Investigation of The Relationship Between The Phenomenon Of Enso On TheDroughts and Wet year In The Douthern Coastal Provinces Of Iran

Studying climatic processes provides plan makers with a suitable tool in different sectors to plan future policies for optimizing cost and maximizing productivity while bearing these studies in mind. Precipitation is associated with complex atmospheric processes including the El Niño–Southern Oscillation (ENSO) that is inextricably linked to the oscillations in the surface water temperature of the Pacific Ocean. The objective of this study was to investigate the relationship between rainfall in wet seasons of the year (cold season for six months) and the El Niño Southern Oscillation (ENSO) in the Persian Gulf and Oman Sea. After conducting adequate investigations, 12 synoptic stations with appropriate statistical period were selected and the homogeneity and adequacy tests of the data collected were carried out on rainfall amounts. The Southern Oscillation Index (SOI) was used to investigate the effect of the El Niño Southern Oscillation. The warm and cold phase was determined using the SOI index. Also, the longest droughts and wet years were identified and the wet and dry years associated with the warm phase (El Niño) and the cold phase (La Niña) was specified as well. The results showed that the wet years occurred in warm phase and droughts occurred during the cold phase so that at the same time as the dry years, rainfall in the stations under investigation was lower than normal, and the numerical value of the SOI index was lower than normal. The numerical value of the SOI index obtained in dry years was negative. While, at the same time as wet years, the amount of rainfall at the stations is more than the average annual precipitation of the investigation period and the numerical value of the SOI index is also positive and indicates higher values than normal.Pearson correlation test was used to investigate the correlation between rainfall and SOI index. The correlation was carried out on a monthly, seasonal, annual, and moving window basis. The results showed that on the monthly basis, the highest correlation was registered at Konarak station, on the seasonal basis, at Bandar Abbas, Bandar-e-Lengeh, Jask, Kish, Konarak, Bushehr and coastal Bushehr stations, and on the annual basis, at Abadan and coastal Bushehr stations at a significant level of 99%. It is also possible to conclude from the correlation of the moving window that the signal has the most effect on Bushehr, coastal Bushehr, Bandar Abbas, Kish, and Konarak stations in autumn and winter.