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Related papers: Data assimilation for stratified convection

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A goal of data assimilation is to infer stochastic dynamical behaviors with available observations. We consider transition phenomena between metastable states for a stochastic system with (non-Gaussian) $\alpha-$stable L\'evy noise. With…

Dynamical Systems · Mathematics 2016-06-29 Ting Gao , Jinqiao Duan , Xingye Kan

In this article, we prove that data assimilation by feedback nudging can be achieved for the three-dimensional quasi-geostrophic equation in a simplified scenario using only large spatial scale observables on the dynamical boundary. On this…

Analysis of PDEs · Mathematics 2016-12-12 Michael S. Jolly , Vincent R. Martinez , Edriss S. Titi

A novel method to improve the accuracy of pressure field estimation from time-resolved Particle Image Velocimetry data is proposed. This method generates several new time-series of velocity field by propagating in time the original one…

Fluid Dynamics · Physics 2025-01-14 Junwei Chen , Marco Raiola , Stefano Discetti

For the 2D incompressible Navier-Stokes equations, with given hypothetical non smooth data at time $T > 0 $that may not correspond to an actual solution at time $T$, a previously developed stabilized backward marching explicit leapfrog…

Numerical Analysis · Mathematics 2024-11-25 Alfred S. Carasso

We have developed a three-dimensional (3D) spectral hydrodynamic code to study vortex dynamics in rotating, shearing, stratified systems (e.g. the atmosphere of gas giant planets, protoplanetary disks around newly forming protostars). The…

Astrophysics · Physics 2009-11-13 Joseph A. Barranco , Philip S. Marcus

Models of stellar structure and evolution are an indispensable tool in astrophysics, yet they are known to incorrectly reproduce the outer convective layers of stars. In the first paper of this series, we presented a novel procedure to…

A real time assimilation and forecasting system for coastal currents is presented. The purpose of the system is to deliver current analyses and forecasts based on assimilation of high frequency radar surface current measurements. The local…

Atmospheric and Oceanic Physics · Physics 2012-10-01 Øyvind Breivik , Øyvind Saetra

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

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…

In this work, we combine a stochastic model reduction with a particle filter augmented with tempering and jittering, and apply the combined algorithm to a damped and forced incompressible 2D Euler dynamics defined on a simply connected…

Applications · Statistics 2020-08-25 Colin Cotter , Dan Crisan , Darryl D. Holm , Wei Pan , Igor Shevchenko

We have developed a variational data assimilation technique for the Sun using a toy {\alpha}{\Omega} dynamo model. The purpose of this work is to apply modern data assimilation techniques to solar data using a physically based model. This…

Solar and Stellar Astrophysics · Physics 2015-05-28 Laurene Jouve , Allan Sacha Brun , Olivier Talagrand

4D-variational data assimilation is applied to the Lorenz '63 model to introduce a new method for parameter estimation in chaotic climate models. The approach aims to optimise an Earth system model (ESM), for which no adjoint exists, by…

Atmospheric and Oceanic Physics · Physics 2025-04-18 Philip David Kennedy , Abhirup Banerjee , Armin Köhl , Detlef Stammer

Results of numerical 3D simulations of propagation of acoustic waves inside the Sun are presented. A linear 3D code which utilizes realistic OPAL equation of state was developed by authors. Modified convectively stable standard solar model…

Astrophysics · Physics 2011-02-11 K. V. Parchevsky , A. G. Kosovichev

Data Assimilation (DA) plays a critical role in atmospheric science by reconstructing spatially continous estimates of the system state, which serves as initial conditions for scientific analysis. While recent advances in diffusion models…

Machine Learning · Computer Science 2025-05-20 Hao Wang , Jindong Han , Wei Fan , Weijia Zhang , Hao Liu

We explore the potential of three-dimensional data assimilation for assimilating sparsely-distributed 2-metre temperature observations across the coupled atmosphere-land interface into the soil moisture. Using idealised twin experiments…

Atmospheric and Oceanic Physics · Physics 2022-09-29 Tobias Finn , Gernot Geppert , Felix Ament

High-quality observations of hub-height winds are valuable but sparse in space and time. Simulations are widely available on regular grids but are generally biased and too coarse to inform wind-farm siting or to assess…

Machine Learning · Computer Science 2025-10-07 Xiaolong Ma , Xu Dong , Ashley Tarrant , Lei Yang , Rao Kotamarthi , Jiali Wang , Feng Yan , Rajkumar Kettimuthu

The phenomenon of solidification of a substance from its liquid phase is of the greatest practical and theoretical importance, and atomistic simulations can provide precious information towards its understanding and control. Unfortunately,…

Soft Condensed Matter · Physics 2021-03-25 Tarak Karmakar , Michele Invernizzi , Valerio Rizzi , Michele Parrinello

This paper presents a direct 3D visual servo scheme for the automatic alignment of point clouds (respectively, objects) using visual information in the spectral domain. Specifically, we propose an alignment method for 3D models/point clouds…

Robotics · Computer Science 2023-04-04 Maxime Adjigble , Brahim Tamadazte , Cristiana de Farias , Rustam Stolkin , Naresh Marturi

We propose closed-form conditional diffusion models for data assimilation. Diffusion models use data to learn the score function (defined as the gradient of the log-probability density of a data distribution), allowing them to generate new…

Machine Learning · Statistics 2026-04-02 Brianna Binder , Agnimitra Dasgupta , Assad Oberai

The four-dimensional variational data assimilation (4D-Var) has emerged as an important methodology, widely used in numerical weather prediction, oceanographic modeling, and climate forecasting. Classical unconstrained gradient-based…

Numerical Analysis · Mathematics 2024-10-08 Bowen Li , Bin Shi
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