Permafrost is a large reservoir of soil organic carbon, accounting for about half of all the terrestrial storage, almost equivalent to twice the atmospheric carbon storage. Hence, permafrost degradation under global warming may induce a release of a substantial amount of additional greenhouse gases, leading to further warming. In addition to gradual degradation through heat conduction, the importance of abrupt thawing or erosion of ice-rich permafrost has recently been recognized. Such ice-rich permafrost has evolved over a long timescale (i.e., tens to hundreds of thousands of years). Although important, knowledge on the distribution of vulnerability to degradation, i.e., location and stored amount of ground ice and soil carbon in ice-rich permafrost, is still limited largely due to the scarcity of accessible in situ data. Improving the future projections for the Arctic using the Earth System Models will lead to a better understanding of the current vulnerability distribution, which is a prerequisite for conducting climatic and biogeochemical assessment that currently constitutes a large source of uncertainty. In this study, present-day circum-Arctic distributions (north of 50° N) in ground ice and organic soil carbon content are produced by a new approach to combine a newly developed conceptual carbon-ice balance model, and a downscaling technique with the topographical and hydrological information derived from a high-resolution digital elevation model (ETOPO1). The model simulated the evolution of ground ice and carbon for the recent 125 thousand years (from the Last Interglacial to the present) at 1° resolution. The 0.2° high-resolution circum-Arctic maps of the present-day ground ice and soil organic carbon, downscaled from the 1° simulations, were reasonable compared to the observation-based previous maps. These data, together with a map of vulnerability of ice-rich permafrost to degradation served as initial and boundary condition data for model improvement and the future projection of additional greenhouse gas release potentially caused by permafrost degradation.

中文翻译：

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绘制模拟的环北极有机碳，地冰以及富含冰的永久冻土易退化的地图

多年冻土是土壤有机碳的大型储集层，约占所有陆地储量的一半，几乎相当于大气碳储量的两倍。因此，在全球变暖下的多年冻土退化可能导致大量额外温室气体的释放，导致进一步变暖。除了通过热传导逐渐降解之外，最近还认识到了融冰或侵蚀富冰永久冻土的重要性。这种富含冰的多年冻土已经演化了很长时间（即数万到数十万年）。尽管很重要，但是由于缺乏可获取的原地数据，有关降解脆弱性分布的知识，即富含冰的永久冻土中地下冰和土壤碳的位置和储存量的知识仍然受到很大限制。利用地球系统模型改进对北极地区的未来预测，将使人们对当前的脆弱性分布有更好的了解，这是进行气候和生物地球化学评估的先决条件，目前这构成了很大的不确定性来源。在这项研究中，通过一种新方法结合了新开发的概念性碳冰平衡模型和降尺度技术，并结合了降冰技术，得出了现今地下冰的周向北极分布（北向北50°）和有机土壤碳含量。来自高分辨率数字高程模型（ETOPO1）的地形和水文信息。该模型以1°分辨率模拟了近125万年来（从上一次冰期到现在）的地下冰和碳的演化。0。与基于观测的以前的地图相比，从1°模拟中缩小的2°高分辨率今天的地面冰和土壤有机碳的外接北极图谱是合理的。这些数据，以及富含冰的多年冻土对降解的脆弱性图，作为模型改进的初始条件和边界条件数据，以及将来可能由永久冻土降解引起的额外温室气体释放的预测。