Advances in Statistical Modeling of Spatial Extremes

TL;DR

This paper reviews recent advances in spatial extremes modeling, highlighting new flexible models that better capture localized severe events and are computationally feasible for large datasets.

Contribution

It introduces novel models with adaptable tail dependence structures and discusses their inference methods, improving over classical rigid asymptotic models.

Findings

New models bridge asymptotic dependence classes

Models are more computationally efficient for large data

Applications demonstrate improved spatial extreme analysis

Abstract

The classical modeling of spatial extremes relies on asymptotic models (i.e., max-stable processes or $r$-Pareto processes) for block maxima or peaks over high thresholds, respectively. However, at finite levels, empirical evidence often suggests that such asymptotic models are too rigidly constrained, and that they do not adequately capture the frequent situation where more severe events tend to be spatially more localized. In other words, these asymptotic models have a strong tail dependence that persists at increasingly high levels, while data usually suggest that it should weaken instead. Another well-known limitation of classical spatial extremes models is that they are either computationally prohibitive to fit in high dimensions, or they need to be fitted using less efficient techniques. In this review paper, we describe recent progress in the modeling and inference for spatial extremes, focusing on new models that have more flexible tail structures that can bridge asymptotic dependence classes, and that are more easily amenable to likelihood-based inference for large datasets. In particular, we discuss various types of random scale constructions, as well as the conditional spatial extremes model, which have recently been getting increasing attention within the statistics of extremes community. We illustrate some of these new spatial models on two different environmental applications.