Long-term trends and wave climate variability in the South Atlantic Ocean: the influence of climate indices

• Published in: Regional Studies in Marine Science
• Main Authors: Maia, Natan, Almeida, Luis Pedro, Nicolodi, João Luiz, Calliari, Lauro, Castelle, Bruno
• Other Authors: Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: South Atlantic Ocean; Wave climate; Storm waves; long-term trends; interannual variability; Climate indices; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere
• Online Access: https://hal.science/hal-04266991; https://hal.science/hal-04266991/document; https://hal.science/hal-04266991/file/Maia%20et%20al%202023_submission.pdf; https://doi.org/10.1016/j.rsma.2023.103131

International audience Linking wave climate variability and trends with climate indices is important to better understand and predict large-scale patterns of wave variability down to wave conditions at the coast. This study investigates such links in the South Atlantic Ocean using 72 years of ERA5 wave hindcast. Different wave parameters are computed, including storm wave statistics, and are further analyzed in terms of long-term trends and interannual changes. Our results indicate that, over the last decades, wave height has been significantly increasing across the entire domain, while extreme events statistics are also increasing, although with more complex spatial variability. The variations of these wave properties are primarily correlated, from low to high latitudes, with the Atlantic Multidecadal Oscillation (AMO), Tropical Southern Atlantic Index (TSA) and Southern Annular Mode (SAM), with different preferred timescales. We think that better understanding and predicting the evolution of these climate indices, including under climate change, will be critical to anticipate coastal hazards in this region.