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Related papers: A numerical MHD model for the solar tachocline

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A hypothesis for sunspot formation is the buoyant emergence of magnetic flux tubes created by the strong radial shear at the tachocline. In this scenario, the magnetic field has to exceed a threshold value before it becomes buoyant and…

Solar and Stellar Astrophysics · Physics 2011-10-25 G. Guerrero , P. Käpylä

We show that if the turbulent magnetic diffusivity used in solar dynamos is assumed to be 'quenched' by increasing toroidal fields, much larger amplitude and more concentrated toroidal fields can be induced by differential rotation from an…

Astrophysics · Physics 2009-11-10 Peter A. Gilman , Matthias Rempel

Although systematic measurements of the solar polar magnetic field exist only from mid 1970s, other proxies can be used to infer the polar field at earlier times. The observational data indicate a strong correlation between the polar field…

Astrophysics · Physics 2009-11-13 Jie Jiang , Piyali Chatterjee , Arnab Rai Choudhuri

In this paper we discuss the transport of toroidal magnetic field by a weak meridional flow at the base of the convection zone. We utilize the differential rotation and meridional flow model developed by Rempel and incorporate feedback of a…

Astrophysics · Physics 2010-11-11 Matthias Rempel

Maps of the radial magnetic field at a heliocentric distance of ten solar radii are used as boundary conditions in the MHD code CRONOS to simulate a 3D inner-heliospheric solar wind emanating from the rotating Sun out to 1 AU. The input…

Space Physics · Physics 2013-03-19 T. Wiengarten , J. Kleimann , H. Fichtner , R. Cameron , J. Jiang , R. Kissmann , K. Scherer

We present nonlinear three-dimensional simulations of the stably-stratified portion of the solar tachocline in which the rotational shear is maintained by mechanical forcing. When a broad toroidal field profile is specified as an initial…

Astrophysics · Physics 2009-11-13 Mark S. Miesch

We conduct 2.5D radiative magnetohydrodynamic (MHD) simulations to investigate the driving mechanisms of the solar spicules in coronal holes and how the different background magnetic fields affect their formation. The simulation model…

Solar and Stellar Astrophysics · Physics 2026-05-26 Jin Li , Lei Ni , Robertus Erdélyi , Jun Lin , Xiaoli Yan , Guanchong Cheng

In recent years, observers have found that the fraction of M-stars demonstrating significant magnetic activity transitions sharply from roughly $10\%$ for main-sequence stars earlier (more massive) than spectral type M3.5 (0.35 M$_\odot$)…

Solar and Stellar Astrophysics · Physics 2020-04-23 Connor P. Bice , Juri Toomre

We study the toroidal magnetic flux budget of the axisymmetric part of a 3D mean-field dynamo model of Solar Cycles 23 and 24. The model simulates the global solar dynamo that includes effects of the formation and evolution of bipolar…

Solar and Stellar Astrophysics · Physics 2023-11-09 V. V. Pipin , A. G. Kosovichev

Strong solar flares occur in $\delta $-spots characterized by the opposite-polarity magnetic fluxes in a single penumbra. Sunspot formation via flux emergence from the convection zone to the photosphere can be strongly affected by…

Solar and Stellar Astrophysics · Physics 2022-09-28 Takafumi Kaneko , Hideyuki Hotta , Shin Toriumi , Kanya Kusano

Modelling the base of the solar convective envelope is a tedious problem. Since the first rotation inversions, solar modellers are confronted with the fact that a region of very limited extent has an enormous physical impact on the Sun.…

To estimate the hemispheric flux generation rate of the large-scale radial magnetic field in the Solar Cycles 23 and 24, we use the photospheric observations of the solar magnetic fields and results of the mean-field dynamo models. Results…

Solar and Stellar Astrophysics · Physics 2024-08-12 V. V. Pipin

The solar tachocline is shown as hydrodynamically stable against nonaxisymmetric disturbances if it is true that no cos^{4}\theta term exists in its rotation law. We also show that the toroidal field of 200 Gauss amplitude which produces…

Solar and Stellar Astrophysics · Physics 2009-11-13 G. Ruediger , L. L. Kitchatinov , M. Gellert

We measure the effects of non-isotropic thermal conduction on generation of solar chromospheric jets through numerical simulations carried out with the use of one fluid MHD code MAGNUS. Following the work of Srivastava et al. (2018), we…

Solar and Stellar Astrophysics · Physics 2020-11-11 Anamaría Navarro , F. D. Lora-Clavijo K. Murawski , Stefaan Poedts

Three-dimensional magnetohydrodynamic simulations of the surface layers of the Sun intrinsically produce a predominantly horizontal magnetic field in the photosphere. This is a robust result in the sense that it arises from simulations with…

Solar and Stellar Astrophysics · Physics 2009-04-15 O. Steiner , R. Rezaei , R. Schlichenmaier , W. Schaffenberger , S. Wedemeyer-Böhm

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

Recent observations of the magnetic field in pre-main sequence stars suggest that the magnetic field topology changes as a function of age. The presence of a tachocline could be an important factor in the development of magnetic field with…

Solar and Stellar Astrophysics · Physics 2017-11-07 Bonnie Zaire , Gustavo Guerrero , Alexander Kosovichev , Piotr Smolarkiewicz , Natalia Landin

The coupling between small and large scale structures and processes on the Sun and in the heliosphere is important in the relation to the global magnetic configuration. Thin heliospheric current sheets play the leading role in this respect.…

Solar and Stellar Astrophysics · Physics 2012-12-24 Igor Veselovsky , Olga Panasenco

We present axisymmetric numerical simulations of the solar interior, including the convection zone and an extended radiative interior. We find that differential rotation in the convection zone induces a toroidal field from an initially…

Solar and Stellar Astrophysics · Physics 2015-05-30 T. M. Rogers

Recent advances in helioseismology, numerical simulations and mean-field theory of solar differential rotation have shown that the meridional circulation pattern may consist of two or more cells in each hemisphere of the convection zone.…

Solar and Stellar Astrophysics · Physics 2018-02-28 V. V. Pipin , A. G. Kosovichev
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