ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Electronic Resource

Sensitivity of regional climates to localized precipitation in global models (1990)

Pitman, A. J. ; Henderson-Sellers, A. ; Yang, Z-L.

[s.l.] : Nature Publishing Group

Nature 346 (1990), S. 734-737

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ISSN: 1476-4687

Source: Nature Archives 1869 - 2009

Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics

Notes: [Auszug] The land surface is an essential component in atmospheric general circulation models (AGCMs). A series of sensitivity experiments12 has shown that the simulation of the Earth's climate is affected by the land surface3'8 and its representation9'13. In the past decade several models for ...

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1038/346734a0

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2

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The impact of implementing the bare essentials of surface transfer land surface scheme into the BMRC GCM (1995)

Yang, Z.-L. ; Pitman, A. J. ; McAvaney, B. ; [et al.]

Springer

Climate dynamics 11 (1995), S. 279-297

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ISSN: 1432-0894

Source: Springer Online Journal Archives 1860-2000

Topics: Geosciences , Physics

Notes: Abstract. This study describes the first order impacts of incorporating a complex land-surface scheme, the bare essentials of surface transfer (BEST), into the Australian Bureau of Meteorology Research Centre (BMRC) global atmospheric general circulation model (GCM). Land seasonal climatologies averaged over the last six years of integrations after equilibrium from the GCM with BEST and without BEST (the control) are compared. The modeled results are evaluated with comprehensive sources of data, including the layer-cloud climatologies from the international satellite cloud climatology project (ISCCP) data from 1983 to 1991 and the surface-observed global data of Warren et al., a five-year climatology of surface albedo estimated from earth radiation budget experiment (ERBE) top-of-the-atmosphere (TOA) radiative fluxes, global grid point datasets of precipitation, and the climatological analyses of surface evaporation and albedo. Emphasis is placed on the surface evaluation of simulations of land-surface conditions such as surface roughness, surface albedo and the surface wetness factor, and on their effects on surface evaporation, precipitation, layer-cloud and surface temperature. The improvements due to the inclusion of BEST are: a realistic geographical distribution of surface roughness, a decrease in surface albedo over areas with seasonal snow cover, and an increase in surface albedo over snow-free land. The simulated reduction in surface evaporation due, in part, to the biophysical control of vegetation, is also consistent with the previous studies. Since the control climate has a dry bias, the overall simulations from the GCM with BEST are degraded, except for significant improvements for the northern winter hemisphere because of the realistic vegetation-masking effects. The implications of our results for synergistic developments of other aspects of model parameterization schemes such as boundary layer dynamics, clouds, convection and rainfall are discussed.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s003820050076

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3

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Key results and implications from phase 1(c) of the Project for Intercomparison of Land-surface Parametrization Schemes (1999)

Pitman, A. J. ; Henderson-Sellers, A. ; Desborough, C. E. ; [et al.]

Springer

Climate dynamics 15 (1999), S. 673-684

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ISSN: 1432-0894

Source: Springer Online Journal Archives 1860-2000

Topics: Geosciences , Physics

Notes: Abstract Using atmospheric forcing data generated from a general circulation climate model, sixteen land surface schemes participating in the Project for the Intercomparison of Land-surface Parametrization Schemes (PILPS) were run off-line to equilibrium using forcing data from a GCM representative of a tropical forest and a mid-latitude grassland grid point. The values for each land surface parameter (roughness length, minimum stomatal resistance, soil depth etc.) were provided. Results were quality controlled and analyzed, focusing on the scatter simulated amongst the models. There were large differences in how the models’ partitioned available energy between sensible and latent heat. Annually averaged, simulations for the tropical forest ranged by 79 1 3;W m-2 for the sensible heat flux and 80 W m-2 for the latent heat flux. For the grassland, simulations ranged by 34 W m-2 for the sensible heat flux and 27 W m-2 for the latent heat flux. Similarly large differences were found for simulated runoff and soil moisture and at the monthly time scale. The models’ simulation of annually averaged effective radiative temperature varied with a range, between all the models, of 1.4 K for tropical forest and 2.2 K for the grassland. The simulation of latent and sensible heat fluxes by a standard ‘bucket’ models was anomalous although this could be corrected by an additional resistance term. These results imply that the current land surface models do not agree on the land surface climate when the atmospheric forcing and surface parameters are prescribed. The nature of the experimental design, it being offline and with artificial forcing, generally precludes judgements concerning the relative quality of any specific model. Although these results were produced de-coupled from a host model, they do cast doubt on the reliability of land surface schemes. It is therefore a priority to resolve the disparity in the simulations, understand the reasons behind the scatter and to determine whether this lack of agreement in de-coupled tests is reproduced in coupled experiments.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s003820050309

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4

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The impact of implementing the bare essentials of surface transfer land surface scheme into the BMRC GCM (1995)

Yang, Z-L ; Pitman, A J ; McAvaney, B ; [et al.]

