Simulating the atmospheric CO<sub>2</sub> concentration across the heterogeneous landscape of Denmark using a coupled atmosphere–biosphere mesoscale model system
<p>Although coastal regions only amount to 7 % of the global oceans, their contribution to the global oceanic air–sea <span class="inline-formula">CO<sub>2</sub></span> exchange is proportionally larger, with fluxes in some estuaries being similar i...
| Published in: | Biogeosciences |
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| Main Authors: | , , , , , , |
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-04-01
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| Online Access: | https://www.biogeosciences.net/16/1505/2019/bg-16-1505-2019.pdf |
| Summary: | <p>Although coastal regions only amount to 7 % of the global oceans, their
contribution to the global oceanic air–sea <span class="inline-formula">CO<sub>2</sub></span> exchange is
proportionally larger, with fluxes in some estuaries being similar in
magnitude to terrestrial surface fluxes of <span class="inline-formula">CO<sub>2</sub></span>.</p>
<p>Across a heterogeneous surface consisting of a coastal marginal sea with
estuarine properties and varied land mosaics, the surface fluxes of
<span class="inline-formula">CO<sub>2</sub></span> from both marine areas and terrestrial surfaces were investigated
in this study together with their impact in atmospheric <span class="inline-formula">CO<sub>2</sub></span>
concentrations by the usage of a high-resolution modelling framework. The
simulated terrestrial fluxes across the study region of Denmark experienced
an east–west gradient corresponding to the distribution of the land cover
classification, their biological activity and the urbanised areas. Annually,
the Danish terrestrial surface had an uptake of approximately
<span class="inline-formula">−7000</span> GgC yr<span class="inline-formula"><sup>−1</sup></span>. While the marine fluxes from the North Sea and the
Danish inner waters were smaller annually, with about <span class="inline-formula">−1800</span> and
1300 GgC yr<span class="inline-formula"><sup>−1</sup></span>, their sizes are comparable to annual terrestrial fluxes
from individual land cover classifications in the study region and hence are not
negligible. The contribution of terrestrial surfaces fluxes was easily
detectable in both simulated and measured concentrations of atmospheric
<span class="inline-formula">CO<sub>2</sub></span> at the only tall tower site in the study region. Although, the
tower is positioned next to Roskilde Fjord, the local marine impact was not
distinguishable in the simulated concentrations. But the regional impact from
the Danish inner waters and the Baltic Sea increased the atmospheric
concentration by up to 0.5 ppm during the winter months.</p> |
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| ISSN: | 1726-4170 1726-4189 |