Investigation of trends in extreme value wave height and wind speed

Global altimeter data spanning a period of more than 20 years is analyzed to determine whether there are measurable trends in extreme value return period estimates of wind speed and wave height. The data is subdivided into sections of 4 years duration and extreme value analysis applied to each section. The trends in values across these sections indicate that there appears to be a positive trend in 100 year return period values of wind speed but no consistent trends for 100 year return period wave height. However, the statistical uncertainty associated with estimates of the extreme value wind speed and wave heights is such that the quantitative values of trend are not reliable. Reliable values will require a longer‐duration data set.