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Related papers: Photospheric downflows observed with SDO/HMI, HINO…

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Using time-distance local helioseismology flow maps within 1 Mm of the solar photosphere, we detect inflows toward activity belts that contribute to solar cycle scale variations in near-surface meridional flow. These inflows stretch out as…

Solar and Stellar Astrophysics · Physics 2023-06-28 Sushant S. Mahajan , Xudong Sun , Junwei Zhao

The Sun is the only star where the superficial turbulent convection can be observed at very high spatial resolution. The Solar Dynamics Observatory (SDO) has continuously observed the full Sun from space with multi-wavelength filters since…

Solar and Stellar Astrophysics · Physics 2021-08-18 J. Ballot , T. Roudier , J. M. Malherbe , Z. Frank

We have discovered small whirlpools in the Sun, with a size similar to the terrestrial hurricanes (<~0.5 Mm). The theory of solar convection predicts them, but they had remained elusive so far. The vortex flows are created at the downdrafts…

Astrophysics · Physics 2009-11-13 J. A. Bonet , I. Marquez , J. Sanchez Almeida , I. Cabello , V. Domingo

Hinode observations have provided a new view of outflows from the Sun. These have been focussed in particular on flows emanating from the edges of active regions. These flows are long lasting and seem to exist to some extent in every active…

Solar and Stellar Astrophysics · Physics 2012-01-24 Louise Harra

Twisting motions of different nature are observed in several layers of the solar atmosphere. Chromospheric sunspot whorls and rotation of sunspots or even higher up in the lower corona sigmoids are examples of the large scale twisted…

Astrophysics · Physics 2009-11-13 R. Attie , D. E. Innes , H. E. Potts

From Doppler velocity maps of active regions constructed from spectra obtained by the Extreme-ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft we observe large areas of outflow (20-50 km/s) that can persist for at least a…

Astrophysics · Physics 2009-11-13 G. A. Doschek , H. P. Warren , J. T. Mariska , K. Muglach , J. L. Culhane , H. Hara , T Watanabe

Convection in the solar interior is thought to comprise structures on a spectrum of scales. This conclusion emerges from phenomenological studies and numerical simulations, though neither covers the proper range of dynamical parameters of…

Solar and Stellar Astrophysics · Physics 2015-06-05 Shravan Hanasoge , Thomas L. Duvall , Katepalli R. Sreenivasan

The operation of the solar dynamo, with all of its remarkable spatio-temporal ordering, remains an outstanding problem of modern solar physics. A number of mechanisms that might plausibly contribute to its operation have been proposed, but…

In this Letter we present a seismological detection of a rising motion of magnetic flux in the shallow convection zone of the Sun, and show estimates of the emerging speed and its decelerating nature. In order to evaluate the speed of…

Solar and Stellar Astrophysics · Physics 2015-06-15 Shin Toriumi , Stathis Ilonidis , Takashi Sekii , Takaaki Yokoyama

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

A comprehensive understanding of the solar magnetic cycle requires detailed modeling of the solar interior including the maintenance and variation of large scale flows (differential rotation and meridional flow), the solar dynamo and the…

Solar and Stellar Astrophysics · Physics 2010-10-29 M. Rempel

Context: Giant-cell convection is believed to be an important component of solar dynamics. For example, it is expected to play a crucial role in maintaining the Sun's differential rotation. Aims: We re-examine early reports of giant…

Solar and Stellar Astrophysics · Physics 2021-01-04 Chris S. Hanson , Thomas L. Duvall , Aaron C. Birch , Laurent Gizon , Katepalli R. Sreenivasan

In addition to sunspots, which represent the most easily visualized manifestation of solar magnetism, cutting-edge observations of the solar atmosphere have uncovered a plethora of magnetic flux tubes, down to the resolving power of modern…

Solar and Stellar Astrophysics · Physics 2025-02-27 M. Stangalini , G. Verth , V. Fedun , D. Perrone , M. Berretti , P. Bushby , S. Jafarzadeh , D. B. Jess , F. Giannattasio , P. H. Keys , R. Bruno , F. Berrilli

It is widely accepted that solar active regions including sunspots are formed by the emerging magnetic flux from the deep convection zone. In previous numerical simulations, we found that the horizontal divergent flow (HDF) occurs before…

Solar and Stellar Astrophysics · Physics 2015-06-04 S. Toriumi , K. Hayashi , T. Yokoyama

High resolution spectropolarimetric observations of 3 sunspots taken with Hinode demonstrate the existence of supersonic downflows at or close to the umbra-penumbra boundary which have not been reported before. These downflows are confined…

Solar and Stellar Astrophysics · Physics 2015-05-20 Rohan E. Louis , Luis R. Bellot Rubio , Shibu K. Mathew , P. Venkatakrishnan

Aims: The interactions of velocity scales on the Sun's surface, from granulation to supergranulation are still not understood, nor are their interaction with magnetic fields. We thus aim at giving a better description of dynamics in the…

Solar and Stellar Astrophysics · Physics 2009-02-16 T. Roudier , M. Rieutord , D. Brito , F. Rincon , J. M. Malherbe , N. Meunier , T. Berger , Z. Frank

The Sun's global meridional circulation is evident as a slow poleward flow at its surface. This flow is observed to carry magnetic elements poleward - producing the Sun's polar magnetic fields as a key part of the 11-year sunspot cycle.…

Solar and Stellar Astrophysics · Physics 2011-03-30 David H. Hathaway

The dynamical origins of the Sun's tachocline and near-surface shear layer (NSSL) are still not well understood. We have attempted to self-consistently reproduce a NSSL in numerical simulations of a solar-like convection zone by increasing…

Solar and Stellar Astrophysics · Physics 2019-02-05 Loren I. Matilsky , Bradley W. Hindman , J. Toomre

A magnetic flux tube may be considered both as a separate body and as a confined field. As a field, it is affected both by the cyclonic convection ($\alpha$-effect) and differential rotation ($\Omega$-effect). As a body, the tube…

Astrophysics · Physics 2007-05-23 L. H. Li , S. Sofia

Helioseismic signatures of dynamo waves have recently been discovered in variations of the solar differential rotation, offering valuable insights into the type of dynamo mechanism operating in the solar convection zone. To characterize…

Solar and Stellar Astrophysics · Physics 2025-05-19 Krishnendu Mandal , Alexander G. Kosovichev , Valery V. Pipin , Sylvain G. Korzennik