Unlike most posts on LinkedIn hailing upcoming attendance at a key event I am saying this time that I am disappointed not to be in Cardiff on 26 September 2023 for the EIC “The Celtic Sea: Beyond the Shore with Floating Wind Energy”. I am sure I am missing an excellent day. My meagre contribution at this time is to share some present thoughts related to an initial exploration of metocean conditions for the Celtic Sea. a. Like the majority of offshore projects, a good understanding of wave conditions is critical for successful design and safe access, however, for the Celtic Sea I would nudge this higher up the list of important issues. b. Freely available wave observations already exist in the area of interest, but the quality of information appears variable between instrument types. c. Spatial variation in wave conditions is typically low due to a deep water location with limited coastal sheltering. d. Standard wave parameters provide some useful insights: - Waves from west-south-west represent the dominant direction (42%) - P50 wave height is estimated around 1.42 m - Largest measured wave height over a four-year period is Hs = 9.75 m, Tz = 10.6 s, Tp = 15.4 s, Dir = 252°N - Wave scatter diagrams of Hs versus Tp suggest a limiting wave steepness of 1/18 for shorter period waves (< 8 s) and 1/22 for longer period waves (> 8 s) e. Standard wave parameters need to be reviewed with associated wave spectra to develop a more complete understanding, such as: - There are periods of both uni-modal and bi-modal sea states with a ratio of occurrence around 70:30. This is due to a balance between locally generated wind-seas and more remote longer period Atlantic Swell. - Extreme conditions appear to be represented by a uni-modal sea state (tbc) - Cross seas are evident during some periods of bi-modal sea states when wind seas occur at a different direction to swell sea - Upcoming metocean surveys need to make directional wave spectra available as a standard part of the output #metocean, #CelticSea, #FloatingOffshorewind, #CelticSeaCluster
Daniel Stevens
11mo
Great insights as ever Bill Be interesting to see that wave climate translated to P50 and P90 weather window predictions for the various floaters being proposed, for tow out and back ops.
Nick Elderfield
11mo
Always spectra by default... parameters don't show the whole picture :-) Nice thoughts Bill Cooper
Paul Evans
11mo
Well put Bill. I’m attending the event and will update you on anything newsworthy.
Director at Cooper Marine Advisors Ltd
7moSince my brief review of the observational record in 2023 we now have seen storm Isha producing wave heights up to 8.25 m, peak period of 13.3 s and a direction from 263°N.