activity
20232026
most citedExact nonlinear state estimation

6 citations · 10 across the 9 of their papers we have counts for

collaborators

10 papers

math.NA2026

Covariance-Informed Ensemble Score Filtering: Embedding Localized Covariance Geometry into Score-Based Transport

Siming Liang, Peter Jan van Leeuwen, Hristo G. Chipilski +3

Background-error covariance models are central to atmospheric data assimilation because they spread partial observational information across space, variables, and dynamically coupl…

math.NA2026

From Variational Optimization to Flow-Based Transport: Posterior-Geometry Regularization for Ill-Conditioned Data Assimilation

Siming Liang, Feng Bao, Hristo G. Chipilski +2

Variational data assimilation computes a Bayesian update through optimization on a fixed posterior geometry, whose conditioning is determined by the prior covariance and the observ…

physics.ao-ph2026

A Two-Step Ensemble Score Filter for Data Assimilation in Partially Observed Systems

Zixiang Xiong, Feng Bao, Hristo G. Chipilski +3

Data assimilation blends model forecasts with observations to estimate the evolving state of complex dynamical systems, but sparse observing networks remain challenging because uno…

cs.LG2026

Global Attention with Linear Complexity for Exascale Generative Data Assimilation in Earth System Prediction

Xiao Wang, Zezhong Zhang, Isaac Lyngaas +10

Accurate Earth system prediction requires state inference from incomplete observations, but conventional two-stage data assimilation (DA) is computationally prohibitive because rep…

stat.CO2026

Two Localization Strategies for Sequential MCMC Data Assimilation with Applications to Nonlinear Non-Gaussian Geophysical Models

Hamza Ruzayqat, Hristo G. Chipilski, Omar Knio

We present a localized data assimilation (DA) scheme based on sequential Markov Chain Monte Carlo (SMCMC) \cite{smcmc}, a provably convergent method for filtering high-dimensional,…

physics.ao-ph2025

On the sensitivity of different ensemble filters to the type of assimilated observation networks

Zixiang Xiong, Siming Liang, Feng Bao +2

Recent advances in data assimilation (DA) have focused on developing more flexible approaches that can better accommodate nonlinearities in models and observations. However, it rem…

physics.ao-ph2025★ 1 cited

Ensemble score filter with image inpainting for data assimilation in tracking surface quasi-geostrophic dynamics with partial observations

Siming Liang, Hoang Tran, Feng Bao +3

Data assimilation plays a pivotal role in understanding and predicting turbulent systems within geoscience and weather forecasting, where data assimilation is used to address three…

cs.LG2024★ 2 cited

A Scalable Real-Time Data Assimilation Framework for Predicting Turbulent Atmosphere Dynamics

Junqi Yin, Siming Liang, Siyan Liu +4

The weather and climate domains are undergoing a significant transformation thanks to advances in AI-based foundation models such as FourCastNet, GraphCast, ClimaX and Pangu-Weathe…

math-ph2024★ 1 cited

Nonlinear ensemble filtering with diffusion models: Application to the surface quasi-geostrophic dynamics

Feng Bao, Hristo G. Chipilski, Siming Liang +2

The intersection between classical data assimilation methods and novel machine learning techniques has attracted significant interest in recent years. Here we explore another promi…

stat.ME2023★ 6 cited

Exact nonlinear state estimation

Hristo G. Chipilski

The majority of data assimilation (DA) methods in the geosciences are based on Gaussian assumptions. While these assumptions facilitate efficient algorithms, they cause analysis bi…