Investigation of the North Atlantic Oscillation and Indian Ocean Dipole Influence on Precipitation in Turkey with Cross-Spectral Analysis

Predicting the future behavior of precipitation is utmost importance for planning agriculture or water resource management and in designing structures. Determining relationships between oceans may enable more accurate predictions. Therefore, oceanic other persistent indices called teleconnection patterns can be used, namely North Atlantic oscillation (NAO) Indian Ocean dipole (IOD). The NAO affects Mediterranean countries, such as Turkey. IOD related to temperature coastal countries some areas far from Ocean. In this study, effects on Turkey were investigated by means cross-spectral analysis monthly total (mm) index values. Phase shift values also calculated selected periods their accuracy was evaluated statistically, using determination coefficient (R2) Akaike information criterion (AIC) performance criteria linear model. results indicated strong correlations 13-, 14-, 16-, 22–23-month values; 16–17-, 20–21-month After values, maximum phase increased increased, while value each period almost half value. Moreover, cross-power spectral density (CPSD) increased. High CPSD observed west east IOD.