A precipitation-dominated, mid-latitude glacier system: Mount Shasta, California
A precipitation-dominated, mid-latitude glacier system: Mount Shasta, California
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以降水为主的中纬度冰川系统：加利福尼亚州沙斯塔山
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发表时间：
2006
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通讯作者：
M. Snyder
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作者：
I. Howat;S. Tulaczyk;P. Rhodes;K. Israel;M. Snyder
温度通常被认为是冰川体积变化的主要控制因素。然而，尽管在过去半个世纪出现了区域性变暖，沙斯塔山冰川在20世纪初的一次长期干旱中出现了收缩，但此后继续扩大，这表明对降水的敏感性大于对温度的敏感性。我们使用沙斯塔山冰川和气候的110年波动记录来校准两个最大冰川的数值冰川模型。重建的平衡和体积的历史显示出更大的相关性，降水比温度和太平洋气候的振荡模式的显着相关性。温度每升高1°C，需要增加约20%的沉淀以保持稳定性。在持续的历史趋势下，气候模式的振荡和随机变率将主导冰量的年代际变率。根据一个区域气候模式所预测的强烈变暖趋势，温度趋势将成为主导力量，导致沙斯塔山的冰川在世纪末几乎全部消失。
Temperature is often seen as the dominant control on inter-decadal glacier volume changes. However, despite regional warming over the past half-century, the glaciers of Mount Shasta have continued to expand following a contraction during a prolonged drought in the early twentieth century, indicating a greater sensitivity to precipitation than temperature. We use the 110 year record of fluctuations in Mount Shasta’s glaciers and climate to calibrate numerical glacier models of the two largest glaciers. The reconstructed balance and volume histories show a much greater correlation to precipitation than temperature and significant correlation to oscillatory modes of Pacific Ocean climate. An approximately 20% increase in precipitation is needed for every 1°C increase in temperature to maintain stability. Under continued historical trends, oscillations in climate modes and random variability will dominate inter-decadal variability in ice volume. Under the strong warming trend predicted by a regional climate model, the temperature trend will be the dominant forcing resulting in near total loss of Mount Shasta’s glaciers by the end of the twenty-first century.