Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    We will mail you new results for this query: keywords==3-dimensional model
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Modeling the relationship between CO2 assimilation and leaf anatomical properties in tomato leaves
Berghuijs, H.N.C. ; Yin, X. ; Ho, Q.T. ; Putten, P.E.L. van der; Verboven, P. ; Retta, M.A. ; Nicolai, B.M. ; Struik, P.C. - \ 2015
Plant Science 238 (2015). - ISSN 0168-9452 - p. 297 - 311.
mesophyll diffusion conductance - gas-exchange - chlorophyll fluorescence - carbonic-anhydrase - internal conductance - 3-dimensional model - transgenic tobacco - c-3 plants - photosynthesis - parameters
The CO2 concentration near Rubisco and, therefore, the rate of CO2 assimilation, is influenced by both leaf anatomical factors and biochemical processes. Leaf anatomical structures act as physical barriers for CO2 transport. Biochemical processes add or remove CO2 along its diffusion pathway through mesophyll. We combined a model that quantifies the diffusive resistance for CO2 using anatomical properties, a model that partitions this resistance and an extended version of the Farquhar–von Caemmerer–Berry model. We parametrized the model by gas exchange, chlorophyll fluorescence and leaf anatomical measurements from three tomato cultivars. There was generally a good agreement between the predicted and measured light and CO2 response curves. We did a sensitivity analysis to assess how the rate of CO2 assimilation responds to changes in various leaf anatomical properties. Next, we conducted a similar analysis for assumed diffusive properties and curvature factors. Some variables (diffusion pathway length in stroma, diffusion coefficient of the stroma, curvature factors) substantially affected the predicted CO2 assimilation. We recommend more research on the measurements of these variables and on the development of 2-D and 3-D gas diffusion models, since these do not require the diffusion pathway length in the stroma as predefined parameter.
The European aerosol budget in 2006
Brugh, J.M.J. Aan de; Schaap, M. ; Vignati, E. ; Dentener, F. ; Kahnert, M. ; Sofiev, M. ; Huijnen, V. ; Krol, M.C. - \ 2011
Atmospheric Chemistry and Physics 11 (2011)3. - ISSN 1680-7316 - p. 1117 - 1139.
general-circulation model - evaluation program emep - light absorbing carbon - air-pollution - sulfuric-acid - sea-salt - tropospheric aerosols - 3-dimensional model - size distributions - particulate matter
This paper presents the aerosol budget over Europe in 2006 calculated with the global transport model TM5 coupled to the size-resolved aerosol module M7. Comparison with ground observations indicates that the model reproduces the observed concentrations quite well with an expected slight underestimation of PM10 due to missing emissions (e.g. resuspension). We model that a little less than half of the anthropogenic aerosols emitted in Europe are exported and the rest is removed by deposition. The anthropogenic aerosols are removed mostly by rain (95%) and only 5% is removed by dry deposition. For the larger natural aerosols, especially sea salt, a larger fraction is removed by dry processes (sea salt: 70%, mineral dust: 35%). We model transport of aerosols in the jet stream in the higher atmosphere and an import of Sahara dust from the south at high altitudes. Comparison with optical measurements shows that the model reproduces the Ångström parameter very well, which indicates a correct simulation of the aerosol size distribution. However, we underestimate the aerosol optical depth. Because the surface concentrations are close to the observations, the shortage of aerosol in the model is probably at higher altitudes. We show that the discrepancies are mainly caused by an overestimation of wet-removal rates. To match the observations, the wet-removal rates have to be scaled down by a factor of about 5. In that case the modelled ground-level concentrations of sulphate and sea salt increase by 50% (which deteriorates the match), while other components stay roughly the same. Finally, it is shown that in particular events, improved fire emission estimates may significantly improve the ability of the model to simulate the aerosol optical depth. We stress that discrepancies in aerosol models can be adequately analysed if all models would provide (regional) aerosol budgets, as presented in the current study
Multi-model ensemble simulations of troposheric NO2 compared with GOME retrievals for the year 2000
Noije, T.P.C. van; Eskes, H.J. ; Dentener, F.J. ; Stevenson, D.S. ; Ellingsen, K. ; Schultz, M.G. ; Wild, O. ; Amann, M. ; Atherton, C.S. ; Bergmann, D. ; Bey, I. ; Boersma, K.F. ; Butler, T. ; Cofala, J. ; Drevet, J. ; Fiore, A.M. ; Gauss, M. ; Hauglustaine, D.A. ; Horowitz, L.W. ; Isaksen, I.S.A. ; Krol, M.C. ; Lamarque, J.F. ; Lawrence, M.G. ; Martin, R.V. ; Montanaro, V. ; Muller, J.F. ; Pitari, G. ; Prather, M.J. ; Pyle, J.A. ; Richter, A. ; Rodriguez, J.M. ; Savage, N.H. ; Strahan, S.E. ; Sudo, K. ; Szopa, S. ; Roozendael, M. van - \ 2006
Atmospheric Chemistry and Physics 6 (2006)10. - ISSN 1680-7316 - p. 2943 - 2979.
