Decadal variability of extreme wave height representing storm severity in the northeast Atlantic & North Sea since the foundation of the Royal Society

• Published in: Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences
• Main Authors: Santo, H, Taylor, P, Gibson, R
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Royal Society 2016
• Subjects: North Atlantic; North Atlantic oscillation; Northeast Atlantic
• Online Access: https://doi.org/10.1098/rspa.2016.0376; https://ora.ox.ac.uk/objects/uuid:9720fa23-26f0-4647-84fc-30fc2a7f5b5b

Long-term estimation of extreme wave height remains a key challenge because of the short duration of available wave data, and also because of the possible impact of climate variability on ocean waves. Here we analyse storm-based statistics to obtain estimates of extreme wave height at locations in the northeast Atlantic and North Sea using the NORA10 wave hindcast (1958 − 2011), and use a five-year sliding window to examine temporal variability. The decadal variability is correlated to the North Atlantic Oscillation and other atmospheric modes using a 6-term predictor model incorporating the climate indices and their Hilbert transforms. This allows reconstruction of the historic extreme climate back to 1661 using a combination of known and proxy climate indices. Significant decadal variability primarily driven by the NAO is observed, and this should be considered for the long-term survivability of offshore structures and marine renewable energy devices. The analysis on wave climate reconstruction reveals that the variation of the mean, 99th percentile and extreme wave climates over decadal timescales for locations close to the dominant storm tracks in the open North Atlantic are comparable, while the wave climates for the rest of the locations including the North Sea are rather different.