Applied Research in Geographical Sciences

Applied Research in Geographical Sciences

Detecting Change Points in Temperature Time Series over Iran

Articles in Press
Author
Seyed Abolfazl Masoodian
Department of Physical Geography
Abstract
Variability is inherent in the nature of climate. Temperature variability may be considered as the most evident indicator of climate change. Temperature variation may be randomly, cyclical, trending, or abrupt. Depending on the type of temperature variability, it can lead to diverse environmental, economic, social, and security consequences.

The trend of temperature on a global scale and temperature trend in Iran have been the subject of extensive research. Many researchers have confirmed the increasing temperature trend globally, and global warming has gained nearly universal acceptance. Similarly, the increasing temperature trend in Iran has been reported in numerous studies. However, comparing these results is not straightforward due to differences in the data and methodologies used to analyze temperature trends in Iran. Additionally, since many of these studies have been station-based—meaning they rely on station data—compiling them does not provide a comprehensive image of temperature trends at a national level. Moreover, the findings of these studies sometimes contradict each other.

If we set aside these challenges, while temperature trends have been extensively studied, abrupt shifts (jump changes) in Iran's temperature data have been less frequently examined. In this research, using station data, gridded Asfezari data, IMDAA gridded data, and ERA5 gridded data, we demonstrate that Iran's minimum and maximum temperatures have experienced jumps rather than gradual trends. Notably, the maximum temperature underwent a significant jump in the year 1998. All data sources used in this study confirm that the timing of the jump in minimum and maximum temperatures aligns approximately.
Keywords
Change point
temperature
Trend
Iran
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Applied Research in Geographical Sciences

Articles in Press, Corrected Proof
Available Online from 21 March 2007