Application of the wind atlas method to extremes of wind climatology

A terrain description model is established for the Risø site through a WA"sP computation. Mean wind profiles for eight wind direction sectors are compared with the model boundary profiles. Wind data from the 72/76 m recording level of the Risø mast are updated, including identification of missing and erroneous data.

The wind atlas procedure (''the double extrapolation method'') is applied to extrapolate Risø data to open-water conditions 10 m above mean sea level. Three different extreme value distributions are applied to the extrapolated storm data - two of which are based on the annual maximum (AM) method, and one on the peak-overthreshold (POT) method.

T-year estimates including standard error estimates are provided. Finally, a verification is performed by comparing extrapolated storm data with corresponding measured wind data form the Dan and Gorm fields in the North Sea. A high correlation is found for severe storms from the west. A significantly lower correlation is found for moderate and easterly storms. (au) (29 tabs., 29 ills., 59 refs.).