English
Related papers

Related papers: Subsurface Flows in Active Regions with Peculiar M…

200 papers

Using highly resolved direct numerical simulations we examine the statistical properties of the local energy flux rate $\Pi_\ell(x)$ towards small scales for three isotropic turbulent magnetohydrodynamic flows, which differ in strength and…

Fluid Dynamics · Physics 2022-07-26 Alexandros Alexakis , Sergio Chibbaro

We study the relationship between decaying active region magnetic fields, coronal holes and the global coronal magnetic structure using Global Oscillations Network Group (GONG) synoptic magnetograms, Solar Terrestrial RElations Observatory…

Solar and Stellar Astrophysics · Physics 2015-06-16 Gordon Petrie , Karl Haislmaier

Magnetic fields are expected to impact the atmospheric dynamics of hot and ultra-hot Jupiters due to their increased ionization fractions, compared to that of cooler exoplanets, but our ability to model these magnetic processes is limited…

Earth and Planetary Astrophysics · Physics 2025-07-14 Duncan A. Christie , Tom M. Evans-Soma , Nathan J. Mayne , Krisztian Kohary

Magnetic field emerges at the surface of the Sun as sunspots and active regions. This process generates a poloidal magnetic field from a rising toroidal flux tube, it is a crucial but poorly understood aspect of the solar dynamo. The…

Solar and Stellar Astrophysics · Physics 2016-07-19 Aaron C. Birch , Hannah Schunker , Douglas C. Braun , Robert Cameron , Laurent Gizon , Björn Löptien , Matthias Rempel

The prominent blue shifts of Ne viii associated with the junctions of the magnetic network in the quiet Sun are still not well understood. By comparing the coronal magnetic-field structures as obtained by a potential-field reconstruction…

Solar and Stellar Astrophysics · Physics 2014-11-20 Hui Tian , Eckart Marsch , Werner Curdt , Jiansen He

Aims. Combining high-resolution and synoptic observations aims to provide a comprehensive description of flux emergence at photospheric level and of the growth process that eventually leads to a mature active region. Methods. Small active…

Recent numerical work in helioseismology has shown that a periodically varying subsurface magnetic field leads to a fanning of the $f$-mode, which emerges from the density jump at the surface. In an attempt to model a more realistic…

Solar and Stellar Astrophysics · Physics 2019-12-16 Nishant K. Singh , Harsha Raichur , Maarit J. Käpylä , Matthias Rheinhardt , Axel Brandenburg , Petri J. Käpylä

We present new measurements of the dependence of the Extreme Ultraviolet radiance on the total magnetic flux in active regions as obtained from the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager on board the…

Solar and Stellar Astrophysics · Physics 2017-09-20 Ignacio Ugarte-Urra , Harry P. Warren , Lisa A. Upton , Peter R. Young

Outflows of plasma at the edges of active regions surrounded by quiet Sun are now a common observation with the Hinode satellite. While there is observational evidence to suggest that the outflows are originating in the magnetic field…

Solar and Stellar Astrophysics · Physics 2015-05-14 M. J. Murray , D. Baker , L. van Driel-Gesztelyi , J. Sun

We have measured zonal and meridional components of subsurface flows up to a depth of 30 Mm below the solar surface by applying the technique of ring diagram on Dopplergrams which are constructed from the spherical harmonic (SH)…

Solar and Stellar Astrophysics · Physics 2023-12-20 Sushanta C. Tripathy , Kiran Jain , Shukurijon Kholikov , Rudolf Komm

Various models of solar sub-surface stratification are tested in the global EULAG-MHD solver to simulate diverse regimes of near-surface convective transport. Sub- and superadiabacity are altered at the surface of the model ($ r >…

Solar and Stellar Astrophysics · Physics 2019-11-19 Andrey M. Stejko , Gustavo Guerrero , Alexander G. Kosovichev , Piotr K. Smolarkiewicz

The formation and evolution of active regions is an inherently complex phenomenon. Magnetic fields generated at the base of the convection zone follow a chaotic evolution before reaching the solar surface. In this article, we use a 2-D…

Astrophysics · Physics 2009-11-07 L. Vlahos , T. Fragos , H. Isliker , M. Georgoulis

In the recent papers, we introduced a method utilised to measure the flow field. The method is based on the tracking of supergranular structures. We did not precisely know, whether its results represent the flow field in the photosphere or…

The goal of local helioseismology is to elicit three-dimensional information about the sub-surface (or far-side) structure and dynamics of the Sun from observations of the helioseismic wave field at the surface. The physical quantities of…

Solar and Stellar Astrophysics · Physics 2015-05-19 Hannah Schunker

For the past few centuries, the temporal variation in the Earth's magnetic field in the Pacific region has been anomalously low. The reason for this is tied to large scale flows in the liquid outer core near the core-mantle boundary, which…

Geophysics · Physics 2022-01-05 Mathieu Dumberry , Colin More

We discuss the lateral dynamics of two active force dipoles, which interact with each other via hydrodynamic interactions in a thin fluid layer that is active and chiral. The fluid layer is modeled as a two-dimensional (2D) compressible…

Soft Condensed Matter · Physics 2023-08-02 Yuto Hosaka , David Andelman , Shigeyuki Komura

Several studies have correlated observations of impulsive solar activity -- flares and coronal mass ejections (CMEs) -- with the amount of magnetic flux near strong-field polarity inversion lines (PILs) in active regions' photospheric…

Astrophysics · Physics 2007-10-03 B. T. Welsch , Y. Li

Convection in rotating spherical geometries is an important physical process in planetary and stellar systems. Using continuation methods at low Prandtl number, we find both strong equatorially asymmetric and symmetric polar nonlinear…

Solar and Stellar Astrophysics · Physics 2019-07-17 F. Garcia , F. R. N. Chambers , A. L. Watts

We review progress in active hydrodynamic descriptions of flowing media on curved and deformable manifolds: the state-of-the-art in continuum descriptions of single-layers of epithelial and/or other tissues during development. First, after…

Biological Physics · Physics 2021-03-24 Sami C. Al-Izzi , Richard G. Morris

Stars and gaseous planets are magnetised objects but the influence of magnetic fields on their tidal responses and dissipation rates has not been well explored. We present the first exploratory nonlinear magnetohydrodynamic (MHD)…

Solar and Stellar Astrophysics · Physics 2024-11-26 Aurélie Astoul , Adrian J. Barker