An assessment of recent global atmospheric reanalyses for Antarctic near surface air temperature

The quality-controlled monthly air temperature records from 32 manned stations and 10 automatic weather stations are used to assess the performance of Climate Forecast System Reanalysis (CFSR), the ECMWF “Interim” reanalysis (ERA-Interim), the Japan Meteorological Agency 55-year Reanalysis (JRA-55), the Modern-Era Retrospective Analysis for Research and Applications 2 (MERRA-2), and four twentieth century reanalysis data sets (20CR, ERA-20C, CERA-20C and ERA-20CM). The performance of the datasets for Antarctic air temperature differs on different time scales and with glaciological regime. In general, these datasets have higher mean absolute error (MAE) in the winter months and lower MAE in the summer months. Overall, MERRA-2 presents highest performance for monthly air temperature values, with MAE <2 °C at any month. ERA-Interim best represents the inter-annual variability in monthly air temperature for the 1979–2010 period. In the 20th century datasets, changes in temperature prior to 1979 are more uncertain than variability after 1979. Furthermore, substantial inhomogeneities occur in the 20th century datasets, and as a result, their temperature trends are found to be largely spurious.