|
Titel |
Multi-model analysis of terrestrial carbon cycles in Japan: limitations and implications of model calibration using eddy flux observations |
VerfasserIn |
K. Ichii, T. Suzuki, T. Kato, A. Ito, T. Hajima, M. Ueyama, T. Sasai, R. Hirata, N. Saigusa, Y. Ohtani, K. Takagi |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1726-4170
|
Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 7, no. 7 ; Nr. 7, no. 7 (2010-07-02), S.2061-2080 |
Datensatznummer |
250004888
|
Publikation (Nr.) |
copernicus.org/bg-7-2061-2010.pdf |
|
|
|
Zusammenfassung |
Terrestrial biosphere models show large differences when simulating carbon
and water cycles, and reducing these differences is a priority for
developing more accurate estimates of the condition of terrestrial
ecosystems and future climate change. To reduce uncertainties and improve
the understanding of their carbon budgets, we investigated the utility of
the eddy flux datasets to improve model simulations and reduce variabilities
among multi-model outputs of terrestrial biosphere models in Japan. Using 9
terrestrial biosphere models (Support Vector Machine – based regressions,
TOPS, CASA, VISIT, Biome-BGC, DAYCENT, SEIB, LPJ, and TRIFFID), we conducted
two simulations: (1) point simulations at four eddy flux sites in Japan and (2)
spatial simulations for Japan with a default model (based on original
settings) and a modified model (based on model parameter tuning using eddy
flux data). Generally, models using default model settings showed large
deviations in model outputs from observation with large model-by-model
variability. However, after we calibrated the model parameters using eddy
flux data (GPP, RE and NEP), most models successfully simulated seasonal
variations in the carbon cycle, with less variability among models. We also
found that interannual variations in the carbon cycle are mostly consistent
among models and observations. Spatial analysis also showed a large
reduction in the variability among model outputs. This study demonstrated
that careful validation and calibration of models with available eddy flux
data reduced model-by-model differences. Yet, site history, analysis of
model structure changes, and more objective procedure of model calibration
should be included in the further analysis. |
|
|
Teil von |
|
|
|
|
|
|