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Related papers: Data assimilation for stratified convection

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This paper proposes an extension to the classical 3D variational data assimilation approach by explicitly incorporating as a prior information, the transform-domain sparsity observed in a large class of geophysical signals. In particular,…

Data Analysis, Statistics and Probability · Physics 2012-07-03 Ardeshir M. Ebtehaj , Efi Foufoula-Georgiou , Sara Q. Zhang , Arthur Y. Hou

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

In this study, two classes of methods including statistical and variational data assimilation algorithms will be described. In statistical methods, the model state is updated sequentially based on the previous estimate. Variational methods,…

Systems and Control · Electrical Eng. & Systems 2021-10-25 Loc Luong

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

In applications such as free-space optical communication, a signal is often recovered after propagation through a turbulent medium. In this setting, it is common to assume that limited information is known about the turbulent medium, such…

Optics · Physics 2025-10-13 Anjali Nair , Qin Li , Samuel N. Stechmann

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

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

We study the numerical performance of a continuous data assimilation (downscaling) algorithm, based on ideas from feedback control theory, in the context of the two-dimensional incompressible Navier--Stokes equations. Our model problem is…

Dynamical Systems · Mathematics 2016-05-04 Masakazu Gesho , Eric Olson , Edriss S. Titi

In this paper we propose a continuous data assimilation (downscaling) algorithm for a two-dimensional B\'enard convection problem. Specifically we consider the two-dimensional Boussinesq system of a layer of incompressible fluid between two…

Analysis of PDEs · Mathematics 2017-02-01 Aseel Farhat , Evelyn Lunasin , Edriss S. Titi

Variational data assimilation is a technique for combining measured data with dynamical models. It is a key component of Earth system state estimation and is commonly used in weather and ocean forecasting. The approach involves a…

Numerical Analysis · Mathematics 2026-04-30 I. Daužickaitė , M. A. Freitag , S. Gürol , A. S. Lawless , A. Ramage , J. A. Scott , J. M. Tabeart

We show how magnetic observations of the Sun can be used in conjunction with an axisymmetric flux-transport solar dynamo model in order to estimate the large-scale meridional circulation throughout the convection zone. Our innovative…

Solar and Stellar Astrophysics · Physics 2017-10-06 Ching Pui Hung , Laurène Jouve , Allan Sacha Brun , Alexandre Fournier , Olivier Talagrand

Data assimilation is an iterative approach to the problem of estimating the state of a dynamical system using both current and past observations of the system together with a model for the system's time evolution. Rather than solving the…

Data Analysis, Statistics and Probability · Physics 2007-05-23 Brian R. Hunt , Eric J. Kostelich , Istvan Szunyogh

We adapt a previously introduced continuous in time data assimilation (downscaling) algorithm for the 2D Navier-Stokes equations to the more realistic case when the measurements are obtained discretely in time and may be contaminated by…

Analysis of PDEs · Mathematics 2016-05-24 Ciprian Foias , Cecilia F. Mondaini , Edriss S. Titi

We introduce a continuous (downscaling) data assimilation algorithm for the 2D B\'enard convection problem using vorticity or local circulation measurements only. In this algorithm, a nudging term is added to the vorticity equation to…

Analysis of PDEs · Mathematics 2017-09-11 Aseel Farhat , Hans Johnston , Michael S. Jolly , Edriss S. Titi

Various types of measurement techniques, such as Light Detection and Ranging (LiDAR) devices, anemometers, and wind vanes, are extensively utilized in wind energy to characterize the inflow. However, these methods typically gather data at…

Fluid Dynamics · Physics 2025-02-13 Chang Yan , Shengfeng Xu , Zhenxu Sun , Thorsten Lutz , Dilong Guo , Guowei Yang

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…

The URANS equations provide a computationally efficient tool to simulate unsteady turbulent flows for a wide range of applications. To account for the errors introduced by the turbulence closure model, recent works have adopted data…

Fluid Dynamics · Physics 2025-01-22 Justin Plogmann , Oliver Brenner , Patrick Jenny

This paper studies the role of sparse regularization in a properly chosen basis for variational data assimilation (VDA) problems. Specifically, it focuses on data assimilation of noisy and down-sampled observations while the state variable…

Data Analysis, Statistics and Probability · Physics 2014-06-25 A. M. Ebtehaj , M. Zupanski , G. Lerman , E. Foufoula-Georgiou

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

We introduce a continuous data assimilation (downscaling) algorithm for the two-dimensional Navier-Stokes equations employing coarse mesh measurements of only one component of the velocity field. This algorithm can be implemented with a…

Analysis of PDEs · Mathematics 2016-03-23 Aseel Farhat , Evelyn Lunasin , Edriss S. Titi