LO-SDA: Latent Optimization for Score-based Atmospheric Data Assimilation

Fuente: arXiv
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Auteurs principaux: Sun, Jing-An, Fan, Hang, Gong, Junchao, Fei, Ben, Chen, Kun, Ling, Fenghua, Zhang, Wenlong, Xu, Wanghan, Yan, Li, Gentine, Pierre, Bai, Lei
Format: Preprint
Publié: 2025
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author Sun, Jing-An
Fan, Hang
Gong, Junchao
Fei, Ben
Chen, Kun
Ling, Fenghua
Zhang, Wenlong
Xu, Wanghan
Yan, Li
Gentine, Pierre
Bai, Lei
author_facet Sun, Jing-An
Fan, Hang
Gong, Junchao
Fei, Ben
Chen, Kun
Ling, Fenghua
Zhang, Wenlong
Xu, Wanghan
Yan, Li
Gentine, Pierre
Bai, Lei
contents Data assimilation (DA) plays a pivotal role in numerical weather prediction by systematically integrating sparse observations with model forecasts to estimate optimal atmospheric initial condition for forthcoming forecasts. Traditional Bayesian DA methods adopt a Gaussian background prior as a practical compromise for the curse of dimensionality in atmospheric systems, that simplifies the nonlinear nature of atmospheric dynamics and can result in biased estimates. To address this limitation, we propose a novel generative DA method, LO-SDA. First, a variational autoencoder is trained to learn compact latent representations that disentangle complex atmospheric correlations. Within this latent space, a background-conditioned diffusion model is employed to directly learn the conditional distribution from data, thereby generalizing and removing assumptions in the Gaussian prior in traditional DA methods. Most importantly, we introduce latent optimization during the reverse process of the diffusion model to ensure strict consistency between the generated states and sparse observations. Idealized experiments demonstrate that LO-SDA not only outperforms score-based DA methods based on diffusion posterior sampling but also surpasses traditional DA approaches. To our knowledge, this is the first time that a diffusion-based DA method demonstrates the potential to outperform traditional approaches on high-dimensional global atmospheric systems. These findings suggest that long-standing reliance on Gaussian priors-a foundational assumption in operational atmospheric DA-may no longer be necessary in light of advances in generative modeling.
format Preprint
id arxiv_https___arxiv_org_abs_2510_22562
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle LO-SDA: Latent Optimization for Score-based Atmospheric Data Assimilation
Sun, Jing-An
Fan, Hang
Gong, Junchao
Fei, Ben
Chen, Kun
Ling, Fenghua
Zhang, Wenlong
Xu, Wanghan
Yan, Li
Gentine, Pierre
Bai, Lei
Atmospheric and Oceanic Physics
Data assimilation (DA) plays a pivotal role in numerical weather prediction by systematically integrating sparse observations with model forecasts to estimate optimal atmospheric initial condition for forthcoming forecasts. Traditional Bayesian DA methods adopt a Gaussian background prior as a practical compromise for the curse of dimensionality in atmospheric systems, that simplifies the nonlinear nature of atmospheric dynamics and can result in biased estimates. To address this limitation, we propose a novel generative DA method, LO-SDA. First, a variational autoencoder is trained to learn compact latent representations that disentangle complex atmospheric correlations. Within this latent space, a background-conditioned diffusion model is employed to directly learn the conditional distribution from data, thereby generalizing and removing assumptions in the Gaussian prior in traditional DA methods. Most importantly, we introduce latent optimization during the reverse process of the diffusion model to ensure strict consistency between the generated states and sparse observations. Idealized experiments demonstrate that LO-SDA not only outperforms score-based DA methods based on diffusion posterior sampling but also surpasses traditional DA approaches. To our knowledge, this is the first time that a diffusion-based DA method demonstrates the potential to outperform traditional approaches on high-dimensional global atmospheric systems. These findings suggest that long-standing reliance on Gaussian priors-a foundational assumption in operational atmospheric DA-may no longer be necessary in light of advances in generative modeling.
title LO-SDA: Latent Optimization for Score-based Atmospheric Data Assimilation
topic Atmospheric and Oceanic Physics
url https://arxiv.org/abs/2510.22562