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Related papers: Effects of cyclic fluctuations in meridional circu…

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The solar wind magnetic field contains rotations at a broad range of scales, which have been extensively studied in the MHD range. Here we present an extension of this analysis to the range between ion and electron kinetic scales. The…

Space Physics · Physics 2015-09-16 C. H. K. Chen , L. Matteini , D. Burgess , T. S. Horbury

Space weather is a matter of practical importance in our modern society. Predictions of forecoming solar cycles mean amplitude and duration are currently being made based on flux-transport numerical models of the solar dynamo. Interested in…

Solar and Stellar Astrophysics · Physics 2013-12-05 Sabrina Maite Sanchez , Alexandre Fournier , Julien Aubert

The Sun, aside from its eleven year sunspot cycle is additionally subject to long term variation in its activity. In this work we analyse a solar-like convective dynamo simulation, containing approximately 60 magnetic cycles, exhibiting…

Solar and Stellar Astrophysics · Physics 2017-10-11 Frederick A. Gent , Maarit J. Käpylä , Jörn Warnecke

We show how magnetic observations of the Sun can be used in conjunction with an axisymmetric flux-transport solar dynamo model in order to estimate the large-scale meridional circulation throughout the convection zone. Our innovative…

Solar and Stellar Astrophysics · Physics 2017-10-06 Ching Pui Hung , Laurène Jouve , Allan Sacha Brun , Alexandre Fournier , Olivier Talagrand

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

The intermittency of density fluctuations in the solar wind at kinetic scales has been examined using high time resolution Faraday cup measurements from the Spektr-R spacecraft. It was found that the probability density functions (PDFs) of…

Space Physics · Physics 2014-06-23 C. H. K. Chen , L. Sorriso-Valvo , J. Šafránková , Z. Němeček

The theory of the solar/stellar activity cycles is presented, based on the mean-field concept in magnetohydrodynamics. A new approach to the formulation of the electromotive force and the theory of differential rotation and meridional…

Astrophysics · Physics 2017-02-22 Günther Rüdiger , Rainer Arlt

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

Temporal variations of the subsurface meridional flow with the solar cycle have been reported by several authors. The measurements are typically averaged over periods of time during which surface magnetic activity existed in the regions…

Astrophysics · Physics 2008-09-05 I. Gonzalez Hernandez , S. Kholikov , F. Hill , R. Howe , R. Komm

As a large-scale motion on the Sun, the meridional flow plays an important role in determining magnetic structure and strength and solar cycle. However, the meridional flow near the solar poles is still unclear. The Hinode observations show…

Solar and Stellar Astrophysics · Physics 2024-07-29 Shuhong Yang , Jie Jiang , Zifan Wang , Yijun Hou , Chunlan Jin , Qiao Song , Yukun Luo , Ting Li , Jun Zhang , Yuzong Zhang , Guiping Zhou , Yuanyong Deng , Jingxiu Wang

Preliminary results are presented which suggest that scaling and singularity characteristics of solar wind and ground based magnetic fluctuations appear to be a significant component in the solar wind - magnetosphere interaction processes.…

Space Physics · Physics 2020-01-29 Z. Vörös , D. Jankovičová , P. Kovács

Fluctuations of the alpha-effect which break equatorial symmetry of the flow in the kinematic Parker's dynamo are considered. We show, that even small (a few percents) fluctuation can leed to the substantial assymmetry of the magnetic field…

Fluid Dynamics · Physics 2011-10-03 M. Reshetnyak , D. Sokoloff

We explore a response of a non-linear non-axisymmetric mean-field solar dynamo model to shallow non-axisymmetric perturbations. After a relaxation period the amplitude of the non-axisymmetric field depends on the initial condition, helicity…

Solar and Stellar Astrophysics · Physics 2015-11-18 V. V. Pipin , A. G. Kosovichev

We analyse the role of a fluctuating alpha-effect in alpha-omega dynamo models, and show that there is a mechanism for magnetic field generation, valid at large scale separation, deriving from the interaction of mean shear and a fluctuating…

Astrophysics · Physics 2009-11-13 Michael R. E. Proctor

Some selected concepts for the solar activity cycle are briefly reviewed. Cycle modulations through a stochastic alpha effect are being identified with limited scale separation ratios. Three-dimensional turbulence simulations with helicity…

Solar and Stellar Astrophysics · Physics 2012-07-17 Axel Brandenburg , Gustavo Guerrero

Stellar variability due to magnetic activity and flows at different spatial scales strongly impacts radial velocities. This variability is seen as oscillations, granulation, supergranulation, and meridional flows. The effect of this latter…

Solar and Stellar Astrophysics · Physics 2020-06-17 Nadège Meunier , Anne-Marie Lagrange

The influence of fluctuating conductivity on the coefficients known from the mean-field electrodynamics is considered. If the conductivity fluctuations are assumed as uncorrelated with the turbulent velocity field then only the effective…

Plasma Physics · Physics 2020-07-15 G. Rüdiger , M. Küker , P. J. Käpylä

Recent data on superflares on sun-like stars and radiocarbon data on solar activity in the past are both indicative of transient epochs of unusually high magnetic activity. We propose an explanation for the grand activity maxima in the…

Solar and Stellar Astrophysics · Physics 2016-05-05 L. L. Kitchatinov , S. V. Olemskoy

We discuss one important aspect of Waldmeier effect which says that the stronger cycles rise rapidly than weaker cycles. We studied four different data set of solar activity indices, and find strong linear correlation between rise rates and…

Solar and Stellar Astrophysics · Physics 2011-02-22 Bidya Binay Karak , Arnab Rai Choudhuri

The hemispheric asymmetry of sunspot activity observed possesses a regular component varying on a time scale of several solar cycles whose origin and properties are currently debated. This paper addresses the question of whether the…

Solar and Stellar Astrophysics · Physics 2019-05-08 Alexander Nepomnyashchikh , Sudip Mandal , Dipankar Banerjee , Leonid Kitchatinov