Evolution of two cirque glaciers in Lombardy and their relation to climatic factors (1962–2016)
Evolution of two cirque glaciers in Lombardy and their relation to climatic factors (1962–2016)
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DOI：
10.1080/04353676.2017.1368834
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发表时间：
2017-10
期刊：
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通讯作者：
W. Hagg;R. Scotti;F. Villa;E. Mayer;A. Heilig;C. Mayer;W. Tamm;Tassilo Hock
中科院分区：
文献类型：
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作者：
W. Hagg;R. Scotti;F. Villa;E. Mayer;A. Heilig;C. Mayer;W. Tamm;Tassilo Hock
摘要为了评估南欧阿尔卑斯山的气候-冰川关系，我们选择了伦巴第的两个小冰川Suretta Sud和Lupo进行调查。2016年的全球定位系统剖面图确定了自2007年以来的海拔变化，从而利用大地测量法确定了冰川物质平衡。较旧的地图已被数字化，以重建1962年以来的大规模变化。这两个冰川的反应是同步的，并显示出整体的质量损失，但Suretta Sud较窄的观测模式显示，从1970年到1982年，质量发生了正变化。对代表站降水和气温的长期气象序列进行了分析，夏季有极显著的增温趋势，每10年增温0.32~0.40℃，冬季降水无明显增温趋势。自2009/2010年以来，利用冰川学方法进行的年度物质平衡测量由Servizio Glaciics o Lombardo进行。这些年度观测表明，尽管大地测量观测到了十年的质量损失，但质量变化为正的年份仍然存在。这些年的冬季降水量低于平均水平，夏季低于平均温度，这表明冰川的行为受到这两个参数的影响。通过回波无线电测深观测到的冰层厚度可以计算出冰川体积和基岩地形。冰层的最大厚度约为40米，冰川侵蚀不会使冰圈变得过深。使用非常简单的观测降耗速率的外推，可以得出这些冰川的理论预期寿命为50-70年。
ABSTRACT In order to assess the climate–glacier relationship in the Southern European Alps, two small glaciers in Lombardy, Suretta Sud and Lupo, have been chosen for investigation. GPS profiling in 2016 allowed the determination of elevation changes since 2007 and thus the determination of the glacier mass balance using the geodetic method. Older maps have been digitized to reconstruct mass changes back to 1962. The two glaciers react synchronously and show overall mass losses, but the narrower observation pattern at Suretta Sud reveals positive mass changes from 1970 to 1982. Long-term meteorological series of precipitation and air temperature of representative stations have been analysed, they show highly significant warming trends of 0.32–0.40°C per decade during summer, but no significant trend in winter precipitation. Since 2009/2010, annual mass balance measurements applying the glaciological method were undertaken by the Servizio Glaciologico Lombardo. These annual observations reveal that, despite the decadal mass loss observed by geodetic observations, years with positive mass changes still occur. These years showed below average winter precipitation and below average summer temperatures, indicating that glacier behaviour is influenced by both parameters. Ice thicknesses observed by echo radio sounding allow to calculate glacier volume and the bedrock topography. Maximum ice thicknesses are around 40 m and the cirques are not overdeepened by glacial erosion. Using very simple extrapolations of observed rates of downwasting results in theoretical life expectancies of these glacierets of 50–70 yr.