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

We present a series of numerical experiments that model the evolution ofmagnetic flux tubes with a different amount of initial twist. As a result ofcalculations, tightly twisted tubes reveal a rapid two-step emergence to theatmosphere with a slight slowdown at the surface, while weakly twisted tubesshow a slow two-step emergence waiting longer the secondary instability to betriggered. This picture of the two-step emergence is highly consistent withrecent observations. These tubes show multiple magnetic domes above thesurface, indicating that the secondary emergence is caused by interchange modeof magnetic buoyancy instability. As for the weakest twist case, the tubeexhibits an elongated photospheric structure and never rises into the corona.The formation of the photospheric structure is due to inward magnetic tensionforce of the azimuthal field component of the rising flux tube (i.e., tube'stwist). When the twist is weak, azimuthal field cannot hold the tube'scoherency, and the tube extends laterally at the subadiabatic surface. Inaddition, we newly find that the total magnetic energy measured above thesurface depends on the initial twist. Strong twist tubes follow the initialrelation between the twist and the magnetic energy, while weak twist tubesdeviates from this relation, because these tubes store their magnetic energy inthe photospheric structures.

Dependence of the Magnetic Energy of Solar Active Regions on the Twist Intensity of the Initial Flux Tubes