CLIMATE SENSITIVITY OF GLACIER NO.1 AT THE SOURCE OF URUMQI RIVER IN THE TIANSHAN MOUNTAINS
Wang Ninglian; Yao Tandong; Liu Shiyin and Tian Lide(Lanzhou Institute of Gleciology and Geocryology, Chinese Academy of Sciences, Lanzhou 730000)
In this paper, a statistical model of the equilibrium－state response of a mountain glacier to climatic change, developed by authors, is applied to study the equilibrium－state length scales of Glacier No. 1 (it is actually made of two separated branches, i. e. the east and west branches) at the source of Urumqi river in the Tianshan Mountains under different climatic scenarios. The results show that: if the climate in the future is the same as the mean condition in the period of 1980~ 1993, the east and west branches would not reach their equilibrium－state lengths until they retreat about 1. 02km and 0. 40km respectively; when the summer temperature rises 1 ℃, the east and west branches of the glacier would retreat about 2. 02km and 1. 16km respectively; but when the summer temperattlre decreases 1℃, the east and west branches will merge into one glacier, and have a length of 4. .48km. The influence of precipitation on the equilibrium－state length of this glacier might not be significant relatively. In addition, it is found that the summer temperature at the source of Urumqi River has risen about 0. 43℃ since the Little Ice Age based on the statistical model and the historical variations of this glacier.