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We present a realistic numerical model of sunspot and active region formation based on the emergence of flux bundles generated in a solar convective dynamo. To this end we use the magnetic and velocity fields in a horizontal layer near the…

Solar and Stellar Astrophysics · Physics 2017-09-20 Feng Chen , Matthias Rempel , Yuhong Fan

In this Letter we present a seismological detection of a rising motion of magnetic flux in the shallow convection zone of the Sun, and show estimates of the emerging speed and its decelerating nature. In order to evaluate the speed of…

Solar and Stellar Astrophysics · Physics 2015-06-15 Shin Toriumi , Stathis Ilonidis , Takashi Sekii , Takaaki Yokoyama

Magnetic flux emergence from the convection zone into the photosphere and beyond is a critical component of the behaviour of large-scale solar magnetism. Flux rarely emerges amid field-free areas at the surface, but when it does, the…

Solar and Stellar Astrophysics · Physics 2024-03-04 Prasad Mani , Chris S. Hanson , Siddarth Dhanpal , Shravan Hanasoge , Srijan Bharati Das , Matthias Rempel

We investigate the rising flux tube and the formation of sunspots in an unprecedentedly deep computational domain that covers the whole convection zone with a radiative magnetohydrodynamics simulation. Previous calculations had shallow…

Solar and Stellar Astrophysics · Physics 2020-04-08 H. Hotta , H. Iijima

Magnetic fields emerging from the Sun's interior carry information about physical processes of magnetic field generation and transport in the convection zone. Soon after appearance on the solar surface the magnetic flux gets concentrated in…

Solar and Stellar Astrophysics · Physics 2009-11-13 A. G. Kosovichev

We simulate the rise through the upper convection zone and emergence through the solar surface of initially uniform, untwisted, horizontal magnetic flux with the same entropy as the non-magnetic plasma that is advected into a domain 48 Mm…

Solar and Stellar Astrophysics · Physics 2015-05-14 R. F. Stein , A. Lagerfjärd , Å. Nordlund , D. Georgobiani

We present a radiative magnetohydrodynamics simulation of the formation of an Active Region on the solar surface. The simulation models the rise of a buoyant magnetic flux bundle from a depth of 7.5 Mm in the convection zone up into the…

Solar and Stellar Astrophysics · Physics 2015-05-19 M. C. M. Cheung , M. Rempel , A. M. Title , M. Schüssler

We study how active-region-scale flux tubes rise buoyantly from the base of the convection zone to near the solar surface by embedding a thin flux tube model in a rotating spherical shell of solar-like turbulent convection. These toroidal…

Solar and Stellar Astrophysics · Physics 2015-06-11 Maria A. Weber , Yuhong Fan , Mark S. Miesch

The buoyant transport of magnetic fields from the solar interior towards the surface plays an important role in the emergence of active regions, the formation of sunspots and the overall solar dynamo. Observations suggest that toroidal flux…

Solar and Stellar Astrophysics · Physics 2018-06-27 Bhishek Manek , Nicholas Brummell , Dongwook Lee

We present results from numerical modeling of emerging flux regions on the solar surface. The modeling was carried out by means of 3D radiative MHD simulations of the rise of buoyant magnetic flux tubes through the convection zone and into…

Astrophysics · Physics 2009-11-13 M. C. M. Cheung , M. Schuessler , T. D. Tarbell , A. M. Title

We use a thin flux tube model in a rotating spherical shell of turbulent convective flows to study how active region scale flux tubes rise buoyantly from the bottom of the convection zone to near the solar surface. We investigate toroidal…

Solar and Stellar Astrophysics · Physics 2015-05-30 Maria A. Weber , Yuhong Fan , Mark S. Miesch

The emergence of active regions on the Sun is an integral feature of the solar dynamo mechanism. However, details about the generation of active-region-scale magnetism and the journey of this magnetic flux to the photosphere are still in…

Solar and Stellar Astrophysics · Physics 2023-06-13 Maria A. Weber , Hannah Schunker , Laurène Jouve , Emre Işık

After a dynamically active emergence phase, magnetic flux at the solar surface soon ceases to show strong signs of the subsurface dynamics of its parent magnetic structure. This indicates that some kind of disconnection of the emerged flux…

Astrophysics · Physics 2009-11-13 M. Schuessler , M. Rempel

We simulate the buoyant rise of a magnetic flux rope from the solar convection zone into the corona to better understand the energetic coupling of the solar interior to the corona. The magnetohydrodynamic model addresses the physics of…

Solar and Stellar Astrophysics · Physics 2015-06-03 Fang Fang , Ward Manchester , William P. Abbett , Bart van der Holst

Strong solar flares occur in $\delta $-spots characterized by the opposite-polarity magnetic fluxes in a single penumbra. Sunspot formation via flux emergence from the convection zone to the photosphere can be strongly affected by…

Solar and Stellar Astrophysics · Physics 2022-09-28 Takafumi Kaneko , Hideyuki Hotta , Shin Toriumi , Kanya Kusano

We propose a phenomenological technique for modelling the emergence of active regions within a three-dimensional, kinematic dynamo framework. By imposing localised velocity perturbations, we create emergent flux-tubes out of toroidal…

Solar and Stellar Astrophysics · Physics 2015-06-17 A. R. Yeates , A. Muñoz-Jaramillo

[Abridged] Bipolar magnetic regions are formed when loops of magnetic flux emerge at the solar photosphere. Our aim is to investigate the flux emergence process in a simulation of granular convection. In particular we aim to determine the…

Solar and Stellar Astrophysics · Physics 2012-08-09 Paul J Bushby , Vasilis Archontis

Context: Observations indicate that the `quiet' solar photosphere outside active regions contains considerable amounts of magnetic energy and magnetic flux, with mixed polarity on small scales. The origin of this flux is unclear. Aims: We…

Astrophysics · Physics 2009-11-13 A. Voegler , M. Schuessler

We present the new results of the two-dimensional numerical experiments on the cross-sectional evolution of a twisted magnetic flux tube rising from the deeper solar convection zone (-20,000 km) to the corona through the surface. The…

Solar and Stellar Astrophysics · Physics 2015-05-28 Shin Toriumi , Takaaki Yokoyama

Sunspots and the plethora of other phenomena occuring in the course of the 11-year cycle of solar activity are a consequence of the emergence of magnetic flux at the solar surface. The observed orientations of bipolar sunspot groups imply…

Solar and Stellar Astrophysics · Physics 2015-06-24 Robert Cameron , Manfred Schüssler
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