Global CO2 fluxes estimated from GOSAT retrievals of total column CO2
<p><strong>Abstract.</strong> We present one of the first estimates of the global distribution of CO<sub>2</sub> surface fluxes using total column CO<sub>2</sub> measurements retrieved by the SRON-KIT RemoTeC algorithm from the Greenhouse gases Observing SAT...
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| Main Authors: | , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
3 September 2013
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| In: |
Atmospheric chemistry and physics
Year: 2013, Volume: 13, Issue: 17, Pages: 8695-8717 |
| ISSN: | 1680-7324 |
| DOI: | 10.5194/acp-13-8695-2013 |
| Online Access: | Verlag, Volltext: http://dx.doi.org/10.5194/acp-13-8695-2013 Verlag, Volltext: https://www.atmos-chem-phys.net/13/8695/2013/ 
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| Author Notes: | S. Basu, S. Guerlet, A. Butz, S. Houweling, O. Hasekamp, I. Aben, P. Krummel, P. Steele, R. Langenfelds, M. Torn, S. Biraud, B. Stephens, A. Andrews, and D. Worthy |
| Summary: | <p><strong>Abstract.</strong> We present one of the first estimates of the global distribution of CO<sub>2</sub> surface fluxes using total column CO<sub>2</sub> 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 CO<sub>2</sub> measurements to use as baselines for comparing GOSAT data-derived fluxes. Assimilating only GOSAT data, we can reproduce the observed CO<sub>2</sub> time series at surface and TCCON sites in the tropics and the northern extra-tropics. In contrast, in the southern extra-tropics GOSAT X<sub>CO<sub>2</sub></sub> 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<sub>CO<sub>2</sub></sub> 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 CO<sub>2</sub> yields plausible global flux estimates which are more tightly constrained than in an inversion using surface CO<sub>2</sub> data alone. We show that assimilating the bias-corrected GOSAT data on top of surface CO<sub>2</sub> data (a) reduces the estimated global land sink of CO<sub>2</sub>, and (b) shifts the terrestrial net uptake of carbon from the tropics to the extra-tropics. It is concluded that while GOSAT total column CO<sub>2</sub> 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.</p> |
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| Item Description: | Im Titel ist die "2" jeweils tiefgestellt Gesehen am 15.01.2019 |
| Physical Description: | Online Resource |
| ISSN: | 1680-7324 |
| DOI: | 10.5194/acp-13-8695-2013 |