Analysis of climate characteristics on the Tibetan Plateau based on mathematical statistics and vegetation response research

Abstract

The Tibetan Plateau(TP)’s profound influence on East Asian atmospheric circulation and its indicative role in shaping global climate patterns have garnered widespread scientific interest. This study employs the statistical method of Rotated Empirical Orthogonal Function (REOF) analysis to conduct an objective climate regionalization of the TP. The plateau is subdivided into five regions, and a detailed analysis is conducted on the 73-year trends of precipitation, temperature, ground temperature, evaporation, and wind speed in each of the five subregions. The study reveals that, since the start of observations, precipitation in the northern TP has undergone a transition from high to low, followed by a gradual increase. In contrast, precipitation in the southern TP has shown a slight decrease in recent years. Both air temperature and ground temperature across the TP exhibit an overall oscillatory warming trend. Meanwhile, evaporation has decreased, and wind speed has declined across the entire plateau. The combined effects of precipitation, temperature, evaporation, and wind speed have led to a pronounced warming and wetting trend in the northern TP, while the southern region exhibits a warming and drying trend. This is closely related to the complex mechanisms driven by the interplay of westerlies and monsoons over the TP. Since 2003, changes in the vegetation index on the plateau have shown a strong positive correlation with precipitation, indicating that precipitation is one of the key factors influencing vegetation on the TP.