VAE-Var: Variational-Autoencoder-Enhanced Variational Assimilation

Fuente: arXiv
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Hauptverfasser: Xiao, Yi, Jia, Qilong, Xue, Wei, Bai, Lei
Format: Preprint
Veröffentlicht: 2024
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author Xiao, Yi
Jia, Qilong
Xue, Wei
Bai, Lei
author_facet Xiao, Yi
Jia, Qilong
Xue, Wei
Bai, Lei
contents Data assimilation refers to a set of algorithms designed to compute the optimal estimate of a system's state by refining the prior prediction (known as background states) using observed data. Variational assimilation methods rely on the maximum likelihood approach to formulate a variational cost, with the optimal state estimate derived by minimizing this cost. Although traditional variational methods have achieved great success and have been widely used in many numerical weather prediction centers, they generally assume Gaussian errors in the background states, which limits the accuracy of these algorithms due to the inherent inaccuracies of this assumption. In this paper, we introduce VAE-Var, a novel variational algorithm that leverages a variational autoencoder (VAE) to model a non-Gaussian estimate of the background error distribution. We theoretically derive the variational cost under the VAE estimation and present the general formulation of VAE-Var; we implement VAE-Var on low-dimensional chaotic systems and demonstrate through experimental results that VAE-Var consistently outperforms traditional variational assimilation methods in terms of accuracy across various observational settings.
format Preprint
id arxiv_https___arxiv_org_abs_2405_13711
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle VAE-Var: Variational-Autoencoder-Enhanced Variational Assimilation
Xiao, Yi
Jia, Qilong
Xue, Wei
Bai, Lei
Machine Learning
Artificial Intelligence
Dynamical Systems
Atmospheric and Oceanic Physics
Data assimilation refers to a set of algorithms designed to compute the optimal estimate of a system's state by refining the prior prediction (known as background states) using observed data. Variational assimilation methods rely on the maximum likelihood approach to formulate a variational cost, with the optimal state estimate derived by minimizing this cost. Although traditional variational methods have achieved great success and have been widely used in many numerical weather prediction centers, they generally assume Gaussian errors in the background states, which limits the accuracy of these algorithms due to the inherent inaccuracies of this assumption. In this paper, we introduce VAE-Var, a novel variational algorithm that leverages a variational autoencoder (VAE) to model a non-Gaussian estimate of the background error distribution. We theoretically derive the variational cost under the VAE estimation and present the general formulation of VAE-Var; we implement VAE-Var on low-dimensional chaotic systems and demonstrate through experimental results that VAE-Var consistently outperforms traditional variational assimilation methods in terms of accuracy across various observational settings.
title VAE-Var: Variational-Autoencoder-Enhanced Variational Assimilation
topic Machine Learning
Artificial Intelligence
Dynamical Systems
Atmospheric and Oceanic Physics
url https://arxiv.org/abs/2405.13711