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Shallow water equations are extensively considered in the domains of oceans, atmospheric modelling, and engineering research (Franca et al., 2022), which play significant roles in floods and tsunami governance. Nonetheless, the accurate…

Fluid Dynamics · Physics 2023-09-22 Ruijia Yu

Data assimilation (DA) integrates observations with model forecasts to produce optimized atmospheric states, whose physical consistency is critical for stable weather forecasting and reliable climate research. Traditional Bayesian DA…

Atmospheric and Oceanic Physics · Physics 2026-03-05 Hang Fan , Lei Bai , Ben Fei , Yi Xiao , Kun Chen , Yubao Liu , Yongquan Qu , Fenghua Ling , Pierre Gentine

The review describes the development of ideas Gury Ivanovich Marchuk in the field of variational data assimilation for ocean models applied in particular in coupled models for long-range weather forecasts. Particular attention is paid to…

Atmospheric and Oceanic Physics · Physics 2016-01-07 Christine Kazantsev , Eugene Kazantsev , Mikhail Tolstykh

Data assimilation (DA) in the geophysical sciences remains the cornerstone of robust forecasts from numerical models. Indeed, DA plays a crucial role in the quality of numerical weather prediction, and is a crucial building block that has…

The understanding of nonlinear, high dimensional flows, e.g, atmospheric and ocean flows, is critical to address the impacts of global climate change. Data Assimilation techniques combine physical models and observational data, often in a…

A simplified model of natural convection, similar to the Lorenz (1963) system, is compared to computational fluid dynamics simulations in order to test data assimilation methods and better understand the dynamics of convection. The…

Dynamical Systems · Mathematics 2012-04-23 Kameron Decker Harris , El Hassan Ridouane , Darren L. Hitt , Christopher M. Danforth

Data assimilation refers to the process of obtaining an estimate of a system's state using a model for the system's time evolution and a time series of measurements that are possibly noisy and incomplete. However, for practical reasons, the…

Chaotic Dynamics · Physics 2007-05-23 Matthew Cornick , Brian Hunt , Edward Ott , Michael F. Schatz

Data assimilation refers to the problem of finding trajectories of a prescribed dynamical model in such a way that the output of the model (usually some function of the model states) follows a given time series of observations. Typically…

Atmospheric and Oceanic Physics · Physics 2015-05-30 Jochen Bröcker , Ivan G. Szendro

Data assimilation is a method that combines observations (that is, real world data) of a state of a system with model output for that system in order to improve the estimate of the state of the system and thereby the model output. The model…

Numerical Analysis · Mathematics 2020-05-18 Melina A. Freitag

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

A thermal convection loop is a circular chamber filled with water, heated on the bottom half and cooled on the top half. With sufficiently large forcing of heat, the direction of fluid flow in the loop oscillates chaotically, forming an…

Dynamical Systems · Mathematics 2016-06-24 Andrew J. Reagan

Four-dimensional variational data assimilation (4D-Var) on a seasonal-to-interdecadal time scale under the existence of unstable modes can be viewed as an optimization problem of synchronized, coupled chaotic systems. The problem is tackled…

Data Analysis, Statistics and Probability · Physics 2015-11-17 Nozomi Sugiura , Shuhei Masuda , Yosuke Fujii , Masafumi Kamachi , Yoichi Ishikawa , Toshiyuki Awaji

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) is a fundamental computational technique that integrates numerical simulation models and observation data on the basis of Bayesian statistics. Originally developed for meteorology, especially weather forecasting, DA…

We develop an algebraic framework for sequential data assimilation of partially observed dynamical systems. In this framework, Bayesian data assimilation is embedded in a non-abelian operator algebra, which provides a representation of…

Statistics Theory · Mathematics 2023-03-29 David Freeman , Dimitrios Giannakis , Brian Mintz , Abbas Ourmazd , Joanna Slawinska

This paper applies variational data assimilation to inundation problems governed by the shallow water equations with wetting and drying. The objective of the assimilation is to recover an unknown time-varying wave profile at an open ocean…

Fluid Dynamics · Physics 2017-06-07 S. W Funke , P. E Farrell , M. D. Piggott

Data assimilation addresses the general problem of how to combine model-based predictions with partial and noisy observations of the process in an optimal manner. This survey focuses on sequential data assimilation techniques using…

Numerical Analysis · Mathematics 2019-08-15 Sebastian Reich

Dynamical weather and climate prediction models underpin many studies of the Earth system and hold the promise of being able to make robust projections of future climate change based on physical laws. However, simulations from these models…

Atmospheric and Oceanic Physics · Physics 2019-09-04 Peter A. G. Watson

In meteorology, engineering and computer sciences, data assimilation is routinely employed as the optimal way to combine noisy observations with prior model information for obtaining better estimates of a state, and thus better forecasts,…

Geophysics · Physics 2009-08-12 M. J. Werner , K. Ide , D. Sornette

This paper presents a novel centralized, variational data assimilation approach for calibrating transient dynamic models in electrical power systems, focusing on load model parameters. With the increasing importance of inverter-based…

Optimization and Control · Mathematics 2023-11-15 Ahmed Attia , D. Adrian Maldonado , Emil Constantinescu , Mihai Anitescu