Evaluation of Global Reanalysis Land Surface Wind Speed Trends to Support Wind Energy Development Using In Situ Observations

Abstract Global reanalysis products are important tools across disciplines to study past meteorological changes and especially useful for wind energy resource evaluations. Studies of observed speed show that land surface declined globally since the 1960s (known as global terrestrial stilling) but reversed with a turning point around 2010. Whether declining trend have been captured by remains unknown so far. To fill this research gap, systematic assessment climatological winds trends in five (ERA5, ERA-Interim, MERRA-2, JRA-55, CFSv2) was conducted comparing gridcell time series 10-m observational data from 1439 situ stations period 1989–2018. Overall, ERA5 is closest observations according evaluation winds. However, substantial discrepancies were found between simulated speeds. No product showed similar change observations, although some regional agreement. This discrepancy indicates need prudence when using prediction The possible reasons inconsistent analyzed. results production should select different regions minimize observations.