Springer

Climate dynamics 11 (1995), S. 279-297

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ISSN: 1432-0894

Source: Springer Online Journal Archives 1860-2000

Topics: Geosciences , Physics

Notes: Abstract This study describes the first order impacts of incorporating a complex land-surface scheme, the bare essentials of surface transfer (BEST), into the Australian Bureau of Meteorology Research Centre (BMRC) global atmospheric general circulation model (GCM). Land seasonal climatologies averaged over the last six years of integrations after equilibrium from the GCM with BEST and without BEST (the control) are compared. The modeled results are evaluated with comprehensive sources of data, including the layer-cloud climatologies from the international satellite cloud climatology project (ISCCP) data from 1983 to 1991 and the surface-observed global data of Warren et al., a five-year climatology of surface albedo estimated from earth radiation budget experiment (ERBE) top-of-the-atmosphere (TOA) radiatioe fluxes, global grid point datasets of precipitation, and the climatological analyses of surface evaporation and albedo. Emphasis is placed on the surface evaluation of simulations of landsurface conditions such as surface roughness, surface albedo and the surface wetness factor, and on their effects on surface evaporation, precipitation, layer-cloud and surface temperature. The improvements due to the inclusion of BEST are: a realistic geographical distribution of surface roughness, a decrease in surface albedo over areas with seasonal snow cover, and an increase in surface albedo over snow-free land. The simulated reduction in surface evaporation due, in part, to the biophysical control of vegetation, is also consistent with the previous studies. Since the control climate has a dry bias, the overall simulations from the GCM with BEST are degraded, except for significant improvements for the northern winter hemisphere because of the realistic vegetation-masking effects. The implications of our results for synergistic developments of other aspects of model parameterization schemes such as boundary layer dynamics, clouds, convection and rainfall are discussed.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00211680

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5

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Evaluation of the Darcy's law performance for two-fluid flow hydrodynamics in a particle debris bed using a lattice-Boltzmann model (2000)

Yang, Z. L. ; Dinh, T. N. ; Nourgaliev, R. R. ; [et al.]

Springer

Heat and mass transfer 36 (2000), S. 295-304

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ISSN: 1432-1181

Source: Springer Online Journal Archives 1860-2000

Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics

Notes: Abstract In the present paper, multiphase flow dynamics in a porous medium are analyzed by employing the lattice-Boltzmann modeling approach. A two-dimensional formulation of a lattice-Boltzmann model, using a D2Q9 scheme, is used. Results of the FlowLab code simulation for single phase flow in porous media and for two-phase flow in a channel are compared with analytical solutions. Excellent agreement is obtained. Additionally, fluid-fluid interaction and fluid-solid interaction (wettability) are modeled and examined. Calculations are performed to simulate two-fluid dynamics in porous media, in a wide range of physical parameters of porous media and flowing fluids. It is shown that the model is capable of determining the minimum body force needed for the nonwetting fluid to percolate through the porous medium. Dependence of the force on the pore size, and geometry, as well as on the saturation of the nonwetting fluid is predicted by the model. In these simulations, the results obtained for the relative permeability coefficients indicate the validity of the reciprocity for the two coupling terms in the modified Darcy's law equations. Implication of the simulation results on two-fluid flow hydrodynamics in a decay-heated particle debris bed is discussed.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s002310000089

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6

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The structure of the Aegilops tauschii genepool and the evolution of hexaploid wheat (1998)

Dvorak, J. ; Luo, M.-C. ; Yang, Z.-L. ; [et al.]

Springer

Theoretical and applied genetics 97 (1998), S. 657-670

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ISSN: 1432-2242

Keywords: Key words Triticum aestivum ; Phylogeny ; Genetic distance ; Genome ; Introgression ; Allopolyploidy ; RFLP ; Glutenin ; rRNA ; Non-transcribed spacers ; Evolution

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract Polymorphism in the lengths of restriction fragments at 53 single-copy loci, the rRNA locus Nor3, and the high-molecular-weight glutenin locus Glu1 was investigated in the D genome of hexaploid Triticum aestivum and that of Aegilops tauschii, the source of the T. aestivum D genome. The distribution of genetic variation in Ae. tauschii suggests gene flow between Ae. tauschii ssp. strangulata and ssp. tauschii in Iran but less in Transcaucasia. The “strangulata” genepool is wider than it appears on the basis of morphology and includes ssp. strangulata in Transcaucasia and southeastern (SE) Caspian Iran and ssp. tauschii in north-central Iran and southwestern (SW) Caspian Iran. In the latter region, Ae. tauschii morphological varieties ‘meyeri’ and ‘typica’ are equidistant to ssp. strangulata in Transcaucasia, and both belong to the “strangulata” genepool. A model of the evolution of Ae. tauschii is presented. On the geographic region basis, the D genomes of all investigated forms of T. aestivum are most closely related to the “strangulata” genepool in Transcaucasia, Armenia in particular, and SW Caspian Iran. It is suggested that the principal area of the origin of T. aestivum is Armenia, but the SW coastal area of the Caspian Sea and a corridor between the two areas may have played a role as well. Little genetic differentiation was found among the D genomes of all investigated free-threshing and hulled forms of T. aestivum, and all appear to share a single D-genome genepool, in spite of the fact that several Ae. tauschii parents were involved in the evolution of T. aestivum.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s001220050942

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7

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The Q locus of Iranian and European spelt wheat (2000)

Luo, M. C. ; Yang, Z. L. ; Dvořák, J.

