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Helioseismology revealed an increase in the rotation rate with depth just beneath the solar surface. The relative magnitude of the radial shear is almost constant with latitude. This rotational state can be interpreted as a consequence of…

Solar and Stellar Astrophysics · Physics 2016-06-01 Leonid Kitchatinov

Delta ($\delta$) sunspots sometimes host fast photospheric flows along the central magnetic polarity inversion line (PIL). Here we study the strong Doppler shift signature in the central penumbral light bridge of solar active region NOAA…

Solar and Stellar Astrophysics · Physics 2023-07-20 Jiayi Liu , Xudong Sun , Peter W. Schuck , Sarah A. Jaeggli , Brian T. Welsch , Carlos Quintero Noda

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…

Solar and Stellar Astrophysics · Physics 2011-10-14 D. Salabert

Context. Several upcoming helioseismology space missions are very limited in telemetry and will have to perform extensive data compression. This requires the development of new methods of data compression. Aims. We give an overview of the…

Solar and Stellar Astrophysics · Physics 2014-12-02 Björn Löptien , Aaron C. Birch , Laurent Gizon , Jesper Schou

Simultaneous measurement of line-of-sight (LOS) magnetic and velocity fields at the photosphere and chromosphere are presented. Fe I line at $\lambda6569$ and $H_{\alpha}$ at $\lambda6563$ are used respectively for deriving the physical…

Astrophysics · Physics 2009-11-13 K. Nagaraju , K. Sankarasubramanian , K. E. Rangarajan

The form of the solar meridional circulation is a very important ingredient for mean field flux transport dynamo models. Yet a shroud of mystery still surrounds this large-scale flow, given that its measurement using current helioseismic…

Solar and Stellar Astrophysics · Physics 2015-02-17 Dario Passos , Paul Charbonneau , Mark Miesch

We present a method for performing data-driven simulations of solar active region formation and evolution. The approach is based on magnetofriction, which evolves the induction equation assuming the plasma velocity is proportional to the…

Solar and Stellar Astrophysics · Physics 2015-06-11 Mark C. M. Cheung , Marc L. DeRosa

A large filament composed principally of two sections erupted sequentially in the southern hemisphere on January 26 2016. The central, thick part of the northern section was first lifted up and lead to the eruption of the full filament.…

Solar and Stellar Astrophysics · Physics 2018-10-24 T. Roudier , B. Schmieder , B. Filippov , R. Chandra , J. M. Malherbe

Active regions often host large-scale gas flows in the chromosphere presumably directed along curved magnetic field lines. Spectropolarimetric observations of these flows are critical to understanding the nature and evolution of their…

Solar and Stellar Astrophysics · Physics 2011-01-05 Tom Schad , Sarah Jaeggli , Haosheng Lin , Matthew Penn

A comprehensive understanding of the structure of Doppler motions in transition region including the center-to-limb variation and its relationship with the magnetic field structure is vital for the understanding of mass and energy transfer…

Solar and Stellar Astrophysics · Physics 2020-01-08 Avyarthana Ghosh , James A. Klimchuk , Durgesh Tripathi

In this dataset we provide a comprehensive collection of magnetograms (images quantifying the strength of the magnetic field) from the National Aeronautics and Space Administration's (NASA's) Solar Dynamics Observatory (SDO). The dataset…

Solar and Stellar Astrophysics · Physics 2024-02-13 Laura E. Boucheron , Ty Vincent , Jeremy A. Grajeda , Ellery Wuest

Helioseismology has discovered a thin layer beneath the solar surface where the rotation rate increases rapidly with depth. The normalized rotational shear in the upper 10 Mm of the layer is constant with latitude. Differential rotation…

Solar and Stellar Astrophysics · Physics 2023-11-27 Leonid Kitchatinov

Laser Doppler holography was introduced as a full-field imaging technique to measure blood flow in the retina and choroid with an as yet unrivaled temporal resolution. We here investigate separating the different contributions to the power…

Medical Physics · Physics 2021-06-02 Léo Puyo , Michel Paques , Mathias Fink , José-Alain Sahel , Michael Atlan

Magnetic helicity quantifies how globally sheared and/or twisted is the magnetic field in a volume. This quantity is believed to play a key role in solar activity due to its conservation property. Helicity is continuously injected into the…

Solar and Stellar Astrophysics · Physics 2013-07-11 K. Dalmasse , E. Pariat , P. Démoulin , G. Aulanier

Linear time-distance helioseismic inversions are carried out for vector flow velocities using travel times measured from two $\sim 100^2\,{\rm Mm^2}\times 20\,{\rm Mm}$ realistic magnetohydrodynamic quiet-Sun simulations of about 20 hr. The…

Solar and Stellar Astrophysics · Physics 2015-06-19 K. DeGrave , J. Jackiewicz , M. Rempel

Understanding the magnetic fields of the Sun is essential for unraveling the underlying mechanisms driving solar activity. Integrating topological data analysis techniques into these investigations can provide valuable insights into the…

Solar and Stellar Astrophysics · Physics 2024-01-31 Pablo Santamarina Guerrero , Yukio Katsukawa , Shin Toriumi , David Orozco Suárez

Global-scale Rossby waves have recently been unambiguously identified on the Sun. Here we study the latitude and depth dependence of the Rossby wave eigenfunctions. By applying helioseismic ring-diagram analysis and granulation tracking to…

Solar and Stellar Astrophysics · Physics 2020-02-05 B. Proxauf , L. Gizon , B. Löptien , J. Schou , A. C. Birch , R. S. Bogart

We report observations of white-light ejecta in the low corona, for two X-class flares on the 2013 May 13, using data from the Helioseismic and Magnetic Imager (HMI) of the Solar Dynamics Observatory. At least two distinct kinds of sources…

Here we present a detailed analysis of solar acoustic mode frequencies and their rotational splittings for modes with degree up to 900. They were obtained by applying spherical harmonic decomposition to full-disk solar images observed by…

Astrophysics · Physics 2008-08-22 M. C. Rabello-Soares , S. G. Korzennik , J. Schou

We present meridional flow measurements of the Sun using a novel helioseismic approach for analyzing SOHO/MDI data in order to push the current limits in radial depth. Analyzing three consecutive months of data during solar minimum, we find…

Astrophysics · Physics 2009-06-23 U. Mitra-Kraev , M. J. Thompson
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