Comparison of Atmospheric Vertical Motion over China in ERA-lnterim, JRA-55, and NCEP/NCAR Reanalysis Datasets

摘要

Vertical motion is an important feature of the atmosphere, being closely linked to clouds and precipitation. Here, we present a comparison of the vertical velocity of air over China, with particular focus on the Tibetan Plateau, during the period 1981–2010 using three reanalysis datasets: ERA-Interim, JRA-55 and NCEP/NCAR. Analysis methods including empirical orthogonal functions analysis and correlation analysis were used to examine consistency between the datasets and their suitability in research and application in China. Our results show that the vertical velocity fields from ERA-Interim and JRA-55 are more consistent than they are with those from NCEP/NCAR. The atmospheric vertical velocity fields from NCEP/NCAR lack details compared with those obtained from ERA-Interim and JRA-55, and part of values for the upper troposphere over the ocean south of 15°N are contrary to the other datasets and the climatic reality. Therefore, use of ERA-Interim or JRA-55 may be preferable over NCEP/NCAR. The intensity of atmospheric vertical motion in the lower troposphere in JRA-55 is significantly higher than in ERA-Interim and NCEP/NCAR. In summer, the JRA-55 data are closest to the observed wind fields and the data stability best for the Tibetan Plateau region. Our results provide guidance for better application of reanalysis data and more accurate climate prediction for this region.