Investigating the Robustness of Extreme Precipitation Super-Resolution Across Climates

Fuente: arXiv
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Main Authors: Largeau, Louise, Beucler, Tom, Leutwyler, David, Mariethoz, Gregoire, Chavez-Demoulin, Valerie, Koch, Erwan
Format: Preprint
Published: 2025
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author Largeau, Louise
Beucler, Tom
Leutwyler, David
Mariethoz, Gregoire
Chavez-Demoulin, Valerie
Koch, Erwan
author_facet Largeau, Louise
Beucler, Tom
Leutwyler, David
Mariethoz, Gregoire
Chavez-Demoulin, Valerie
Koch, Erwan
contents The coarse spatial resolution of gridded climate models, such as general circulation models, limits their direct use in projecting socially relevant variables like extreme precipitation. Most downscaling methods estimate the conditional distributions of extremes by generating large ensembles, complicating the assessment of robustness under distributional transformations, such as those induced by climate change. To better understand and potentially improve robustness, we propose super-resolving the parameters of the target variable's probability distribution directly using analytically tractable mappings. Within a perfect-model framework over Switzerland, we demonstrate that vector generalized linear and additive models can super-resolve the generalized extreme value distribution of summer hourly precipitation extremes from coarse precipitation fields and topography. We introduce the notion of a "robustness gap", defined as the difference in predictive error between present-trained and future-trained models, and use it to diagnose how model structure affects the generalization of each quantile to a pseudo-global warming scenario. By evaluating multiple model configurations, we also identify an upper limit on the super-resolution factor based on the spatial auto- and cross-correlation of precipitation and elevation, beyond which coarse precipitation loses predictive value. Our framework is broadly applicable to variables governed by parametric distributions and offers a model-agnostic diagnostic for understanding when and why empirical downscaling generalizes to climate change and extremes.
format Preprint
id arxiv_https___arxiv_org_abs_2507_09166
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Investigating the Robustness of Extreme Precipitation Super-Resolution Across Climates
Largeau, Louise
Beucler, Tom
Leutwyler, David
Mariethoz, Gregoire
Chavez-Demoulin, Valerie
Koch, Erwan
Atmospheric and Oceanic Physics
Machine Learning
The coarse spatial resolution of gridded climate models, such as general circulation models, limits their direct use in projecting socially relevant variables like extreme precipitation. Most downscaling methods estimate the conditional distributions of extremes by generating large ensembles, complicating the assessment of robustness under distributional transformations, such as those induced by climate change. To better understand and potentially improve robustness, we propose super-resolving the parameters of the target variable's probability distribution directly using analytically tractable mappings. Within a perfect-model framework over Switzerland, we demonstrate that vector generalized linear and additive models can super-resolve the generalized extreme value distribution of summer hourly precipitation extremes from coarse precipitation fields and topography. We introduce the notion of a "robustness gap", defined as the difference in predictive error between present-trained and future-trained models, and use it to diagnose how model structure affects the generalization of each quantile to a pseudo-global warming scenario. By evaluating multiple model configurations, we also identify an upper limit on the super-resolution factor based on the spatial auto- and cross-correlation of precipitation and elevation, beyond which coarse precipitation loses predictive value. Our framework is broadly applicable to variables governed by parametric distributions and offers a model-agnostic diagnostic for understanding when and why empirical downscaling generalizes to climate change and extremes.
title Investigating the Robustness of Extreme Precipitation Super-Resolution Across Climates
topic Atmospheric and Oceanic Physics
Machine Learning
url https://arxiv.org/abs/2507.09166