The New Year Wave: Spatial Evolution of an Extreme Sea State

Abstract

In the past years the existence of freak waves has been affirmed by observations, registrations, and severe accidents. Many publications investigated the occurrence of extreme waves, their characteristics and their impact on offshore structures, but their formation process is still under discussion. One of the famous real world registrations is the so called “New Year wave,” recorded in the North Sea at the Draupner jacket platform on January 1st, 1995. Since there is only a single point registration available, it is not possible to draw conclusions on the spatial development in front of and behind the point of registration, which is indispensable for a complete understanding of this phenomenon. This paper presents the spatial development of the New Year wave generated in a model basin. To transfer the recorded New Year wave into the wave tank, an optimization approach for the experimental generation of wave sequences with predefined characteristics is applied. The extreme sea state obtained with this method is measured at different locations in the tank, in a range from 2163 m (full scale) ahead of to 1470 m behind the target position—520 registrations altogether. The focus lies on the detailed description of a possible evolution of the New Year wave over a large area and time interval. It is observed that the extreme wave at the target position develops mainly from a wave group of three smaller waves. The group velocity, wave propagation, and the energy flux of this wave group are analyzed, in particular.

The Draupner wave: A fresh look and the emerging view

“…Somehow the Draupner wave became the iconic item for the subject and several papers suggested possible explanations for the event, among them Trulsen [], Walker et al . [], Jensen [], and Clauss and Klein []. Adcock et al .…”

Did the Draupner wave occur in a crossing sea?

“…So we may be reasonably confident that green water reached this level and the wave record is reliable. Numerous others have studied the properties of this wave: see, for instance, Trulsen (2001), Walker et al (2005), Jensen (2005) and Clauss & Klein (2009). The most common explanation given for the Draupner wave is that resonant wave-wave interactions caused a nonlinear focusing of wave energy.…”

Reconstruction of Extreme Events Through Numerical Simulations

“…The adopted here method differs from the one developed and applied by Clauss et al [21] in the part, that the wave dynamics is permitted to be significantly nonlinear, so that the wave spectrum may change. The approach is validated by means of cross-simulations of different Dysthe models, and also with the help of the fully nonlinear simulation of the Euler equations.…”

“…[17][18][19][20]). [21], and references therein) with the help of an iterative procedure on the basis of the "nonlinear" dispersive law for Stokes waves. [21], and references therein) with the help of an iterative procedure on the basis of the "nonlinear" dispersive law for Stokes waves.…”