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151.
Heiko Paeth Anja Scholten Petra Friederichs Andreas Hense 《Global and Planetary Change》2008,60(3-4):265-288
The sensitivity of climate phenomena in the low latitudes to enhanced greenhouse conditions is a scientific issue of high relevance to billions of people in the poorest countries of the globe. So far, most studies dealt with individual model results. In the present analysis, we refer to 79 coupled ocean–atmosphere simulations from 12 different climate models under 6 different IPCC scenarios. The basic question is as to what extent various state-of-the-art climate models agree in predicting changes in the main features of El Niño-Southern Oscillation (ENSO) and the monsoon climates in South Asia and West Africa. The individual model runs are compared with observational data in order to judge whether the spatio-temporal characteristics of ENSO are well reproduced. The model experiments can be grouped into multi-model ensembles. Thus, climate change signals in the classical index time series, in the principal components and in the time series of interannual variability can be evaluated against the background of internal variability and model uncertainty.There are large differences between the individual model predictions until the end of the 21st century, especially in terms of monsoon rainfall and the Southern Oscillation index (SOI). The majority of the models tends to project La Niña-like anomalies in the SOI and an intensification of the summer monsoon precipitation in India and West Africa. However, the response barely exceeds the level of natural variability and the systematic intermodel variations are larger than the impact of different IPCC scenarios. Nonetheless, there is one prominent climate change signal, which stands out from model variations and internal noise: All forced model experiments agree in predicting a substantial warming in the eastern tropical Pacific. This oceanic heating does not necessarily lead to a modification of ENSO towards more frequent El Niño and/or La Niña events. It simply represents a change in the background state of ENSO. Indeed, we did not find convincing multi-model evidence for a modification of the wavelet spectra in terms of ENSO or the monsoons. Some models suggest an intensification of the annual cycle but this signal is fairly model-dependent. Thus, large model uncertainty still exists with respect to the future behaviour of climate in the low latitudes. This has to be taken into account when addressing climate change signals in individual model experiments and ensembles. 相似文献
152.
Holtstam Dan Cámara Fernando Skogby Henrik Karlsson Andreas Langhof Jörgen 《Mineralogy and Petrology》2019,113(1):7-16
Mineralogy and Petrology - Potassic-richterite, ideally AKB(NaCa)CMg5TSi8O22W(OH)2, is recognized as a valid member of the amphibole supergroup (IMA-CNMNC 2017–102). Type material is from the... 相似文献
153.
Andreas J. Scheib Manfred Birke Enrico Dinelli GEMAS Project Team 《Boreas: An International Journal of Quaternary Research》2014,43(1):175-192
Hafnium (Hf) and zirconium (Zr) concentrations measured in over 4100 agricultural soil samples from Europe were assessed with the focus on their relationship to the distribution of aeolian deposits, such as loess and coversands. Comparison of extractable (aqua regia; ICP‐MS) and total (XRFS) concentrations shows that only 1.0 to 1.7% of the total Hf and Zr is chemically extractable because of the resistant nature of their host minerals. Resistate minerals, such as zircon, are commonly found in the predominantly silty fraction of loess deposits. In this study a statistical analysis of total Hf and Zr soil data from areas with and without loess was carried out to derive threshold values of 10 mg kg?1 (Hf) and 318 mg kg?1 (Zr). These values were subsequently applied across the project area in an attempt to indicate the presence of aeolian deposits. The spatial distribution of above‐threshold concentrations suggests a more extensive and coherent loess belt across central and eastern Europe, providing additional evidence of loess across Brittany, Aquitaine and near the Vosges mountains in France as well as in the basins of central and northern Spain. Above‐threshold concentrations were also detected in loess regardless of its thickness, emphasising the importance of the abundance of zircon in the upper part of the soil profile rather than the actual thickness of the deposit. Soil data however, failed to indicate various loess facies within most of the Pannonian Basin, suggesting that this approach only works where deposits contain a sufficient amount of zircon. This may also explain why the extensive coversands across northern Germany and Poland were largely undetected. This study demonstrates that continental‐scale soil geochemical data can help identify and map the distribution of zircon‐rich loess and coversand, and subsequently enhance and improve current knowledge of the extent of these deposits. 相似文献
154.
