How can mountaintop CO<sub>2</sub> observations be used to constrain regional carbon fluxes?
Despite the need for researchers to understand terrestrial biospheric carbon fluxes to account for carbon cycle feedbacks and predict future CO<sub>2</sub> concentrations, knowledge of these fluxes at the regional scale remains poor. This is particularly true in mountainous areas, where...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2017-05-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/17/5561/2017/acp-17-5561-2017.pdf |
| _version_ | 1818304381186998272 |
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| author | J. C. Lin D. V. Mallia D. Wu B. B. Stephens |
| author_facet | J. C. Lin D. V. Mallia D. Wu B. B. Stephens |
| author_sort | J. C. Lin |
| collection | DOAJ |
| description | Despite the need for researchers to understand terrestrial biospheric carbon
fluxes to account for carbon cycle feedbacks and predict future CO<sub>2</sub>
concentrations, knowledge of these fluxes at the regional scale remains
poor. This is particularly true in mountainous areas, where complex
meteorology and lack of observations lead to large uncertainties in carbon
fluxes. Yet mountainous regions are often where significant forest cover and
biomass are found – i.e., areas that have the potential to serve as carbon
sinks. As CO<sub>2</sub> observations are carried out in mountainous areas, it is
imperative that they are properly interpreted to yield information about
carbon fluxes. In this paper, we present CO<sub>2</sub> observations at three sites in
the mountains of the western US, along with atmospheric simulations that
attempt to extract information about biospheric carbon fluxes from the
CO<sub>2</sub> observations, with emphasis on the observed and simulated diurnal
cycles of CO<sub>2</sub>. We show that atmospheric models can systematically
simulate the wrong diurnal cycle and significantly misinterpret the CO<sub>2</sub>
observations, due to erroneous atmospheric flows as a result of terrain that
is misrepresented in the model. This problem depends on the selected
vertical level in the model and is exacerbated as the spatial resolution is
degraded, and our results indicate that a fine grid spacing of
∼ 4 km or less may be needed to simulate a realistic diurnal
cycle of CO<sub>2</sub> for sites on top of the steep mountains examined here in
the American Rockies. In the absence of higher resolution models, we
recommend coarse-scale models to focus on assimilating afternoon CO<sub>2</sub>
observations on mountaintop sites over the continent to avoid
misrepresentations of nocturnal transport and influence. |
| first_indexed | 2024-12-13T06:09:47Z |
| format | Article |
| id | doaj.art-9decb223178b408e9c72d22b1ab9e746 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-13T06:09:47Z |
| publishDate | 2017-05-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-9decb223178b408e9c72d22b1ab9e7462022-12-21T23:57:07ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242017-05-011795561558110.5194/acp-17-5561-2017How can mountaintop CO<sub>2</sub> observations be used to constrain regional carbon fluxes?J. C. Lin0D. V. Mallia1D. Wu2B. B. Stephens3Department of Atmospheric Sciences, University of Utah, Salt Lake City, Utah 84112, USADepartment of Atmospheric Sciences, University of Utah, Salt Lake City, Utah 84112, USADepartment of Atmospheric Sciences, University of Utah, Salt Lake City, Utah 84112, USAEarth Observing Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80301, USADespite the need for researchers to understand terrestrial biospheric carbon fluxes to account for carbon cycle feedbacks and predict future CO<sub>2</sub> concentrations, knowledge of these fluxes at the regional scale remains poor. This is particularly true in mountainous areas, where complex meteorology and lack of observations lead to large uncertainties in carbon fluxes. Yet mountainous regions are often where significant forest cover and biomass are found – i.e., areas that have the potential to serve as carbon sinks. As CO<sub>2</sub> observations are carried out in mountainous areas, it is imperative that they are properly interpreted to yield information about carbon fluxes. In this paper, we present CO<sub>2</sub> observations at three sites in the mountains of the western US, along with atmospheric simulations that attempt to extract information about biospheric carbon fluxes from the CO<sub>2</sub> observations, with emphasis on the observed and simulated diurnal cycles of CO<sub>2</sub>. We show that atmospheric models can systematically simulate the wrong diurnal cycle and significantly misinterpret the CO<sub>2</sub> observations, due to erroneous atmospheric flows as a result of terrain that is misrepresented in the model. This problem depends on the selected vertical level in the model and is exacerbated as the spatial resolution is degraded, and our results indicate that a fine grid spacing of ∼ 4 km or less may be needed to simulate a realistic diurnal cycle of CO<sub>2</sub> for sites on top of the steep mountains examined here in the American Rockies. In the absence of higher resolution models, we recommend coarse-scale models to focus on assimilating afternoon CO<sub>2</sub> observations on mountaintop sites over the continent to avoid misrepresentations of nocturnal transport and influence.http://www.atmos-chem-phys.net/17/5561/2017/acp-17-5561-2017.pdf |
| spellingShingle | J. C. Lin D. V. Mallia D. Wu B. B. Stephens How can mountaintop CO<sub>2</sub> observations be used to constrain regional carbon fluxes? Atmospheric Chemistry and Physics |
| title | How can mountaintop CO<sub>2</sub> observations be used to constrain regional carbon fluxes? |
| title_full | How can mountaintop CO<sub>2</sub> observations be used to constrain regional carbon fluxes? |
| title_fullStr | How can mountaintop CO<sub>2</sub> observations be used to constrain regional carbon fluxes? |
| title_full_unstemmed | How can mountaintop CO<sub>2</sub> observations be used to constrain regional carbon fluxes? |
| title_short | How can mountaintop CO<sub>2</sub> observations be used to constrain regional carbon fluxes? |
| title_sort | how can mountaintop co sub 2 sub observations be used to constrain regional carbon fluxes |
| url | http://www.atmos-chem-phys.net/17/5561/2017/acp-17-5561-2017.pdf |
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