Comprehensive Warming Assessment in a High-Altitude Region: Observational Evidence From Qinghai Province, Northwest China

The recent trends of global warming slowdown have garnered increased attention in the field of climate science. The Qinghai province, a high-altitude region in northwest China, is highly sensitive to climate change, and understanding its response to the warming slowdown is crucial. Using data from 34 meteorological stations between 1960 and 2016, we analyzed the temperature variations in Qinghai via Mann-Kendall trend analysis, Sen's slope method, and ANUSPLIN interpolation. The findings were compared with data from other regions to examine the response of temperature variations during the warming slowdown. Furthermore, we explored the influence of large-scale climate patterns on temperature variation using wavelet transform coherence analysis. The results indicated that both annual and seasonal temperatures exhibit a consistent warming trend, with a significant upward shift post ∼2,000. The most pronounced warming occurred in the autumn minimum and winter maximum temperatures. Temperature magnitudes were lower in high-altitude areas in the southwest, southeast, and northeast, and higher in the relatively lower-altitude areas in the east and northwest of Qinghai. The warming trend exhibited a clear southeast-to-northwest gradient, reflecting both latitudinal and meridional distribution characteristics. During the warming slowdown, a hiatus phenomenon was observed in the annual, autumn, and winter temperatures of northern Qinghai, although the overall warming trend remained consistent with that of the Tibetan Plateau. The Arctic oscillation was found to play a key role in influencing the annual mean temperatures in the region, while the Pacific decadal oscillation may be another climatic pattern contributing to the observed hiatus period.