Dynamically learning the parameters of a chaotic system using partial observations

E Carlson, J Hudson, A Larios, VR Martinez… - arxiv preprint arxiv …, 2021 - arxiv.org
Motivated by recent progress in data assimilation, we develop an algorithm to dynamically
learn the parameters of a chaotic system from partial observations. Under reasonable …

Identifying the body force from partial observations of a two-dimensional incompressible velocity field

A Farhat, A Larios, VR Martinez, JP Whitehead - Physical Review Fluids, 2024 - APS
Using limited observations of the velocity field of the two-dimensional Navier-Stokes
equations, we successfully reconstruct the steady body force that drives the flow. The …

Concurrent MultiParameter Learning Demonstrated on the Kuramoto--Sivashinsky Equation

B Pachev, JP Whitehead, SA McQuarrie - SIAM Journal on Scientific …, 2022 - SIAM
We develop an algorithm based on the nudging data assimilation scheme for the concurrent
(on-the-fly) estimation of scalar parameters for a system of evolutionary dissipative partial …

Downscaling data assimilation algorithm with applications to statistical solutions of the Navier–Stokes equations

A Biswas, C Foias, CF Mondaini, ES Titi - … de l'Institut Henri Poincaré C …, 2019 - Elsevier
Based on a previously introduced downscaling data assimilation algorithm, which employs a
nudging term to synchronize the coarse mesh spatial scales, we construct a determining …

Data assimilation in large Prandtl Rayleigh--Bénard convection from thermal measurements

A Farhat, NE Glatt-Holtz, VR Martinez… - SIAM Journal on Applied …, 2020 - SIAM
This work applies a continuous data assimilation scheme---a framework for reconciling
sparse and potentially noisy observations to a mathematical model---to Rayleigh--Bénard …

Fully discrete numerical schemes of a data assimilation algorithm: uniform-in-time error estimates

HA Ibdah, CF Mondaini, ES Titi - IMA Journal of Numerical …, 2020 - academic.oup.com
Our aim is to approximate a reference velocity field solving the two-dimensional Navier–
Stokes equations (NSE) in the absence of its initial condition by utilizing spatially discrete …

Super-Exponential Convergence Rate of a Nonlinear Continuous Data Assimilation Algorithm: The 2D Navier–Stokes Equation Paradigm

E Carlson, A Larios, ES Titi - Journal of Nonlinear Science, 2024 - Springer
We study a nonlinear-nudging modification of the Azouani–Olson–Titi continuous data
assimilation (downscaling) algorithm for the 2D incompressible Navier–Stokes equations …

Analysis of continuous data assimilation with large (or even infinite) nudging parameters

AE Diegel, X Li, LG Rebholz - Journal of Computational and Applied …, 2025 - Elsevier
This paper considers continuous data assimilation (CDA) in partial differential equation
(PDE) discretizations where nudging parameters can be taken arbitrarily large. We prove …

Continuous data assimilation for the 3D primitive equations of the ocean

Y Pei - arxiv preprint arxiv:1805.06007, 2018 - arxiv.org
In this article, we show that the continuous data assimilation algorithm is valid for the 3D
primitive equations of the ocean. Namely, the $ L^ 2$ norm of the assimilated solution …

Data assimilation with model error: Analytical and computational study for Sabra shell model

N Chen, A Farhat, E Lunasin - Physica D: Nonlinear Phenomena, 2023 - Elsevier
Understanding the impact of model error on data assimilation is an important practical topic.
Model error in the subgrid scale is commonly seen in various applications as a natural …