English
Related papers

Related papers: Assimilating data into an {\alpha}{\omega} dynamo …

200 papers

We propose a novel learning-based surrogate data assimilation (DA) model for efficient state estimation in a limited area. Our model employs a feedforward neural network for online computation, eliminating the need for integrating…

Numerical Analysis · Mathematics 2023-07-17 Wei Kang , Liang Xu , Hong Zhou

Galactic dynamo models have generally relied on input parameters that are very challenging to constrain. We address this problem by developing a model that uses observable quantities as input: the galaxy rotation curve, the surface…

Astrophysics of Galaxies · Physics 2024-04-04 Luke Chamandy , Rion Glenn Nazareth , Gayathri Santhosh

Dynamo models relying on the Babcock-Leighton mechanism are successful in reproducing most of the solar magnetic field dynamical characteristics. However, considering that such models operate only above a lower magnetic field threshold,…

Solar and Stellar Astrophysics · Physics 2013-07-17 Sabrina Sanchez , Alexandre Fournier , Katia Pinheiro , Julien Aubert

We investigate the behaviour of $\alpha\Omega$ dynamos with a dynamic $\alpha$, whose evolution is governed by the imbalance between a driving and a damping term. We focus on truncated versions of such dynamo models which are often studied…

Astrophysics · Physics 2007-05-23 Eurico Covas , Andrew Tworkowski , Axel Brandenburg , Reza Tavakol

For the Research Topic Data Assimilation and Control: Theory and Applications in Life Sciences we first review the formulation of statistical data assimilation (SDA) and discuss algorithms for exploring variational approximations to the…

Neurons and Cognition · Quantitative Biology 2018-09-17 Anna Miller , Dawei Li , Jason Platt , Arij Daou , Daniel Margoliash , Henry Abarbanel

Data assimilation combines prior (or background) information with observations to estimate the initial state of a dynamical system over a given time-window. A common application is in numerical weather prediction where a previous forecast…

Optimization and Control · Mathematics 2021-07-27 Coralia Cartis , Maha H. Kaouri , Amos S. Lawless , Nancy K. Nichols

We give a short introduction to the subject and review advances in understanding the basic ingredients of the mean-field dynamo theory. The discussion includes the recent analytic and numerical work in developments for the mean…

Solar and Stellar Astrophysics · Physics 2015-06-12 V. V. Pipin

In-situ measurements of the solar wind, a turbulent and anisotropic plasma flow originating at the Sun, are mostly carried out by single spacecraft, resulting in one-dimensional time series. The conversion of these measurements to the…

Solar and Stellar Astrophysics · Physics 2024-05-22 Norbert Magyar , Jaye Verniero , Adam Szabo , Jiyuan Zhang , Tom Van Doorsselaere

Fluctuations in the Sun's magnetic activity, including episodes of grand minima such as the Maunder minimum have important consequences for space and planetary environments. However, the underlying dynamics of such extreme fluctuations…

Solar and Stellar Astrophysics · Physics 2014-06-12 Soumitra Hazra , Dário Passos , Dibyendu Nandy

Although the occurrence of solar irradiance variations induced by magnetic surface features (e.g., sunspots, faculae, magnetic network) is generally accepted, the existence of intrinsic luminosity changes due to the internal magnetic fields…

Solar and Stellar Astrophysics · Physics 2018-12-26 F. Spada , R. Arlt , M. Kueker , S. Sofia

We propose a new method for combining in situ buoy measurements with Earth system models (ESMs) to improve the accuracy of temperature predictions in the ocean. The technique utilizes the dynamics \textit{and} modes identified in ESMs…

Atmospheric and Oceanic Physics · Physics 2024-06-21 Derek DeSantis , Ayan Biswas , Earl Lawrence , Phillip Wolfram

Traditional data assimilation uses information obtained from the propagation of one physics-driven model and combines it with information derived from real-world observations in order to obtain a better estimate of the truth of some natural…

Computational Engineering, Finance, and Science · Computer Science 2022-10-24 Andrey A Popov , Adrian Sandu

This study evaluates a data assimilation framework based on reduced-order modeling (ROM-DA), complemented by a hybrid data-filling strategy, to reconstruct dynamic temperature fields in a phase-change-material (PCM) integrated solar chimney…

Numerical Analysis · Mathematics 2025-10-21 Diego R. Rivera , Ernesto Castillo , Felipe Galarce , Douglas R. Q. Pacheco

We commonly refer to state-estimation theory in geosciences as data assimilation. This term encompasses the entire sequence of operations that, starting from the observations of a system, and from additional statistical and dynamical…

Atmospheric and Oceanic Physics · Physics 2018-06-11 Alberto Carrassi , Marc Bocquet , Laurent Bertino , Geir Evensen

Understanding the reasons of the cyclic variation of the total solar irradiance is one of the most challenging targets of modern astrophysics. These studies prove to be essential also for a more climatologic issue, associated to the global…

Solar and Stellar Astrophysics · Physics 2011-03-28 P. Ventura , V. Penza , L. Li , S. Sofia , S. Basu , P. Demarque

Data assimilation is widely used in many disciplines such as meteorology, oceanography, and robotics to estimate the state of a dynamical system from noisy observations. In this work, we propose a lightweight and general method to perform…

Machine Learning · Computer Science 2025-10-02 Thomas Savary , François Rozet , Gilles Louppe

Motivated by the challenge of moment recovery in hydrodynamic approximation in kinetic theory, we propose a data-driven approach for the hydrodynamic models. Inspired by continuous data assimilation, our method introduces a relaxation-based…

Numerical Analysis · Mathematics 2025-07-25 Jingcheng Lu , Kunlun Qi , Li Wang , Jeff Calder

The implicit particle filter is a sequential Monte Carlo method for data assimilation that guides the particles to the high-probability regions via a sequence of steps that includes minimizations. We present a new and more general…

Data Analysis, Statistics and Probability · Physics 2017-02-01 Ethan Atkins , Matthias Morzfeld , Alexandre J. Chorin

We present a method of conducting data-driven simulations of solar active regions and flux emergence with the MURaM radiative magnetohydrodynamics (MHD) code. The horizontal electric field derived from the full velocity and magnetic…

Solar and Stellar Astrophysics · Physics 2023-06-14 Feng Chen , Mark C. M. Cheung , Matthias Rempel , Georgios Chintzoglou

Feature tracking and recognition are increasingly common tools for data analysis, but are typically implemented on an ad-hoc basis by individual research groups, limiting the usefulness of derived results when selection effects and…

Astrophysics · Physics 2009-06-23 C. E. DeForest , H. J. Hagenaar , D. A. Lamb , C. E. Parnell , B. T. Welsch
‹ Prev 1 8 9 10 Next ›