Spatial dependence of extreme seas in the North East Atlantic from satellite altimeter measurements

• Published in: Environmetrics
• Main Authors: Shooter, R., Ross, E., Ribal, A., Young, I.R., Jonathan, P.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2021
• Subjects: Laplace; Iceland; North East Atlantic
• Online Access: https://eprints.lancs.ac.uk/id/eprint/152340/; https://doi.org/10.1002/env.2674

The extremal spatial dependence of significant wave height in the North East Atlantic is explored using Joint Altimetry Satellite Oceanography Network satellite altimeter observations for the period 2002–2018, and a spatial conditional extremes model motivated by the work of Heffernan and Tawn. The analysis involves (a) registering individual satellite passes onto a template transect, (b) marginal extreme value analysis at a set of locations on the template transect and transformation from physical to standard Laplace scale, (c) estimation of the spatial conditional extremes model for a set of locations on a template transect, and (d) comparison of extreme spatial dependence for different template transects. Inferences for two transects considered are qualitatively similar; however, for the “normal ascending” transect running approximately south-west to north-east lying between Iceland and the United Kingdom, extremal spatial dependence is found to decay more quickly than for the second “opposite descending” transect running approximately north-west to south-east to the west of Ireland.