Comparison of Wind Velocity among Reanalysis and Radiosonde Datasets over China

Using radiosonde and reanalysis data from NCEP/NCAR, European Center for Medium Range Weather Forecasts Reanalysis (ERA), and Modern Era Retrospective-Analysis for Research and Application (MERRA), the applicability evaluation of the atmospheric wind velocity in the area of China are conducted in this paper. The annual mean wind velocity shows a downward trend in the middle and upper tropospheres, and a downward trend in the lower troposphere over the East and South China. Results indicate that the ERA-interim and MERRA wind velocities have better evaluation applicability. In general, the wind velocities of the three reanalysis datasets are lower than observations. In the upper troposphere, ERA-interim is significantly closer to the observed values in the 1980s and 1990s, whereas NCEP/NCAR is much better in the 21st century. In the middle and lower tropospheres, NCEP/NCAR wind velocities agree well with the observed values. In terms of seasonal mean field, wind velocity shows an upward trend in the middle and upper tropospheres in winter, and downward trends in spring, summer, and autumn. The smallest deviation between radiosonde and reanalysis datasets appears in winter, and the largest appears in summer. In the middle and lower tropospheres, NCEP/NCAR and MERRA wind velocities are significantly closer to the observed values in winter, whereas MERRA values are significantly closer in summer. In the tropopause and lower stratospheres, ERA-interim and MERRA wind velocities show significantly better performance in all four seasons.