Analysis of The Effect of Atmosphere-Ocean Interaction on Winter Rainfall in Iran

Abstract

Abstract Decades of drought and heavy rainfall are the most important climatic hazards in Iran. Anomalies and concentration of winter rainfall are effective in the challenge and water shortage. Iran's rainfall is strongly influenced by teleconnection. So that changes in SLP[1],SST[2] and changes in the level of 500 hPa have an effective role in the temporal distribution and volume of rainfall. The effect of three factors of sea level pressure, 2.5°*2.5° were evaluated from 1984 to 2018.The results indicated that decreased pressure on the Red Sea (Sudan Low) and the Pacific Ocean and increased pressure on the Atlantic and Indian oceans increase Iran's winter precipitation. In 500hpa, the results indicated that increased winter precipitation in Iran is associated with an increase in altitude of 500hPa on the Baltic Sea and the Indian Ocean and a decrease in altitude of 500hPa on the Caspian Sea, the Mediterranean Sea, the Arabian Sea and the Red Sea. In SST, the results indicated that the linkage between SST and precipitation of Iran is positive in regions such as the Arabian and Red sea, Madagascar, and north Atlantic Ocean. Therefore, any change in sea level pressure, 500hPa level and sea surface temperature leads to positive and negative anomalies on Iran's rainfall. Therefore, global warming, which leads to changes in SLP, atmospheric thickness (1000-500) and SST, has a greater impact on Iran's rainfall and leads to challenges in water resources and climate risks. [1] -Sea level pressure [2] -Sea surface temperature