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Related papers: Prediction of Sunspot Cycles by Data Assimilation …

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Working with a two-stage ice sheet model, we explore how statistical data assimilation methods can be used to improve predictions of glacier melt and relatedly, sea level rise. We find that the EnKF improves model runs initialized using…

Dynamical Systems · Mathematics 2023-05-23 Emily Corcoran , Logan Knudsen , Talea Mayo , Hannah Park-Kaufmann , Alexander Robel

The use of different solar activity indices like sunspot numbers, sunspot areas, flare index, magnetic fields, etc., allows us to investigate the time evolution of some specific features of the solar activity and the underlying dynamo…

Solar and Stellar Astrophysics · Physics 2013-10-11 Stefano Sello

A review of solar cycle prediction methods and their performance is given, including forecasts for cycle 24 and focusing on aspects of the solar cycle prediction problem that have a bearing on dynamo theory. The scope of the review is…

Solar and Stellar Astrophysics · Physics 2015-05-20 K. Petrovay

Data assimilation (DA) for compressible flows with shocks is challenging because many classical DA methods generate spurious oscillations and nonphysical features near uncertain shocks. We focus here on the ensemble Kalman filter (EnKF). We…

The Ensemble Kalman Filter (EnKF) is a popular sequential data assimilation method that has been increasingly used for parameter estimation and forecast prediction in epidemiological studies. The observation function plays a critical role…

Methodology · Statistics 2021-07-20 Leah Mitchell , Andrea Arnold

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

In this paper Fourier Transform and Wavelet Transform are applied in case of recent 300 years of sunspot numbers to explain the solar cycles. Here basically parallel study of Fourier and Wavelet analysis are done and we have observed that…

Computational Engineering, Finance, and Science · Computer Science 2013-12-11 Sabyasachi Mukhopadhyay , Debadatta Dash , Asish Mitra , Prasanta K. Panigrahi

The paper presents experiments of driving a physics-based thermosphere model by assimilating electron density (Ne) and temperature (Tn) data using the ensemble adjustment Kalman filter (EAKF) technique. This study not only helps to gauge…

Space Physics · Physics 2019-03-22 Timothy Kodikara , Kefei Zhang

Data assimilation (DA) integrates numerical model forecasts with observations to achieve the optimal state estimation. Ensemble-based methods, such as the ensemble Kalman filter (EnKF), are widely used for state estimation for…

Atmospheric and Oceanic Physics · Physics 2026-05-25 Zhou Yao , Zhilin Li , Li Zhao , Zeng Liu , Zhaokuan Lu , Seungnam Kim , Guangyao Wang

We estimate here a flux-transport dynamo model's response time to changes in meridional flow speed. Time-variation in meridional flow primarily determines the shape of a cycle in this class of dynamo models. In order to simultaneously…

Solar and Stellar Astrophysics · Physics 2015-06-05 Mausumi Dikpati , Jeffrey L. Anderson

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

Accurate and timely prediction of crop growth is of great significance to ensure crop yields and researchers have developed several crop models for the prediction of crop growth. However, there are large difference between the simulation…

Artificial Intelligence · Computer Science 2024-03-07 Siqi Zhou , Ling Wang , Jie Liu , Jinshan Tang

Data assimilation provides algorithms for widespread applications in various fields. It is of practical use to deal with a large amount of information in the complex system that is hard to estimate. Weather forecasting is one of the…

Optimization and Control · Mathematics 2023-03-23 Yihua Yang

Data assimilation (DA) aims to optimally combine model forecasts and observations that are both partial and noisy. Multi-model DA generalizes the variational or Bayesian formulation of the Kalman filter, and we prove that it is also the…

Methodology · Statistics 2023-01-23 Eviatar Bach , Michael Ghil

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

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

The rise and fall in the number of sunspots have served as a lynchpin in many investigations on solar dynamics. Arising from magnetic disturbances in the sun, variations in sunspot numbers have helped define a solar cycle of around eleven…

Solar and Stellar Astrophysics · Physics 2023-06-27 Reynan L. Toledo , Reinabelle Reyes , Christopher C. Bernido

Because of physical assumptions and numerical approximations, low-order models are affected by uncertainties in the state and parameters, and by model biases. Model biases, also known as model errors or systematic errors, are difficult to…

Methodology · Statistics 2024-10-10 Andrea Nóvoa , Alberto Racca , Luca Magri

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

We study the ensemble Kalman filter (EnKF) algorithm for sequential data assimilation in a general situation, that is, for nonlinear forecast and measurement models with non-additive and non-Gaussian noises. Such applications traditionally…

Methodology · Statistics 2018-08-17 Weixuan Li , W. Steven Rosenthal , Guang Lin