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The concept of surface-flux transport (SFT) is commonly used in evolving models of the large-scale solar surface magnetic field. These photospheric models are used to determine the large-scale structure of the overlying coronal magnetic…

Solar and Stellar Astrophysics · Physics 2023-04-12 Graham Barnes , Marc L. DeRosa , Shaela I. Jones , Charles N. Arge , Carl J. Henney , Mark C. M. Cheung

The multi-scale structure of the solar surface magnetic field is essential for understanding both the Sun's internal dynamo processes and its external magnetic activity. The surface flux transport (SFT) model has been successful in…

Solar and Stellar Astrophysics · Physics 2025-09-09 Yukun Luo , Jie Jiang , Ruihui Wang

Global maps of the solar photospheric magnetic flux are fundamental drivers for simulations of the corona and solar wind and therefore are important predictors of geoeffective events. However, observations of the solar photosphere are only…

Mathematical Physics · Physics 2015-06-23 Kyle S. Hickmann , Humberto C. Godinez , Carl J. Henney , C. Nick Arge

Maps of the magnetic field at the Sun's surface are commonly used as boundary conditions in space-weather modeling. However, continuous observations are only available from the Sun's Earth-facing side. One commonly used approach to mitigate…

Solar and Stellar Astrophysics · Physics 2024-12-02 Dan Yang , Stephan G. Heinemann , Robert H. Cameron , Laurent Gizon

Accurate knowledge of time-variation in meridional flow-speed and profile is crucial for estimating a solar cycle's features, which are ultimately responsible for causing space climate variations. However, no consensus has been reached yet…

Solar and Stellar Astrophysics · Physics 2014-08-22 Mausumi Dikpati , Jeffrey L. Anderson , Dhrubaditya Mitra

Complex systems are often described with competing models. Such divergence of interpretation on the system may stem from model fidelity, mathematical simplicity, and more generally, our limited knowledge of the underlying processes.…

Numerical Analysis · Mathematics 2017-07-21 Lun Yang , Akil Narayan , Peng Wang

Prediction of solar activity cycles is challenging because physical processes inside the Sun involve a broad range of multiscale dynamics that no model can reproduce and because the available observations are highly limited and cover mostly…

Solar and Stellar Astrophysics · Physics 2020-09-30 Irina N. Kitiashvili

Observations the Sun's photospheric magnetic field are often confined to the Sun-Earth line. Surface flux transport (SFT) models, such as the Advective Flux Transport (AFT) model, simulate the evolution of the photospheric magnetic field to…

Solar and Stellar Astrophysics · Physics 2024-04-09 Lisa A. Upton , Ignacio Ugarte-Urra , Harry P. Warren , David H. Hathaway

Global solar photospheric magnetic maps play a critical role in solar and heliospheric physics research. Routine magnetograph measurements of the field occur only along the Sun-Earth line, leaving the far-side of the Sun unobserved. Surface…

Active regions (ARs) play an important role in the magnetic dynamics of the Sun. Solar surface flux transport models (SFTMs) are used to describe the evolution of the radial magnetic field at the solar surface. There is however uncertainty…

Solar and Stellar Astrophysics · Physics 2022-03-30 Nils Gottschling , Hannah Schunker , Aaron C. Birch , Robert Cameron , Laurent Gizon

Accurately modeling the solar magnetic field is important for understanding long-term solar activity and space weather, but it is challenging due to limited observations, especially near the poles. The Surface Flux Transport (SFT) model…

Solar and Stellar Astrophysics · Physics 2026-03-25 Subhadip Pal , Gopal Hazra , Sudip Mandal

The coupled evolution of the magnetic field and the flow at the Earth's core mantle boundary is modeled within the 1900.0-2014.0 time period. To constraint the dynamical behavior of the system with a core field model deriving from direct…

The choice of free parameters in surface flux transport (SFT) models describing the evolution of the large-scale poloidal magnetic field of the Sun is critical for the correct reproduction of the polar magnetic flux built up during a solar…

Solar and Stellar Astrophysics · Physics 2019-12-18 K. Petrovay , M. Talafha

The surface flux transport (SFT) model of solar magnetic fields involves empirically well-constrained velocity and magnetic fields. The basic evolution of the Sun's large-scale surface magnetic field is well described by this model. The…

Solar and Stellar Astrophysics · Physics 2015-06-05 R. H. Cameron , D. Schmitt , J. Jiang , E. Isik

The solar wind (SW) is a vital component of space weather, providing a background for solar transients such as coronal mass ejections, stream interaction regions, and energetic particles propagating toward Earth. Accurate prediction of…

Solar and Stellar Astrophysics · Physics 2025-08-25 Dinesha V. Hegde , Tae K. Kim , Nikolai V. Pogorelov , Shaela I. Jones , Charles N. Arge

The FFT EnKF data assimilation method is proposed and applied to a stochastic cell simulation of an epidemic, based on the S-I-R spread model. The FFT EnKF combines spatial statistics and ensemble filtering methodologies into a localized…

Computation · Statistics 2010-03-10 Jan Mandel , Jonathan D. Beezley , Loren Cobb , Ashok Krishnamurthy

We review the surface flux transport model for the evolution of magnetic flux patterns on the Sun's surface. Our underlying motivation is to understand the model's prediction of the polar field (or axial dipole) strength at the end of the…

Solar and Stellar Astrophysics · Physics 2023-05-31 Anthony R. Yeates , Mark C. M. Cheung , Jie Jiang , Kristof Petrovay , Yi-Ming Wang

Aims: We aim to determine the effect of converging flows on the evolution of a bipolar magnetic region (BMR), and to investigate the role of these inflows in the generation of poloidal flux. We also discuss whether the flux dispersal due to…

Solar and Stellar Astrophysics · Physics 2016-01-27 David Martin-Belda , Robert H. Cameron

Filtering - the task of estimating the conditional distribution for states of a dynamical system given partial and noisy observations - is important in many areas of science and engineering, including weather and climate prediction.…

Machine Learning · Computer Science 2025-03-25 Eviatar Bach , Ricardo Baptista , Enoch Luk , Andrew Stuart

In this paper, we introduce a new, local formulation of the ensemble Kalman Filter approach for atmospheric data assimilation. Our scheme is based on the hypothesis that, when the Earth's surface is divided up into local regions of moderate…

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