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Related papers: Helioseismic tests of diffusion theory

200 papers

Estimating and disentangling epistemic uncertainty, uncertainty that is reducible with more training data, and aleatoric uncertainty, uncertainty that is inherent to the task at hand, is critically important when applying machine learning…

Machine Learning · Computer Science 2024-11-08 Matthew A. Chan , Maria J. Molina , Christopher A. Metzler

We consider structural equation modeling (SEM) with latent variables for diffusion processes based on high-frequency data. We derive the quasi-likelihood estimators for parameters in the SEM. The goodness-of-fit test based on the…

Statistics Theory · Mathematics 2022-10-24 Shogo Kusano , Masayuki Uchida

During the last 50 years we have been witness of an extraordinary revolution in the knowledge and understanding of our star thanks to the development of Helioseismology, the study of solar oscillations. Similar to what happens on the Earth…

Solar and Stellar Astrophysics · Physics 2017-06-08 M. P. Di Mauro

We construct updated solar models with different sets of solar abundances, including the most recent determinations by Asplund et al. (2009). The latter work predicts a larger ($\sim 10%$) solar metallicity compared to previous measurements…

Solar and Stellar Astrophysics · Physics 2011-03-31 Aldo Serenelli , Sarbani Basu , Jason W. Ferguson , Martin Asplund

Helioseismology has been widely acclaimed as having been a great success: it appears to have answered nearly all the questions that we originally asked, some with unexpectedly high precision. We have learned how the sound speed and matter…

Solar and Stellar Astrophysics · Physics 2012-10-03 Douglas Gough

Accurate, reliable solar flare prediction is crucial for mitigating potential disruptions to critical infrastructure, while predicting solar flares remains a significant challenge. Existing methods based on heuristic physical features often…

Computer Vision and Pattern Recognition · Computer Science 2025-08-12 Shunya Nagashima , Komei Sugiura

We investigate the effect of localized opacity modifications on the sound-speed profile of solar models. The sound-speed difference between the Sun and a solar model is used to deduce the opacity correction that would be required to bring…

Astrophysics · Physics 2008-02-03 S. C. Tripathy , Sarbani Basu , J. Christensen-Dalsgaard

The solar wind, a stream of charged particles originating from the Sun and transcending interplanetary space, poses risks to technology and astronauts. In this work, we develop a prediction model to forecast the solar wind speed at the…

Solar and Stellar Astrophysics · Physics 2025-01-22 Daniel Collin , Yuri Shprits , Stefan J. Hofmeister , Stefano Bianco , Guillermo Gallego

Context. The metal mass fraction of the Sun Z is a key constraint in solar modelling, but its value is still under debate. The standard solar chemical composition of the late 2000s have the ratio of metals to hydrogen Z/X = 0.0181, with a…

Solar and Stellar Astrophysics · Physics 2023-08-28 G. Buldgen , A. Noels , V. A. Baturin , A. V. Oreshina , S. V. Ayukov , R. Scuflaire , A. M. Amarsi , N. Grevesse

We use a three-dimensional magnetohydrodynamic simulation of the solar wind to calculate cosmic ray diffusion coefficients throughout the inner heliosphere ($2~R_\odot - 3$ AU). The simulation resolves large-scale solar wind flow, which is…

In this paper, we construct background solar models that are stable against convection, by modifying the vertical pressure gradient of Model S (Christensen-Dalsgaard et al., 1996, Science, 272, 1286) relinquishing hydrostatic equilibrium.…

Solar and Stellar Astrophysics · Physics 2015-05-28 Hannah Schunker , Robert Cameron , Laurent Gizon , Hamed Moradi

Weather forecasting remains a crucial yet challenging domain, where recently developed models based on deep learning (DL) have approached the performance of traditional numerical weather prediction (NWP) models. However, these DL models,…

Atmospheric and Oceanic Physics · Physics 2024-02-13 Zhanxiang Hua , Yutong He , Chengqian Ma , Alexandra Anderson-Frey

Solar oscillations frequencies show a distinct change with solar activity. The changes in frequencies can be used to study the time variation of solar structure. We discuss constraints on the changes in solar structure with time as obtained…

Astrophysics · Physics 2007-05-23 Sarbani Basu

The energetic balance of the Standard Solar Model (SSM) results from an equilibrium between nuclear energy production, energy transfer, and photospheric emission. In this letter, we derive an order of magnitude of several % for the loss of…

Solar and Stellar Astrophysics · Physics 2015-05-27 Sylvaine Turck-Chieze , Laurent Piau , Sébastien Couvidat

Oscillations detected on the solar surface provide a unique possibility for investigations of the interior properties of a star. Through major observational efforts, including extensive observations from space, as well as development of…

Astrophysics · Physics 2008-11-26 J. Christensen-Dalsgaard

The SoHO spacecraft made astrophysicists achieve a major breakthrough in the knowledge of the Sun. In helioseismology, both GOLF and MDI experiments aboard SoHO greatly improve the accuracy of seismic data. More specifically, the detection…

Astrophysics · Physics 2009-11-07 S. Couvidat , S. Turck-Chieze , A. G. Kosovichev

The goal of local helioseismology is to elicit three-dimensional information about the sub-surface (or far-side) structure and dynamics of the Sun from observations of the helioseismic wave field at the surface. The physical quantities of…

Solar and Stellar Astrophysics · Physics 2015-05-19 Hannah Schunker

We use very precise frequencies of low-degree solar-oscillation modes measured from 4752 days of data collected by the Birmingham Solar-Oscillations Network (BiSON) to derive seismic information on the solar core. We compare these…

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