山地冰川平衡线高度作为气候变化代用指标的讨论

对以平衡线高度作为气候变化代用指标的理论依据进行了讨论,依据天山乌鲁木齐河源1号冰川的大量观测资料,建立和完善现代冰川平衡线高度与气候统计关系,从传统方法以区域范围内气候因子为参数改造为以冰川范围内气候因子为参数,通过检验认为改造后的公式比较合理.将公式外推到小冰期第二次冰进时的1号冰川,并运用侧碛垄最大高度法确定了小冰期第二次冰进时冰川的平衡线高度,给出了该次冰进时气候条件的半定量推算结果.证明利用山地冰川平衡线高度作为气候变化的代用指标,并且对气候状况进行半定量推断是可行的.

Equilibrium Line Altitude of Mountain Glacier as a Proxy of Climate Changes

The theory that equilibrium line altitude acts as a proxy of climate changes is discussed. Based on the abundant observation data on the Glacier No. 1 at the headwaters of Urtimqi River in Tianshan Mountains, since the 1960s, a statistical equation relating the present equilibrium line altitude and climate is established and improved, which is verified of rationality in the region. Extrapolating the equation to the second phase of the Little Ice Age of the glacier, and inferring the equilibrium line altitude at that time from maximum elevation of lateral moraines, the climate condition during the phase can be determined. The result is closed to the previous outcomes deduced by other methods. All these show that taking the equilibrium line altitude of alpine glacier as a proxy of climate changes and calculating the climate condition from the equation is feasible.