Response of High Latitude Wetland Fluxes of Methane to Changes in Temperature and Water

Abstract:

High latitude methane fluxes represent between 5 – 20% of the total methane budget. This large range in methane emissions estimates are due to poor knowledge of wetland extent, dependency of emissions to temperature and water, the seasonal cycle of freezing and thawing, and a poor measurement network. In turn, these uncertainties limit our ability to predict future methane fluxes in response to a warming climate. Temperature and rainfall at high-latitudes changed dramatically between 2009 and 2010, likely in response to variations in ENSO and the Arctic Anomaly. We might therefore expect that high-latitude methane fluxes significantly changed between 2009 and 2010 because these methane fluxes primarily depend on these environmental parameters. In this study, we implement several wetland models and their corresponding methane fluxes for 2009 and 2010 into the GEOS-Chem global chemistry model. We evaluate whether satellite measurements such as total column measurement from GOSAT or TROP-OMI can distinguish between these models, allowing for better estimates of the magnitude and timing of wetland fluxes and improved process understanding of high-latitude methane emissions.