Tailored pressure indices link atmospheric variability to decadal wave activity along the Atlantic coast of Europe
Abstract
Winter wave variability along the Atlantic coast of Europe is strongly influenced by large-scale atmospheric circulation patterns. Understanding how these large-scale modes translate into regional wave climate variability across timescales remains a key challenge for coastal hazard predictability. Here, we investigate the relationships between winter-mean significant wave height and sea-level pressure (SLP) indices, using ERA5 reanalysis (1979–2025). We focus on the established North Atlantic Oscillation (NAO) and the West Europe Pressure Anomaly (WEPA), and extend these indices by reverse-engineering optimal SLP-based indices, both as single points and SLP differences. Our results confirm that NAO and WEPA together explain the majority of winter wave variability along Europe’s Atlantic coasts at interannual scales, but the relative importance of each index changes with latitude and time-averaging window. At decadal timescales, the NAO becomes increasingly dominant, particularly at northern locations, while WEPA correlations decrease southward. Reverse-engineered SLP indices systematically outperform NAO and WEPA across all locations, but with marginal improvement for the NAO at the northern latitudes. Single-point SLP indices show skill close to SLP-difference indices in regions dominated by a single atmospheric dipole, but not where wave climates are more complex. Increasing the moving-average time window reveals spatially coherent far-field correlations between local wave activity and global SLP variability, pointing to potential large-scale climate connections whose underlying mechanisms remain to be established. Our study provides a methodological framework to identify optimal climate indices tailored to regional wave climates, improving prospects for annual to decadal forecasts of wave energy and coastal hazards along the Atlantic coast of Europe.
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BibTeX
@article{castelle2026tailored,
title = {{Tailored pressure indices link atmospheric variability to decadal wave activity along the Atlantic coast of Europe}},
author = {Bruno Castelle and Théodore Raymond and Didier Swingedouw and Ramdane Alkama},
journal = {Global and Planetary Change},
year = {2026},
month = oct,
doi = {10.1016/j.gloplacha.2026.105777},
url = {https://hal.science/hal-05843868v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Tailored pressure indices link atmospheric variability to decadal wave activity along the Atlantic coast of Europe
AU - Bruno Castelle
AU - Théodore Raymond
AU - Didier Swingedouw
AU - Ramdane Alkama
PY - 2026
DA - 2026/10/25
JO - Global and Planetary Change
DO - 10.1016/j.gloplacha.2026.105777
UR - https://hal.science/hal-05843868v1
AB - Winter wave variability along the Atlantic coast of Europe is strongly influenced by large-scale atmospheric circulation patterns. Understanding how these large-scale modes translate into regional wave climate variability across timescales remains a key challenge for coastal hazard predictability. Here, we investigate the relationships between winter-mean significant wave height and sea-level pressure (SLP) indices, using ERA5 reanalysis (1979–2025). We focus on the established North Atlantic Oscillation (NAO) and the West Europe Pressure Anomaly (WEPA), and extend these indices by reverse-engineering optimal SLP-based indices, both as single points and SLP differences. Our results confirm that NAO and WEPA together explain the majority of winter wave variability along Europe’s Atlantic coasts at interannual scales, but the relative importance of each index changes with latitude and time-averaging window. At decadal timescales, the NAO becomes increasingly dominant, particularly at northern locations, while WEPA correlations decrease southward. Reverse-engineered SLP indices systematically outperform NAO and WEPA across all locations, but with marginal improvement for the NAO at the northern latitudes. Single-point SLP indices show skill close to SLP-difference indices in regions dominated by a single atmospheric dipole, but not where wave climates are more complex. Increasing the moving-average time window reveals spatially coherent far-field correlations between local wave activity and global SLP variability, pointing to potential large-scale climate connections whose underlying mechanisms remain to be established. Our study provides a methodological framework to identify optimal climate indices tailored to regional wave climates, improving prospects for annual to decadal forecasts of wave energy and coastal hazards along the Atlantic coast of Europe.
SN - 0921-8181
ER -