The impacts of warming on rapidly retreating high-altitude, low-latitude glaciers and ice core-derived climate records
The impacts of warming on rapidly retreating high-altitude, low-latitude glaciers and ice core-derived climate records
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DOI：
10.1016/j.gloplacha.2021.103538
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发表时间：
2021-06
影响因子：
3.9
通讯作者：
L. Thompson;M. Davis;E. Mosley‐Thompson;S. Porter;Gustavo Valdivia Corrales;C. Shuman;C. Tucker
中科院分区：
文献类型：
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作者：
L. Thompson;M. Davis;E. Mosley‐Thompson;S. Porter;Gustavo Valdivia Corrales;C. Shuman;C. Tucker
低纬度和中纬度的高山冰川比大型极地冰盖对温度、降水、云量、湿度和辐射的变化反应更快。许多高海拔冰川都是通过地面观测、航空摄影和卫星传感器监测的。无论纬度和海拔如何，几乎所有的非极地冰川和冰盖都在经历质量损失，这损害了保存在其中的过去气候记录。几乎无一例外，这些冰原的退缩是持续的，一个非常重要的驱动因素是最近热带对流层和海洋的变暖。在这里，我们提出的数据减少表面积的四个冰川从低纬度到中纬度山区：秘鲁和北方玻利维亚，赤道东非，赤道巴布亚，印度尼西亚和青藏高原西部的安第斯山脉。根据从这些地区几个冰川钻取的冰芯中测得的氧同位素比值（δ 18 O）的气候记录表明，海拔6000米以下的记录已被季节性融化和融水通过多孔上层积雪层的运动所大大改变。幸运的是，从海拔较高的地点恢复的δ 18 O记录仍然包含保存完好的季节变化;然而，预计大气变暖速度的增加意味着来自海拔较高的冰川的气候记录最终也会退化。对地球上最大的热带冰帽秘鲁的奎尔卡亚冰帽进行的一项长期冰芯收集计划表明，其气候记录的恶化是伴随着对流层中层温度的上升。冰的融化和由此产生的冰前湖的增长对附近的社区构成了迫在眉睫的危险。冰川加速融化，如果持续下去，将确保最终失去独特和不可替代的气候历史，以及对当地社区的深刻经济，农业和文化影响。
Alpine glaciers in the low- and mid-latitudes respond more quickly than large polar ice sheets to changes in temperature, precipitation, cloudiness, humidity, and radiation. Many high-altitude glaciers are monitored by ground observations, aerial photography, and satellite-borne sensors. Regardless of latitude and elevation, nearly all nonpolar glaciers and ice caps are undergoing mass loss, which compromises the records of past climate preserved within them. Almost without exception, the retreat of these ice fields is persistent, and a very important driver is the recent warming of the tropical troposphere and oceans. Here we present data on the decrease in the surface area of four glaciers from low- to mid-latitude mountainous regions: the Andes of Peru and northern Bolivia, equatorial east Africa, equatorial Papua, Indonesia, and the western Tibetan Plateau. Climate records based on oxygen isotopic ratios (δ18O) measured in ice cores drilled from several glaciers in these regions reveal that the records from elevations below ~6000 m above sea level have been substantially modified by seasonal melting and the movement of meltwater through porous upper firn layers. Fortunately, δ18O records recovered from higher altitude sites still contain well-preserved seasonal variations to the surface; however, the projected increase in the rate of atmospheric warming implies that climate records from higher elevation glaciers will eventually also be degraded. A long-term ice core collection program on the Quelccaya ice cap in Peru, Earth's largest tropical ice cap, illustrates that the deterioration of its climate record is concomitant with the increase in mid-troposphere temperatures. The melting ice and resulting growth of proglacial lakes presents an imminent hazard to nearby communities. The accelerating melting of glaciers, if sustained, ensures the eventual loss of unique and irreplaceable climate histories, as well as profound economic, agricultural, and cultural impacts on local communities.