 |
| Titel |
Novel applications of carbon isotopes in atmospheric CO2: what can atmospheric measurements teach us about processes in the biosphere? |
| VerfasserIn |
A. P. Ballantyne, J. B. Miller, I. T. Baker, P. P. Tans, J. W. C. White |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 8, no. 10 ; Nr. 8, no. 10 (2011-10-31), S.3093-3106 |
| Datensatznummer |
250006176
|
| Publikation (Nr.) |
 copernicus.org/bg-8-3093-2011.pdf |
|
|
|
|
|
| Zusammenfassung |
| Conventionally, measurements of carbon isotopes in atmospheric CO2
(δ13CO2) have been used to partition fluxes between
terrestrial and ocean carbon pools. However, novel analytical approaches
combined with an increase in the spatial extent and frequency of δ13CO2 measurements allow us to conduct a global analysis of
δ13CO2 variability to infer the isotopic composition of
source CO2 to the atmosphere (δs). This global analysis yields
coherent seasonal patterns of isotopic enrichment. Our results indicate that
seasonal values of δs are more highly correlated with vapor pressure
deficit (r = 0.404) than relative humidity (r = 0.149). We then evaluate two
widely used stomatal conductance models and determine that the Leuning
Model, which is primarily driven by vapor pressure deficit is more effective
globally at predicting δs (RMSE = 1.6‰) than the Ball-Woodrow-Berry
model, which is driven by relative humidity (RMSE = 2.7‰). Thus stomatal
conductance on a global scale may be more sensitive to changes in vapor
pressure deficit than relative humidity. This approach highlights a new
application of using δ13CO2 measurements to validate global
models. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|