Carbon balance of China constrained by CONTRAIL aircraft CO<sub>2</sub> measurements
Terrestrial carbon dioxide (CO<sub>2</sub>) flux estimates in China using atmospheric inversion method are beset with considerable uncertainties because very few atmospheric CO<sub>2</sub> concentration measurements are available. In order to improve these estimates, nested a...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-09-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/14/10133/2014/acp-14-10133-2014.pdf |
| Summary: | Terrestrial carbon dioxide (CO<sub>2</sub>) flux estimates in China using
atmospheric inversion method are beset with considerable uncertainties
because very few atmospheric CO<sub>2</sub> concentration measurements are
available. In order to improve these estimates, nested atmospheric CO<sub>2</sub> inversion during 2002–2008 is performed in this study using passenger
aircraft-based CO<sub>2</sub> measurements over Eurasia from the Comprehensive
Observation Network for Trace gases by Airliner (CONTRAIL) project. The
inversion system includes 43 regions with a focus on China, and is based on
the Bayesian synthesis approach and the TM5 transport model. The terrestrial
ecosystem carbon flux modeled by the Boreal Ecosystems Productivity Simulator (BEPS) model and the ocean exchange
simulated by the OPA-PISCES-T model are considered as the prior fluxes. The
impacts of CONTRAIL CO<sub>2</sub> data on inverted China terrestrial carbon
fluxes are quantified, the improvement of the inverted fluxes after adding
CONTRAIL CO<sub>2</sub> data are rationed against climate factors and evaluated
by comparing the simulated atmospheric CO<sub>2</sub> concentrations with three
independent surface CO<sub>2</sub> measurements in China. Results show that with
the addition of CONTRAIL CO<sub>2</sub> data, the inverted carbon sink in China
increases while those in South and Southeast Asia decrease. Meanwhile, the
posterior uncertainties over these regions are all reduced (2–12%). CONTRAIL CO<sub>2</sub> data also have a large effect on the
inter-annual variation of carbon sinks in China, leading to a better
correlation between the carbon sink and the annual mean climate factors.
Evaluations against the CO<sub>2</sub> measurements at three sites in China also
show that the CONTRAIL CO<sub>2</sub> measurements may have improved the inversion
results. |
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| ISSN: | 1680-7316 1680-7324 |