Estimating extreme currents by combining tidal and surge probabilities

Abstract

The need to obtain realistic estimates of extreme currents for the design of off-shore structures requires optimum use to be made of the data available. Methods of applying joint tide-surge probability techniques to the data are considered, and illustrated by analysis of one year of current meter observations in the North Sea. Tidal and meteorologically-induced vector components of the total observed current vector are isolated and their separate two-dimensional frequency distributions are computed. These distributions are then recombined to give probabilities of extreme total currents from several directions.