大陆型冰川与海洋型冰川物质平衡对比研究--以天山和阿尔卑斯山典型冰川为例

A comparative study on mass balance between the continental glaciers and the temperate glaciers: Taking the typical glaciers in the Tianshan Mountains and the Alps as examples

物质平衡是冰川对气候变化最直接的响应,是冰川变化的重要参数.大陆型冰川与海洋型冰川发育在不同的水热环境下,它们对气候变化的响应程度、过程和机理存在很大差异,因此在全球变暖背景下对这两类不同性质冰川物质平衡变化特征及其机理做一全面的对比研究意义重大.以东、西天山的乌鲁木齐河源1号冰川和图尤克苏冰川以及阿尔卑斯山东、中、西部的欣特雷斯冰川、Caresèr冰川和Sarennes冰川为参照冰川,在对比分析这五条参照冰川近60 a来物质平衡变化幅度差异和阶段性差异基础上,对大陆型冰川与海洋型冰川物质平衡变化特征及其机理进行了对比研究.结果表明:在物质平衡阶段性变化上,阿尔卑斯山参照冰川物质平衡变化具有相似的阶段性,而天山和阿尔卑斯山参照冰川之间以及天山内部两条参照冰川之间物质平衡阶段性变化存在很大的差异,可见,无论不同性质冰川还是同一性质的不同冰川,其物质平衡的阶段性变化都可能存在差异,这与不同冰川所处环境水热变化的时间差异有关,而与冰川性质无关;在物质平衡变化幅度上,海洋型冰川变化幅度明显大于大陆型冰川,原因是不同性质冰川发育的水热环境及其对气候变化敏感性差异;在前人对冰川加速消融机理的研究基础上,本文也讨论了大陆型冰川与海洋型冰川物质平衡变化的机理及其异同.

Under the background of global warming,most of glaciers retreat all over the world. According to the water-thermal environment that glaciers developed in,as well as glacier physical properties,continental glaciers and temperate glaciers can be classified out. The two type glaciers exist significant differences in degree,process and mechanism in respond to climate change. So it is of great significance to conduct the comparative study on mass balance characteristics and mechanisms in respond to climate change between the two type glaciers. In this paper,the Glacier No. 1 at the headwaters of the rümqi River and Tuyuksu Glacier,respectively in east and west Tianshan Mountains,and Hintereisferner Glacier,Caresèr Glacier and Sarennes Glacier in the eastern,central and western Alps,respectively,are taken as sample glaciers. The characteristics and mechanisms of the mass balance change are compared for the two glacier types. Based on a comparative analysis on the differences in amplitude of fluctuation and phasic change of the mass balance during the 60 years. The results showthat the temperate glaciers have greater amplitude of fluctuation than that of the continental glaciers due to their differences in water-thermal environment and in sensitivity to climate change. Phasic change of mass balance was similar in the Alps,but was much different not only between the glaciers in the Tianshan Mountains and the Alps,but also between the two glaciers in the Tianshan Mountains. This indicates that the difference not only exist between different property glaciers but also among the same type glaciers. In addition,on the basis of predecessors＇ research on glacial retreat mechanisms,the similarities and differences in mechanisms of glacier mass balance between the continental glaciers and the temperate glaciers also studied. The air temperature rising during ablation season and the glacier surface albedo reduction are considered responsible for the accelerated ablation not only for the continental glaciers but also for the temperate glaciers. Moreover,the ice temperature rising and the glacier fragmentation are another important mechanism for speeding up ablation of the continental glaciers and the temperate glaciers.