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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 show how magnetic observations of the Sun can be used in conjunction with an axisymmetric flux-transport solar dynamo model in order to estimate the large-scale meridional circulation throughout the convection zone. Our innovative…

Solar and Stellar Astrophysics · Physics 2017-10-06 Ching Pui Hung , Laurène Jouve , Allan Sacha Brun , Alexandre Fournier , Olivier Talagrand

Variational Data Assimilation (DA) has enabled huge improvements in the skill of operational weather forecasting. In this study, we use a simple solar-wind propagation model to develop the first solar-wind variational DA scheme. This scheme…

Space Physics · Physics 2018-10-19 Matthew Lang , Mathew Owens

Forecasting future solar activity has become crucial in our modern world, where intense eruptive phenomena mostly occurring during solar maximum are likely to be strongly damaging to satellites and telecommunications. We present a 4D…

Solar and Stellar Astrophysics · Physics 2025-07-02 L. Jouve , C. P. Hung , A. S. Brun , S. Hazra , A. Fournier , O. Talagrand , B. Perri , A. Strugarek

Secular variations of the geomagnetic field have been measured with a continuously improving accuracy during the last few hundred years, culminating nowadays with satellite data. It is however well known that the dynamics of the magnetic…

Geophysics · Physics 2015-10-28 Alexandre Fournier , Céline Eymin , Thierry Alboussière

We review recent advances and results in enhancing and developing helioseismic analysis methods and in solar data assimilation. In the first part of this paper we will focus on selected developments in time-distance and global…

Solar and Stellar Astrophysics · Physics 2016-03-16 Ariane Schad , Laurene Jouve , Tom L. Duvall , Markus Roth , Sergei V. Vorontsov

This paper is a contribution in the context of variational data assimilation combined with statistical learning. The framework of data assimilation traditionally uses data collected at sensor locations in order to bring corrections to a…

Numerical Analysis · Mathematics 2023-05-09 Amina Benaceur , Barbara Verfürth

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

Variational data assimilation optimizes for an initial state of a dynamical system such that its evolution fits observational data. The physical model can subsequently be evolved into the future to make predictions. This principle is a…

Machine Learning · Computer Science 2021-05-21 Thomas Frerix , Dmitrii Kochkov , Jamie A. Smith , Daniel Cremers , Michael P. Brenner , Stephan Hoyer

Context: Most solar and stellar dynamo models use the alpha-Omega scenario where the magnetic field is generated by the interplay between differential rotation (the Omega effect) and a mean electromotive force due to helical turbulent…

Solar and Stellar Astrophysics · Physics 2009-12-08 N. Seehafer , V. V. Pipin

It can be shown on observational grounds that two basic effects of dynamo theory for solar activity - production of the toroidal field from the poloidal one by differential rotation and reverse conversion of the toroidal field to the…

Solar and Stellar Astrophysics · Physics 2015-06-19 L. L. Kitchatinov

The prediction of solar flares is still a significant challenge in space weather research, with no techniques currently capable of producing reliable forecasts performing significantly above climatology. In this paper, we present a flare…

Solar and Stellar Astrophysics · Physics 2022-10-12 Christian Thibeault , Antoine Strugarek , Paul Charbonneau , Benoit Tremblay

An essential ingredient in kinematic dynamo models is the velocity field within the solar convection zone. In particular, the differential rotation is now well constrained by helioseismic observations. Helioseismology also gives us…

Astrophysics · Physics 2009-06-30 Andrés Muñoz-Jaramillo , Dibyendu Nandy , Petrus C. H. Martens

Physical models aimed to reproduce basic features of the solar sunspot cycle are typically based on the solar dynamo mechanism. Usually qualitative arguments are used to define parameters of the model, among which a challenging component is…

Solar and Stellar Astrophysics · Physics 2026-03-12 E. Illarionov , R. Stepanov , K. M. Kuzanyan , V. Kisielius

The solar surface dynamo has become an active area of research in an attempt to understand the origin of a variety of magnetic field structures on the sun. The major modification that needs to be incorporated in the standard dynamo process…

Solar and Stellar Astrophysics · Physics 2009-03-23 V. Krishan

Data Assimilation (DA) is a computational tool that uses value from the model and the real measurement to arrive to an optimally acceptable value. Rather, this technique relies on the idea of Kalman gain. We point out that DA has two…

Optimization and Control · Mathematics 2020-12-15 Mohammad N. Murshed , Zarin Subah , M. Monir Uddin

Data assimilation techniques, developed in the last two decades mainly for weather prediction, produce better forecasts by taking advantage of both theoretical/numerical models and real-time observations. In this paper, we explore the…

Astrophysics · Physics 2015-05-13 Eric Bélanger , Alain Vincent , Paul Charbonneau

Increasing observations are becoming available about a relatively weak, but persistent, non-axisymmetric magnetic field co-existing with the dominant axisymmetric field on the Sun. It indicates that the non-axisymmetric magnetic field plays…

Astrophysics · Physics 2008-11-26 J. Jiang , J. X. Wang

The solar coronal magnetic field is a pivotal element in the study of eruptive phenomena, and understanding its dynamic evolution has long been a focal point in solar physics. Numerical models, driven directly by observation data, serve as…

Solar and Stellar Astrophysics · Physics 2024-10-15 Zhi-Peng Liu , Chao-Wei Jiang , Xin-Kai Bian , Qing-Jun Liu , Peng Zou , Xue-Shang Feng

In this work, we introduce a novel generative denoising diffusion model for synthesizing the Sun's three-dimensional coronal magnetic field, a complex and dynamic region characterized by evolving magnetic structures. Despite daily…

Solar and Stellar Astrophysics · Physics 2025-10-03 Daniel E. da Silva , Michael Kirk , Nat Mathews , Andrés Muñoz-Jaramillo
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