Analysis of atmosphere–ocean interaction on cold season precipitation in Iran

Anomalies and concentrations of winter precipitation are effective in the challenges regarding water shortage. Iran's precipitation is strongly influenced by teleconnection, where changes in SLP (sea level pressure), SST (sea surface temperature), and 500 hpa levels contribute highly to the temporal distribution and precipitation volume. The effect of the SST, SLP, and 500 hpa, 2.5 ° × 2.5° factors are assessed from 1984 to 2018. The results indicate that a decrease in the Red Sea pressure (Sudan Low) and the Pacific Ocean and an increase in the Atlantic and Indian oceans’ pressures increase Iran's winter precipitation. At 500 hpa level, the results reveal that the increased winter precipitation in Iran is associated with an increase of 500 hPa in altitude on the Baltic Sea and the Indian Ocean and a decrease in altitude of 500 hpa on the Caspian Sea, the Mediterranean Sea, the Arabian Sea, and the Red Sea. In SST, the results indicate that the linkage between SST and precipitation of Iran is positive in regions of the Arabian and Red sea, Madagascar, and north Atlantic Ocean regions. Any change in SLP, 500 hPa level, and SST introduces positive or negative anomalies in Iran's precipitation. Global warming, which changes SLP, atmospheric thickness (1000–500), and SST, has a greater impact on Iran's precipitation, thus challenging water resources and facing climate risks.