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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

Model uncertainty quantification is an essential component of effective data assimilation. Model errors associated with sub-grid scale processes are often represented through stochastic parameterizations of the unresolved process. Many…

Methodology · Statistics 2021-04-13 Sahani Pathiraja , Peter Jan van Leeuwen

This study evaluates the effectiveness of three-dimensional variational (3D-Var) data assimilation coupled with a Rapid Update Cycle (RUC) framework for improving short-range precipitation forecasts over the Indonesian Maritime Continent…

Continuous data assimilation (CDA) is successfully implemented for the first time for efficient dynamical downscaling of a global atmospheric reanalysis. A comparison of the performance of CDA with the standard grid and spectral nudging…

Atmospheric and Oceanic Physics · Physics 2019-07-31 Srinivas Desamsetti , Hari Prasad Dasari , Sabique Langodan , Edriss S Titi , Omar Knio , Ibrahim Hoteit

Improved estimation of hydrometeorological states from down-sampled observations and background model forecasts in a noisy environment, has been a subject of growing research in the past decades. Here, we introduce a unified framework that…

Data Analysis, Statistics and Probability · Physics 2014-09-15 Ardeshir Mohammad Ebtehaj , Efi Foufoula-Georgiou

Data-driven prediction and physics-agnostic machine-learning methods have attracted increased interest in recent years achieving forecast horizons going well beyond those to be expected for chaotic dynamical systems. In a separate strand of…

Data Analysis, Statistics and Probability · Physics 2021-05-19 Georg A. Gottwald , Sebastian Reich

Using a dynamical model to make predictions about a system has many sources of error. These can include errors in how the model was initialised but also errors in the dynamics of the model itself. For many applications in data assimilation,…

Numerical Analysis · Mathematics 2025-07-07 P. A. Browne

A Bayesian data assimilation scheme is formulated for advection-dominated or hyperbolic evolutionary problems, and observations. The method is referred to as the dynamic likelihood filter because it exploits the model physics to dynamically…

Dynamical Systems · Mathematics 2017-04-26 Juan M. Restrepo

Data assimilation (DA) integrates observations with a dynamical model to estimate states of PDE-governed systems. Model-driven methods (e.g., Kalman, particle) presuppose full knowledge of the true dynamics, which is not always satisfied in…

Signal Processing · Electrical Eng. & Systems 2025-06-06 Siyi Chen , Yixuan Jia , Qing Qu , He Sun , Jeffrey A Fessler

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

Data assimilation (DA) aims to estimate the full state of a dynamical system by combining partial and noisy observations with a prior model forecast, commonly referred to as the background. In atmospheric applications, this problem is…

Atmospheric and Oceanic Physics · Physics 2025-05-29 Jing-An Sun , Hang Fan , Junchao Gong , Ben Fei , Kun Chen , Fenghua Ling , Wenlong Zhang , Wanghan Xu , Li Yan , Pierre Gentine , Lei Bai

Data assimilation schemes are confronted with the presence of model errors arising from the imperfect description of atmospheric dynamics. These errors are usually modeled on the basis of simple assumptions such as bias, white noise, first…

Chaotic Dynamics · Physics 2009-11-13 A. Carrassi , S. Vannitsem , C. Nicolis

We develop an optimal experimental design framework for adapting the covariance inflation and localization in data assimilation problems. Covariance inflation and localization are ubiquitously employed to alleviate the effect of using…

Computational Engineering, Finance, and Science · Computer Science 2019-03-26 Ahmed Attia , Emil Constantinescu

Data assimilation (DA) estimates the state of an evolving dynamical system from noisy, partial observations, and is widely used in scientific simulation as well as weather and climate science. In practice, filtering methods rely on…

Image and Video Processing · Electrical Eng. & Systems 2026-05-15 Yixuan Jia , Siyi Chen , Yida Pan , Xiao Li , Lianghe Shi , Chanyong Jung , Haijie Yuan , Ismail Alkhouri , Yue Cynthia Wu , Saiprasad Ravishankar , Jeffrey A Fessler , Qing Qu

Wind speed at sea surface is a key quantity for a variety of scientific applications and human activities. Due to the non-linearity of the phenomenon, a complete description of such variable is made infeasible on both the small scale and…

Machine Learning · Computer Science 2024-10-28 Matteo Zambra , Nicolas Farrugia , Dorian Cazau , Alexandre Gensse , Ronan Fablet

Data assimilation is uniquely challenging in weather forecasting due to the high dimensionality of the employed models and the nonlinearity of the governing equations. Although current operational schemes are used successfully, our…

Atmospheric and Oceanic Physics · Physics 2018-05-09 Lea Oljača , Jochen Bröcker , Tobias Kuna

In this paper we propose the use of a continuous data assimilation algorithm for miscible flow models in a porous medium. In the absence of initial conditions for the model, observed sparse measurements are used to generate an approximation…

Numerical Analysis · Mathematics 2022-06-23 Hakima Bessaih , Victor Ginting , Bradley McCaskill

Data assimilation is a vital component in modern global medium-range weather forecasting systems to obtain the best estimation of the atmospheric state by combining the short-term forecast and observations. Recently, AI-based data…

Machine Learning · Computer Science 2024-06-05 Kun Chen , Tao Chen , Peng Ye , Hao Chen , Kang Chen , Tao Han , Wanli Ouyang , Lei Bai

Data assimilation algorithms combine prior and observational information, weighted by their respective uncertainties, to obtain the most likely posterior of a dynamical system. In variational data assimilation the posterior is computed by…

Numerical Analysis · Mathematics 2021-05-24 Jemima M. Tabeart , Sarah L. Dance , Amos S. Lawless , Nancy K. Nichols , Joanne A. Waller

A lot of work has been done to reach the best possible performance of predictive models on images. There are fewer studies about the resilience of these models when they are trained on image datasets that suffer modifications altering their…

Computer Vision and Pattern Recognition · Computer Science 2023-01-19 Pau Gallés , Katalin Takats , Javier Marin