Glacier algae accelerate melt rates on the western Greenland Ice Sheet
Glacier algae accelerate melt rates on the western Greenland Ice Sheet
复制标题
DOI：
10.5194/tc-2019-58
复制
发表时间：
2019-04
期刊：
影响因子：
--
通讯作者：
J. Cook;A. Tedstone;C. Williamson;J. McCutcheon;A. Hodson;A. Dayal;M. Skiles;Stefan Hofer
中科院分区：
文献类型：
--
作者：
J. Cook;A. Tedstone;C. Williamson;J. McCutcheon;A. Hodson;A. Dayal;M. Skiles;Stefan Hofer
抽象的。格陵兰冰盖的融化是海平面上升的最大单一因素，并因冰面上色素藻类的生长而扩大，增加了太阳辐射的吸收。这一生物学上的减毒作用及其对海平面上升的影响以前没有被量化。在这里，我们结合联合收割机场光谱与一种新的辐射传输模型，无人机和卫星遥感数据和径流建模的监督分类计算生物驱动的冰面消融，并将其与当地矿物粉尘的减蚀效果进行比较。我们证明，藻类生长导致2016年夏季GrIS西部地区额外增加5.5-8.0 Gt径流，占总量的6- 9%。我们的分析证实了生物的反馈的重要性，它从预测模型的遗漏导致系统低估格陵兰岛的未来海平面的贡献，特别是因为裸冰区可供藻类殖民化和活跃的生长季节的长度将在未来扩大。
Abstract. Melting of the Greenland Ice Sheet (GrIS) is the largest single contributor to eustatic sea level and is amplified by the growth of pigmented algae on the ice surface that increase solar radiation absorption. This biological albedo reducing effect and its impact upon sea level rise has not previously been quantified. Here, we combine field spectroscopy with a novel radiative transfer model, supervised classification of UAV and satellite remote sensing data and runoff modelling to calculate biologically-driven ice surface ablation and compare it to the albedo reducing effects of local mineral dust. We demonstrate that algal growth led to an additional 5.5–8.0 Gt of runoff from the western sector of the GrIS in summer 2016, representing 6–9 % of the total. Our analysis confirms the importance of the biological albedo feedback and that its omission from predictive models leads to the systematic underestimation of Greenland’s future sea level contribution, especially because both the bare ice zones available for algal colonization and the length of the active growth season are set to expand in the future.