Journal
ATMOSPHERIC CHEMISTRY AND PHYSICS
Volume 13, Issue 17, Pages 8695-8717Publisher
COPERNICUS GESELLSCHAFT MBH
DOI: 10.5194/acp-13-8695-2013
Keywords
-
Funding
- Emmy-Noether program of the Deutsche Forschungsgemeinschaft (DFG) [BU2599/1-1]
- Gebruikersondersteuning ruimteonderzoek program of the Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO) [ALW-GO-AO/08-10]
- European Space Agency's Climate Change Initiative on Greenhouse Gases (ESA GHG-CCI)
- SARA through NCF [SH-026-12]
- Terrestrial Ecology Program of the National Aeronautics and Space Administration (NASA) [NNX11AG01G]
- Orbiting Carbon Observatory Program
- Space (ACOS) Program
- DOE/ARM Program
- NASA
- Australian Research Council [LE0668470, DP0879468, DP110103118, LP0562346]
- Bialystok TCCON site from Senate of Bremen
- Orleans TCCON site from Senate of Bremen
- EU project IMECC
- EU project GEOmon
Ask authors/readers for more resources
We present one of the first estimates of the global distribution of CO2 surface fluxes using total column CO2 measurements retrieved by the SRON-KIT RemoTeC algorithm from the Greenhouse gases Observing SATellite (GOSAT). We derive optimized fluxes from June 2009 to December 2010. We estimate fluxes from surface CO2 measurements to use as baselines for comparing GOSAT data-derived fluxes. Assimilating only GOSAT data, we can reproduce the observed CO2 time series at surface and TC-CON sites in the tropics and the northern extra-tropics. In contrast, in the southern extra-tropics GOSAT X-CO2 leads to enhanced seasonal cycle amplitudes compared to independent measurements, and we identify it as the result of a land-sea bias in our GOSAT X-CO2 retrievals. A bias correction in the form of a global offset between GOSAT land and sea pixels in a joint inversion of satellite and surface measurements of CO2 yields plausible global flux estimates which are more tightly constrained than in an inversion using surface CO2 data alone. We show that assimilating the biascorrected GOSAT data on top of surface CO2 data (a) reduces the estimated global land sink of CO2, and (b) shifts the terrestrial net uptake of carbon from the tropics to the extratropics. It is concluded that while GOSAT total column CO2 provide useful constraints for source-sink inversions, small spatiotemporal biases -beyond what can be detected using current validation techniques - have serious consequences for optimized fluxes, even aggregated over continental scales.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available