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We review recent insights into the dynamics of the solar convection zone obtained from global numerical simulations, focusing on two recent developments in particular. The first is quasi-cyclic magnetic activity in a long-duration dynamo…

Solar and Stellar Astrophysics · Physics 2015-05-20 Mark S. Miesch , Benjamin P. Brown , Matthew K. Browning , Allan Sacha Brun , Juri Toomre

As the global magnetic field of the Sun has an activity cycle, one expects to observe some variation of the dynamical properties of the flows visible in the photosphere. We investigate the flow field during the solar cycle by analysing…

Solar and Stellar Astrophysics · Physics 2017-02-15 Th. Roudier , J. M. Malherbe , G. M. Mirouh

We report on the spatial distribution of magnetogram oscillatory power and phase angles between velocity and magnetogram signals as observed with the Michelson Doppler Imager. The dataset is 151.25 arcsec times 151.25 arcsec containing…

Astrophysics · Physics 2009-10-31 A. A. Norton , R. K. Ulrich , R. I. Bush , T. D. Tarbell

The convectively driven, weakly magnetized regions of the solar photosphere dominate the Sun's surface at any given time, but the temporal variations of these quiet regions of the photosphere throughout the solar cycle are still not well…

Solar and Stellar Astrophysics · Physics 2025-05-05 James Crowley , Ivan Milic , Gianna Cauzzi , Kevin Reardon

We study the emergence of magnetic flux at very small spatial scales (less than 2 arcsec) in the quiet Sun internetwork. To this aim, a time series of spectropolarimetric maps was taken at disk center using the instrument SP/SOT on board…

We estimate the temporal change of magnetic flux perpendicular to the solar surface in a decaying active region by using a time series of the spatial distribution of vector magnetic fields in the photosphere. The vector magnetic fields are…

Astrophysics · Physics 2009-11-13 M. Kubo , B. W. Lites , T. Shimizu , K. Ichimoto

Structures seen in idealized numerical experiments on compressible magnetoconvection in an imposed strong vertical magnetic field show important differences from those detected in observations or realistic numerical simulations of sunspot…

Solar and Stellar Astrophysics · Physics 2016-03-08 C. Tian , K. Petrovay

A number of observational and theoretical aspects of solar magnetoconvection are considered in this review. We discuss recent developments in our understanding of the small-scale structure of the magnetic field on the solar surface and its…

Solar and Stellar Astrophysics · Physics 2015-12-29 J. M. Borrero , S. Jafarzadeh , M. Schüssler , S. K. Solanki

Aims. Moreno-Insertis et al. (2018) recently discovered two types of flux emergence in their numerical simulations: magnetic loops and magnetic sheet emergence. Whereas magnetic loop emergence has been documented well in the last years, by…

Solar and Stellar Astrophysics · Physics 2019-02-13 C. E. Fischer , J. M. Borrero , N. Bello González , A. J. Kaithakkal

We derive a first order linear differential equation describing the shape of the probability density function of magnetic field strengths in the quiet Sun (PDF). The modeling is very schematic. It considers convective motions which…

Astrophysics · Physics 2008-11-26 J. Sanchez Almeida

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

We study the velocity field of umbral dots at a resolution of 0.14". Our analysis is based on full Stokes spectropolarimetric measurements of a pore taken with the CRISP instrument at the Swedish 1-m Solar Telescope. We determine the flow…

Solar and Stellar Astrophysics · Physics 2015-05-18 Ada Ortiz , Luis R. Bellot Rubio , Luc Rouppe van der Voort

Guided by the recent observational result that the meridional circulation of the Sun becomes weaker at the time of the sunspot maximum, we have included a parametric quenching of the meridional circulation in solar dynamo models such that…

Solar and Stellar Astrophysics · Physics 2012-09-04 Bidya Binay Karak , Arnab Rai Choudhuri

We study the properties of solar magnetic fields on scales less than the spatial resolution of solar telescopes. A synthetic infrared spectropolarimetric diagnostics based on a 2D MHD simulation of magnetoconvection is used for this. We…

Solar and Stellar Astrophysics · Physics 2009-02-10 V. A. Sheminova

We have measured the meridional motions of the magnetic elements in the Sun's surface layers since 1996 and find systematic and substantial variations. In general the meridional flow speed is fast at cycle minima and slow at cycle maxima.…

Solar and Stellar Astrophysics · Physics 2015-06-19 David H. Hathaway , Lisa Upton

In the solar convection zone, rotation couples with intensely turbulent convection to drive a strong differential rotation and achieve complex magnetic dynamo action. Our sun must have rotated more rapidly in its past, as is suggested by…

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 report on new spectro-polarimetric measurements with simultaneous filter imaging observation, revealing the frequent appearance of polarization signals indicating high-speed, probably supersonic, downflows that are associated with at…

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

Motivated by the significant interaction of convection, rotation and magnetic field in many astrophysical objects, we investigate the interplay between large-scale flows driven by rotating convection and an imposed magnetic field. We…

Solar and Stellar Astrophysics · Physics 2016-11-23 Laura K. Currie