Evaluation of maximum and minimum temperature of NCEP-NCAR reanalysis data over Greece

Summary

Assessment of the reliability of NCEP-NCAR reanalysis data has been the subject of much recent climatological research. In this study, an attempt is made to evaluate the reanalysis data for maximum and minimum temperatures over Greece for the period 1958–2000. Considering that available observations for Greek stations are not included as input in the NCEP-NCAR reanalysis data, the evaluation was made using gridded observational data derived from long time series for the examined area, using an objective scheme. The reanalysis data were compared with respect to the intra-annual variability for extreme years, the inter-annual variability of the corresponding temperature anomalies, and their ability to represent cold and warm spells. Also, the correlation patterns between the two datasets of daily and monthly values were examined. In general, it was found that there was good agreement between the two datasets, although some regional and seasonal differences existed and these were associated with topographical features not correctly represented by the reanalysis model resolution, such as land-sea distribution and orography.