资源环境科技发展态势分析平台

The comparison between seven reanalyses - ERA-Interim, National Centres for Environmental Predictions (NCEP)-National Center for Atmospheric Research reanalysis, NCEP Department of Energy reanalysis, NCEP-Climate Forecast System Reanalysis, Modern-Era Retrospective Analysis for Research and Application (MERRA), MERRA-2 and JRA-55 - and assimilated radiosonde measurements was performed for eight radiosonde stations in the Baltic Sea region during 1980-2015 at five levels. In addition to raw radiosonde measurements, data sets corrected for temperature-dependence (TD) and time-lag errors in RS80-A humidity measurements were investigated. While temperature differences between reanalyses and radiosonde stayed below 0.1 degrees C at the higher levels, differences up to 1.2 and 2.3 degrees C were revealed for the 2 m level at 00 UTC and 12 UTC, respectively. At the same time, biases in relative humidity increased with height. The new techniques assimilated in reanalyses were found to be in a disagreement and in unison with radiosonde data, depending on the level, time of the day and reanalysis investigated. The RS80-A TD correction had a significant effect on tropospheric humidity measurements, increasing specific humidity up to 0.3 g kg(-1) at the 2 m level. Based on the ranking results, JRA-55 is the most accurate reanalysis in representing the radiosonde measurements.