Vetting atmospheric CO2 and CH4 from ecosystem models and satellites by comparison to ground-based observations

Nicole Jacobs, University of Alaska Fairbanks, najacobs@alaska.edu
William Simpson, University of Alaska Fairbanks, wrsimpson@alaska.edu
Eugenie Euskirchen, University of Alaska, Fairbanks, seeuskirchen@alaska.edu
Debra Wunch, University of Toronto, dwunch@atmosp.physics.utoronto.ca
Róisín Commane, Harvard University, rcommane@g.harvard.edu (Presenter)
Taylor Jones, Harvard University, taylorjones@g.harvard.edu
Steven Wofsy, Harvard University, wofsy@fas.harvard.edu
Harrison Parker, California Institute of Technology, hparker2@gmail.com
Manvendra K Dubey, Los Alamos National Laboratory, dubey@lanl.gov
Thomas Blumenstock, Karlsruhe Institute of Technology, thomas.blumenstock@kit.edu
Frank Hase, Karlsruhe Institute of Technology, frank.hase@kit.edu
Qiansi Tu, Karlsruhe Institute of Technology, qiansi.tu@partner.kit.edu
Gregory Osterman, JPL, gregory.b.osterman@jpl.nasa.gov

The Boreal Forest and Northern wetlands exchange globally significant amounts of greenhouse gases and are undergoing rapid ecosystem change, including thawing of permafrost, motivating the need to study carbon gas exchange in the region. In August of 2016, we began the Arctic Mobile Infrared Greenhouse Gas Observations (AMIGGO) campaign in the region around Fairbanks, Alaska with the goal of satellite validation and measurement of natural ecosystem carbon exchange fluxes in the Boreal Forest. In this campaign, we used the EM27/SUN mobile solar-viewing Fourier-transform infrared spectrometer (EM27/SUN FTS) to retrieve column-averaged dry-air mole fractions of CO2 and CH4 (XCO2 and XCH4) with the GGG2014 algorithm. The EM27/SUN FTS was developed / designed by the Karlsruhe Institute of Technology (KIT) in cooperation with Bruker Optics and has been deployed in urban areas to measure anthropogenic fluxes of CO2, CH4, and CO (Gisi et al., 2012, doi:10.5194/amt-5-2969-2012, Hase et al., 2016, doi: 10.5194/amt-9-2303-2016). In the past year, applications for the EM27/SUN FTS have expanded beyond urban settings and they have been deployed by many groups for the purposes of cost-effective satellite validation and measurement of agricultural emissions across regional scales. These instruments show great potential for use in vetting model estimates of regional CH4 fluxes from Boreal forest and tundra ecosystems in Alaska and Canada and improving satellite observations of atmospheric CO2 and CH4 over the high latitude Boreal forest regions. These measurements can improve our ability to scale up fluxes from kilometer-scale eddy covariance observations to the regional-scale. We present observations of CH4 gradients during the fall of 2016 with two EM27/SUN FTS simultaneously deployed in Nenana and Fairbanks and comparisons of ground-based and satellite-based observations of XCO2 coordinated with OCO-2 target overpasses in 2016 and 2017. A comparison between XCO2 observations around Fairbanks and from the TCCON station in East Trout Lake, Saskatchewan will also be shown. We plan to continue CH4 gradient observations within the Boreal Forest / Northern wetlands in summer of 2018 and are seeking collaboration and support for an expanded project that would observe over larger regions of Alaska. Analysis of CH4 gradient observations also involves inverse modeling and vetting of forward model flux predictions from established ecosystem models such as CLM4.5-BGC. Both inverse and forward modeling interpretations will incorporate eddy covariance observations in Bonanza Creek LTER and eco-regions maps of Alaska constructed from data collected by other ABoVE projects. Once sound methods are developed for interpreting CH4 gradients amongst EM27/SUN FTS on 50-100km scales we intend to evaluate gradients over the entire North American Boreal Forest between Fairbanks and East Trout Lake.

Associated Project(s): 

• Wunch-01

Poster Location ID: 57

Session Assigned: Carbon Dynamics