$-effect are found to be comparable in intensitywithin the fluctuating dipolar dynamo regime, where their ratio does not varysignificantly with the shell thickness. In contrast, within the mean-fielddipolar dynamo regime the helicity $\alpha$-effect dominates by approximatelytwo orders of magnitude and becomes stronger with decreasing shell thickness.

Effects of shell thickness on cross-helicity generation in convection-driven spherical dynamos