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We compare measurements of horizontal flows on the surface of the Sun using helioseismic time--distance inversions and coherent structure tracking of solar granules. Tracking provides 2D horizontal flows on the solar surface, whereas the…

Solar and Stellar Astrophysics · Physics 2015-06-15 M. Svanda , Th. Roudier , M. Rieutord , R. Burston , L. Gizon

Using a 3D global solver of the linearized Euler equations, we model acoustic oscillations over background velocity flow fields of single-cell meridional circulation with deep and shallow return flows as well as double-cell meridional…

Solar and Stellar Astrophysics · Physics 2022-02-15 Andrey M. Stejko , Alexander G. Kosovichev , Valery V. Pipin

Context: Helioseismic inversions rely largely on sensitivity kernels, 3-D spatial functions describing how do the changes in the solar interior translate into the changes of helioseismic observables. These sensitivity kernels come in most…

Solar and Stellar Astrophysics · Physics 2024-09-25 Michal Svanda , Daniel Chmurny

Helioseismic waves observable at the solar surface can be used to probe the properties of the Sun's interior. By measuring helioseismic travel times between different location on the surface, flows and other interior properties can be…

Solar and Stellar Astrophysics · Physics 2021-03-24 Thomas Hartlep , Junwei Zhao

Inversions for local helioseismology are an important and necessary step for obtaining three-dimensional maps of various physical quantities in the solar interior. Frequently, the full inverse problems that one would like to solve prove…

Solar and Stellar Astrophysics · Physics 2015-04-01 J. Jackiewicz , A. C. Birch , L. Gizon , S. M. Hanasoge , T. Hohage , J. -B. Ruffio , M. Svanda

We perform helioseismic holography to assess the noise in p-mode travel-time shifts which would form the basis of inferences of large-scale flows throughout the solar convection zone. We also derive the expected travel times from a…

Astrophysics · Physics 2009-11-13 D. C. Braun , A. C. Birch

In time-distance helioseismology, information about the solar interior is encoded in measurements of travel times between pairs of points on the solar surface. Travel times are deduced from the cross-covariance of the random wave field.…

Solar and Stellar Astrophysics · Physics 2014-09-05 Damien Fournier , Laurent Gizon , Thorsten Hohage , Aaron C. Birch

Global hydrodynamic simulations of internal solar dynamics have focused on replicating the conditions for solar-like differential rotation and meridional circulation using the results of helioseismic inversions as a constraint. Inferences…

We derive expectations for signatures in the measured travel times of waves that interact with thermal anomalies and jets. A series of numerical experiments that involve the dynamic linear evolution of an acoustic wave field in a solar-like…

Astrophysics · Physics 2011-02-11 Shravan M. Hanasoge , Thomas L. Duvall

Time-distance helioseismology has shown that f-mode travel times contain information about horizontal flows in the Sun. The purpose of this study is to provide a simple interpretation of these travel times. We study the interaction of…

Astrophysics · Physics 2009-06-25 J. Jackiewicz , L. Gizon , A. C. Birch , T. L. Duvall

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

The solar meridional flow is a crucial ingredient in modern dynamo theory. Seismic estimates of this flow have, however, been contradictory in deeper layers below about $0.9\,R_\odot$. Results from time-distance helioseismology have so far…

Solar and Stellar Astrophysics · Physics 2017-08-16 Vincent G. A. Böning , Markus Roth , Jason Jackiewicz , Shukur Kholikov

We use a publicly available numerical wave-propagation simulation of Hartlep et al. 2011 to test the ability of helioseismic holography to detect signatures of a compact, fully submerged, 5% sound-speed perturbation placed at a depth of 50…

Solar and Stellar Astrophysics · Physics 2015-06-11 Douglas C. Braun

In the same way that seismologists study the interior of the earth from the waves generated by earthquakes, heliosismology is the science that is interested in the study of oscillatory waves inside the Sun. Temperature, chemical…

Solar and Stellar Astrophysics · Physics 2017-09-22 Massinissa Hadjara

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

Accurate inference of solar meridional flow is of crucial importance for the understanding of solar dynamo process. Wave travel times, as measured on the surface, will change if the waves encounter perturbations e.g. in the sound speed or…

Solar and Stellar Astrophysics · Physics 2018-08-15 K. Mandal , S. M. Hanasoge , S. P. Rajaguru , H. M. Antia

Supergranules are divergent 30-Mm sized cellular flows observed everywhere at the solar photosphere. Their place in the hierarchy of convective structures and their origin remain poorly understood (Rincon et al., 2018). Estimating…

Solar and Stellar Astrophysics · Physics 2019-10-09 Vedant Dhruv , Jishnu Bhattacharya , Shravan Hanasoge

Normal-mode coupling is a helioseismic technique that uses measurements of mode eigenfunctions to infer the interior structure of the Sun. This technique has led to insights into the evolution and structure of toroidal flows in the solar…

Solar and Stellar Astrophysics · Physics 2020-08-21 Prasad Subramanian , Shravan 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

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