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冰川冻土 ›› 2000, Vol. 22 ›› Issue (3): 223-229.

• 研究论文 • 上一篇    下一篇

小冰期以来中国季风温冰川对全球变暖的响应

苏珍, 施雅风   

  1. 中国科学院寒区旱区环境与工程研究所, 甘肃兰州730000
  • 收稿日期:2000-05-18 修回日期:2000-06-27 出版日期:2000-08-25 发布日期:2012-04-26
  • 基金资助:
    中国科学院寒区旱区环境与工程研究所创新项目(210010):中国科学院"九五"重大项目"西部冰川资源变化及其对社会经济发展的影响"(KZ951-B1-212)资助

Response of Monsoonal Temperate Glaciers in China to Global Warming Since the Little Ice Age

SU Zhen, SHI Ya-feng   

  1. Cold and Arid Regions Environmental and Engineering Research Institute, CCAS, Lanzhou Gansu 730000, China
  • Received:2000-05-18 Revised:2000-06-27 Online:2000-08-25 Published:2012-04-26

摘要: 中国的季风温冰川主要分布在青藏高原东南部,冰川覆盖面积为占我国冰川 总面积的22.2%由于这类冰川的特性,对气候变暖极为敏感自小冰期最盛时(1世纪)以来,温冰川区平均升温0.8C,冰川面积减小相当现代面积的30%.为3921.2预估中国季风温冰川区2100年的升温值2.1℃,届时冰川面积将减少75%。达9900左右,考虑到降水增加趋势等因素,实际冰川退缩比例不大于80%,但这已足以说明温冰川的大规模衰退,其后果将对当地水资源和环境产生重大影响.

关键词: 季风温冰川, 小冰期, 全球变暖

Abstract: The monsoonal glaciers with temperate characteristics are mainly distributed over the southeast part of the Tibetan Plateau, i.e., the Hengduan Mountains, the eastern section and southern slopes of the Himalayas and the mid-eastern sections of the Nyainqentanglha Range. These glaciers have an area of about 13 200 km2 and about 22% of the total glacier area of China at present. Summer monsoon from Indian Ocean carries abundant precipitation to these regions with an annual precipitation of 1000-3000 mm. The equilibrium line altitude (ELA) of most glaciers reaches 4 200 m to 5 200 m a. s. l., which is about 800-1200 m lower than that of polar type glaciers in the western Tibetan Plateau. The annual mean air temperature at the ELA is higher than -6 ℃,with the mean air temperature during summer (from June to August) ranging from 1℃ to 5℃. The ice temperature of all ice layers ranges between 0℃ and -4 ℃. and usually higher than -1℃. Therefore ablation is intense. The ablation depth reaches 15.3 m at the mid-section of the Ruogou Glacier and 9.36 m in the Hailuogou Glacier. The ice movement mainly belongs to basal sliding with a large velocity and a high amplitude of fluctuations. The annual mean velocity was recorded as 438 m·a-1 at the Azha Glacier and 533 m·a-1 at the Melang Glacier. These glaciers are more sensitive to climate change, i. e. a small rise in air temperature can result in a large shrinkage in glacier area. The Little Ice Age (LIA) is referred to a relatively cold period from the 15th to 19th century around the world. There were 3 colder phases in the LIA, which resulted in many glaciers to advance, with clear end moraine appeared at the end of glaciers. The 3 colder phases can be distinguished according to ice core and tree-ring records. The second colder event in the 17th century was extreme, which was related to the minimum solar irradiance known as Maunder Minimum during 1645-1715. and induced that the second end moraine usually overlapped on the first or the former one. Variation of snowline of the monsoonal temperate glaciers lead to speculate that the mean temperature from the 17th century to the 20th century was about 0.8K (0.6-1.1 K) lower than now. Based on a field surveying of 1139 glaciers, which were located in representative regions with various sizes, accounting for 13.2% of total amount of monsoonal temperate glaciers in the southeast part of the Tibetan Plateau, it was measured that the area of these glaciers was 1862 km2, 14.1% of the total area. However an extension statistics indicated that since the LIA. the reduction of the total glacier area has been 3 921.2 km2. equivalent to 30% of the glacier area at present. greater than that of the sub-polar type glaciers and the polar type glaciers in West China, 23% and 10%, but less than that of the westerly temperate glaciers in the Alps. 50%. According to the newest information of the Intergovernmental Panel on Climatic Change (IPCC). the average air temperature around the world in 2100 will be higher than that during the late 20th century. with a 2.1 K rise in the monsoonal temperate glacier area. Along with a warming, the area will largely shrink in the monsoonal temperate glacier area. It is predicted that the glacier area will be reduced 75% as compared with the glaciers at present and will reach about 9 900 km2. But the shrinkage proportion will not greater than 80%. This is enough to indicate that the most monsoonal temperate glaciers will disappear. The remained glacier area will occupy only 25% of the glacier area at present, about 3 300 km2. It will bring enormous infection to the water resources and environment in this area.

Key words: monsoonal temperate glacier, Little Ice Age, global warming

中图分类号: 

  • P343.6