Does CRA-40 outperform other reanalysis products in evaluating near-surface wind speed changes over China?

Global reanalysis products have become essential tools employed towards the understanding of past climates, which are extensively employed by the wind energy industry to assess and develop wind resources. In this study, the terrestrial near-surface wind speed (NSWS) in the 40 year global reanalysis dataset released by China Meteorological Administration (CRA-40) was employed and compared with four state-of-the-art global reanalysis products, namely the European Centre for Medium-Range Weather Forecasts reanalysis version 5 (ERA5), National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis (NCEP1), National Centers for Environmental Prediction-Department of Energy reanalysis (NCEP2), and the Japanese 55 year reanalysis (JRA55). Large discrepancies were revealed among the reanalysis products in NSWSs across China. CRA-40 captures the climatology, seasonal, interannual, and monthly changes, as well as the terrestrial stilling compared with the recent observed increase. In contrast, NCEP1 and NCEP2 fail to reproduce the climatology and monthly changes in the observed NSWSs. Although JRA55 captures the terrestrial stilling in observations, it underestimates the mean value of NSWS. Therefore, CRA-40 provides the best agreement with stronger and more significant correlations against the observations when compared to other reanalysis products, and reproduces the observed multi-decadal variability. Thus, CRA-40 is the optimal choice to investigate NSWS with high spatial and temporal resolution across China, with a wide array of socioeconomic and environmental impacts.