تحقیقات کاربردی علوم جغرافیایی

تحقیقات کاربردی علوم جغرافیایی

آشکارسازی جهش‎های سری زمانی دما در ایران

نویسنده
سیدابوالفضل مسعودیان
گروه جغرافیای طبیعی
چکیده
وردش در سرشت آب و هواست. وردش دما می‎تواند آشکارترین نماد تغییر اقلیم باشد. وردش دما ممکن است تصادفی، چرخه‎وار، روندی یا جهشی باشد. بسته به این که وردش دما از چه نوعی باشد می‎تواند پیامدهای زیست‎محیطی، اقتصادی، اجتماعی، و امنیتی گوناگونی به دنبال داشته باشد. روند دما در مقیاس جهانی و در ایران موضوع مطالعات گسترده‎ای بوده است. پژوهشگران زیادی روند افزایش دما در مقیاس جهانی را تأیید کرده‎اند و گرمایش جهانی تقریباً پذیرش همگانی یافته است. روند افزایش دما در ایران نیز در مقالات بسیاری گزارش شده است. به دلیل تفاوت داده‎ها و روش‎هایی که در بررسی روند دما در ایران به کار گرفته شده مقایسه نتایج آنها آسان نیست. از سوی دیگر چون بسیاری از این بررسی‎ها ایستگاه محور بوده‎اند یعنی بر پایه داده‎های ایستگاهی انجام شده‎اند از کنار هم چیدن آنها نیز نمی‎توان تصویری جامع از وضعیت روند دمای ایران به دست آورد. افزون بر این گاه نتایج این بررسی‎ها با یکدیگر ناسازگار است. اگر این دشواری‎ها را کنار بگذاریم با این که روند دما زیاد بررسی شده اما جهش در داده‎های دمای ایران کم‎تر بررسی شده است. در این پژوهش به کمک داده‎های ایستگاهی، داده‎های شبکه‎ای اسفزاری، IMDAA ، و ERA5 نشان داده‎ایم که دمای کمینه و بیشینه ایران بیش از آن که روند را تجربه کرده باشد دستخوش جهش شده است. به ویژه دمای بیشینه در سال 1377 جهش معناداری پیدا کرده است. همه منابع داده به کار رفته در این پژوهش زمان جهش دمای بیشینه را در زمان تقریباً یکسانی تأیید می‎کنند.
کلیدواژه‌ها
گشتگاه
دما
روند
ایران

عنوان مقاله English

Detecting Change Points in Temperature Time Series over Iran

نویسنده English

Seyed Abolfazl Masoodian
Department of Physical Geography
چکیده English

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.

کلیدواژه‌ها English

Change point
temperature
Trend
Iran
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