LONG TIME SERIES OF 3-HOURLY SPECTRAL SHAPE PARAMETERS

A model for long time series of sea-state parameters (many decades) is presented and fitted to wave data for Figueira da Foz, off the west coast of Portugal, 90m depth. A set of variables usually used to parametrize the (3-hourly) energy spectrum shapes for this specific location has been selected - significant wave height Hs, energy period Te, upward zero-crossing period Tz and the peak period Tp. The long-term behaviour of these parameters can be considered as a sample of a multivariate stochastic process. As such, it is modelled with a set of coupled auto-regressive equations, using Hs for the master variable. It has been possible to parametrize the model coefficients solely by the monthly averages of Hs. These, in turn, not only convey into the model the seasonal trends, but can be made to change from year to year, thus enabling the reproduction of interannual climatic variability as well as of (possible) long term trends.

  • Supplemental Notes:
    • OMAE 1995, 14th Intl Conf on Offshore Mechanics & Arctic Engng; 18-22 June 1995; Copenhagen, Denmark. Sponsored by ASME et al. Procs. Publ by ASME, ISBN 0-7918-1306-1. Vol I, Pt A, p 57 [8 p, 10 ref, 1 tab, 7 fig]
  • Authors:
    • Bettencourt, J A
    • de
    • Agular, R J
    • Pontes, T
  • Publication Date: 1995

Language

  • English

Subject/Index Terms

Filing Info

  • Accession Number: 00717685
  • Record Type: Publication
  • Source Agency: British Maritime Technology
  • Files: TRIS
  • Created Date: Mar 4 1996 12:00AM