Glacier volume and area change by 2050 in high mountain Asia
Glacier volume and area change by 2050 in high mountain Asia
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DOI：
10.1016/j.gloplacha.2014.08.006
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发表时间：
2014-11
影响因子：
3.9
通讯作者：
Liyun Zhao;R. Ding;J. Moore
中科院分区：
文献类型：
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作者：
Liyun Zhao;R. Ding;J. Moore
根据Randolph Glacier Inventory 2.0 of high mountain Asia (HMA)，估算了到2050年所有67,028个冰川的面积和体积变化，这些冰川的总面积为122,969 km2。采用IPCC A1B情景强迫的25 km分辨率区域气候模式RegCM 3.0预估的温度和降水变化。冰川模拟基于一种拟合观测数据的新型地表质量平衡-高度参数化方法，以及利用航天飞机雷达地形任务中每个冰川表面地形的各种体积-面积缩放方法。我们使用最近可用的冰川测量值，按区域生成所有冰川的质量平衡-高度关系。根据升华和融化过程的相对重要性，平衡线海拔对温度和降水变化的敏感性因地区而异。我们还对质量平衡进行了模拟，以匹配2003年至2009年HMA冰川厚度变化的卫星观测。使用调整模型的净质量损失是仅使用冰川学校准数据的一半，这表明基准冰川的代表性是未来HMA对海平面上升贡献的不确定性的更大来源，而不是冰川清单或体积-面积尺度的误差。两种模式都预测，喀喇昆仑和喜马拉雅西北部约35%的冰川正在推进，这与近年来这些地区观测到的冰川质量略有增加相一致。然而，我们发现76%的冰川将会退缩，其中大部分是海洋性冰川。我们预计，到2050年，亚洲高山地区的总冰川面积损失将是2000年的22%（在调整模型中）或35%（未调整模型中），它们将导致全球海平面上升5毫米（调整模型）。
We estimate individual area and volume change by 2050 of all 67,028 glaciers, with a total area of 122,969 km2, delineated in the Randolph Glacier Inventory 2.0 of high mountain Asia (HMA). We used the 25 km resolution regional climate model RegCM 3.0 temperature and precipitation change projections forced by the IPCC A1B scenario. Glacier simulations were based on a novel surface mass balance–altitude parameterization fitted to observational data, and various volume–area scaling approaches using Shuttle Radar Topography Mission surface topography of each individual glacier. We generate mass balance–altitude relations for all the glaciers by region using nearest available glacier measurements. Equilibrium line altitude (ELA) sensitivities to temperature and precipitation change vary by region based on the relative importance of sublimation and melting processes. We also made simulations with mass balance tuned to match satellite observations of glacier thickness changes in HMA from 2003 to 2009. Net mass loss is half as much using the tuned model than using just glaciological calibration data, suggesting the representativity of benchmark glaciers is a larger source of uncertainty in future HMA contributions to sea level rise than errors in glacier inventories or volume–area scaling. Both models predict that about 35% of the glaciers in Karakoram and the northwestern Himalaya are advancing, which is consistent with the observed slight mass gain of glaciers in these regions in recent years. However, we find that 76% of all the glaciers will retreat, most of which are of the maritime type. We project total glacier area loss in high mountain Asia in 2050 to be 22% (in the tuned model) or 35% (un-tuned) of their extent in 2000, and they will contribute 5 mm (tuned model) to global sea level rise.