Observations of Rogue Seas in the Southern Ocean

We report direct observations of surface waves from a stereo camera system along with concurrent measurements of wind speed during an expedition across the Southern Ocean in the austral winter aboard the South African icebreaker S.A. Agulhas II. Records include water surface elevation across a range...

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Bibliographic Details
Published in:Physical Review Letters
Main Authors: Toffoli, A., Alberello, A., Clarke, H., Nelli, F., Benetazzo, A., Bergamasco, F., Ntamba, B. Ntamba, Vichi, M., Onorato, M.
Other Authors: Swinburne University of Technology
Format: Article in Journal/Newspaper
Language:unknown
Published: American Physical Society (APS) 2024
Subjects:
Online Access:http://hdl.handle.net/1959.3/478223
https://doi.org/10.1103/PhysRevLett.132.154101
Description
Summary:We report direct observations of surface waves from a stereo camera system along with concurrent measurements of wind speed during an expedition across the Southern Ocean in the austral winter aboard the South African icebreaker S.A. Agulhas II. Records include water surface elevation across a range of wave conditions spanning from early stages of wave growth to full development. We give experimental evidence of rogue seas, i.e., sea states characterized by heavy tails of the probability density function well beyond the expectation based on bound mode theory. These conditions emerge during wave growth, where strong wind forcing and high nonlinearity drive wave dynamics. Quasiresonance wave-wave interactions, which are known to sustain the generation of large amplitude rogue waves, capture this behavior. Wave statistics return to normality as the wind forcing ceases and waves switch to a full developed condition.