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| Titel |
Investigation of a long time series of CO2 from a tall tower using WRF-SPA |
| VerfasserIn |
Luke Smallman, Mathew Williams, John B. Moncrieff |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250079468
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| Zusammenfassung |
| Atmospheric observations from tall towers are an important source of information about CO2
exchange at the regional scale. Here, we have used a forward running model, WRF-SPA, to
generate a time series of CO2 at a tall tower for comparison with observations from Scotland
over multiple years (2006-2008). We use this comparison to infer strength and distribution of
sources and sinks of carbon and ecosystem process information at the seasonal
scale.
The specific aim of this research is to combine a high resolution (6 km) forward running
meteorological model (WRF) with a modified version of a mechanistic ecosystem model
(SPA). SPA provides surface fluxes calculated from coupled energy, hydrological and carbon
cycles. This closely coupled representation of the biosphere provides realistic surface
exchanges to drive mixing within the planetary boundary layer. The combined model is used
to investigate the sources and sinks of CO2 and to explore which land surfaces contribute to
a time series of hourly observations of atmospheric CO2 at a tall tower, Angus,
Scotland.
In addition to comparing the modelled CO2 time series to observations, modelled
ecosystem specific (i.e. forest, cropland, grassland) CO2 tracers (e.g., assimilation and
respiration) have been compared to the modelled land surface assimilation to investigate how
representative tall tower observations are of land surface processes. WRF-SPA modelled
CO2 time series compares well to observations (R2 = 0.67, rmse = 3.4 ppm, bias =
0.58 ppm). Through comparison of model-observation residuals, we have found
evidence that non-cropped components of agricultural land (e.g., hedgerows and forest
patches) likely contribute a significant and observable impact on regional carbon
balance. |
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