Regional variability of seasonal precipitation over Turkey

Principal components (PCs) of the parametric spatial Pearson and non-parametric Spearman rank correlation matrices are used to depict the seasonal precipitation characteristics or features over Turkey. Eighty-five irregularly scattered meteorology stations over Turkey were chosen to study the monthly totals of precipitation observed from 1931 to 1990 inclusive. There are similarities among the rotated and unrotated first four components of the seasonal precipitation distributions. Meteorological processes, such as cyclonic storms during autumn and winter, are represented by the first PC over the whole study region. The influences of continentality towards the inland in Anatolia and the effect of mountains in the east of Turkey are shown by the second PC. The third PC explains the marine influence of the surrounding seas on the precipitation. Finally, it is shown that in this study, a non-parametric spatial correlation matrix produces quite similar fields with those of a parametric spatial correlation matrix.