A33F-0246
Constraining the 2012-2014 growing season Alaskan methane budget using CARVE aircraft measurements
Wednesday, 16 December 2015
Poster Hall (Moscone South)
Sean Hartery1, Rachel Ying-Wen Chang1, Roisin Commane2, Jakob Lindaas2, Scot M Miller2, Steven C Wofsy2, Anna Karion3, Colm Sweeney3, Charles E Miller4, Steven J Dinardo4, Nicholas Steiner5, Kyle C McDonald5, Jennifer D Watts6, Donatella Zona7, Walter C Oechel7, John S Kimball8, John Henderson9 and Marikate Ellis Mountain10, (1)Dalhousie University, Halifax, NS, Canada, (2)Harvard University, Cambridge, MA, United States, (3)NOAA Boulder, ESRL, Boulder, CO, United States, (4)NASA Jet Propulsion Laboratory, Pasadena, CA, United States, (5)CUNY City College, Earth and Atmospheric Science, New York, NY, United States, (6)NTSG, University of Montana, Missoula, MT, United States, (7)San Diego State University, San Diego, CA, United States, (8)University of Montana, Missoula, MT, United States, (9)Atmospheric and Environmental Research, Lexington, MA, United States, (10)Atmospheric and Environmental Research, Inc., Lexington, MA, United States
Abstract:
Soil in northen latitudes contains rich carbon stores which have been historically preserved via permafrost within the soil bed; however, recent surface warming in these regions is allowing deeper soil layers to thaw, influencing the net carbon exchange from these areas. Due to the extreme nature of its climate, these eco-regions remain poorly understood by most global models. In this study we analyze methane fluxes from Alaska using in situ aircraft observations from the 2012-2014 Carbon in Arctic Reservoir Vulnerability Experiment (CARVE). These observations are coupled with an atmospheric particle transport model which quantitatively links surface emissions to atmospheric observations to make regional methane emission estimates. The results of this study are two-fold. First, the inter-annual variability of the methane emissions was found to be <1 Tg over the area of interest and is largely influenced by the length of time the deep soil remains unfrozen. Second, the resulting methane flux estimates and mean soil parameters were used to develop an empirical emissions model to help spatially and temporally constrain the methane exchange at the Alaskan soil surface. The empirical emissions model will provide a basis for exploring the sensitivity of methane emissions to subsurface soil temperature, soil moisture, organic carbon content, and other parameters commonly used in process-based models.
