A comparison of nonlinear extensions to the ensemble Kalman filter: Gaussian anamorphosis and two-step ensemble filters

I Grooms - Computational Geosciences, 2022 - Springer
Ensemble Kalman filters are based on a Gaussian assumption, which can limit their
performance in some non-Gaussian settings. This paper reviews two nonlinear, non …

A multigrid/ensemble Kalman filter strategy for assimilation of unsteady flows

G Moldovan, G Lehnasch, L Cordier, M Meldi - Journal of Computational …, 2021 - Elsevier
A sequential estimator based on the Ensemble Kalman Filter for Data Assimilation of fluid
flows is presented in this research work. The main feature of this estimator is that the Kalman …

[HTML][HTML] Calculating Bayesian model evidence for porous-media flow using a multilevel estimator

T Mannseth, K Fossum, SI Aanonsen - Journal of Computational Physics, 2024 - Elsevier
We consider calculation of the Bayesian model evidence, which is an essential component
in realistic uncertainty quantification. The main motivation is large-scale porous-media-flow …

Multilevel ensemble Kalman filtering based on a sample average of independent EnKF estimators

H Hoel, G Shaimerdenova, R Tempone - arxiv preprint arxiv:2002.00480, 2020 - arxiv.org
We introduce a new multilevel ensemble Kalman filter method (MLEnKF) which consists of a
hierarchy of independent samples of ensemble Kalman filters (EnKF). This new MLEnKF …

Optimized parametric inference for the inner loop of the Multigrid Ensemble Kalman Filter

G Moldovan, G Lehnasch, L Cordier, M Meldi - Journal of Computational …, 2022 - Elsevier
Essential features of the Multigrid Ensemble Kalman Filter (Moldovan et al.(2021)[24])
recently proposed for Data Assimilation of fluid flows are investigated and assessed in this …

Multigrid sequential data assimilation for the Large Eddy Simulation of a massively separated bluff-body flow

GI Moldovan, A Mariotti, L Cordier, G Lehnasch… - Computers & …, 2024 - Elsevier
The potential of sequential Data Assimilation (DA) techniques to improve the numerical
accuracy of Large Eddy Simulation (LES) performed on coarse grid is assessed …

[HTML][HTML] Multi-level data assimilation for ocean forecasting using the shallow-water equations

F Beiser, HH Holm, KO Lye, J Eidsvik - Journal of Computational Physics, 2025 - Elsevier
Abstract Multi-level Monte Carlo methods have become an established technique in
uncertainty quantification as they provide the same statistical accuracy as traditional Monte …

Iterative multilevel assimilation of inverted seismic data

M Nezhadali, T Bhakta, K Fossum… - Computational …, 2022 - Springer
In ensemble-based data assimilation (DA), the ensemble size is usually limited to around
one hundred. Straightforward application of ensemble-based DA can therefore result in …

Multi-index ensemble Kalman filtering

H Hoel, G Shaimerdenova, R Tempone - Journal of Computational Physics, 2022 - Elsevier
In this work we combine ideas from multi-index Monte Carlo and ensemble Kalman filtering
(EnKF) to produce a highly efficient filtering method called multi-index EnKF (MIEnKF) …

Multilevel Ensemble Kalman-Bucy Filters

NK Chada, A Jasra, F Yu - arxiv preprint arxiv:2011.04342, 2020 - arxiv.org
In this article we consider the linear filtering problem in continuous-time. We develop and
apply multilevel Monte Carlo (MLMC) strategies for ensemble Kalman-Bucy filters (EnKBFs) …