Explaining the seasonal cycle of the globally averaged CO<sub>2</sub> with a carbon-cycle model
The seasonal changes in the globally averaged atmospheric carbon-dioxide concentrations reflect an important aspect of the global carbon cycle: the gas exchange between the atmosphere and terrestrial biosphere. The data on the globally averaged atmospheric carbon-dioxide concentrations, which are re...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2014-10-01
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| Series: | Earth System Dynamics |
| Online Access: | http://www.earth-syst-dynam.net/5/345/2014/esd-5-345-2014.pdf |
| Summary: | The seasonal changes in the globally averaged atmospheric carbon-dioxide
concentrations reflect an important aspect of the global carbon cycle: the
gas exchange between the atmosphere and terrestrial biosphere. The data on
the globally averaged atmospheric carbon-dioxide concentrations, which are
reported by Earth System Research Laboratory of the US National Oceanic & Atmospheric
Administration (NOAA/ESRL), could be used to demonstrate the adequacy of the global
carbon-cycle models. However, it was recently found that the observed
amplitude of seasonal variations in the atmospheric carbon-dioxide
concentrations is higher than simulated. In this paper, the factors that
affect the amplitude of seasonal variations are explored using a carbon-cycle
model of reduced complexity. The model runs show that the low amplitude of
the simulated seasonal variations may result from underestimated effect of
substrate limitation on the seasonal pattern of heterotrophic respiration and
from an underestimated magnitude of the annual gross primary production (GPP) in the
terrestrial ecosystems located to the north of 25° N. |
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| ISSN: | 2190-4979 2190-4987 |