Spatial analysis and investigation of Tele-connection patterns with drought in central Iran

Abstract

This study, adopting an environmental approach to atmospheric circulation, estimates drought periods over a 20-year period (1992-2011) in 21 synoptic stations in Kerman, Yazd and Isfahan provinces, which share a long-term statistical period, using Standardized Precipitation Index (SPI). The data pertinent to 18 teleconnection patterns were derived and compared with climatic data of provinces under study and the relationship between major droughts in the region and these patterns was evaluated in accordance with correlation methods and multivariate regression model. According to the results, a total of 37.42% of annual SPI variation in Isfahan province, 51.09 % of SPI variation in Kerman province and 42.17% of SPI variation in Yazd province can be explained by the above patterns. Finally, the multivariate Scandinavia pattern (SCA) in Isfahan, East Atlantic (EA) pattern in Kerman and Tropical Southern Atlantic (TSA) pattern in Yazd were found to be the most effective patterns in explaining annual SPI changes in central Iran.