Die horizontale Verteilung von Natrium im Bielersee     

Dr. J. von Orelli 《Aquatic Sciences - Research Across Boundaries》1981,43(1):151-167

Lake Biel comprises three basins and has two main affluents, which can be distinguished in their Naconcentrations during the stagnation period. From the Na-concentrations in the lake, conclusions can be drawn upon the distribution of the affluents' waters in the basins of the lake.   相似文献   

Zur paläogeographischen Rekonstruktion erdgeschichtlicher Ozeane     

Dipl.-Geol. Volker Maack 《International Journal of Earth Sciences》1981,70(1):78-90

Zusammenfassung Für Simulationsrechnungen der Gezeiten erdgeschichtlicher Ozeane werden hinreichend detaillierte paläogeographische Karten vorgestellt, die global die ungefähre Lage der ozeanischen und kontinentalen Bereiche sowie paläobathymetrische Informationen wiedergeben.Ausgehend von vorhandenen paläokontinentalen Karten, die auf den modernen Konzepten der Plattentektonik und des sea-floor spreading basieren, sind für einige erdgeschichtliche Stadien die einstige Verteilung von Land, Flachmeer und Tiefsee dargestellt. Mittels zusammengefaßter Ergebnisse paläobiogeographischer, geotektonischer, geophysikalischer, sedimentologischer und palökologischer Untersuchungen sind paläogeographische Rekonstruktionen für ein pleistozänes Hochglazial (Saale-Eiszeit), für die Obere Kreide (Ober-Campan), für das Obere Perm (Zechstein) sowie für das Mittlere Silur (Wenlock) abgebildet.Die Problematik bei der Rekonstruktion von Paläozeanen sowie die Interpretation und Kompilation paläogeographischer Daten wird diskutiert.

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For modeling the paleotides of ancient oceans you need quiet detailed paleogeographical maps projecting the global distribution of oceanic and continental areas as well as some paleobathymetrical informations. Using available paleocontinental maps which are based upon the modern concepts of the plate tectonics and sea-floor spreading, ancient distributions of land, shallow and deep sea are presented for some geological stages. By means of compiling the results of paleobiogeographical, geotectonical, geophysical, sedimentological, and paleoecological investigations paleogeographical reconstructions are shown for a Pleistocene ice-age (Saale stage), the Upper Cretaceous (Upper Campanian), the Upper Permian (Zechstein), and for the Middle Silurian (Wenlockian).Problems of paleoceanical reconstructions as well as the interpretation and compilation of paleogeographical data are discussed.

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Résumé Des cartes paléogéographiques à point détaillées sont présentées pour le calcul des marées des anciens océans; elles reproduisent globalement la situation approximative des domaines océaniques et continentaux, et donnent aussi des informations paléobathymétriques.Partant de cartes paléocontinentales existantes basées sur les concepts modernes de tectonique de plaques et d'expansion des océans, on a figuré pour quelques périodes géologiques la répartition ancienne des terres, des mers intérieures et des mers profondes. Utilisant les données condensees provenant des recherches paléobiogéographiques, géotectoniques, géophysigues, sédimentologiques et paléoécologiques, on a effectué les reconstructions paléogéographiques relatives à un Pleistocene glaciaire ancien (stade de la Saale), au Crétacique supérieur (Campanien supérieur), au Permien supérieur (Zechstein), ainsi qu au Silurien moyen (Wenlockien).Le problème concernant la reconstruction des paléoocéans ainsi que les interprétations et compilations des données paléogéographiques sont discutés.

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Heat flow and age of the Gulf of Oman     

I. Hutchison  K.E. Louden  R.S. White  R.P. von Herzen 《Earth and Planetary Science Letters》1981

We present the results of twenty heat flow stations in the Gulf of Oman which are used to infer the first reliable age estimates for the basin. A mean surface heat flux of 42.6±3.6 mW m^?2 exhibits no significant regional variation. After correction for thick and rapidly deposited sediments this yields an age of 70 to 100 Ma according to oceanic thermal models. This age is also consistent with the sediment corrected basement depths of 5.5–6.0 km and with formation during the Cretaceous quiet zone. The latter can explain the absence of magnetic sea-floor spreading lineations. Heat flow measurements are also used to confirm the presence of gas hyrdate layers. The measured thermal gradient yields a depth for the solid to free gas phase transition which is the same as that deduced from “bright spots” seen on seismic reflection profiles.  相似文献   

Competition for the general cargo transports of Sweden's foreign trade     

Christopher von Schirach-Szmigiel 《GeoJournal》1981,2(2):133-146

The object of the paper is to analyze changes in modal and port allocation of general cargo flows in Sweden's foreign trade between 1960 and 1976. It summarizes some results of a forthcoming report on the project Tendencies in Liner Shipping financed by the Transport Research Delegation, Stockholm.  相似文献   

Uncertainty in an emissions-constrained world     

Matthias Jonas  Gregg Marland  Volker Krey  Fabian Wagner  Zbigniew Nahorski 《Climatic change》2014,124(3):459-476

