Doctoral Dissertation Research: Another piece of the Arctic carbon puzzle: quantifying emissions from Arctic lakes in drier regions

湖泊是北极景观的主要特征，可能是大气中二氧化碳的重要来源，但北极大规模的碳预算通常会忽视湖泊的碳排放。此外，对北方湖泊碳排放的研究在很大程度上局限于湖泊与融化的永久冻土有关的地区。位于较干旱地区的湖泊的排放研究相对较少，这些地区覆盖了北部永久冻土地区约25%的面积。因此，目前还不确定位于较干旱地区的湖泊对碳排放的贡献程度，这个问题可能会恶化，因为预计未来北极大部分地区将变得更加温暖和干燥。该项目解决了这两个关键差距。首先，研究人员正在使用自动化传感器来测量西格陵兰岛湖泊的碳排放，该地区正在经历快速变暖和降水减少。研究人员还将他们的湖泊排放测量与之前发表的观测结果进行综合，以评估气候模式的差异如何影响湖泊和大气之间的二氧化碳通量。这项研究的结果将在跨学科学术小组、科普杂志、青年科学项目中公布，并与西格陵兰岛社区讨论。格陵兰岛西部的Kangerlussuaq地区位于水文-气候梯度，是研究北极变暖和变干对内陆水域碳动态的影响的模式景观。研究人员正在使用高频现场传感器，沿着气候-降水梯度对一系列湖泊的碳排放进行量化，这种梯度模拟了全年从较凉爽和潮湿的气候到较干燥和较温暖条件的变化。这些传感器正在提供第一个时间分辨率良好的年度二氧化碳排放量测量数据，这些数据来自水文连通程度较差的北极干旱地区的湖泊。研究人员正在将他们的测量结果提升到区域水平，并将其与周围景观中的陆地碳通量进行比较。这项研究突出了北极碳循环的异质性及其在整个北极系统中的作用。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Lakes are a dominant feature of the Arctic landscape and can be important sources of carbon dioxide to the atmosphere, but large-scale Arctic carbon budgets usually neglect carbon emissions from lakes. Moreover, studies of carbon emissions from northern lakes have largely been limited to regions where lakes are connected to thawing permafrost. Emissions from lakes located in drier landscapes, which cover about 25% of the northern permafrost region, have been relatively understudied. Consequently, it is uncertain to what degree lakes located in drier regions contribute to carbon emissions, a problem that likely will worsen as much of the Arctic is predicted to become warmer and drier in the future. This project addresses both critical gaps. First, the researchers are using automated sensors to measure carbon emissions from lakes in West Greenland, a region experiencing rapid warming and declining precipitation. The researchers are also synthesizing their lake emission measurements with previously published observations to assess how differences in climate patterns impact fluxes of carbon dioxide between lakes and the atmosphere. The results of this research will be presented in interdisciplinary academic panels, popular science magazines, youth science programs, and discussed with West Greenland communities. The Kangerlussuaq region in West Greenland located along a hydro-climatic gradient serves as a model landscape for studying the implications of warmer and drier Arctic conditions for carbon dynamics in inland waters. The researchers are quantifying carbon emissions from a suite of lakes along a climate-precipitation gradient that mimics shifts from cooler and wetter climate to drier and warmer conditions throughout the whole year, using high-frequency, in situ sensors. These sensors are providing the first annual, temporally well resolved measurements of carbon dioxide emissions from lakes in poorly hydrologically connected, arid Arctic landscapes. The researchers are upscaling their measurements to the regional level and comparing them with terrestrial carbon fluxes in the surrounding landscape. This research is highlighting the heterogeneity of the Arctic carbon cycle and its role in the full Arctic system.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.