Asymmetric copula–based distribution models for met-ocean data in offshore wind engineering applications. Issue 4 (August 2018)

• Record Type: Journal Article
• Authors: Fazeres-Ferradosa, Tiago; Taveira-Pinto, Francisco; Vanem, Erik; Reis, Maria Teresa; Neves, Luciana das
• Other Names: Rebelo Carlos guest-editor.; Correia José guest-editor.; Baniotopoulos Charalampos guest-editor.; De Jesus Abílio guest-editor.
• Is Part Of: Wind engineering. Volume 42:Issue 4(2018)
• Page Start: 304
• Page End: 334
• Publication Date: 2018-08
• Subjects: Offshore wind -- significant wave height -- mean wave period -- copula -- extra-parametrization -- joint statistical model -- Crámer–von Mises -- asymmetry; Wind-pressure -- Periodicals; Winds -- Periodicals; Wind power -- Periodicals; Engineering meteorology -- Periodicals; Pression du vent; Vents; Énergie éolienne; Météorologie appliquée; Engineering meteorology; Wind power; Wind-pressure; Winds; Periodicals; 621.4505
• DOI: 10.1177/0309524X18777323
• Languages: English
• ISSNs: 0309-524X

Abstract

Joint statistical models for long-term wave climate are a key aspect of offshore wind engineering design. However, to find a joint model for sea-state characteristics is often difficult due to the complex nature of the wave climate and the physical constraints of sea-states phenomena. The available records of wave heights and periods are often very asymmetric in their nature. This article presents a copula-based approach to obtain the joint cumulative distribution function of the significant wave heights and the up-crossing mean period. This study is based on 124-month hindcast data concerning Horns Rev 3 offshore wind farm. The extra-parametrization technique of symmetric copulas is implemented to account for the asymmetry present in the data. The analysis of the total sea, the wind-sea and primary swell components is performed separately. The results show that the extra-parametrization technique with pairwise copulas consistently provided a better goodness-of-fit when compared to symmetric copulas. Moreover, it is demonstrated that the separation of the total sea into its components does not always improve the extra-parametrized copula's performance. Furthermore, this article also discusses copulas application to offshore wind engineering.