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چکیده
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An investigation of climatic extreme events presents the valuable opportunities to evaluate the potential impacts of climate change on human activities, agriculture, and economy. These analyses are useful procedures in monitoring climate change on a synoptic scale. The present study is a trend analysis of the extreme temperature events, which have been based on the gridded daily temperatures of Iranian climatic database within 1962–2004. The aim of the present study is to identify the frequency and intensity of extreme events, which have been increased with over Iran in the last four decades. Both the Mann–Kendall trend test and simple linear regression were utilized to detect trends in annual temperature extremes. The results showed that the frequency of hot extreme temperature events has increased over the study area within 1962–2004, while a negative trend has been observed in the frequency of cold extreme temperatures. About 66 % of the surface area has a significant positive trend in frequency of hot days and nights, while about 40.9 and 68.5%of surface area have a significant decrease in frequency of cold days and nights, respectively. The strongest increasing tendency is detected in the case of the annual numbers of hot nights, warm nights, summer days, warm days, and the heat wave duration indices.
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