Andreas Pilger 《International Journal of Earth Sciences》1950,38(2):139-144
Zusammenfassung In der vorliegenden Arbeit werden Aufwölbungen im Eis der Wattenküste vor Büsum mit den von H. Cloos beschriebenen Beulen in der Erdoberfläche verglichen. Beide entstehen durch vertikalen Druck von unten ohne Sehnenverkürzung, in deren Folge sich Spalten im Scheitel der Gewölbe bilden. Die völlige übereinstimmung in Form und Entstehung beider Erscheinungen lä\t die Watteisbeulen als geeignetes Beispiel erscheinen, um den Werdegang der Gro\formen zu verfolgen. Die kurze Notiz von H. Cloos über einen Scheitelgraben im Eise (1948) erschien erst nach Abschlu\ dieses Aufsatzes. 相似文献
155.
Walther Klüpfel 《International Journal of Earth Sciences》1930,21(3):151-162
Zusammenfassung Die komplexen tertiären Vulkangebiete lassen sich auf Grund der Störungsphasen und Reliefgenerationen in verschiedene natürliche Gruppen gliedern. An Beispielen (Westerwald, Vogelsberg, Habichtswald, Hegau, Böhmisches Mittelgebirge) wird gezeigt, wie man durch Ermittlung der Reliefgenerationen die bisher zugrunde gelegte, rein petrographische Unterscheidung der Vulkangebilde ergänzen, berichtigen oder ersetzen kann und dabei zu einer richtigen Analyse des Aufbaues und der vulkanischen Ereignisse gelangt. 相似文献
156.
Walther Klüpfel 《International Journal of Earth Sciences》1935,26(3):227-228
Ohne Zusammenfassung 相似文献
157.
W. Klüpfel 《International Journal of Earth Sciences》1934,25(2):141-142
Ohne Zusammenfassung 相似文献
158.
Walther Klüpfel 《International Journal of Earth Sciences》1931,22(3-4):187-188
Ohne Zusammenfassung 相似文献
159.
José?Rodríguez-AlgecirasEmail authorView authors OrcID profile Abel?Tablada Andreas?Matzarakis 《Theoretical and Applied Climatology》2018,133(3-4):663-679
Walkability and livability in cities can be enhanced by creating comfortable environments in the streets. The profile of an urban street canyon has a substantial impact on outdoor thermal conditions at pedestrian level. This paper deals with the effect of asymmetrical street canyon profiles, common in the historical centre of Camagüey, Cuba, on outdoor thermal comfort. Temporal-spatial analyses are conducted using the Heliodon2 and the RayMan model, which enable the generation of accurate predictions about solar radiation and thermal conditions of urban spaces, respectively. On these models, urban settings are represented by asymmetrical street canyons with five different height-to-width ratios and four street axis orientations (N-S, NE-SW, E-W, SE-NW). Results are evaluated for daytime hours across the street canyon, by means of the physiologically equivalent temperature (PET index) which allows the evaluation of the bioclimatic conditions of outdoor environments. Our findings revealed that high profiles (façades) located on the east-facing side of N-S streets, on the southeast-facing side of NE-SW streets, on the south-facing side of E-W street, and on the southwest-facing side of SE-NW streets, are recommended to reduce the total number of hours under thermal stress. E-W street canyons are the most thermally stressed ones, with extreme PET values around 36 °C. Deviating from this orientation ameliorates the heat stress with reductions of up to 4 h in summer. For all analysed E-W orientations, only about one fifth of the street can be comfortable, especially for high aspect ratios (H/W > 3). Optimal subzones in the street are next to the north side of the E-W street, northwest side of the NE-SW street, and southwest side of the SE-NW street. Besides, when the highest profile is located on the east side of N-S streets, then the subzone next to the east-facing façade is recommendable for pedestrians. The proposed urban guidelines enable urban planners to create and renovate urban spaces which are more efficient in diminishing pedestrian thermal stress. 相似文献
160.
A geography of insurance exclusion: perceptions of unemployment risk and actuarial risk assessment 总被引:4,自引:0,他引:4
Andreas Cebulla 《Area》1999,31(2):111-121
Summary Proposed welfare reform in Great Britain advocates joint public and private provision of insurance. Using omnibus survey data, this paper projects the availability and geographical coverage of private unemployment insurance in Britain among currently employed persons, on the basis of actuarial risk assessment criteria. It compares actuarial risk assessments with the respondents' subjective job risk assessments and their declared intention to take out private unemployment insurance. The paper identifies the extent and geography of structural/self-exclusion from insurance. 相似文献