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

University Of Washington, Seattle WA

Investigators

Abstract

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.