SWOT for Global Inland Water Gas Exchange and Carbon Biogeochemistry

Principle Investigator: Dongmei Feng (University of Cincinnati)

Co-Investigator(s): Peter Raymond

Collaborator(s): Craig Brinkerhoff

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Inland waters are important sources of greenhouse gases (GHG). They are one of the largest sources of methane globally and a conduit for the loss of CO2 from terrestrial gross primary productivity. Despite their importance to GHG emissions, we’ve only recently been able to model them at the global scale. Due to the infancy of this science, there are still large knowledge gaps in our understanding of these fluxes and uncertainties in global flux estimates that could benefit from the SWOT mission.

In this project, we propose to leverage SWOT to make major advancements in our ability to model global GHG evasion from inland waters and understand freshwater carbon biogeochemistry. To this end, we will first create a new, high-accuracy, and spatiotemporally continuous global river discharge product by assimilating SWOT discharge into hydrologic models using a state-of-the-art data assimilation scheme, as discharge is an important driver controlling GHG evasion. Second, we will use SWOT measurements and our new discharge product to estimate GHG evasion explicitly for every river and linked lake on Earth, and create a new and more accurate global inland water GHG evasion product. Finally, we will use the better-constrained data to determine scales of the longitudinal transport of GHGs through drainage networks, in order to improve our ability to inversely determine sources and fate of GHGs in inland water systems.