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

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We simulate the rise through the upper convection zone and emergence through the solar surface of initially uniform, untwisted, horizontal magnetic flux with the same entropy as the non-magnetic plasma that is advected into a domain 48 Mm…

Solar and Stellar Astrophysics · Physics 2015-05-14 R. F. Stein , A. Lagerfjärd , Å. Nordlund , D. Georgobiani

Solar "magnetic tornadoes" are produced by rotating magnetic field structures that extend from the upper convection zone and the photosphere to the corona of the Sun. Recent studies show that such rotating features are an integral part of…

Solar and Stellar Astrophysics · Physics 2017-05-24 Yoshiaki Kato , Sven Wedemeyer

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

Supra-arcade downflows (SADs) are dark voids descending towards the post-reconnection flare loops and exhibit obvious variation in properties like width. However, due to the lack of further statistical studies, the mechanism behind such…

Solar and Stellar Astrophysics · Physics 2023-05-03 Guangyu Tan , Yijun Hou , Hui Tian

The influence of the basic rotation on anisotropic and inhomogeneous turbulence is discussed in the context of differential rotation theory. An improved representation for the original turbulence leads to a $\Lam$-effect which complies with…

Astrophysics · Physics 2009-11-11 L. L. Kitchatinov , G. Rüdiger

A helioseismic statistical waveform analysis of subsurface flow was performed on two 720-day time series of SOHO/MDI Medium-l spherical-harmonic coefficients. The time series coincide with epochs of high and low solar activity.…

Solar and Stellar Astrophysics · Physics 2016-05-23 M. F. Woodard

Solar magnetic fields comprise an 11-year activity cycle, represented by the number of sunspots. The maintenance of such a solar magnetic field can be attributed to fluid motion in the convection zone, i.e. a dynamo. This study conducts the…

Solar and Stellar Astrophysics · Physics 2022-08-24 Ryota Shimada , Hideyuki Hotta , Takaaki Yokoyama

We derive horizontal fluid motions on the solar surface over large areas covering the quiet-Sun magnetic network from local correlation tracking of convective granules imaged in continuum intensity and Doppler velocity by the Helioseismic…

Solar and Stellar Astrophysics · Physics 2016-06-29 C. R. Sangeetha , S. P. Rajaguru

Spectroscopic observations of the emission lines formed in the solar transition region (TR) commonly show persistent downflows of the order of 10--15 km/s. The cause of such downflows, however, is still not fully clear and has remained a…

The Helioseismic Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) records line-of-sight Dopplergram images of convective flows on the surface. These images are used to obtain the multi-scale convective spectrum. We design…

Solar and Stellar Astrophysics · Physics 2021-08-09 Samarth G Kashyap , Shravan M Hanasoge

The contribution of plumes to the solar wind has been subject to hot debate in the past decades. The EUV Imaging Spectrometer (EIS) on board Hinode provides a unique means to deduce outflow velocities at coronal heights via direct Doppler…

Solar and Stellar Astrophysics · Physics 2015-06-22 Hui Fu , Lidong Xia , Bo Li , Zhenghua Huang , Fangran Jiao , Chaozhou Mou

The Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory (SDO/HMI) provides continuous full-disk observations of solar oscillations. We develop a data-analysis pipeline based on the time-distance helioseismology method to…

Solar and Stellar Astrophysics · Physics 2015-05-27 J. Zhao , S. Couvidat , R. S. Bogart , K. V. Parchevsky , A. C. Birch , T. L. Duvall , J. G. Beck , A. G. Kosovichev , P. H. Scherrer

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…

Small-scale magnetic features are present everywhere in the solar photosphere. Theoretical models, numerical calculations, and simulations describing the formation of these features have existed for a few decades, but there are only a few…

Solar and Stellar Astrophysics · Physics 2015-05-27 G. Narayan

The aim of this paper is to extend our previous study of the solar-cycle variations of the meridional flows and to investigate their latitudinal and longitudinal structure in the subphotospheric layer, especially their variations in…

Astrophysics · Physics 2009-11-13 Michal Svanda , Alexander G. Kosovichev , Junwei Zhao

The origin of solar transition region redshifts is not completely understood. Current research is addressing this issue by investigating three-dimensional magneto-hydrodynamic models that extend from the photosphere to the corona. By…

Solar and Stellar Astrophysics · Physics 2015-05-28 Pia Zacharias , Sven Bingert , Hardi Peter

Using solar-cycle long helioseismic measurements of meridional and zonal flows in the near-surface shear layer (NSSL) of the Sun, we study their spatio-temporal variations and connections to active regions. We find that near-surface inflows…

Solar and Stellar Astrophysics · Physics 2025-12-16 Anisha Sen , S. P. Rajaguru , Abhinav Govindan Iyer , Ruizhu Chen , Junwei Zhao , Shukur Kholikov

Convection, differential rotation, and meridional circulation of solar plasma are studied based on helioseismic data covering the period from May 2010 to August 2024, significantly prolonged compared to that previously considered. Depth…

Solar and Stellar Astrophysics · Physics 2025-04-22 A. V. Getling , A. G. Kosovichev

The study of spatial and temporal scales on which small magnetic structures (magnetic elements) are organized in the quiet Sun may be approached by determining how they are transported on the solar photosphere by convective motions. The…

Solar and Stellar Astrophysics · Physics 2015-06-16 F. Giannattasio , D. Del Moro , F. Berrilli , L. Bellot Rubio , M. Gosic , D. Orozco Suarez

Several recent studies utilizing different helioseismic methods have confirmed the presence of large-scale vorticity waves known as solar Rossby waves within the Sun. Rossby waves are distinct from acoustic waves, typically with longer…

Solar and Stellar Astrophysics · Physics 2023-08-15 M. Waidele , Junwei Zhao
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