English
Related papers

Related papers: Quantifying the Difference Between the Flux-Tube E…

200 papers

Empirical solar wind speed models play an important role in enabling space weather forecasting with low computational cost. Among these, one model called WS model is based on the asymptotic expansion factor. However, it is known that it…

Solar and Stellar Astrophysics · Physics 2026-01-30 Kyogo Tokoro , Munehito Shoda , Shinsuke Imada

The properties of the solar wind measured in-situ in the heliosphere are largely controlled by energy deposition in the solar. Previous studies have shown that long duration and large scale magnetic structures show an inverse relation…

Solar and Stellar Astrophysics · Physics 2024-10-30 J-B. Dakeyo , A. P. Rouillard , V. Réville , P. Démoulin , M. Maksimovic , A. Chapiron , R. F. Pinto , P. Louarn

The solar wind speed at 1 AU shows variations in latitude and in time which reflect the evolution of the global background magnetic field during the activity cycle. It is commonly accepted that the terminal wind speed in a magnetic…

Solar and Stellar Astrophysics · Physics 2016-07-27 R. F. Pinto , A. S. Brun , A. P. Rouillard

We present a new model, MULTI-VP, that computes the three-dimensional structure of the solar wind which includes the chromosphere, the transition region, and the corona and low heliosphere. MULTI-VP calculates a large ensemble of wind…

Solar and Stellar Astrophysics · Physics 2017-04-05 Rui F. Pinto , Alexis P. Rouillard

By explicitly taking into account effects of Alfven waves, I derive from a simple energetics argument a fundamental relation which predicts solar wind (SW) speeds in the vicinity of the earth from physical properties on the sun. Kojima et…

Astrophysics · Physics 2009-11-11 Takeru K. Suzuki

We describe, test, and apply a technique to incorporate full-sun, surface flux evolution into an MHD model of the global solar corona. Requiring only maps of the evolving surface flux, our method is similar to that of Lionello et al.…

Solar and Stellar Astrophysics · Physics 2023-10-12 Roberto Lionello , Cooper Downs , Emily I. Mason , Jon A. Linker , Ronald M. Caplan , Pete Riley , Viacheslav S. Titov , Marc L. DeRosa

The surface flux transport (SFT) model of solar magnetic fields involves empirically well-constrained velocity and magnetic fields. The basic evolution of the Sun's large-scale surface magnetic field is well described by this model. The…

Solar and Stellar Astrophysics · Physics 2015-06-05 R. H. Cameron , D. Schmitt , J. Jiang , E. Isik

Aims: Propagation and energy transfer of torsional Alfv\'en waves in solar magnetic flux tubes of axial symmetry is studied. Methods: An analytical model of a solar magnetic flux tube of axial symmetry is developed by specifying a magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-20 K. Murawski , A. Solov'ev , Z. E. Musielak , A. K. Srivastava , J. Kraskiewicz

High-resolution observations of the solar photosphere have identified a wide variety of spiralling motions in the solar plasma. These spirals vary in properties, but are observed to be abundant at the solar surface. In this work these…

Solar and Stellar Astrophysics · Physics 2015-04-01 S. J. Mumford , R. Erdélyi

For the past 30+ years, the magnetic expansion factor ($f_s$) has been used in empirical relationships to predict solar wind speed ($v_{obs}$) at 1 AU, based on an inverse relationship between these two quantities. Coronal unipolar…

Solar and Stellar Astrophysics · Physics 2020-08-03 Samantha Wallace , Charles N. Arge , Nicholeen M. Viall , Ylva Pihlstrom

An accurate solar wind speed model is important for space weather predictions, catastrophic event warnings, and other issues concerning solar wind - magnetosphere interaction. In this work, we construct a model based on convolutional neural…

Solar and Stellar Astrophysics · Physics 2023-04-05 Rong Lin , Zhekai Luo , Jiansen He , Lun Xie , Chuanpeng Hou , Shuwei Chen

The aim of this work is to identify the physical processes that occur in the network and contribute to its dynamics and heating. We model the network as consisting of individual flux tubes with a non-potential field structure that are…

Astrophysics · Physics 2009-11-10 S. S. Hasan , A. A. van Ballegoiijen , W. Kalkofen , O. Steiner

Identifying the heating mechanisms of the solar corona and the driving mechanisms of solar wind are key challenges in understanding solar physics. A full three-dimensional compressible magnetohydrodynamic (MHD) simulation was conducted to…

Solar and Stellar Astrophysics · Physics 2020-11-25 Takuma Matsumoto

Four decades have gone by since the discovery that the solar wind at 1 AU seems to exist in two relatively distinct states: slow and fast. There is still no universal agreement concerning the primary physical cause of this apparently…

Astrophysics · Physics 2007-05-23 Steven R. Cranmer

A potential field solution is widely used to extrapolate the coronal magnetic field above the Sun's surface to a certain height. This model applies the current-free approximation and assumes that the magnetic field is entirely radial beyond…

Solar and Stellar Astrophysics · Physics 2024-03-05 Zhenguang Huang , Gabor Toth , Jia Huang , Nishtha Sachdeva , Bart van der Holst , Ward B. Manchester

(abridged) We investigate how the properties of the corona and solar wind in the open coronal holes depend on the properties of the magnetic fields and their footpoint motions at the surface, by perfoming 1D MHD simulations from the…

Astrophysics · Physics 2015-06-24 Takeru K. Suzuki , Shu-ichiro Inutsuka

The dynamics of the solar wind depends intrinsically on the structure of the global solar magnetic field, which undergoes fundamental changes over the 11-yr solar cycle. For instance, the wind terminal velocity is thought to be…

Solar and Stellar Astrophysics · Physics 2017-11-29 Victor Réville , Allan Sacha Brun

The solar wind is connected to the Sun's atmosphere by flux tubes that are rooted in an ever-changing pattern of positive and negative magnetic polarities on the surface. Observations indicate that the magnetic field is filamentary and…

Solar and Stellar Astrophysics · Physics 2015-06-15 Steven R. Cranmer , Adriaan A. van Ballegooijen , Lauren N. Woolsey

We investigate numerically Alfv\'en waves propagating along an axisymmetric and non-isothermal solar flux tube embedded in the solar atmosphere. The tube magnetic field is current-free and diverges with height, and the waves are excited by…

Solar and Stellar Astrophysics · Physics 2017-02-08 D. Wójcik , K. Murawski , Z. E. Musielak , P. Konkol , A. Mignone

We present numerical simulations of reduced magnetohydrodynamic (RMHD) turbulence in a magnetic flux tube at the center of a polar coronal hole. The model for the background atmosphere is a solution of the momentum equation, and includes…

Solar and Stellar Astrophysics · Physics 2016-04-27 A. A. van Ballegooijen , M. Asgari-Targhi
‹ Prev 1 2 3 10 Next ›