Ocean Waves Reanalysis of Operational Based Method: Wave Forecast Error based on the encountered OCTOPUS wave database

Ocean Waves Reanalysis of Operational Based Method: Wave Forecast Error based on the encountered OCTOPUS wave database

Van der Meij, A.B.

Huijsmans, R.H.M. (mentor)
Romeijn, A. (mentor)
Van Gelder, P.H.A.J.M. (mentor)
Morales-Napoles, O. (mentor)
De Jonge, J.B. (mentor)

Mechanical, Maritime and Materials Engineering

Ship Hydromechanics & Structures

Offshore & Dredging Engineering

2015-06-15

Dockwise started in 2008 with the OCTOPUS motion monitoring and captain decision support system for performance optimization and bad weather routing capacity. The OCTOPUS-Onboard system gathers weather and motion data, which is collected in the OCTOPUS database. This database includes the encountered weather data and the measured accelerations and ship motions along the route of the vessel. A new calculation algorithm is developed which reflects the data collected with the motion monitoring project of the Dockwise fleet of vessels. The time record of the wave data is converted into wave scatter diagrams and implemented in the design process as a new weather database to evaluate the design sea states. The Wave Forecast Error (WFE) which is currently included is a conservative assumption. Sensitivity analysis shows that this value has a large influence in the resulting design wave height. Furthermore, the WFE might be different when only a specific area is investigated. Knowing the error per area will improve the accuracy of data. This research describes the local and seasonal wave forecast error of the encountered OCTOPUS wave database. The encountered OCTOPUS wave database consists of nowcasted weather data based on the actual position, heading and speed of the Dockwise vessels. There are some concerns about the predicted wave climate in the Southern Hemisphere due to the lack of taking surface currents into account. The area around Cape of Good Hope is situated at convergence of two current systems, strengthened by the bottom topography.

WaveWatch III
WAve Model
reanalysis intercomparison
Cape of Good Hope
copulas dependence measures
goodness-of-fit
pair-copulae
conditional distribution
Wave Forecast Error
bivariate offshore environment
extreme value statistics

http://resolver.tudelft.nl/uuid:18304ff7-6589-40af-8f9a-d87764ef9bc5

Student theses

master thesis

(c) 2015 Van der Meij, A.B.