An asymmetric relationship between Tibetan Plateau surface temperature regimes and oceanic–atmospheric circulations

Abstract

As a high-altitude region, the Tibetan Plateau (TP) is sensitive to climate change. Since the 1960s, the TP has experienced significant spatial-variant warming, vital to changing the region's terrestrial ecosystem. To understand surface air temperature (SAT) regimes over the TP, we investigated their link with teleconnections using observational and reanalysis datasets from 1982 to 2019. We employed wavelet analysis, empirical orthogonal teleconnection (EOT), partial regression, canonical correlation analysis and t test. Our results indicate an asymmetrical connection between teleconnections and SAT, with Atlantic Multidecadal Oscillation (AMO) predominant over the northern TP. In contrast, the El Niño–Southern Oscillation (ENSO) is more prevalent in the southern part. The spatial variance was potentially related to windspeed, total cloud cover (TCC), net longwave radiation (NLWR), net shortwave radiation (NSWR), cloud-forcing net longwave flux (CF-NLWF) and cloud-forcing net shortwave flux (CF-NLWF) anomalies. ENSO and Pacific Decadal Oscillation (PDO) modulate cloud cover variation in the southern TP, mainly the southwest, via the monsoon and subtropical westerlies. In the north, cloud cover variation is related to the moisture transported by the AMO-induced prevailing westerlies. The study examined the complex interplay between teleconnections, SAT and cloud radiative forcing by examining the cloud cover and radiation balance relationship. These findings contribute to understanding climate change impacts on the TP, informing climate projections and guiding adaptation strategies by elucidating the relationship between TP temperature variation and oceanic–atmospheric oscillation patterns.