Intercomparison of temperature and precipitation data sets based on observations in the Mediterranean and the Middle East

This paper presents an intercomparison and evaluation of gridded temperature and precipitation data sets, based on observations in the Mediterranean and the Middle East region. Using available global and regional data, we investigate the spatial and seasonal distributions of these two parameters, including uncertainties and trends for eight subregions that signify distinct climate regimes. All data sets represent the overall spatial features well though partly with biases. Using the seasonal means, standard deviations and cumulative density functions for the eight subregions, we identify outliers among the data sets. The correlations between data sets are high except for some regional data products. Desert areas such as Saudi Arabia and Libya-Egypt appear problematic due to their sparse station network. Similar upward trends of temperature and downward trends in precipitation are found for most of the region in all data sets, while differences appear in their magnitude and level of significance. © 2012 American Geophysical Union. All Rights Reserved.