Comment on “Biases in Estimating Long-Term Recurrence Intervals of
Extreme Events Due To Regionalized Sampling” by El Rafei et al. (2023)
Abstract
The ‘super-station’ approach has been adopted since 1980s as a pragmatic
method of improving extreme‑value predictions by grouping short-length
datasets from several measurement stations to become a larger dataset to
reduce uncertainties due to random sampling variation. El Rafei et al.
(2023, https://doi.org/10.1029/2023GL105286) analyzed reanalysis and
randomly generated wind extremes datasets and claimed that this
technique can introduce unexpected biases in typical situations. We
demonstrate by Monte-Carlo simulation, assuming the same number of
grouped stations and data lengths used, that applying the grouping
technique to samples from homogeneous datasets does not lead to biased
prediction of extremes. In addition, the grouping technique effectively
reduces the uncertainty and sampling errors that result from
short-length datasets from individual stations of consistent
meteorology.