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Related papers: Velocity Fields in the Solar Photosphere

200 papers

We estimated photospheric velocities by separately applying the Fourier Local Correlation Tracking (FLCT) and Differential Affine Velocity Estimator (DAVE) methods to 2708 co-registered pairs of SOHO/MDI magnetograms, with nominal 96-minute…

Solar and Stellar Astrophysics · Physics 2009-11-13 B. T. Welsch , Y. Li , P. W. Schuck , G. H. Fisher

The Sun's axisymmetric flows, differential rotation and meridional flow, govern the dynamics of the solar magnetic cycle and variety of methods are used to measure these flows, each with its own strengths and weaknesses. Flow measurements…

Solar and Stellar Astrophysics · Physics 2021-09-08 Sushant S. Mahajan , David H. Hathaway , Andrés Muñoz-Jaramillo , Petrus C. Martens

A statistical study has been carried out of the relationship between plasma flow Doppler velocities and magnetic field parameters during the emergence of active regions at the solar photospheric level with data acquired by the Michelson…

Solar and Stellar Astrophysics · Physics 2017-05-01 A. Khlystova

Time-distance helioseismology provides information about vector flows in the near-surface layers of the Sun by measuring wave travel times between points on the solar surface. Specific spatial averages of travel times have been proposed for…

Solar and Stellar Astrophysics · Physics 2015-01-05 Jan Langfellner , Laurent Gizon , Aaron C. Birch

The Polarimetric and Helioseismic Imager (SO/PHI) onboard Solar Orbiter is a spectropolarimeter scanning the Fe I line at 617.3 nm, providing data of the solar photosphere. The same line is sampled by the Helioseismic and Magnetic Imager…

The published Mount Wilson Doppler-shift measurements of the solar velocity field taken in 1967--1982 are revisited with a more accurate model, which includes two terms representing the meridional flow and three terms corresponding to the…

Solar and Stellar Astrophysics · Physics 2015-05-18 Valeri V. Makarov

The dynamics of horizontal plasma flows during the first hours of the emergence of active region magnetic flux in the solar photosphere have been analyzed using SOHO/MDI data. Four active regions emerging near the solar limb have been…

Solar and Stellar Astrophysics · Physics 2017-05-01 A. Khlystova

Observations of the Sun in the visible spectral range belong to standard measurements obtained by instruments both on the ground and in the space. Nowadays, both nearly continuous full-disc observations with medium resolution and dedicated…

Solar and Stellar Astrophysics · Physics 2020-06-30 Michal Švanda , Jan Jurčák , David Korda , Jana Kašparová

We show that systematic differences between surface Doppler and magnetic element tracking measures of solar meridional flow can be explained by the effects of surface turbulent magnetic diffusion. Feature-tracking speeds are lower than…

Solar and Stellar Astrophysics · Physics 2015-05-19 Mausumi Dikpati , Peter A. Gilman , Roger K. Ulrich

In this dissertation, several components of large-scale solar flows are studied observationally: solar equatorial Rossby waves (waves of radial vorticity), large-scale convection, and surface flows around active regions. Maps of horizontal…

Solar and Stellar Astrophysics · Physics 2023-01-25 Bastian Proxauf

Doppler imaging spectroscopy is the most reliable way to directly measure wind speeds of planetary atmospheres of the Solar system. However, most knowledge about atmospheric dynamics has been obtained with cloud-tracking technique, which…

Earth and Planetary Astrophysics · Physics 2019-06-14 Patrick Gaulme , Francois-Xavier Schmider , Ivan Goncalves

We use a novel global helioseismic analysis method to infer the meridional flow in the deep Solar interior. The method is based on the perturbation of eigenfunctions of Solar p modes due to meridional flow. We apply this method to time…

Solar and Stellar Astrophysics · Physics 2013-12-02 A. Schad , J. Timmer , M. Roth

Many phenomena taking place in the solar photosphere are controlled by plasma motions. Although the line-of-sight component of the velocity can be estimated using the Doppler effect, we do not have direct spectroscopic access to the…

Solar and Stellar Astrophysics · Physics 2017-08-02 A. Asensio Ramos , I. S. Requerey , N. Vitas

The measurement of the Sun's surface motions with a high spatial and temporal resolution is still a challenge. We wish to validate horizontal velocity measurements all over the visible disk of the Sun from Solar Dynamics Observatory/…

Solar and Stellar Astrophysics · Physics 2015-06-15 Th. Roudier , M. Rieutord , V. Prat , J. M. Malherbe , N. Renon , Z. Frank , M. Svanda , T. Berger , R. Burston , L. Gizon

The meridional flow in the Sun is an axisymmetric flow that is generally poleward directed at the surface, and is presumed to be of fundamental importance in the generation and transport of magnetic fields. Its true shape and strength,…

Solar and Stellar Astrophysics · Physics 2015-06-11 Thomas Hartlep , Junwei Zhao , Alexander G. Kosovichev , Nagi N. Mansour

Observations of quiet Sun from the Solar Optical Telescope/Spectro-Polarimeter (SOT/SP) aboard the Hinode spacecraft would reveal the magnetic characters of the solar photosphere. By making use of the deep mode observations of three quiet…

Astrophysics · Physics 2008-12-18 Chunlan Jin , Jingxiu Wang , Meng Zhao

We use high spatial resolution observations and numerical simulations to study the velocity distribution of solar photospheric magnetic bright points. The observations were obtained with the Rapid Oscillations in the Solar Atmosphere…

Large scale flows in the Sun play an important role in the dynamo process linked to the solar cycle. The important large scale flows are the differential rotation and the meridional circulation with an amplitude of km/s and few m/s ,…

Solar and Stellar Astrophysics · Physics 2018-04-25 Th. Roudier , M. Svanda , J. Ballot , J. M. Malherbe , M. Rieutord

To address the problem of the low accuracy of transverse velocity field measurements for small targets in high-resolution solar images, we proposed a novel velocity field measurement method for high-resolution solar images based on PWCNet.…

Solar and Stellar Astrophysics · Physics 2023-05-29 Z. -H. Shang , S. -Y. Mu , K. -H Ji , Z. -P. Qiang

We suggest a method that evaluates the horizontal velocity in the solar photosphere with easily observable values using a combination of neural network and radiative magnetohydrodynamics simulations. All three-component velocities of…

Solar and Stellar Astrophysics · Physics 2023-09-06 Hiroyuki Masaki , Hideyuki Hotta , Yukio Katsukawa , Ryohtaroh T. Ishikawa