Abstract
We compared the correspondence of tropopause heights over China calculated from the gridded temperature data provided by the ERA-Interim project, NCEP/NCAR Reanalysis Projects-1 (NCEP-1), and Japanese 25-year Reanalysis (JRA-25) project with the radiosonde observational data for 1979–2012. The results indicate that the annual mean ERA-Interim, NCEP-1, and JRA-25 tropopause heights are higher than observations by 203, 228, and 293 gpm, respectively. Large positive differences for the majority of subtropical China primarily contribute to this high bias. An error analysis indicates that the internal coherence of the ERA-Interim data is better than that of NCEP-1 or JRA-25. Although JRA-25 was a second-generation reanalysis, the biases of the JRA-25 and NCEP-1 data relative to the observations remain substantially larger than those of the ERA-Interim. Furthermore, a spatial and temporal comparison of trends also indicates that the ERA-Interim tropopause height changes correspond most closely to the observed trends in China. Overall, our comprehensive analysis of the three reanalysis products indicates that on both seasonal and annual bases, the ERA-Interim tropopause heights are closer to the observations than those of the NCEP-1 or JRA-25 reanalyses. Furthermore, the biases are mainly a result of the algorithm that determines the tropopause height, which is limited by the coarse vertical resolution of the input data.
Published Version
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