A comparison of atmospheric temperature over China between radiosonde observations and multiple reanalysis datasets
The quality controlled (RAW)and homogenized (ADJ)radiosonde temperatures at 850—30 hPa collected at 118 sta-tions in China are compared,on a monthly mean basis,with the temperatures extracted from 8 reanalysis datasets (REA)in-cluding NCEPv1,NCEPv2,ERA-40 (ECMWF 45-yr Reanalysis),ERA-Interim,JRA55 (Japanese 55-yr Reanalysis),20CR (20th Century Reanalysis),MERRA (Modern Era Retrospective-Analysis),and CFSR (Climate Forecast System Reanalysis). Average differences,correlations,standard deviations,and linear trends among RAW,ADJ,and REA for the period 1981 -2010 are analyzed.The results reveal significant inhomogeneity in the time series of RAW radiosonde temperature in China;an overall negative adjustment was thus applied to obtain the ADJ temperatures,and the effect the negative adjustment is the most significant within 200—100 hPa.Such a homogenization rocess has removed the system errors in RAW possibly caused by ra-diosonde instrument changes and observation system upgrades.Hence,the correlation is higher between ADJ and REA than that between RAW and REA.The mean difference between ADJ and REA is about 1℃ during 1981 -2010,while REA are mostly cooler in the troposphere and warmer in the stratosphere than ADJ;nonetheless,they have a high positive significant correlation and their annual varialility is notably consistent annual variability.Furthermore,the trends in REA and ADJ both demonstrate warming in the lower-mid troposphere and cooling in the mid stratosphere,with large uncertainties found in the upper troposphere and lower stratosphere.In general,ERA-Interim,JRA55,and MERRA are more consistent with ADJ than other reanalysis datasets.
RadiosondeAir temperatureReanalysis dataChinaRaw versus homogenized data
国家科技期刊平台
NSTL
万方数据
维普
