Spatiotemporal patterns of the fossil-fuel CO<sub>2</sub> signal in central Europe: results from a high-resolution atmospheric transport model
The emission of CO<sub>2</sub> from the burning of fossil fuel is a prime determinant of variations in atmospheric CO<sub>2</sub>. Here, we simulate this fossil-fuel signal together with the natural and background components with a regional high-resolution atmospheric tran...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-11-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/17/14145/2017/acp-17-14145-2017.pdf |
| Summary: | The emission of CO<sub>2</sub> from the burning of fossil fuel is a prime
determinant of variations in atmospheric CO<sub>2</sub>. Here, we simulate this
fossil-fuel signal together with the natural and background components with a
regional high-resolution atmospheric transport model for central and southern
Europe considering separately the emissions from different sectors and
countries on the basis of emission inventories and hourly emission time
functions. The simulated variations in atmospheric CO<sub>2</sub> agree very well with observation-based estimates, although the observed variance is slightly underestimated, particularly for the fossil-fuel component. Despite
relatively rapid atmospheric mixing, the simulated fossil-fuel signal reveals
distinct annual mean structures deep into the troposphere, reflecting the
spatially dense aggregation of most emissions. The fossil-fuel signal
accounts for more than half of the total (fossil fuel + biospheric + background)
temporal variations in atmospheric CO<sub>2</sub> in most areas of
northern and western central Europe, with the largest variations occurring on
diurnal timescales owing to the combination of diurnal variations in
emissions and atmospheric mixing and transport out of the surface layer. The
covariance of the fossil-fuel emissions and atmospheric transport on diurnal
timescales leads to a diurnal fossil-fuel rectifier effect of up to 9 ppm
compared to a case with time-constant emissions. The spatial pattern of
CO<sub>2</sub> from the different sectors largely reflects the distribution and
relative magnitude of the corresponding emissions, with power plant emissions
leaving the most distinguished mark. An exception is southern and western
Europe, where the emissions from the transportation sector dominate the
fossil-fuel signal. Most of the fossil-fuel CO<sub>2</sub> remains within the
country responsible for the emission, although in smaller countries up to
80 % of the fossil-fuel signal can come from abroad. A fossil-fuel emission
reduction of 30 % is clearly detectable for a surface-based observing system
for atmospheric CO<sub>2</sub>, while it is beyond the edge of detectability for
the current generation of satellites with the exception of a few hotspot
sites. Changes in variability in atmospheric CO<sub>2</sub> might open an
additional door for the monitoring and verification of changes in fossil-fuel
emissions, primarily for surface-based systems. |
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| ISSN: | 1680-7316 1680-7324 |