Springer

Theoretical and applied genetics 100 (2000), S. 602-606

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ISSN: 1432-2242

Keywords: Key words Triticum ; Hexaploid ; Mapping ; RFLP ; RSL ; Spelt

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract A dominant allele at the Q locus on chromosome 5A is believed to be the principal factor responsible for free-threshing, square-head spikes with a non-fragile rachis in bread wheat, Triticum aestivum ssp. aestivum. The spelt syndrome, resulting in pyramidal spikes with a brittle rachis and hulled grain in T. aestivum, is believed to be principally caused by the q allele. Chromosome 5A of European and Iranian spelt was substituted for 5A of bread wheat and the lines were characterized with molecular markers. The substitution of bread wheat chromosome 5A by 5A of European spelt resulted in weakly hulled, pyramidal spikes with a non-brittle rachis, whereas and the substitution of 5A by 5A of Iranian spelt did not alter spike morphology at all. It is concluded that the expression of the spelt syndrome depends, to a large extent, on the interactions of q with genes controlling glume tenacity and rachis fragility on other chromosomes. The genetic basis for the spelt syndrome and the apparent presence of the Q allele in Iranian spelt are discussed.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s001220050079

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8

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Comparative analyses of RFLP diversity in landraces of Triticum aestivum and collections of T. tauschii from China and Southwest Asia (1998)

Ward, R. W. ; Yang, Z. L. ; Kim, H. S. ; [et al.]

Springer

Theoretical and applied genetics 96 (1998), S. 312-318

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ISSN: 1432-2242

Keywords: Key words Genetic diversity ; Triticum tauschii ; Triticum aestivum ; RFLP ; Landrace wheat

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract Chinese accessions of Triticum tauschii and T. aestivum L. from the Sichuan white (SW), Yunnan hulled (YH), Tibetan weedrace (TW), and Xinjiang rice (XR) wheat groups were subjected to RFLP analysis. T. tauschii and landraces of T. aestivum from countries in Southwest Asia were also evaluated. For T. tauschii, a west to east gradient was apparent where the Chinese accessions exhibited less diversity than those from Southwest Asia. Compared to the Southwest Asian gene pool, the Chinese T. tauschii was highly homogeneous giving a low frequency of polymorphic bands (16%) and banding patterns (1.33 per probe) with 75 RFLP probe-HindIII combinations. Accessions of T. tauschii from Afghanistan and Pakistan were genetically more similar to the Chinese T. tauschii than those from Iran. Of 368 bands found for 39 Chinese hexaploid wheat accessions with 63 RFLP probe-HindIII combinations, 28.3% were polymorphic with an average of 2.6 banding patterns per probe and 5.0 bands per genotype. The individual Chinese landrace wheat groups revealed less variation than those from Afghanistan, Iran, and Turkey. When classified into country based groups, however, the diversity level over all Chinese landraces was greater than that of some Southwest Asian landraces, especially those from Afghanistan and Iran . The XR wheat group was genetically distinct from the other three Chinese landrace groups and was more related to the Southwest Asian landraces. The TW group was genetically similar to, but more diverse than, the SW and YH groups. The Chinese landraces had a higher degree of genetic relatedness to the Southwest Asian T. tauschii, particularly to accessions from Iran, rather than to the Chinese T. tauschii. ‘Chinese Spring’ was most related to ‘Chengdu-guang-tou’, a cultivar from the SW wheat group.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s001220050742

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9

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Copper bilirubinate and black pigment gallstone (1995)

Li, W.-H. ; Shen, G.-R. ; Soloway, R. D. ; [et al.]

New York, NY [u.a.] : Wiley-Blackwell

Biospectroscopy 1 (1995), S. 149-156

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ISSN: 1075-4261

Keywords: Chemistry ; Analytical Chemistry and Spectroscopy

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Biology , Physics

Notes: A series of copper bilirubinate complexes (CuBR) was synthesized in solution and in solid state to mimic the black color of the black-pigment gallstone and to explore the formation mechanism of the gallstonein vitro. The variation of the copper contents of these samples indicated that CuBR also exhibits nonstoichiometric characteristics from the FTIR study, i.e., both the so-called acid and neutral copper complex moieties exist in CuBR. The NH groups in pyrrole and lactam groups of bilirubin (H2BR) are binding to the copper ions. An EPR study demonstrates the generation of free radicals and the variation of its electronic structure and conjugation system in the skeleton of H2BR molecule during complex formation. A polymer of CuBR may form through the reaction of H2BR with copper ions. © 1995 John Wiley & Sons, Inc.

Additional Material: 5 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/bspy.350010209

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