中国和瑞士冰川波动之对比研究

Glacier Fluctuations: Comparison Between Long-Term of Measurements in China and Switzerland

主要分析和比较了中国和瑞士冰川物质平衡和长度(末端位置)变化的时空特征。两国冰川物质平衡的变化在几年或10a尺度内似乎存在着反相变化的趋势。对于目前变暖的气候条件,地形因素对某些冰川物质平衡的变化极为重要,尤其是冰川朝向和冰川面积随高度的分配状况显示出对冰川接受水汽能力的主导作用。两国长度小于10km的冰川,其长度的变化不但显示出定性(前进、后退)的可比性,而且很大程度上还可定量(变化速率)地比较。最后,本文对气候变化对冰川长度变化的影响进行了分析和讨论。总体上,长度小于10km的冰川对气候变化较为敏感,其中小于2km的冰川与气候变化几乎同步。

Mass balance and length variations of glaciers in China are compared with those in the Swiss Alps. Annual variations of mass balance appear to be different, but slight anti-variations seem to exist between considered mass balances of both countries. A marked accelerated tendency towards negative balance in both regions appears to be obvious in the most recent years. For present warming climate,topograghic factors appear to exert a strong influence on the trends of mass change of individual glaciers and cause considerable uncertainty, possibly it is related to hypsography and the glacier exposure to the predominant humidity sources. Variations of the glacier positions in front are analyzed for different classes of glacier length. Length changes of the glaciers shorter than 10 km appear to be quite comparable qualitatively (advance / retreat) and quantitatively (rates of change) in both countries, with a decelerating retreat tendency since the 1960s leading to a(transient) period of glacier advance from the middle of the 1970s to the beginning of the 1980s. From the comparison of variations of mass balance for various classes of length change, it is concluded that the reactions of the smaller glaciers shorter than 10 km in length to climatic change are quite sensitive. For the smallest glaciers shorter than 2 km in length, the variations of mass balance and those of length are completely synchronous, while for the smaller glaciers in the length of 2 to 10 km, the variations appear to have a very short time lag. However, steady retreat has been observed for most glaciers since the 1950s, which are longer than 10 km may have long response time to the decadal change of climate.