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Related papers: Time-Dependence of Subsurface Solar Convection Usi…

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Supergranulation is characterized by horizontally divergent flows with typical length scales of 32 Mm in the solar photosphere. Unlike granulation, the size of which is comparable to both the thickness of the radiative boundary layer and…

Solar and Stellar Astrophysics · Physics 2016-10-05 Jean-Francois Cossette , Mark Peter Rast

Helioseismic inversions reveal a major discrepancy in sound speed between the Sun and the standard solar model just below the base of solar convection zone. We demonstrate that this discrepancy is caused by the inherent shortcomings of the…

Solar and Stellar Astrophysics · Physics 2012-10-17 Chunguang Zhang , Licai Deng , Darun Xiong , Jørgen Christensen-Dalsgaard

Convection plays a central role in the dynamics of any stellar interior, and yet its operation remains largely-hidden from direct observation. As a result, much of our understanding concerning stellar convection necessarily derives from…

Solar and Stellar Astrophysics · Physics 2016-02-17 Nicholas A. Featherstone , Bradley W. Hindman

The solar photosphere provides us with a laboratory for understanding turbulence in a layer where the fundamental processes of transport vary rapidly and a strongly superadiabatic region lies very closely to a subadiabatic layer. Our tools…

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

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

Linear time-distance helioseismic inversions are carried out using several filtering schemes to determine vector flow velocities within two $\sim100^2\,{\rm Mm^2}\times 20\,{\rm Mm}$ realistic magnetohydrodynamic sunspot simulations of…

Solar and Stellar Astrophysics · Physics 2015-06-22 K. DeGrave , J. Jackiewicz , M. Rempel

The global scales of solar convection are studied through three-dimensional simulations of compressible convection carried out in spherical shells of rotating fluid which extend from the base of the convection zone to within 15 Mm of the…

Astrophysics · Physics 2009-11-13 Mark S. Miesch , Allan Sacha Brun , Marc L. Derosa , Juri Toomre

According to time-distance helioseismology, information about internal fluid motions is encoded in the travel times of solar waves. The inverse problem consists of inferring 3-D vector flows from a set of travel-time measurements. Here we…

Solar and Stellar Astrophysics · Physics 2015-05-27 M. Svanda , L. Gizon , S. M. Hanasoge , S. D. Ustyugov

Convection is the mechanism by which energy is transported through the outermost 30% of the Sun. Solar turbulent convection is notoriously difficult to model across the entire convection zone where the density spans many orders of…

Solar and Stellar Astrophysics · Physics 2012-08-31 Laurent Gizon , Aaron C. Birch

The consistency of time--distance inversions for horizontal components of the plasma flow on supergranular scales in the upper solar convection zone is checked by comparing the results derived using two k--\omega filtering procedures --…

Solar and Stellar Astrophysics · Physics 2015-06-16 Michal Svanda

As large--distance rays (say, 10\,-\,$24 ^\circ$) approach the solar surface approximately vertically, travel times measured from surface pairs for these large separations are mostly sensitive to vertical flows, at least for shallow flows…

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

Meridional flow is thought to play a very important role in the dynamics of the solar convection zone; however, because of its relatively small amplitude, precisely measuring it poses a significant challenge. Here we present a complete…

Solar and Stellar Astrophysics · Physics 2015-06-02 J. Jackiewicz , A. Serebryanskiy , S. Kholikov

Frequencies of intermediate-degree f-modes of the Sun seem to indicate that the solar radius is smaller than what is normally used in constructing solar models. We investigate the possible consequences of an error in radius on results for…

Astrophysics · Physics 2009-10-30 Sarbani Basu

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

I represent results three-dimensional numerical simulation of solar surface convection on scales local supergranulation with realistic model physics. I study thermal structure of convective motions in photosphere, the range of convection…

Astrophysics · Physics 2009-11-13 Sergey Ustyugov

We present a formalism for investigating the interaction between pmode oscillations and convection by analyzing realistic, three-dimensional simulations of the near-surface layers of the solar convection zone. By choosing suitable…

Astrophysics · Physics 2009-10-31 Å. Nordlund , R. F. Stein

We derive formulae connecting the frequency variations in the spectrum of solar oscillations to the dynamical quantities that are expected to change over the solar activity cycle. This is done for both centroids and the asymmetric part of…

Astrophysics · Physics 2009-11-10 W. A. Dziembowski , P. R. Goode

Using a nonlinear mean-field solar dynamo model, we study relationships between the amplitude of the `extended' mode of migrating zonal flows (`torsional oscillations') and magnetic cycles, and investigate whether properties the torsional…

Solar and Stellar Astrophysics · Physics 2020-09-02 V. V. Pipin , A. G. Kosovichev

Time-distance helioseismology is the method of the study of the propagation of waves through the solar interior via the travel times of those waves. The travel times of wave packets contain information about the conditions in the interior…

Solar and Stellar Astrophysics · Physics 2019-02-20 David Korda , Michal Švanda