Towards a comprehensive approach to parameter estimation in land surface parameterization schemes     

Rafael Rosolem  Hoshin V. Gupta  W. James Shuttleworth  Luis Gustavo Gonçalves de Gonçalves  Xubin Zeng 《水文研究》2013,27(14):2075-2097

In climate models, the land–atmosphere interactions are described numerically by land surface parameterization (LSP) schemes. The continuing improvement in realism in these schemes comes at the expense of the need to specify a large number of parameters that are either directly measured or estimated. Also, an emerging problem is whether the relationships used in LSPs are universal and globally applicable. One plausible approach to evaluate this is to first minimize uncertainty in model parameters by calibration. In this paper, we conduct a comprehensive analysis of some model diagnostics using a slightly modified version of the Simple Biosphere 3 model for a variety of biomes located mainly in the Amazon. First, the degree of influence of each individual parameter in simulating surface fluxes is identified. Next, we estimate parameters using a multi‐operator genetic algorithm applied in a multi‐objective context and evaluate simulations of energy and carbon fluxes against observations. Compared with the default parameter sets, these parameter estimates improve the partitioning of energy fluxes in forest and cropland sites and provide better simulations of daytime increases in assimilation of net carbon during the dry season at forest sites. Finally, a detailed assessment of the parameter estimation problem was performed by accounting for the decomposition of the mean squared error to the total model uncertainty. Analysis of the total prediction uncertainty reveals that the parameter adjustments significantly improve reproduction of the mean and variability of the flux time series at all sites and generally remove seasonality of the errors but do not improve dynamical properties. Our results demonstrate that error decomposition provides a meaningful and intuitive way to understand differences in model performance. To make further advancements in the knowledge of these models, we encourage the LSP community to adopt similar approaches in the future. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Cosmic structures, parameters & temperature anisotropies: Status and perspectives     

François R. Bouchet 《Astrophysics and Space Science》2004,290(1-2):69-85

After recalling the current understanding of the formation of the large scale structures of the Universe which the distribution of galaxies revealed, I review what the imprint on the Cosmic Microwave Background (CMB) of the seeds of these structures can tell us, has already told us, and what it should tell us within the next five years.  相似文献   

Star formation in starburst galaxies from near-IR spectroscopy and evolutionary population synthesis     

A. Lançon  B. Rocca-Volmerange 《Astrophysics and Space Science》1994,217(1-2):271-272

We show that the combined study of the near-IR Stellar Energy Distribution (SED) and emission lines in IR luminous starburst galaxies, using evolutionary population synthesis, gives constraints both on the star formation (SF) parameters and on the relative spatial distribution of the components (burst stars, evolved stars, H II regions, dust). We also note that the He I λ 2.06/Br _γ ratio, used to constrain the stellar upper mass limit, is sensitive to a variety of other factors that should be accounted for.  相似文献   

Cosmological Models with Variable G and Λ     

Can Battal Kılınç 《Astrophysics and Space Science》2004,289(1-2):103-109

Einstein's equations with variable gravitational and cosmological constants are considered in the presence of a perfect fluid for the anizotropic Bianchi I universe in a way which conserving the energy-momentum tensor. Two solutions are found, one of which the cosmological term varies inversely with power law of time. The other of which cosmological term is constant.  相似文献   

A rational method for determining the swelling pressure of expansive soils: Paired swell test (PS-test)     

Selçuk  Levent 《Acta Geotechnica》2022,17(8):3161-3180

Acta Geotechnica - Experimental investigations on the expansion behavior of clayey soils are of great importance to correctly understand the response of the soil–foundation. In this context,...  相似文献   

Properties and Comparison of Some Kriging Sub-model Aggregation Methods     

Bachoc  François  Durrande  Nicolas  Rullière  Didier  Chevalier  Clément 《Mathematical Geosciences》2022,54(5):941-977

Mathematical Geosciences - Kriging is a widely employed technique across computer experiments, machine learning and geostatistics. An important challenge for kriging is its high costs when dealing...  相似文献   

Accelerated weathering of hydrophobized sands     

Lin  Hongjie  Lourenço  Sérgio D. N. 《Acta Geotechnica》2022,17(2):377-390

Acta Geotechnica - Hydrophobized sands have been suggested as materials for hydraulic barriers in infrastructure. When placed at the interface ground–atmosphere, environmental factors such as...  相似文献   

A uranium bioremediation reactive transport benchmark     

Steven B. Yabusaki  Sevinç S. Şengör  Yilin Fang 《Computational Geosciences》2015,19(3):551-567

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Can shallow open-loop hydrothermal well-doublets help remediate seawater intrusion?     

François De Keuleneer  Philippe Renard 《Hydrogeology Journal》2015,23(4):619-629

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Multiple advances of Alpine glaciers into the Jura Mountains in the Northwestern Switzerland     

Angela Graf  Naki Akçar  Susan Ivy-Ochs  Stefan Strasky  Peter W. Kubik  Marcus Christl  Martin Burkhard  Rainer Wieler  Christian Schlüchter 《Swiss Journal of Geoscience》2015,108(2-3):225-238

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