Spatiotemporal Trends of Extreme Temperature Events Along the Qinghai‐Tibet Plateau Transportation Corridor From 1981 to 2019 Based on Estimated Near‐Surface Air Temperature

• Published in: Journal of geophysical research. Atmospheres Vol. 128; no. 22
• Main Authors: Wang, Bin, Gao, Meiling, Li, Yumin, Xu, Huihui, Li, Zhenhong, Peng, Jianbing
• Format: Journal Article
• Language: English
• Published: 27.11.2023
• Subjects: extreme temperature events; near‐surface air temperature estimation; Qinghai‐Tibet Plateau transportation corridor; spatiotemporal trends
• DOI: 10.1029/2023JD039040
• ISSN: 2169-897X

The intensification of global warming leads to the increased frequency of extreme temperature events. Many studies have reported on numerous regions facing extreme hot and cold temperatures to some degree. In this study, the daily maximum, minimum and mean near‐surface air temperatures were estimated to explore the detailed spatial trends of extreme temperature events along the Qinghai‐Tibet Plateau Transportation Corridor (QTPTC). Sixteen extreme temperature indices were used to represent extreme temperature events, and the Mann‐Kendall trend test and Sen's slope estimation method were employed to explore the spatiotemporal trends of extreme temperatures along the QTPTC during 1981–2019. The possible factors that affect the trends of extreme temperature events were also discussed, indicating that: (a) There was an exacerbation of extreme hot events, while the prevalence of extreme cold events weakened along the QTPTC. This was in accordance with the trend of global warming. (b) The trends of extreme temperature indices based on daily minimum temperature were stronger than those based on daily maximum temperature in most areas, except for the eastern region. Furthermore, as altitude increased, the amplitude of warming intensified. (c) Unlike the trend in most areas, the intensified warming trend occurred in the low‐altitude areas in the eastern region where there are more human activities and rapid urbanization, and the daily maximum temperature trend was more severe there. The results can provide references for policymakers to formulate corresponding adaptation strategies, addressing the impacts of extreme temperature events on transportation facilities with significant elevation differences. Plain Language Summary With the intensification of global warming, extreme hot events occur more frequently. The frequent extreme temperature events may induce many natural disasters along the QTPTC. Many studies represent extreme temperature events by calculating the extreme temperature indices based on meteorological stations in situ. Due to the sparse meteorological stations in this region, we have produced a gridded air temperature product for nearly 40 years and conducted extreme indices calculations and trend analysis to obtain the spatiotemporal trends of extreme temperature events. The results indicate the intensification of extreme hot events and the reduction of extreme cold events in the region, and this was in accordance with the trend of global warming. As the altitude increased, the amplitude of warming intensified except the low‐altitude areas. The low‐altitude areas in the east did not follow this pattern, possibly due to more human activities here. It could provide comprehensive references for infrastructure construction, railway operation and the safety of residents along the QTPTC, as well as other transportation projects in mountainous areas. Key Points Spatial trends of extreme temperature events were detected using the gridded temperature product Extreme hot events generally increase with altitude The intensification of extreme hot events in the low‐altitude areas is likely due to human activities and urbanization