The Characteristics of Climate Change over the Tibetan Plateau the Last 40 Years and the Detection of Climatic Jumps

Abstract

Through analyzing the yearly average data obtained from 123 regular meteorological observatorieslocated in the Tibetan Plateau (T-P), this article studies the characteristics of climate change in T-P inthe last 40 years. From the distribution of the linear trend, it can be concluded that the southeasternpart of T-P becomes warmer and wetter, with an obvious increase of rainfall. The same characteristicsare found in the southwestern part of T-P, but the shift is smaller. In the middle of T-P, temperature andhumidity obviously increase with the center of the increase in Bangoin-Amdo. The south of the TarimBasin also exhibits the same tendency. The reason for this area being humid is that it gets less sunshineand milder wind. The northeastern part of T-P turns warmer and drier. Qaidam Basin and its westernand southern areas are the center of this shift, in which the living environment is deteriorating. Analyzingthe characteristics of the regional average time series, it can be found that in the mid-1970s, a significantsudden change occurred to annual rainfall, yearly average snow-accumulation days and surface pressurein the eastern part of T-P. In the mid-1980s, another evident climatic jump happened to yearly averagetemperature, total cloud amount, surface pressure, relative humidity, and sunshine duration in the samearea. That is, in the mid 1980s, the plateau experienced a climatic jump that is featured by the increase oftemperature, snow-accumulation days, relative humidity, surface pressure, and by the decrease of sunshineduration and total cloud amount. The sudden climatic change of temperature in T-P is later than that ofthe global-mean temperature. From this paper it can be seen that in the middle of the 1980s, a climaticjump from warm-dry to warm-wet occurred in T-P.