Our study focuses on uncertainty in greenhouse gas (GHG) emissions from anthropogenic sources, including land use and land-use change activities. We aim to understand the relevance of diagnostic (retrospective) and prognostic (prospective) uncertainty in an emissions-temperature setting that seeks to constrain global warming and to link uncertainty consistently across temporal scales. We discuss diagnostic and prognostic uncertainty in a systems setting that allows any country to understand its national and near-term mitigation and adaptation efforts in a globally consistent and long-term context. Cumulative emissions are not only constrained and globally binding but exhibit quantitative uncertainty; and whether or not compliance with an agreed temperature target will be achieved is also uncertain. To facilitate discussions, we focus on two countries, the USA and China. While our study addresses whether or not future increase in global temperature can be kept below 2, 3, or 4 °C targets, its primary aim is to use those targets to demonstrate the relevance of both diagnostic and prognostic uncertainty. We show how to combine diagnostic and prognostic uncertainty to take more educated (precautionary) decisions for reducing emissions toward an agreed temperature target; and how to perceive combined diagnostic and prognostic uncertainty-related risk. Diagnostic uncertainty is the uncertainty contained in inventoried emission estimates and relates to the risk that true GHG emissions are greater than inventoried emission estimates reported in a specified year; prognostic uncertainty refers to cumulative emissions between a start year and a future target year, and relates to the risk that an agreed temperature target is exceeded.  相似文献   

The Canadian Fourth Generation Atmospheric Global Climate Model (CanAM4). Part I: Representation of Physical Processes     

Knut von Salzen  John F. Scinocca  Norman A. McFarlane  Jiangnan Li  Jason N. S. Cole  David Plummer 《大气与海洋》2013,51(1):104-125

The Canadian Centre for Climate Modelling and Analysis (CCCma) has developed the fourth generation of the Canadian Atmospheric Global Climate Model (CanAM4). The new model includes substantially modified physical parameterizations compared to its predecessor. In particular, the treatment of clouds, cloud radiative effects, and precipitation has been modified. Aerosol direct and indirect effects are calculated based on a bulk aerosol scheme. Simulation results for present-day global climate are analyzed, with a focus on cloud radiative effects and precipitation. Good overall agreement is found between climatological mean short- and longwave cloud radiative effects and observations from the Clouds and Earth's Radiant Energy System (CERES) experiment. An analysis of the responses of cloud radiative effects to variations in climate will be presented in a companion paper.

[Traduit par la rédaction] Le Centre canadien de la modélisation et de l'analyse climatique (CCmaC) a mis au point la quatrième génération du modèle canadien de circulation générale de l'atmosphère (CanAM4). Le nouveau modèle comprend des paramétrisations physiques passablement modifiées comparativement à son prédécesseur. En particulier, le traitement des nuages, des effets radiatifs des nuages et des précipitations a été modifié. Les effets directs et indirects des aérosols sont calculés à l'aide d'un schéma d'aérosols en bloc. Nous analysons des résultats de simulation pour le climat général du jour présent en mettant l'accent sur les effets radiatifs des nuages et les précipitations. Nous trouvons un bon accord général entre la moyenne climatologique des effets radiatifs des nuages pour les courtes et les grandes longueurs d'onde et les observations de l'expérience CERES (Clouds and Earth's Radiant Energy System). Une analyse de la réponse des effets radiatifs des nuages aux variations du climat sera présentée dans un article connexe.  相似文献   

The simulation of European heat waves from an ensemble of regional climate models within the EURO-CORDEX project   总被引：4，自引：1，他引：3  

Robert Vautard  Andreas Gobiet  Daniela Jacob  Michal Belda  Augustin Colette  Michel Déqué  Jesús Fernández  Markel García-Díez  Klaus Goergen  Ivan Güttler  Tomáš Halenka  Theodore Karacostas  Eleni Katragkou  Klaus Keuler  Sven Kotlarski  Stephanie Mayer  Erik van Meijgaard  Grigory Nikulin  Mirta Patarčić  John Scinocca  Stefan Sobolowski  Martin Suklitsch  Claas Teichmann  Kirsten Warrach-Sagi  Volker Wulfmeyer  Pascal Yiou 《Climate Dynamics》2013,41(9-10):2555-2575

