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Related papers: Spatial Scales and Time Variation of Solar Subsurf…

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We analyze spectral properties of solar convection in the range of depths from 0 to 19~Mm using subsurface flow maps obtained by the time-distance heiioseismology analysis of solar-oscillation data from the Helioseismic and Magnetic Imager…

Solar and Stellar Astrophysics · Physics 2022-03-01 Alexander V. Getling , Alexander G. Kosovichev

We use subsurface-flow velocity maps inferred by time--distance helioseismology from Doppler measurements with the Helioseismic and Magnetic Imager (HMI) of the Solar Dynamics Observatory (SDO) to investigate variations of large-scale…

Solar and Stellar Astrophysics · Physics 2025-10-01 Alexander V. Getling , Alexander G. Kosovichev

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

We apply time-distance helioseismology, local correlation tracking and Fourier spatial-temporal filtering methods to realistic supergranule scale simulations of solar convection and compare the results with high-resolution observations from…

Local helioseismology has opened new frontiers in our quest for understanding of the internal dynamics and dynamo on the Sun. Local helioseismology reconstructs subsurface structures and flows by extracting coherent signals of acoustic…

Solar and Stellar Astrophysics · Physics 2016-07-20 Alexander G. Kosovichev , Junwei Zhao

Understanding convection is important in stellar physics, for example as an input in stellar evolution models. Helioseismic estimates of convective flow amplitudes in deeper regions of the solar interior disagree by orders of magnitude…

Solar and Stellar Astrophysics · Physics 2021-05-12 Vincent G. A. Böning , Aaron C. Birch , Laurent Gizon , Thomas L. Duvall

We re-examine the deep-focus methodology of time-distance helioseismology previously used to estimate the power spectrum of the solar convection at a depth of about 30 Mm, which was found to be significantly weaker than predicted by theory…

Solar and Stellar Astrophysics · Physics 2026-02-11 John T. Stefan , Alexander G. Kosovichev , Gustavo Guerrero , Andrey M. Stejko

We model the solar horizontal velocity power spectrum at scales larger than granulation using a two-component approximation to the mass continuity equation. The model takes four times the density scale height as the integral (driving) scale…

Solar and Stellar Astrophysics · Physics 2015-06-22 J. W. Lord , R. H. Cameron , M. P. Rast , M. Rempel , T. Roudier

Large-scale plasma flows in the Sun's convection zone likely play a major role in solar dynamics on decadal timescales. In particular, quantifying meridional motions is a critical ingredient for understanding the solar cycle and the…

Solar and Stellar Astrophysics · Physics 2015-06-19 Shukur Kholikov , Alexander Serebryanskiy , Jason Jackiewicz

We constrain the velocity spectral distribution of global-scale solar convective cells at depth using techniques of local helioseismology. We calibrate the sensitivity of helioseismic waves to large-scale convective cells in the interior by…

Solar and Stellar Astrophysics · Physics 2015-05-18 S. M. Hanasoge , T. L. Duvall , M. L. DeRosa

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

We perform helioseismic holography on realistic solar convection simulations and compare the observed travel-time perturbations with the expected travel times from the horizontal flows in the simulations computed from forward models under…

Astrophysics · Physics 2016-03-28 D. C. Braun , A. C. Birch , D. Benson , R. F. Stein , Å. Nordlund

The results of determinations of the azimuthal and meridional velocities by time-distance helioseismology from Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory (SDO) from May 2010 to September 2020 at latitudes from…

Solar and Stellar Astrophysics · Physics 2021-02-26 Alexander V. Getling , Alexander G. Kosovichev , Junwei Zhao

We present and discuss results from time-distance helioseismic measurements of meridional circulation in the solar convection zone using 4 years of Doppler velocity observations by the Helioseismic and Magnetic Imager (HMI) onboard the…

Solar and Stellar Astrophysics · Physics 2015-11-11 S. P. Rajaguru , H. M. Antia

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

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 Sun supports a rich spectrum of internal waves that are continuously excited by turbulent convection. The GONG network and the MDI/SOHO space instrument provide an exceptional data base of spatially-resolved observations of solar…

Solar and Stellar Astrophysics · Physics 2015-05-14 L. Gizon , A. C. Birch , H. C. Spruit

Results of forward modelling of acoustic wave propagation in a realistic solar sub-photosphere with two cases of steady horizontal flows are presented and analysed by the means of local helioseismology. The simulations are based on fully…

Astrophysics · Physics 2009-11-13 S. Shelyag , R. Erdelyi , M. J. Thompson

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

Recent progress in realistic simulations of solar convection have given us an unprecedented opportunity to evaluate the robustness of solar interior structures and dynamics obtained by methods of local helioseismology. We present results of…

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