Variability in temperature extremes across the Tibetan Plateau and its non-uniform responses to different ENSO types

Abstract

The variability of extreme temperatures has an important in uence on the sensitive ecosystem and human activities on the Tibetan Plateau (TP). Nevertheless, the uncertainties of different El Niño-Southern Oscillation (ENSO) effects on extreme temperatures on the TP are poorly understood. Thus, this study focuses on variations in temperature extremes across the TP during 1980-2015 based on the daily maximum temperature, and minimum temperature. Then, we quantitatively examined the different effects of different ENSO types and related large-scale atmospheric circulation variables on the changes in temperature extremes. The results show that more intense and more frequent warm extremes, less intense and less frequent cold extremes were observed from 1980 to 2015. It was observed that cold extremes exhibited signi cant variations. In particular, the area with a signi cant increase in the minimum daily minimum temperature accounted for 72% of the area of the TP. Moreover, our results also suggested that there was an asymmetric relationship between temperature extremes and different ENSO types (the Eastern Paci c (EP) and Central Paci c (CP) ENSO events). especially the signi cant increase of cold extreme during EP El Niño episodes (slopes of frequency and intensity of cold extremes were 6.58 and -1.03). In addition, the different ENSO types had a zonal in uence on temperature extreme variability on the TP through the modulation of large-scale atmospheric circulation. The changes in the intensity and frequency of the extreme warm events on the southeastern TP were distinct during the EP E1 Niño years, while the extreme warm events during the CP E1 Niño years tended to occur more frequently on the central of TP. Furthermore, the cold extremes over the western TP have experienced decreasing trends in EP La Niña years, while the frequency of warm extremes increased. The geopotential height anomaly and cyclonic circulation anomaly in the CP La Niña years enhanced cold extremes on the northeastern TP. In conclusion, within the context of the global warming, the different ENSO types are critical factor that in uences temperature extremes on the TP due to these non-uniform responses of atmospheric circulation. This study provided some insight for understanding the dynamics of regional extreme temperatures in different ENSO episodes.

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

“…Therefore, the abundant distribution of vegetation may be a driving factor in these areas. Besides, this may also be related to the EP (Eastern Pacific) El Niño, which resulted in more extreme cold events in the southeastern part of TP (Yong et al, 2023).…”