CR prepress abstract   -  DOI: https://doi.org/10.3354/cr01740

ABSTRACT: In this paper we investigate recent changes in frequency, intensity, and duration of the heat and cold waves in western Iran, a semi-arid region where agricultural activities represent the major contribution to the region’s economy. Results showed that heat waves became significantly more frequent, longer, and more intense from the end of the 20th century, while cold waves behaved in the inverse way. A detailed synoptic analysis found that the action centers derived from the expansion of Azores high pressure over the Arabian desert and the Iranian plateau were the main responsible for all heat waves. However, cold waves responded to four different patterns from which the Siberian high pressure was the main atmospheric configuration leading to the most intense and persistent events.