GC11B-0564:
Low-Altitude CH4 and δ13CH4 spatial Heterogeneity over the Northern Slope of Alaska
Monday, 15 December 2014
Claire E Healy1, David S Sayres1, Jason Brent Munster1, Edward J Dumas2, Ronald Dobosy3, John Kochendorfer4, Jordan Wilkerson1, Bruce Baker3, Mark Heuer2, Tilden P Meyers2, Manvendra Krishna Dubey5 and James G Anderson1, (1)Harvard University, Cambridge, MA, United States, (2)NOAA/ATDD, Oak Ridge, TN, United States, (3)NOAA Oak Ridge, Oak Ridge, TN, United States, (4)NOAA Oak Ridge, Atmospheric Turbulence and Diffusion Division, Oak Ridge, TN, United States, (5)Los Alamos National Laboratory, Los Alamos, NM, United States
Abstract:
Increased methane emissions from arctic environments due to amplified polar warming have long been postulated as a potent positive feedback mechanism for climate change. However, measuring methane in the Arctic for the purpose of monitoring the feedback presents a daunting observational challenge since techniques must ideally be able distinguish between biological and anthropogenic methane sources, have the ability to cover large spatial ranges, and have the sensitivity to distinguish changes from season to season, and year to year. The FOCAL platform has been engineered to address this niche and help bridge the gap in spatial coverage between ground based and inverse modelling studies. It consists of a small aircraft equipped with the best atmospheric turbulence (BAT) probe, and gas sensors for in situ measurements of CH4, CO2, δ13CH4, δ13CO2 to make regional scale surface eddy-covariance flux measurements of methane and carbon dioxide as well as their stable isotopologues to gain mechanisitic insight and assist in source determination. The initial FOCAL flight series in August 2013 based out of Deadhorse, AK was a low altitude (<50m) survey mission to observe spatial and temporal variability of CH4 and CO2 over the Northern Slope. We will present the CH4 concentration and δ13CH4 data, and discuss some of the possible drivers behind their observed spatial heterogeneity.
