Collaborative Research: CAS-Climate: The Hydrologic Connection between Permafrost-Plateaus and Thaw-Bogs: Impact on Methane Emissions

甲烷是一种强有力的温室气体，湿地是大气中甲烷的最大自然来源。在有永久冻土的地区，当永久冻土融化，土地下沉时，湿地就会形成。这一过程创造了一种景观，低海拔湿地散布在较高海拔的永久冻土高原上。这个项目调查了从永久冻土高原流入湿地的水如何影响湿地排放的甲烷的量。可能是水将热能和营养物质从永久冻土高原输送到湿地，从而支持甲烷的生产。该项目可能会从根本上改变研究人员研究湿地甲烷排放并对其进行建模的方式。该项目的研究人员将与阿拉斯加大学费尔班克斯分校的培育科学和气候学者计划合作，为阿拉斯加州的大学生和寄养家庭的年轻人创造教育和研究机会。此前在阿拉斯加内陆融化沼泽进行的研究表明，春季降雨导致甲烷排放量增加约30%。来自永久冻土高原的土壤水流入沼泽，迅速使沼泽土壤变暖，刺激了微生物和植物过程，增加了甲烷排放。这些结果突显了高原与沼泽的水文联系如何影响甲烷。然而，这种联系的许多方面仍然不清楚。最值得注意的是，之前的研究捕捉到了有记录以来最多雨的两年，但沼泽甲烷排放只在这两年中的一年有所增加。因此，为了改进对北纬甲烷排放的预测，科学家们将：1)确定永久冻土高原内促进热能和营养物质从高原向沼泽输送的气象、土壤和生态条件；2)确定这些输入是否以及何时影响沼泽甲烷排放；3)评估冬季条件如何影响这些过程。这些任务将通过进行实地考察和使用水文模型检查来自多个不同热岩溶沼泽的历史数据来完成，以确定促进高原沼泽运输和增加沼泽甲烷排放的过程和条件的子集。然后，项目组将在整个热喀斯特湿地景观中寻找这些过程和条件的共同出现，并更新甲烷模型，以适当地对已确定的情况做出反应。该奖项由水文科学和北极自然科学项目共同资助。该奖项反映了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。

Methane is a potent greenhouse gas and wetlands are the largest natural source of methane to the atmosphere. In areas with permafrost, wetlands can develop when permafrost thaws and the land subsides. This process creates a landscape with pockets of low-elevation wetlands couched within higher elevation permafrost plateaus. This project investigates how the flow of water from permafrost plateaus into wetlands affects the amount of methane emitted from the wetlands. It may be that the water transports thermal energy and nutrients from the permafrost plateau into the wetland, that support methane production. This project could fundamentally change the way researchers study and model wetland methane emissions. The project researchers will collaborate with the Fostering Science and Climate Scholars programs at University of Alaska Fairbanks to create educational and research opportunities for university students, and youths in foster care in the State of Alaska.Previous research at a thaw bog in Interior Alaska showed that spring rainfall facilitated about 30% increase in methane emissions. Soil water from the permafrost-plateau flowed into the bog and rapidly warmed bog soils, stimulating microbial and plant processes that enhanced methane emissions. These results highlight how the plateau-bog hydrologic connection can influence methane. However, many aspects of this connection remain unclear. Most notably, the previous study captured two of the rainiest years on record, but bog methane emissions only increased in one of the two years. Therefore, to improve the prediction of methane emissions from northern latitudes, the scientists will: 1) determine the meteorological, soil and ecological conditions within the permafrost plateau that facilitate transport of thermal energy and nutrients from the plateau into the bog, 2) identify if and when these inputs affect bog methane emissions, and 3) assess how winter conditions impact these processes. These tasks will be accomplished by conducting fieldwork and by using a hydrologic model to examine historic data from multiple different thermokarst bogs to identify the subset of processes and conditions that facilitate plateau-bog transport and enhance bog methane emissions. The project team will then look for the co-occurrence of these processes and conditions throughout the thermokarst wetland landscape and update methane models to appropriately respond to identified circumstances. This award is co-funded by the Hydrologic Sciences and Arctic Natural Sciences programs.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.