Spatio-temporal modelling of extreme storms

TL;DR

This paper develops a flexible spatio-temporal model to analyze extreme storms over the Atlantic and Europe, revealing how the North Atlantic Oscillation influences storm extremity and providing bounds on storm intensity.

Contribution

It introduces a novel spatio-temporal modeling approach incorporating covariates and random effects to study extreme storm behavior.

Findings

NAO significantly affects storm extremity, especially in Northern Europe and Iberia.

Estimated lower bounds on sea-level pressure are 10-50 hPa below historical storm minima.

Storm extremity estimates vary with NAO index, indicating climate influence.

Abstract

A flexible spatio-temporal model is implemented to analyse extreme extra-tropical cyclones objectively identified over the Atlantic and Europe in 6-hourly re-analyses from 1979-2009. Spatial variation in the extremal properties of the cyclones is captured using a 150 cell spatial regularisation, latitude as a covariate, and spatial random effects. The North Atlantic Oscillation (NAO) is also used as a covariate and is found to have a significant effect on intensifying extremal storm behaviour, especially over Northern Europe and the Iberian peninsula. Estimates of lower bounds on minimum sea-level pressure are typically 10-50 hPa below the minimum values observed for historical storms with largest differences occurring when the NAO index is positive.