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，也是大气中二氧化碳的重要来源，但大规模的北极碳预算通常忽略了湖泊的碳排放。此外，对北方湖泊碳排放的研究在很大程度上仅限于湖泊与永久冻土融化有关的地区。位于干旱地区的湖泊的排放占北部永久冻土区的25%左右，对它们的研究相对不足。因此，尚不确定位于干旱地区的湖泊在多大程度上导致了碳排放，这一问题可能会恶化，因为据预测，北极的大部分地区未来将变得更加温暖和干燥。这个项目解决了这两个关键的差距。首先，研究人员正在使用自动传感器测量西格陵兰岛湖泊的碳排放量，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结果与先前发表的观测结果相结合，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、大众科学杂志、青年科学计划中发表，并与西格陵兰社区进行讨论。西格陵兰岛的Kangerlussuaq地区位于水文气候梯度上，可作为研究温暖干燥的北极条件对内陆水域碳动态影响的模型景观。研究人员正在利用高频原位传感器，沿着气候降水梯度对一组湖泊的碳排放进行量化，该梯度模拟了全年从凉爽潮湿的气候到干燥温暖的气候的变化。这些传感器提供了第一个年度的、暂时分辨率很好的测量数据，这些数据来自水文联系不佳、干旱的北极地区的湖泊。研究人员正在将他们的测量扩大到区域水平，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。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.