The covariation of Northern Hemisphere summertime CO2 with surface temperature in boreal regions D. Wunch1, P. O. Wennberg1, J. Messerschmidt1, N. C. Parazoo2,3, G. C. Toon1,2, N. M. Deutscher4, G. Keppel-Aleks5, C. M. Roehl1, J. T. Randerson5, T. Warneke4, and J. Notholt4 1California Institute of Technology, Pasadena, CA, USA 2Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA 3Joint Institute for Regional Earth System Science and Engineering, University of California, Los Angeles, CA, USA 4University of Bremen, Bremen, Germany 5Department of Earth System Science, University of California, Irvine, CA, USA
Abstract. We observe significant interannual variability in the strength of the
seasonal cycle drawdown in northern midlatitudes from measurements of CO2
made by the Total Carbon Column Observing Network (TCCON) and the Greenhouse
Gases Observing Satellite (GOSAT). This variability correlates with surface
temperature in the boreal regions. Using TCCON measurements, we find that the
slope of the relationship between the XCO2 seasonal cycle minima
and boreal surface temperature is 1.2 ± 0.7 ppm K−1.
Assimilations from CarbonTracker 2011 and CO2 simulations using the Simple
Biosphere exchange Model (SiB) transported by GEOS-Chem underestimate this
covariation. Both atmospheric transport and biospheric activity contribute to
the observed covariation.
Citation: Wunch, D., Wennberg, P. O., Messerschmidt, J., Parazoo, N. C., Toon, G. C., Deutscher, N. M., Keppel-Aleks, G., Roehl, C. M., Randerson, J. T., Warneke, T., and Notholt, J.: The covariation of Northern Hemisphere summertime CO2 with surface temperature in boreal regions, Atmos. Chem. Phys., 13, 9447-9459, doi:10.5194/acp-13-9447-2013, 2013.