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| Titel |
Developing multi-tracer approaches to constrain the parameterisation of leaf and soil CO2 and H2O exchange in land surface models |
| VerfasserIn |
Jerome Ogee, Richard Wehr, Roisin Commane, Thomas Launois, Laura Meredith, Bill Munger, David Nelson, Scott Saleska, Mark Zahniser, Steve Wofsy, Lisa Wingate |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250135848
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| Publikation (Nr.) |
 EGU/EGU2016-16764.pdf |
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| Zusammenfassung |
| The net flux of carbon dioxide between the land surface and the atmosphere is dominated
by photosynthesis and soil respiration, two of the largest gross CO2 fluxes in the
carbon cycle. More robust estimates of these gross fluxes could be obtained from
the atmospheric budgets of other valuable tracers, such as carbonyl sulfide (COS)
or the carbon and oxygen isotope compositions (δ13C and δ18O) of atmospheric
CO2. Over the past decades, the global atmospheric flask network has measured
the inter-annual and intra-annual variations in the concentrations of these tracers.
However, knowledge gaps and a lack of high-resolution multi-tracer ecosystem-scale
measurements have hindered the development of process-based models that can simulate the
behaviour of each tracer in response to environmental drivers. We present novel
datasets of net ecosystem COS, 13CO2 and CO18O exchange and vertical profile data
collected over 3 consecutive growing seasons (2011-2013) at the Harvard forest flux
site. We then used the process-based model MuSICA (multi-layer Simulator of the
Interactions between vegetation Canopy and the Atmosphere) to include the transport,
reaction, diffusion and production of each tracer within the forest and exchanged
with the atmosphere. Model simulations over the three years captured well the
impact of diurnally and seasonally varying environmental conditions on the net
ecosystem exchange of each tracer. The model also captured well the dynamic
vertical features of tracer behaviour within the canopy. This unique dataset and model
sensitivity analysis highlights the benefit in the collection of multi-tracer high-resolution
field datasets and the developement of multi-tracer land surface models to provide
valuable constraints on photosynthesis and respiration across scales in the near
future. |
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