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We explore a two-dimensional kinematic solar dynamo model in a full sphere, based on the helioseismically determined solar rotation profile and with an $\alpha$ effect concentrated near the solar surface, which captures the…

Astrophysics · Physics 2009-11-10 Piyali Chatterjee , Dibyendu Nandy , Arnab Rai Choudhuri

Observations reveal a relatively small but statistically significant North-South (NS) asymmetry in sunspot activity varying on a time scale of several solar cycles. This paper proposes a dynamo model for the phenomenon of long-term NS…

Solar and Stellar Astrophysics · Physics 2021-09-29 Leonid Kitchatinov , Anna Khlystova

We investigate the interaction of a fluctuating alpha-effect with large-scale shear in a simple nonlinear 1-dimensional dynamo wave model. We firstly extend the calculations of Proctor (2007, MNRAS, 41, L39-L42) to include spatial variation…

Solar and Stellar Astrophysics · Physics 2015-05-20 K. J. Richardson , M. R. E. Proctor

It can be shown on observational grounds that two basic effects of dynamo theory for solar activity - production of the toroidal field from the poloidal one by differential rotation and reverse conversion of the toroidal field to the…

Solar and Stellar Astrophysics · Physics 2015-06-19 L. L. Kitchatinov

A brief summary of the various observations and constraints that underlie solar dynamo research are presented. The arguments that indicate that the solar dynamo is an alpha-omega dynamo of the Babcock-Leighton type are then shortly…

Solar and Stellar Astrophysics · Physics 2017-09-26 R. H. Cameron , M. Dikpati , A. Brandenburg

A solar-type dynamo model in a spherical shell is developed with allowance for random dependence of the poloidal field generation mechanism on time and latitude. The model shows repeatable epochs of strongly decreased amplitude of magnetic…

Solar and Stellar Astrophysics · Physics 2015-06-17 S. V. Olemskoy , L. L. Kitchatinov

Sunspot groups observed by Royal Greenwich Observatory/US Air Force/NOAA from May 1874 to November 2008 and the Carte Synoptique solar filaments from March 1919 to December 1989 are used to investigate the relative phase shift of the paired…

Solar and Stellar Astrophysics · Physics 2015-05-19 Kejun Li , Hongfei Liang , Wen Feng

The paper presents a study of a solar dynamo model operating in the bulk of the convection zone with the toroidal magnetic field flux concentrated in the subsurface rotational shear layer. We explore how this type of dynamo may depend on…

Solar and Stellar Astrophysics · Physics 2015-05-28 V. V. Pipin , A. G. Kosovichev

We investigate symmetry properties of the solar magnetic field in the framework of the linear Parker's migratory dynamo model. We show that the problem can be mapped onto the well-known quantum-mechanical double-well problem. Using the WKB…

Astrophysics · Physics 2009-11-07 Victor Galitski , K. M. Kuzanyan , D. D. Sokoloff

The irregular polarity reversals of the Earth's magnetic field have attracted much interest during the last decades. Despite the fact that recent numerical simulations of the geodynamo have shown nice polarity transitions, the very reason…

Geophysics · Physics 2007-05-23 F. Stefani , G. Gerbeth , U. Guenther

During the solar magnetic activity cycle the emergence latitudes of sunspots change, leading to the well-known butterfly diagram. This phenomenon is poorly understood for other stars as starspot latitudes are generally unknown. The related…

Solar and Stellar Astrophysics · Physics 2019-02-06 M. B. Nielsen , L. Gizon , R. H. Cameron , M. Miesch

Parameters of a special kind of \alpha-effect known in dynamo theory as the Babcock-Leighton mechanism are estimated using the data of sunspot catalogs. The estimates evidence the presence of the Babcock-Leighton \alpha-effect on the Sun.…

Solar and Stellar Astrophysics · Physics 2013-05-14 S. V. Olemskoy , A. R. Choudhuri , L. L. Kitchatinov

Observations of chromospheric and coronal emissions from various solar-type stars show that the stellar magnetic activity varies with the rotation rates of the stars. The faster the star rotates, its magnetic activity gets stronger but…

Solar and Stellar Astrophysics · Physics 2019-10-16 Gopal Hazra , Jie Jiang , Bidya Binay Karak , Leonid Kitchatinov

Decay and dispersal of the tilted Bipolar Magnetic Regions (BMRs) on the solar surface are observed to produce large-scale poloidal field, which acts as the seed for the toroidal field and, thus, the next sunspot cycle. However, various…

Solar and Stellar Astrophysics · Physics 2024-04-17 Pawan Kumar , Bidya Binay Karak , Anu Sreedevi

We explore effects of random non-axisymmetric perturbations of kinetic helicity (the $\alpha$ effect) and diffusive decay of bipolar magnetic regions on generation and evolution of large-scale non-axisymmetric magnetic fields on the Sun.…

Solar and Stellar Astrophysics · Physics 2018-11-28 V. V. Pipin , A. G. Kosovichev

Fluctuations in the Sun's magnetic activity, including episodes of grand minima such as the Maunder minimum have important consequences for space and planetary environments. However, the underlying dynamics of such extreme fluctuations…

Solar and Stellar Astrophysics · Physics 2014-06-12 Soumitra Hazra , Dário Passos , Dibyendu Nandy

Dynamo models relying on the Babcock-Leighton mechanism are successful in reproducing most of the solar magnetic field dynamical characteristics. However, considering that such models operate only above a lower magnetic field threshold,…

Solar and Stellar Astrophysics · Physics 2013-07-17 Sabrina Sanchez , Alexandre Fournier , Katia Pinheiro , Julien Aubert

We study a mesoscopic superconducting ring threaded by a magnetic flux when the single particle level spacing is not negligible. It is shown that, for a superconducting ring with even parity, the behavior of persistent current is equivalent…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Kicheon Kang

We considered variations the dipole and the quadrupole components of the solar large-scale magnetic field. Both the axial and the equatorial dipoles exhibit a systematic decrease in the past four cycles in accordance with the general…

Solar and Stellar Astrophysics · Physics 2020-02-19 V. N. Obridko , D. D. Sokoloff , B. D. Shelting , A. S. Shibalova , I. M. Livshits

The variable magnetic field of the solar photosphere exhibits periodic reversals as a result of dynamo activity occurring within the solar interior. We decompose the surface field as observed by both the Wilcox Solar Observatory and the…

Solar and Stellar Astrophysics · Physics 2015-06-11 M. L. DeRosa , A. S. Brun , J. T. Hoeksema