Flexible and efficient emulation of spatial extremes processes via variational autoencoders

Fuente: arXiv
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Autori principali: Zhang, Likun, Ma, Xiaoyu, Wikle, Christopher K., Huser, Raphaël
Natura: Preprint
Pubblicazione: 2023
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author Zhang, Likun
Ma, Xiaoyu
Wikle, Christopher K.
Huser, Raphaël
author_facet Zhang, Likun
Ma, Xiaoyu
Wikle, Christopher K.
Huser, Raphaël
contents Many real-world processes have complex tail dependence structures that cannot be characterized using classical Gaussian processes. More flexible spatial extremes models exhibit appealing extremal dependence properties but are often exceedingly prohibitive to fit and simulate from in high dimensions. In this paper, we aim to push the boundaries on computation and modeling of high-dimensional spatial extremes via integrating a new spatial extremes model that has flexible and non-stationary dependence properties in the encoding-decoding structure of a variational autoencoder called the XVAE. The XVAE can emulate spatial observations and produce outputs that have the same statistical properties as the inputs, especially in the tail. Our approach also provides a novel way of making fast inference with complex extreme-value processes. Through extensive simulation studies, we show that our XVAE is substantially more time-efficient than traditional Bayesian inference while outperforming many spatial extremes models with a stationary dependence structure. Lastly, we analyze a high-resolution satellite-derived dataset of sea surface temperature in the Red Sea, which includes 30 years of daily measurements at 16703 grid cells. We demonstrate how to use XVAE to identify regions susceptible to marine heatwaves under climate change and examine the spatial and temporal variability of the extremal dependence structure.
format Preprint
id arxiv_https___arxiv_org_abs_2307_08079
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Flexible and efficient emulation of spatial extremes processes via variational autoencoders
Zhang, Likun
Ma, Xiaoyu
Wikle, Christopher K.
Huser, Raphaël
Machine Learning
Methodology
68T07 (Primary), 60G70, 62H11 (Secondary)
Many real-world processes have complex tail dependence structures that cannot be characterized using classical Gaussian processes. More flexible spatial extremes models exhibit appealing extremal dependence properties but are often exceedingly prohibitive to fit and simulate from in high dimensions. In this paper, we aim to push the boundaries on computation and modeling of high-dimensional spatial extremes via integrating a new spatial extremes model that has flexible and non-stationary dependence properties in the encoding-decoding structure of a variational autoencoder called the XVAE. The XVAE can emulate spatial observations and produce outputs that have the same statistical properties as the inputs, especially in the tail. Our approach also provides a novel way of making fast inference with complex extreme-value processes. Through extensive simulation studies, we show that our XVAE is substantially more time-efficient than traditional Bayesian inference while outperforming many spatial extremes models with a stationary dependence structure. Lastly, we analyze a high-resolution satellite-derived dataset of sea surface temperature in the Red Sea, which includes 30 years of daily measurements at 16703 grid cells. We demonstrate how to use XVAE to identify regions susceptible to marine heatwaves under climate change and examine the spatial and temporal variability of the extremal dependence structure.
title Flexible and efficient emulation of spatial extremes processes via variational autoencoders
topic Machine Learning
Methodology
68T07 (Primary), 60G70, 62H11 (Secondary)
url https://arxiv.org/abs/2307.08079