Page 224 - 《高原气象》2023年第1期

高 原 气 象 42 卷
220

Evaluation of the ERA5 Reanalysis Data on the Near-Surface Wind

Speed Climate Characteristics and Change Trend Reproduction
Ability in Gansu Province

1， 2
MA Yihao ， MAO Rui ， YANG Yang ， MA Li ， GOU Shang 2
3
4
2
（1. Faculty of Geographical Science， Beijing Normal University， Beijing 100875， China；
2. Lanzhou Central Meteorological Observatory， Lanzhou 730020， Gansu， China；
3. School of National Safety and Emergency Management， Beijing Normal University， Beijing 100875， China；
4. Lanzhou Institute of Arid Meteorological， China Meteorological Administration， Lanzhou 730020， Gansu， China）
Abstract： In order to explore the reanalysis data of ERA5's ability to reproduce wind speed in the surface layer
of Gansu Province， this paper uses the surface wind speed data of 80 national meteorological stations in Gansu
Province from 1981 to 2020 to analyze the wind speed changes in Gansu Province in the past 40 years， by com‐
paring the similarities and differences between the fifth set of European Center for Mid-range Weather Forecast
（ERA5） and the change trend of observational data， its ability to reproduce the surface wind speed in Gansu
province is discussed. The result shows： The average surface wind speed in the four seasons in Gansu Province
gradually decreases from west to east， the season with the highest surface wind speed is spring， and the seasons
with low wind speed vary in different regions； The change of surface wind speed in the past 40 years has general‐
ly stabilized， However， the spring wind speed at each site mainly showed a significant downward trend， and the
other three seasons mostly showed an upward trend； Before the early 1990s， the average wind speed in the four
seasons showed a decreasing trend， with the strongest change trend in spring and the weakest change trend in au‐
tumn， after that， it turned to a stable change or an upward trend， and the upward trend of wind speed in winter
and summer was stronger. The ERA5 reanalysis data has good reproducibility for the inter month variation of
wind speed and main seasonal characteristics in Gansu Province， but poor reproducibility for the seasonal aver‐
age wind speed value and long-term variation trend of wind speed， and it only performs well in the period of
wind speed decline， and the ERA5 wind speed data does not have the ability to reproduce the long-term trend of
wind speed in Gansu Province in each season； The ERA5 reanalysis data cannot be directly used to estimate the
wind energy density in Gansu Province， but after correcting the linear deviation， it has a good reproducibility in
terms of the multi-year average value of wind energy density.
Key words： Gansu； ERA5； wind speed change； reappearance abilitys