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Related papers: The mean-field solar dynamo with double cell merid…

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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

The peculiar behaviour of the solar cycle 23 and its prolonged minima has been one of the most studied problems over the last few years. In the present paper, we study the asymmetries in active region magnetic flux in the northern and…

Solar and Stellar Astrophysics · Physics 2015-02-03 Juie Shetye , Durgesh Tripathi , Mausumi Dikpati

Babcock-Leighton type solar dynamo models with single-celled meridional circulation are successful in reproducing many solar cycle features. Recent observations and theoretical models of meridional circulation do not indicate a…

Solar and Stellar Astrophysics · Physics 2015-04-03 Bernadett Belucz , Mausumi Dikpati , Emese Forgacs-Dajka

We report the results of a magneto-hydrodynamic (MHD) simulation of a convective dynamo in a model solar convective envelope driven by the solar radiative diffusive heat flux. The convective dynamo produces a large-scale mean magnetic field…

Solar and Stellar Astrophysics · Physics 2014-06-18 Yuhong Fan , Fang Fang

Context: Most solar and stellar dynamo models use the alpha-Omega scenario where the magnetic field is generated by the interplay between differential rotation (the Omega effect) and a mean electromotive force due to helical turbulent…

Solar and Stellar Astrophysics · Physics 2009-12-08 N. Seehafer , V. V. Pipin

The need for reliable predictions of the solar activity cycle motivates the development of dynamo models incorporating a representation of surface processes sufficiently detailed to allow assimilation of magnetographic data. In this series…

Solar and Stellar Astrophysics · Physics 2015-11-30 Alexandre Lemerle , Paul Charbonneau , Arnaud Carignan-Dugas

The Sun's global meridional circulation is evident as a slow poleward flow at its surface. This flow is observed to carry magnetic elements poleward - producing the Sun's polar magnetic fields as a key part of the 11-year sunspot cycle.…

Solar and Stellar Astrophysics · Physics 2011-03-30 David H. Hathaway

Helioseismology provides important constraints for the solar dynamo problem. However, the basic properties and even the depth of the dynamo process, which operates also in other stars, are unknown. Most of the dynamo models suggest that the…

Solar and Stellar Astrophysics · Physics 2014-02-11 Alexander G. Kosovichev , Valery V. Pipin , Junwei Zhao

Meridional flow in the solar interior plays an important role in redistributing angular momentum and transporting magnetic flux inside the Sun. Although it has long been recognized that the meridional flow is predominantly poleward at the…

Solar and Stellar Astrophysics · Physics 2015-06-16 Junwei Zhao , R. S. Bogart , A. G. Kosovichev , T. L. Duvall, , Thomas Hartlep

We point out the difficulties in carrying out direct numerical simulation of the solar dynamo problem and argue that kinematic mean-field models are our best theoretical tools at present for explaining various aspects of the solar cycle in…

Solar and Stellar Astrophysics · Physics 2015-06-05 Arnab Rai Choudhuri

The Sun's magnetic dynamo cycle features a distinct pattern: a propagating region of sunspot emergence appears around 30 degrees latitude and vanishes near the equator every 11 years. Moreover, longitudinal flows called "torsional…

We present a nonlinear mean-field model of the solar interior dynamics and dynamo, which reproduces the observed cyclic variations of the global magnetic field of the Sun, as well as the differential rotation and meridional circulation.…

Solar and Stellar Astrophysics · Physics 2020-01-08 V. V. Pipin , A. G. Kosovichev

We explore the importance of meridional circulation variations in modelling the irregularities of the solar cycle by using the flux transport dynamo model. We show that a fluctuating meridional circulation can reproduce some features of the…

Solar and Stellar Astrophysics · Physics 2015-06-05 Bidya Binay Karak , Arnab Rai Choudhuri

We give a short introduction to the subject and review advances in understanding the basic ingredients of the mean-field dynamo theory. The discussion includes the recent analytic and numerical work in developments for the mean…

Solar and Stellar Astrophysics · Physics 2015-06-12 V. V. Pipin

Using a 3D global solver of the linearized Euler equations, we model acoustic oscillations over background velocity flow fields of single-cell meridional circulation with deep and shallow return flows as well as double-cell meridional…

Solar and Stellar Astrophysics · Physics 2022-02-15 Andrey M. Stejko , Alexander G. Kosovichev , Valery V. Pipin

Solar magnetic fields comprise an 11-year activity cycle, represented by the number of sunspots. The maintenance of such a solar magnetic field can be attributed to fluid motion in the convection zone, i.e. a dynamo. This study conducts the…

Solar and Stellar Astrophysics · Physics 2022-08-24 Ryota Shimada , Hideyuki Hotta , Takaaki Yokoyama

Variations of the sunspot number are important indicators of the solar activity cycles. The sunspot formation is a result of a dynamo process inside the Sun, which is far from being understood. We use simple dynamical models of the dynamo…

Astrophysics · Physics 2009-02-11 I. N. Kitiashvili , A. G. Kosovichev

Global and semi-global convective dynamo simulations of solar-like stars are known to show a transition from an anti-solar (fast poles, slow equator) to solar-like (fast equator, slow poles) differential rotation (DR) for increasing…

Solar and Stellar Astrophysics · Physics 2019-11-25 M. Viviani , M. J. Käpylä , J. Warnecke , P. J. Käpylä , M. Rheinhardt

(abridged) Results from kinematic solar dynamo models employing alpha-effect and turbulent pumping from local convection calculations are presented. We estimate the magnitude of these effects to be around 2-3 m/s. The rotation profile of…

Astrophysics · Physics 2008-11-26 P. J. Käpylä , M. J. Korpi , I. Tuominen

Several solar-like stars exhibit cyclic magnetic activity similar to the Sun as found in photospheric and chromospheric emission. We want to understand the physical mechanism involved in rotational dependence of these activity cycle…

Solar and Stellar Astrophysics · Physics 2018-08-22 Jörn Warnecke