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The objective of this article is to use Fourier-Hankel decomposition as suggested earlier by Braun & Fan (1998) to estimate the integrated horizontal meridional flow velocity as a function of mode penetration depth, and to find ways of…

Astrophysics · Physics 2009-11-13 Lars Krieger , Markus Roth , Oskar von der Luehe

Understanding the generation and distribution of the Sun's interior magnetic (B-) field is a longstanding challenge. Here we describe how measurements of the Sun's oscillation eigenfunctions might be used to measure the Sun's interior…

Solar and Stellar Astrophysics · Physics 2017-06-23 Curt Cutler

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

We present an efficient method for two dimensional inversions for the solar rotation rate using the Subtractive Optimally Localized Averages (SOLA) method and a modification of the R1 X R1 technique proposed by Sekii (1993). The SOLA method…

Astrophysics · Physics 2015-06-24 F. P. Pijpers , M. J. Thompson

Normalizing flows are a promising tool for modeling probability distributions in physical systems. While state-of-the-art flows accurately approximate distributions and energies, applications in physics additionally require smooth energies…

Machine Learning · Statistics 2021-12-01 Jonas Köhler , Andreas Krämer , Frank Noé

Context. Local helioseismology has detected spatially extended converging surface flows into solar active regions. These play an important role in flux-transport models of the solar dynamo. Aims. We aim to validate the existence of the…

Solar and Stellar Astrophysics · Physics 2017-10-04 B. Löptien , A. C. Birch , T. L. Duvall , L. Gizon , B. Proxauf , J. Schou

Mapping the large-scale subsurface plasma flow profile within the Sun has been attempted using various methods for several decades. One such flow in particular is the meridional circulation, for which numerous studies have been published.…

Solar and Stellar Astrophysics · Physics 2023-08-23 Aleczander Herczeg , Jason Jackiewicz

Recently discovered inertial waves, observed on the solar surface, likely extend to the deeper layers of the Sun. Utilizing helioseismic techniques, we explore these motions, allowing us to discern inertial-mode eigenfunctions in both…

Solar and Stellar Astrophysics · Physics 2024-03-14 Krishnendu Mandal , Shravan M. Hanasoge

We present in this work the development of a solar data assimilation method based on an axisymmetric mean field dynamo model and magnetic surface data, our mid-term goal is to predict the solar quasi cyclic activity. Here we focus on the…

Solar and Stellar Astrophysics · Physics 2017-11-15 Ching Pui Hung , Allan Sacha Brun , Alexandre Fournier , Laurène Jouve , Olivier Talagrand , Mustapha Zakari

We describe a novel framework for estimating subsurface properties, such as rock permeability and porosity, from time-lapse observed seismic data by coupling full-waveform inversion, subsurface flow processes, and rock physics models. For…

Geophysics · Physics 2020-05-06 Dongzhuo Li , Kailai Xu , Jerry M. Harris , Eric Darve

We present a new method for helioseismic diagnostics of the three-dimensional structure of sound speed, magnetic fields and flow velocities in the convection zone by inversion of acoustic travel-time data. The data are measurements of the…

Solar and Stellar Astrophysics · Physics 2018-06-11 A. G. Kosovichev , T. L. Duvall

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

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

We report our first results on comparing the variations of the solar internal rotation with solar activity, as predicted by non-linear solar dynamo modelling, with helioseismic measurements using the SOHO MDI data.

Astrophysics · Physics 2007-05-23 S. Vorontsov , R. Tavakol , E. Covas , D. Moss

Helioseismic inversions, carried out for several years on various ground-based and spatial observations, have shown that the solar rotation rate presents two principal regimes: a quasi-rigid rotation in the radiative interior and a…

Astrophysics · Physics 2007-05-23 T. Corbard , G. Berthomieu , J. Provost , P. Morel

Stokes inversion techniques are very powerful methods for obtaining information on the thermodynamic and magnetic properties of solar and stellar atmospheres. In recent years, very sophisticated inversion codes have been developed that are…

Solar and Stellar Astrophysics · Physics 2022-03-23 C. J. Díaz Baso , A. Asensio Ramos , J. de la Cruz Rodríguez

Inertial modes have been observed on the Sun at low longitudinal wavenumbers. These modes probe the dynamics and structure of the solar convection zone down to the tachocline. While linear analysis allows the complex eigenfrequencies and…

Solar and Stellar Astrophysics · Physics 2023-05-31 J. Philidet , L. Gizon

This article reviews some of the leading results obtained in solar dynamo physics by using temporal oscillator models as a tool to interpret observational data and dynamo model predictions. We discuss how solar observational data such as…

Solar and Stellar Astrophysics · Physics 2014-07-21 Ilídio Lopes , Dário Passos , Melinda Nagy , Kristof Petrovay

The detection of multiple mode harmonic kink oscillations in coronal loops enables to obtain information on coronal density stratification and magnetic field expansion using seismology inversion techniques. The inference is based on the…

Solar and Stellar Astrophysics · Physics 2015-06-15 I. Arregui , A. Asensio Ramos , A. J. Diaz

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