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Observations show that solar activity is distributed non-axisymmetrically, concentrating at "preferred longitudes". This indicates the important role of non-axisymmetric magnetic fields in the origin of solar activity. We investigate the…

Astrophysics · Physics 2009-11-10 Alberto Bigazzi , Alexander Ruzmaikin

Convectively driven dynamos with rotation generating magnetic fields on scales large compared with the scale of the turbulent eddies are being reviewed. It is argued that such fields can be understood as the result of an alpha effect.…

Solar and Stellar Astrophysics · Physics 2011-08-19 A. Brandenburg , P. J. Käpylä , M. J. Korpi

The periodically varying Lorentz force of the periodic solar magnetic field generated by the solar dynamo can induce two kinds of motions: torsional oscillations and periodic variations in the meridional circulation. Observational evidence…

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

Our attention focuses on the stochastic dynamo equation with non-normal operator that give an insight into the role of stochastics and non-normality in the galactic magnetic field generation. The main point of this Letter is a discussion of…

Astrophysics · Physics 2009-11-07 Sergei Fedotov

Since the discovery of solar cycle related with magnetic field in 1908, deep seated oscillatory dynamo has been studied extensively. However, there are still open questions on the solar dynamo, e.g., asymmetric conversion between…

Solar and Stellar Astrophysics · Physics 2018-10-16 Biping Gong

Simple models of magnetic field generation by convection in rotating spherical shells exhibit properties resembling those observed on the sun. The {assumption of the Boussinesq approximation made in these models} prevents a realistic…

Solar and Stellar Astrophysics · Physics 2015-06-03 Radostin D. Simitev , Friedrich H. Busse

We study how anisotropy of turbulent convection affects diffusion of large-scale magnetic fields and the dynamo process on the Sun. The effect of anisotropy is calculated in a mean-field magneto-hydrodynamics framework using the minimal…

Solar and Stellar Astrophysics · Physics 2015-06-16 V. V. Pipin , A. G. Kosovichev

Contex: Solar magnetic activity exhibits variations with periods between 1.5--4 years, the so-called quasi-biennial oscillations (QBOs), in addition to the well-known 11-year Schwabe cycles. Solar dynamo is thought to be the responsible…

Solar and Stellar Astrophysics · Physics 2019-05-29 Fadil Inceoglu , Rosaria Simoniello , Rainer Arlt , Matthias Rempel

We study the connections between the sun's convection zone and the evolution of the solar wind and corona. We let the magnetic fields generated by a 2.5D axisymmetric kinematic dynamo code (STELEM) evolve in a 2.5D axisymmetric coronal…

Solar and Stellar Astrophysics · Physics 2015-05-28 Rui F. Pinto , Allan Sacha Brun , Laurène Jouve , Roland Grappin

Theoretical models for the solar dynamo range from simple low-dimensional ``toy models'' to complex 3D-MHD simulations. Here we mainly discuss appproaches that are motivated and guided by solar (and stellar) observations. We give a brief…

Solar and Stellar Astrophysics · Physics 2023-05-04 Robert Cameron , Manfred Schüssler

We present the first global, three-dimensional simulations of solar/stellar convection that take into account the influence of magnetic flux emergence by means of the Babcock-Leighton (BL) mechanism. We have shown that the inclusion of a BL…

Solar and Stellar Astrophysics · Physics 2015-06-03 Mark S. Miesch , Benjamin P. Brown

The meridional circulation of the solar magnetic fields in Solar Cycles 21-24 was considered. Data from both ground-based and space observatories were used. Three types of time-latitude distributions of photospheric magnetic fields and…

Solar and Stellar Astrophysics · Physics 2023-11-17 Irina A. Bilenko

We explore the impact of magnetic helicity conservation on the mean-field solar dynamo using the axisymmetric dynamo model which includes the subsurface shear. Our results support the recent findings by Hubbard & Brandenburg (2012), who…

Solar and Stellar Astrophysics · Physics 2015-06-12 V. V. Pipin , D. D. Sokoloff , H. Zhang , K. M. Kuzanyan

Meridional flow is crucial in generating the solar poloidal magnetic field by facilitating the poleward transport of the field from the decayed Bipolar Magnetic Regions (BMRs). As the meridional circulation changes with the stellar rotation…

Solar and Stellar Astrophysics · Physics 2024-07-24 Vindya Vashishth , Bidya Binay Karak

We investigate spatio-temporal evolution of high-degree acoustic mode frequencies of the Sun and the surface magnetic activity, over the course of multiple solar cycles, to improve our understanding of the connection between the solar…

Solar and Stellar Astrophysics · Physics 2023-12-20 Mackenzie A. Baird , Sushanta C. Tripathy , Kiran Jain

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

The predictability, or lack thereof, of the solar cycle is governed by numerous separate physical processes that act in unison in the interior of the Sun. Magnetic flux transport and the finite time delay it introduces, specifically in the…

Astrophysics · Physics 2009-11-13 A. R. Yeates , D. Nandy , D. H. Mackay

The Sun is a magnetic star whose cyclic activity is thought to be linked to internal dynamo mechanisms. A combination of numerical modelling with various levels of complexity is an efficient and accurate tool to investigate such intricate…

Solar and Stellar Astrophysics · Physics 2015-05-19 L. Jouve , M. R. E. Proctor , G. Lesur

We present results from a model for magnetic flux generation and transport in cool stars and a qualitative comparison of models with observations. The method combines an alpha-omega dynamo at the base of the convection zone, buoyant rise of…

Solar and Stellar Astrophysics · Physics 2015-06-03 Emre Işık

The meridional circulation of the Sun is observationally found to vary with the solar cycle, becoming slower during the solar maxima. We explain this by constructing a theoretical model in which the equation of the meridional circulation…

Solar and Stellar Astrophysics · Physics 2019-01-30 Gopal Hazra , Arnab Rai Choudhuri