Using Atmospheric Column Measurements to Estimate the Impact of Climate Variables on CO2 Uptake by the Biosphere

Debra Wunch, California Institute of Technology, dwunch@caltech.edu (Presenter)
Paul Wennberg, Caltech, wennberg@gps.caltech.edu
William Simpson, University of Alaska Fairbanks, william simpson
Geoffrey C. Toon, JPL, geoffrey.c.toon@jpl.nasa.gov
Nick Parazoo, UCLA, nicholas.c.parazoo@jpl.nasa.gov
Arlyn Elizabeth Andrews, NOAA ESRL, arlyn.andrews@noaa.gov
Dylan Jones, University of Toronto, dbj@atmosp.physics.utoronto.ca
Coleen Marie Roehl, California Institute of Technology, coleen@gps.caltech.edu
Kimberly Strong, University of Toronto, strong@atmosp.physics.utoronto.ca
Ray Nassar, Environment Canada, ray.nassar@ec.gc.ca

Regional scale carbon fluxes between the biosphere and atmosphere are strongly coupled to the spatial and temporal gradients in the atmospheric column abundances of CO2 (denoted XCO2). Remote sensing measurements of XCO2 over the Northern hemisphere, both from the ground and from space, show significant interannual variability in the strength of the seasonal cycle drawdown. Significant interannual variability in XCO2 is also seen in model output from CarbonTracker and in simulations using GEOS-CHEM with biospheric fluxes derived from the Simple Biosphere (SiB) model.

The variability in XCO2 drawdown is significantly correlated with anomalies in August surface temperature in the Boreal region, although the relationship between temperature and drawdown strength differs between the models and measurements. Using the models, we show that the drawdown strength variability is related both to variability in biospheric fluxes and atmospheric transport, in roughly equal parts. We then attempt to infer the biogeochemical mechanisms that contribute to the variability of the drawdown, and describe an experiment designed to more fully disentangle these processes.

Presentation Type:  Poster

Session:  Theme 4: Human influence on global ecosystems   (Mon 4:30 PM)

Associated Project(s): 

• Wennberg, Paul: CO₂ column distribution at Park Falls Wisconsin ...details
• Wennberg, Paul: Quantifying Changes in the Distribution and Cycling of Carbon With Total Column Measurements of CO2 and CH4 ...details
• Wennberg, Paul: The Total Carbon Column Observing Network (TCCON): Ground-based Observations in Support of the Orbiting Carbon Observatory ...details

Poster Location ID: 95