Influence of average time interval and observation spacing of wind speed records on prediction results of extreme wind speed

The average time interval adopted by the historical wind climate observation data of different meteorological stations worldwide is not uniform, leading to a conversion difficulty of the average time interval in the extreme wind speed estimation process. Early observation equipment requires manual intervention, leading to discontinuous data and estimated deviation. This study analyzed wind speed data recorded by 11 meteorological stations in normal wind climate areas to obtain average wind speed sequences with different average time intervals. The extreme wind speeds for some return periods were calculated. Subsequently, the influence of the average time intervals on the prediction results of extreme wind speeds was analyzed. Simultaneously, the data were extracted into a 2 min average wind speed series with hourly, 6-hourly, and no-spacing observation. The estimation results of extreme wind speed for the return periods based on these three data series were calculated and compared in detail. Extreme wind speed for a given return period decreases with an increase in the average time interval in normal wind climate areas and approximates an exponential attenuation. The difference between the extreme wind speed corresponding to the continuous observation series and that corresponding to the observation data series with a spacing of 1 or 6 h meets the Rayleigh distribution. This study proposes a conversion formula for extreme wind speed with different average time intervals in normal wind climate areas. A set of correction methods for wind speed observation data with observation spacings was provided for more accurate estimation results.