Pagli Bastien auteur aut IRD Duphil Maxime auteur aut IRD Jullien S. auteur aut IRD Dutheil C. auteur aut IRD Peltier A. auteur aut IRD Menkès Christophe auteur aut IRD text journalArticle eng text/pdf born digital access Pacific islands are widely exposed to several strong wave events all year long. However, comprehensive analyses of coastal vulnerabilities to wave climates and their extremes are often lacking in those islands. In the present paper, the wave climate around the reef of New Caledonia is analyzed using a 28-year simulation performed with the Wave Watch III model, and accounting for realistic wind intensity forcing from tropical cyclones. Four mean wave regimes are defined with clustering methods, and are shown to vary along the reef depending on its main orientation. The western reef is mostly exposed to energetic south-western swells (significant height over 1.5 m, peak period of similar to 12 s) generated in the Tasman Sea that are reinforced during austral winter. The northern sector and the Loyalty Islands, are hit by shorter waves (similar to 8 to 9 s period) coming from the south-east to the north-east, with height ranging on average from 0.8 m in the Loyalty Channel to 1.5 m at the northern tip of the Grande Terre reef. These waves mainly result from the south-eastern trade winds that blow over the central south-western Pacific all year long. In austral summer, additional swell remotely generated by both the extra-tropical westerlies and the north-eastern trade winds of the northern hemisphere reach the north-eastern reef of the archipelago. These wave regimes also strongly vary in response to the interannual El Nino-Southern Oscillation. El Nino events tend to increase the frequency of the south-western swell regime in austral spring and fall, and of the south-eastern trade wind waves in austral summer. In contrast, during La Nina, waves generated in the northern hemisphere are more likely to reach New Caledonia all year long. Finally, extreme wave events and their return periods were assessed. Wave amplitude reaching 7 m is estimated to occur every 100 years. On the west and southern tip of the Grande Terre reef, extreme waves are 80% of the time westerly waves generated by storms in the Tasman Sea or in the Coral Sea, while on the eastern reefs (Loyalty Islands and Channel), 70% of the extreme wave episodes are associated to tropical cyclone-induced waves. During La Nina episodes, more tropical cyclones pass by New Caledonia, increasing their contribution to extreme wave events along the western and southern coasts of the island. Conversely, in El Nino conditions, the exposure to tropical cyclone-induced waves is predominantly concentrated on the northeastern side. specialized Wave climate Clustering Extreme values analysis Tropical cyclones ENSO New caledonia NOUVELLE CALEDONIE 032CLIMET 032DYNEAU [Early access] [23 p.] 2024 0930-7575 https://www.documentation.ird.fr/hor/fdi:010091239 10.1007/s00382-024-07365-1 0930-7575 [F B010091239] https://www.documentation.ird.fr/hor/fdi:010091239 https://www.documentation.ird.fr/intranet/publi/2024-09/010091239.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2024-09-27 2026-06-12 fdi:010091239 fre