Resolving the carbon-climate feedback potential of wetland CO2 and CH4 fluxes in Alaska
Shuang Ma, Jet Propulsion Laboratory / Caltech, shuang.ma@jpl.nasa.gov (Presenter)
Alexis Anthony Bloom, Jet Propulsion Lab, California Institute of Technology, abloom@jpl.nasa.gov
Jennifer Dawn Watts, Woodwell Climate Research Center, jwatts@woodwellclimate.org
Gregory Quetin, University of California, Santa Barbara, gquetin@gmail.com
Donatella Zona, San Diego State University, dzona@sdsu.edu
Eugenie Euskirchen, University of Alaska, Fairbanks, seeuskirchen@alaska.edu
Alexander Norton, Jet Propulsion Laboratory/California Institute of Technology, alexander.j.norton@jpl.nasa.gov
Yi Yin, Caltech, yiyin@caltech.edu
Paul A Levine, JPL, paul.a.levine@jpl.nasa.gov
Renato K Braghiere, Caltech/NASA JPL, renato.k.braghiere@jpl.nasa.gov
Nicholas Parazoo, JPL, nicholas.c.parazoo@jpl.nasa.gov
John R. Worden, JPL, john.r.worden@jpl.nasa.gov
David Schimel, JPL, david.schimel@jpl.nasa.gov
Charles Miller, NASA JPL, charles.e.miller@jpl.nasa.gov
Boreal Arctic regions are key stores of organic carbon (C) and play a major role in the greenhouse gas balance of high-latitude ecosystems. The carbon-climate (C-climate) feedback potential of northern high-latitude remains poorly understood due to uncertainty in temperature and precipitation controls on carbon dioxide (CO2) uptake and the decomposition of soil C into CO2 and methane (CH4) fluxes. While CH4 fluxes account for a smaller component of the C balance, the climatic impact of CH4 outweighs CO2 (28 times larger Global Warming Potential (GWP) on a 100-year scale), highlighting the need to jointly resolve the climatic sensitivities of both CO2 and CH4. We jointly constrain a terrestrial biosphere model with in situ CO2 and CH4 flux observations at seven eddy covariance sites using a data-model integration approach to resolve the integrated environmental controls on land-atmosphere CO2 and CH4 exchanges in Alaska. Based on the combined CO2 and CH4 flux responses, we find that 1970-present climate trends will induce positive carbon-climate feedback at all tundra sites, and negative carbon-climate feedback at the boreal and shrub fen sites. The positive C-climate feedback at the tundra sites is predominantly driven by increased CH4, while the negative C-climate feedback at the boreal site is predominantly driven by decreased CO2 (80% from decreased heterotrophic respiration, and 20% from increased photosynthesis). Our study demonstrates the need for joint observational constraints on CO2 and CH4 biogeochemical processes – and their associated climatic sensitivities – for resolving the sign and magnitude of high-latitude ecosystem C-climate feedback in the coming decades.
Associated Project(s):
Poster Location ID: 2-29
Presentation Type: Poster
Session: Poster Session 2
Session Date: Wed (May 10) 5:15-7:15 PM
CCE Program: TE