chemical-transport model - ozone monitoring experiment - radiative-transfer model - aircraft mozaic data - satellite-observations - nitrogen-dioxide - nonmethane hydrocarbons - surface reflectivity - global distributions - 3-dimensional model
We present a systematic comparison of tropospheric NO2 from 17 global atmospheric chemistry models with three state-of-the-art retrievals from the Global Ozone Monitoring Experiment (GOME) for the year 2000. The models used constant anthropogenic emissions from IIASA/EDGAR3.2 and monthly emissions from biomass burning based on the 1997¿2002 average carbon emissions from the Global Fire Emissions Database (GFED). Model output is analyzed at 10:30 local time, close to the overpass time of the ERS-2 satellite, and collocated with the measurements to account for sampling biases due to incomplete spatiotemporal coverage of the instrument. We assessed the importance of different contributions to the sampling bias: correlations on seasonal time scale give rise to a positive bias of 30¿50% in the retrieved annual means over regions dominated by emissions from biomass burning. Over the industrial regions of the eastern United States, Europe and eastern China the retrieved annual means have a negative bias with significant contributions (between ¿25% and +10% of the NO2 column) resulting from correlations on time scales from a day to a month. We present global maps of modeled and retrieved annual mean NO2 column densities, together with the corresponding ensemble means and standard deviations for models and retrievals. The spatial correlation between the individual models and retrievals are high, typically in the range 0.81¿0.93 after smoothing the data to a common resolution. On average the models underestimate the retrievals in industrial regions, especially over eastern China and over the Highveld region of South Africa, and overestimate the retrievals in regions dominated by biomass burning during the dry season. The discrepancy over South America south of the Amazon disappears when we use the GFED emissions specific to the year 2000. The seasonal cycle is analyzed in detail for eight different continental regions. Over regions dominated by biomass burning, the timing of the seasonal cycle is generally well reproduced by the models. However, over Central Africa south of the Equator the models peak one to two months earlier than the retrievals. We further evaluate a recent proposal to reduce the NOx emission factors for savanna fires by 40% and find that this leads to an improvement of the amplitude of the seasonal cycle over the biomass burning regions of Northern and Central Africa. In these regions the models tend to underestimate the retrievals during the wet season, suggesting that the soil emissions are higher than assumed in the models. In general, the discrepancies between models and retrievals cannot be explained by a priori profile assumptions made in the retrievals, neither by diurnal variations in anthropogenic emissions, which lead to a marginal reduction of the NO2 abundance at 10:30 local time (by 2.5¿4.1% over Europe). Overall, there are significant differences among the various models and, in particular, among the three retrievals. The discrepancies among the retrievals (10¿50% in the annual mean over polluted regions) indicate that the previously estimated retrieval uncertainties have a large systematic component. Our findings imply that top-down estimations of NOx emissions from satellite retrievals of tropospheric NO2 are strongly dependent on the choice of model and retrieval.
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