用树木年轮研究我国温性冰川进退及其对气候变化的响应

项目名称： 用树木年轮研究我国温性冰川进退及其对气候变化的响应

项目编号： No.40801033

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 朱海峰

作者单位： 中国科学院地理科学与资源研究所

项目金额： 25万元

中文摘要： 近几十年来，我国温性冰川剧烈退缩。了解过去的冰川变化及其与气候变化的关系，对预测未来气候变化情景下的冰川变化至关重要。本项目以藏东南米堆冰川为例，利用树木年轮研究了小冰期以来藏东南温性冰川经历了怎样的变化，气候是如何变化的，二者之间是什么样的关系？ （1）自小冰期最盛期（约1767）以来，米堆冰川总体呈退缩趋势，期间经历了至少四次明显的进退波动。每次波动中冰川转变为后退的最晚时间分别为约1767，1875，1924和1964年。 （2）在过去618年中，藏东南夏季在17-18世纪较为凉爽，20世纪是最暖的百年。自18世纪以来，该地区夏季总体呈明显升温趋势，期间伴随着1740s,1810s,1910s和1960s四次明显的冷暖波动。 （3）在百年尺度上，米堆冰川的进退与温度冷暖变化的长期趋势相一致。在年代际尺度上，冰川进退对温度变化总体上存在至少约8年的滞后期。 本项目中的冰碛垄测年数据和夏季温度重建数据，可以为研究冰川水资源变化，冰川-气候模型提供长时间的资料，对研究过去气候变化特征、规律和原因也具有重要的意义。就学科而言，进一步拓展了我国的树轮研究领域，将之成功应用到冰川变化研究。

中文关键词： 树轮；小冰期；冰川波动；气候变化；重建

英文摘要： Temperate glaciers in China have experienced tremendous retreat in recent decades. To evaluate the recent glacier retreats and predict possible changes under future climate scenarios, it is essential to know glaciers changed in the past and their relation to climate change. Using tree rings, here we investigate what changes the glaciers in the southeastern Tibetan Plateau (SETP) have experienced since the Little Ice Age (LIA), how about the climate during that period, and what relations are there between them? （1）Dating results of several moraines of Midui Glacier (MG) indicated MG retreated in general since the LIA maximum at about AD 1767. There are at least 4 times of glacier advance/retreat fluctuations, which happened at least before AD 1767, AD 1875, AD 1924 and AD 1964. （2）We reconstructed summer temperature variations during the past 600 years for the SETP. Summers were quite cooler during the 17-18th century and were unprecedented warmer during the 20th century. There was a general warming trend since the 1750s. （3）We compared the reconstructed glacier fluctuations and climate variations. The glacier advance/retreat fluctuations are in good agreement with summer cold/warm variations on both centennial and decadal timescales. On average, there is at least an 8-year lag between glacier fluctuation and temperature variation. The dating of moraines and temperature reconstructions could provide long-term datasets for the study on glacial water resources, glacier-climate models, and also helpful for past climate studies using glaciers. This pioneering work successfully broaded a new category,dendroglaciology, of tree-ring research in China.

英文关键词： tree ring; Little Ice Age; glacier fluctuation; climate change; reconstruction