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| Titel |
A Consistent View on the Terrestrial Carbon Cycle through Assimilation of Multiple Data Streams |
| VerfasserIn |
Thomas Kaminski, Gregor Schürmann, Simon Blessing, Wouter Dorigo, Ralf Giering, Jennifer Grant, Wolfgang Knorr, Christoph Köstler, Christoph Paulik, Marko Scholze, Klaus Scipal, Michael Voßbeck, Sönke Zaehle |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250095540
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| Publikation (Nr.) |
 EGU/EGU2014-10997.pdf |
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| Zusammenfassung |
| ESA’s CarbonFlux project assimilates the information from three Earth Observation (EO)
data streams into two models of the terrestrial carbon cycle. The EO products are soil
moisture provided by ASCAT/AMSR-E, Fraction of Photosynthetically Active Radiation
(FAPAR) derived by the Two-stream Inversion Package (TIP) from MODIS broadband
albedos, as well as column-integrated atmospheric CO2 (XCO2) derived from SCIAMACHY
through the Bremen Optimal Estimation Differential Optical Absorption Spectroscopy
(BESD) retrieval algorithm. Using the derivative-based variational Carbon Cycle Data
Assimilation System (CCDAS) approach, these data streams are applied in a mathematically
rigorous way together with prior information to act as simultaneous constraints on process
parameters/initial conditions of the Biosphere Energy Transfer HYdrology Scheme
(BETHY), and the Jena Scheme for Biosphere-Atmosphere Coupling in Hamburg
(JSBACH). We describe the assessment of data uncertainties (i.e. observational and
model-related) uncertainties as well as dedicated bias-correction schemes for each data
stream. Using second-derivative information, we infer posterior parameter/initial state
uncertainties and map them forward onto simulated net and gross surface carbon
fluxes over multiple scales. This means CCDAS derives higher-level multi-year
reanalysis products with uncertainty ranges from our EO input products, which allows
us a rigorous assessment of the indirect constraint on carbon fluxes provided by
the EO products. We present the CarbonFlux reanalyses products, validate them
against independent observations and compare them with further CCDAS reanalysis
products derived through assimilation of different data streams, such as SMOS L3
soil moisture products and flask samples of the atmospheric CO2 concentrations. |
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