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相关论文: Models of solar surface dynamics: impact on eigenf…

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Alfv\'en-wave-driven 3D magnetohydrodynamic (MHD) models, which are increasingly used to predict stellar wind properties, contain unconstrained parameters and rely on low-resolution stellar magnetograms. We explore the effects of the input…

太阳与恒星天体物理 · 物理学 2020-04-08 S. Boro Saikia , M. Jin , C. P. Johnstone , T. Lüftinger , M. Güdel , V. S. Airapetian , K. G. Kislyakova , C. P. Folsom

The sunspot penumbra is a transition zone between the strong vertical magnetic field area (sunspot umbra) and the quiet Sun. The penumbra has a fine filamentary structure that is characterized by magnetic field lines inclined toward the…

太阳与恒星天体物理 · 物理学 2010-12-02 I. N. Kitiashvili , A. G. Kosovichev , N. N. Mansour , A. A. Wray

We present high-cadence observations and simulations of the solar photosphere, obtained using the Rapid Oscillations in the Solar Atmosphere imaging system and the MuRAM magneto-hydrodynamic code, respectively. Each dataset demonstrates a…

太阳与恒星天体物理 · 物理学 2015-06-03 D. B. Jess , S. Shelyag , M. Mathioudakis , P. H. Keys , D. J. Christian , F. P. Keenan

Using full-disk observations obtained with the Michelson Doppler Imager (MDI) on board the Solar and Heliospheric Observatory (SOHO) spacecraft, we present variations of the solar acoustic mode frequencies caused by the solar activity…

天体物理学 · 物理学 2008-11-26 M. C. Rabello-Soares , S. G. Korzennik , J. Schou

Some of the small-scale solar magnetic flux can be attributed to a small-scale dynamo (SSD) operating in the near-surface convection. The SSD fields have consequences for solar granular convection, basal flux, as well as chromospheric…

We used solar observations of a plage/enhanced network with the Atacama Large Millimeter/sub-millimeter Array (ALMA) in Band 3 and Band 6 together with synthetic continuum maps from numerical simulations with Bifrost at the same bands to…

High degree solar mode frequencies as measured by ring diagrams are known to change in the presence of the strong magnetic fields found in active regions. We examine these changes in frequency for a large sample of active regions analyzed…

太阳与恒星天体物理 · 物理学 2015-05-27 Charles S. Baldner , Richard S. Bogart , Sarbani Basu

The complex dynamics that lead to the emergence of active regions on the sun are poorly understood. One possibility is that magnetic structures (flux tubes, etc.) rise from below the surface by self induction and convection that lead to the…

太阳与恒星天体物理 · 物理学 2009-01-30 T. Hartlep , A. G. Kosovichev , J. Zhao , N. N. Mansour

We present a radiative magnetohydrodynamics simulation of the formation of an Active Region on the solar surface. The simulation models the rise of a buoyant magnetic flux bundle from a depth of 7.5 Mm in the convection zone up into the…

太阳与恒星天体物理 · 物理学 2015-05-19 M. C. M. Cheung , M. Rempel , A. M. Title , M. Schüssler

Three-dimensional large eddy simulations of solar surface convection using realistic model physics are conducted. The thermal structure of convective motions into the upper radiative layers of the photosphere, the range of convection cell…

天体物理学 · 物理学 2007-10-17 Sergey Ustyugov

In this paper we present a numerical study of the time evolution of solar prominences embedded in sheared magnetic arcades. The prominence is represented by a density enhancement in a background stratified atmosphere and is connected to the…

太阳与恒星天体物理 · 物理学 2015-06-23 J. Terradas , R. Soler , M. Luna , R. Oliver , J. L. Ballester

The space-borne missions have provided us with a wealth of high-quality observational data that allows for seismic inferences of stellar interiors. This requires the computation of precise and accurate theoretical frequencies, but imperfect…

太阳与恒星天体物理 · 物理学 2015-11-04 T. Sonoi , R. Samadi , K. Belkacem , H. -G. Ludwig , E. Caffau , B. Mosser

Solar inertial modes are believed to play important diagnostic and dynamical roles in the Sun's differentially rotating convection zone. However, the coupling of these modes to the radiative interior has not yet been discussed. We aim to…

太阳与恒星天体物理 · 物理学 2026-04-15 Suprabha Mukhopadhyay , Yuto Bekki , Xiaojue Zhu , Laurent Gizon

Using turbulent MHD simulations (magnetic Reynolds numbers up to 8000) and Hinode observations, we study effects of turbulence on measuring the solar magnetic field outside active regions. Firstly, from synthetic Stokes V profiles for the…

天体物理学 · 物理学 2011-02-11 Jonathan Pietarila Graham , Sanja Danilovic , Manfred Schuessler

We study the anisotropy of II-order structure functions defined in a frame attached to the local mean field in three-dimensional (3D) direct numerical simulations of magnetohydrodynamic turbulence, including or not the solar wind expansion.…

太阳与恒星天体物理 · 物理学 2015-08-06 Andrea Verdini , Roland Grappin

All cool main sequence stars including our Sun are thought to have magnetic fields. Observations of the Sun revealed that even in quiet regions small-scale turbulent magnetic fields are present. Simulations further showed that such magnetic…

太阳与恒星天体物理 · 物理学 2023-02-01 V. Witzke , H. B. Duehnen , A. I. Shapiro , D. Przybylski , T. S. Bhatia , R. Cameron , S. K. Solanki

The success of helioseismology is due to its capability to accurately measure the p-mode parameters of the solar eigenmode spectrum, which allow us to infer unique information about the internal structure and dynamics of the Sun. It also…

太阳与恒星天体物理 · 物理学 2011-10-14 D. Salabert

The Sun's surface vibrates in characteristic 5-minute oscillations, known as p-modes, generated by sound waves trapped within the convection zone. Although these oscillations have long been hypothesized to reach into the solar wind, direct…

In stratified atmospheres, acoustic waves can only propagate if their frequency is above the cutoff value. Different theories provide different cutoff values. We developed an alternative method to derive the cutoff frequency in several…

太阳与恒星天体物理 · 物理学 2020-07-29 T. Felipe , C. R. Sangeetha

I represent results three-dimensional numerical simulation of solar surface convection on scales local supergranulation with realistic model physics. I study thermal structure of convective motions in photosphere, the range of convection…

天体物理学 · 物理学 2009-11-13 Sergey Ustyugov