Collaborative Research: Is the export of ancient, labile carbon from glacial ecosystems driven by the deposition of fossil fuel combustion byproducts?

合作研究：冰川生态系统中古代不稳定碳的输出是否是由化石燃料燃烧副产品的沉积驱动的？

• 批准号: 1146161
• 负责人: Aron Stubbins
• 金额: $ 22.4万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1146161&HistoricalAwards=false
• 关键词: Collaborative; Research; export; ancient; labile

Glaciers and ice sheets represent the second largest reservoir of water and cover 10% of the earth. They also constitute an important, but poorly understood ecosystem. Improving knowledge of glacier biogeochemistry is particularly important as they are among the environments most sensitive to climate warming. Most notably, glacier melting is accelerating due to rising temperatures, changing precipitation patterns and the deposition of black carbon, which darkens glacier surfaces enhancing their absorption of light and heat. Glacier ecosystems were recently identified as a significant source of ancient, yet highly bioavailable dissolved organic carbon to downstream aquatic ecosystems. This finding runs counter to logical perceptions of age-reactivity relationships, in which the least reactive material withstands degradation the longest and is therefore the oldest. The remnants of ancient peatlands and forests since overrun by glaciers have been invoked as a source of this ancient, labile organic carbon. Preliminary results upon which this study is based, challenge the peatland/forest source hypothesis, indicating instead that glacier organic carbon is predominantly from aerosol deposition and enters glaciers in a pre-aged form. This study will determine the contribution to the glacial organic carbon pool made by fossil fuel derived aerosols, verify whether this organic carbon is indeed ancient and labile, and quantify the extent to which it is being exported to downstream ecosystems.Today, around 60% of organic aerosols are derived from anthropogenic activities, indicating that organic deposition has also increased dramatically since the industrial revolution. Therefore, if the organics found on, within and being exported from Gulf of Alaska glaciers are from aerosols, the glacier ecosystem structure we observe today is fed by the waste products of industrial activity occurring thousands of miles away. If this is the case, then the organic carbon which is exported to ecosystems downstream of glaciers would also be of anthropogenic origin, suggesting these receiving ecosystems are also transformed relative to their pre-industrial status. As deposition of combustion products is a global phenomenon, all ecosystems may be receiving this ancient, labile carbon subsidy. In warmer ecosystems, the labile carbon windfall is presumably rapidly processed and its signal is lost. In frigid glacier environments, these inputs stand out, making glaciers sentinel ecosystems for the detection and study of anthropogenic deposition. Although the study focuses upon glaciers along the Gulf of Alaska, findings will be relevant to any ecosystem receiving depositional inputs. The project provides a highly interdisciplinary and collaborative research environment from which the undergraduates from under-represented groups in science, a masters student, and a postdoctoral researcher will all benefit. The collaboration extends beyond the funded US scientists to include German colleagues supported by the Max Planck Institute's Marine Geochemistry Group. This international component expands the possibilities for knowledge transfer and provides the US-based researchers access to unique, state-of-the-art analytical facilities. Results will be disseminated to the public through the U.S. Forest Service Mendenhall Glacier Visitor Center in Juneau, providing an opportunity for public outreach on the effects of climate change on glaciers.

冰川和冰盖代表了第二大水库，并覆盖了10％的地球。它们也构成了一个重要但知之甚少的生态系统。提高冰川生物地球化学的知识尤为重要，因为它们是对气候变暖最敏感的环境。最值得注意的是，冰川熔化由于温度的升高，降水模式的升高以及黑碳的沉积而加速，这会使冰川表面变黑，从而增强了它们的光和热量吸收。冰川生态系统最近被确定为古老而又高度可生物利用的有机碳到下游生态系统的重要来源。这一发现与对年龄反应关系的逻辑看法背道而驰，在这种关系中，最低反应性材料承受最长的降解，因此是最古老的。自被冰川淹没以来，古代泥炭地和森林的残余物被作为这种古老的，不稳定的有机碳的来源。这项研究基于的初步结果，挑战泥炭地/森林源假设，相反，表明冰川有机碳主要来自气溶胶沉积，并以预龄形式进入冰川。这项研究将确定化石燃料衍生的气溶胶对冰川有机碳池的贡献，验证这种有机碳的确确实是古老而不稳定的，并量化了其被导出到下游生态系统的程度。today，大约60％的有机气溶胶是从人类学活动中增加了有机化学的，这也增加了有机习惯。因此，如果在阿拉斯加冰川的内部，内部发现并出口的有机物是来自气溶胶，那么我们今天观察到的冰川生态系统结构是由数千英里外的工业活动的废物提供的。如果是这种情况，那么冰川下游的有机碳也将具有人为的起源，这表明这些接收生态系统也相对于它们的工业前地位进行了转化。由于燃烧产物的沉积是一种全球现象，因此所有生态系统都可能正在获得这种古老的，不稳定的碳补贴。在温暖的生态系统中，不稳定的碳意思可能会迅速处理，并且其信号丢失。在冰冷的冰川环境中，这些输入脱颖而出，使冰川前哨生态系统用于检测和研究人为沉积。尽管该研究的重点是沿阿拉斯加湾的冰川，但发现将与任何接收沉积输入的生态系统有关。该项目提供了一个高度的跨学科和协作研究环境，来自代表性不足的科学群体，硕士学生和博士后研究人员的本科生都将受益。该合作范围超出了资助的美国科学家，包括由马克斯·普朗克学院（Max Planck Institute）海洋地球化学组支持的德国同事。该国际组成部分扩大了知识转移的可能性，并为美国的研究人员提供了独特的最先进的分析设施。结果将通过位于朱诺的美国森林服务门森尔冰川游客中心向公众传播，为气候变化对冰川的影响提供了机会。