The ability of a large ensemble of regional climate models to accurately simulate heat waves at the regional scale of Europe was evaluated. Within the EURO-CORDEX project, several state-of-the art models, including non-hydrostatic meso-scale models, were run for an extended time period (20 years) at high resolution (12 km), over a large domain allowing for the first time the simultaneous representation of atmospheric phenomena over a large range of spatial scales. Eight models were run in this configuration, and thirteen models were run at a classical resolution of 50 km. The models were driven with the same boundary conditions, the ERA-Interim re-analysis, and except for one simulation, no observations were assimilated in the inner domain. Results, which are compared with daily temperature and precipitation observations (ECA&D and E-OBS data sets) show that, even forced by the same re-analysis, the ensemble exhibits a large spread. A preliminary analysis of the sources of spread, using in particular simulations of the same model with different parameterizations, shows that the simulation of hot temperature is primarily sensitive to the convection and the microphysics schemes, which affect incoming energy and the Bowen ratio. Further, most models exhibit an overestimation of summertime temperature extremes in Mediterranean regions and an underestimation over Scandinavia. Even after bias removal, the simulated heat wave events were found to be too persistent, but a higher resolution reduced this deficiency. The amplitude of events as well as the variability beyond the 90th percentile threshold were found to be too strong in almost all simulations and increasing resolution did not generally improve this deficiency. Resolution increase was also shown to induce large-scale 90th percentile warming or cooling for some models, with beneficial or detrimental effects on the overall biases. Even though full causality cannot be established on the basis of this evaluation work, the drivers of such regional differences were shown to be linked to changes in precipitation due to resolution changes, affecting the energy partitioning. Finally, the inter-annual sequence of hot summers over central/southern Europe was found to be fairly well simulated in most experiments despite an overestimation of the number of hot days and of the variability. The accurate simulation of inter-annual variability for a few models is independent of the model bias. This indicates that internal variability of high summer temperatures should not play a major role in controlling inter-annual variability. Despite some improvements, especially along coastlines, the analyses conducted here did not allow us to generally conclude that a higher resolution is clearly beneficial for a correct representation of heat waves by regional climate models. Even though local-scale feedbacks should be better represented at high resolution, combinations of parameterizations have to be improved or adapted accordingly.  相似文献   

Testing ensembles of climate change scenarios for “statistical significance”   总被引：1，自引：1，他引：0  

Hans von Storch  Francis Zwiers 《Climatic change》2013,117(1-2):1-9

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Nephelines from the Somma-Vesuvius volcanic complex (Southern Italy): crystal-chemical,structural and genetic investigations     

Giuseppina Balassone  Volker Kahlenberg  Angela Altomare  Angela Mormone  Rosanna Rizzi  Michele Saviano  Nicola Mondillo 《Mineralogy and Petrology》2014,108(1):71-90

Sixteen nephelines from different geological occurrences were sampled at the type-locality, the Somma-Vesuvius volcanic complex (southern Italy), and investigated for their chemistry and crystal structure obtained by both single-crystal and powder X-ray diffraction. Nepheline-bearing samples are metamorphic or from magmatic ejecta and pumice deposits. The lower K contents characterize the pumice- and some metamorphic-derived nephelines, whereas the higher ones are found in some samples from magmatic nodules. The amount of the anorthite molecule, quite low on average, can be more variable in the metamorphic nephelines. The crystal-structure investigations on Somma-Vesuvius samples compare well with previous studies of natural nephelines. All 16 nepheline samples adopt space group P6₃. The observed lattice parameters vary between 9.9768–9.9946 Å (for a) and 8.3614–8.3777 Å (for c), respectively. Furthermore, chemical analysis revealed that all specimens exhibit an excess of Si relative the ideal Si:Al ratio of 1:1. The analysis of the T-O distances in our samples clearly indicates a distinct ordering process of aluminium and silicon on the tetrahedral sites which is an agreement with Loewenstein’s rule. A linear correlation between the distance of symmetry equivalent split atoms O(1)-O(1)’ and the T(1)-O(1)-T(2) tilt angle was observed. The average <B-O> (B = Na) distances of all crystals are very similar which is consistent with the outcome of the site population refinement indicating full occupancy with sodium. Oriented precession-type sections of reciprocal space indicated the presence of at least the most intense family of satellite peaks, demonstrating that this group of satellite reflections can occur not only in nephelines from pegmatites and ijolites but also in rocks from completely different petrological settings.  相似文献   

Towards a Higher Comparability of Geothermometric Data obtained by Raman Spectroscopy of Carbonaceous Material. Part I: Evaluation of Biasing Factors   总被引：1，自引：0，他引：1  

Nils K. Lünsdorf  Istvan Dunkl  Burkhard C. Schmidt  Gerd Rantitsch  Hilmar von Eynatten 《Geostandards and Geoanalytical Research》2014,38(1):73-94

Raman spectroscopy of carbonaceous material (RSCM) is frequently used to determine metamorphic peak temperatures from the structural order of carbonaceous material enclosed in metasediments. This method provides a quick, robust and relatively cheap geothermometer. However, the comparability of the RSCM parameter is low as there are at least three major sources of biasing factors. These sources are the spectral curve‐fitting procedure, the sample characteristics itself and the experimental design including the used Raman system. To assess the impacts of the biasing factors on RSCM, a series of experiments was performed. The experiments showed that curve‐fitting is strongly influenced by individual operator‐bias and the degrees of freedom in the model, implying the need for a standardised curve‐fitting procedure. Due to the diversity of components (optics, light detection device, gratings, etc.) and their combinations within the Raman systems, different Raman instruments generally give differing results. Consequently, to estimate comparable metamorphic temperatures from RSCM data, every Raman instrument needs its own calibration. This demands a reference material series that covers the entire temperature calibration range. Although sample heterogeneity will still induce some variation, a reference material series combined with standardised curve‐fitting procedures will significantly increase the overall comparability of RSCM data from different laboratories.  相似文献