Influence of low ozone episodes on erythemal UV-B radiation in Austria     

Schwarz  Matthias  Baumgartner  Dietmar J.  Pietsch  Helga  Blumthaler  Mario  Weihs  Philipp  Rieder  Harald E. 《Theoretical and Applied Climatology》2018,133(1-2):319-329

This study investigates the influence of low ozone episodes on UV-B radiation in Austria during the period 1999 to 2015. To this aim observations of total column ozone (TCO) in the Greater Alpine Region (Arosa, Switzerland; Hohenpeissenberg, Germany; Hradec Kralove, Czech Republic; Sonnblick, Austria), and erythemal UV-B radiation, available from 12 sites of the Austrian UV-B monitoring network, are analyzed. As previous definitions for low ozone episodes are not particularly suited to investigate effects on UV radiation, a novel threshold approach—considering anomalies—is developed to provide a joint framework for the analysis of extremes. TCO and UV extremes are negatively correlated, although modulating effects of sunshine duration impact the robustness of the statistical relationship. Therefore, information on relative sunshine duration (SD_rel), available at (or nearby) UV-B monitoring sites, is included as explanatory variable in the analysis. The joint analysis of anomalies of both UV index (UVI) and total ozone (∆UVI, ∆TCO) and SD_rel across sites shows that more than 65% of observations with strongly negative ozone anomalies (∆TCO < −1) led to positive UVI anomalies. Considering only days with strongly positive UVI anomaly (∆UVI > 1), we find (across all sites) that about 90% correspond to negative ∆TCO. The remaining 10% of days occurred during fair weather conditions (SD_rel ≥ 80%) explaining the appearance of ∆UVI > 1 despite positive TCO anomalies. Further, we introduce an anomaly amplification factor (AAF), which quantifies the expected change of the ∆UVI for a given change in ∆TCO.

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Population dynamics and natural hazard risk management: conceptual and practical linkages for the case of Austrian policy making     

Clar  Christoph  Löschner  Lukas  Nordbeck  Ralf  Fischer  Tatjana  Thaler  Thomas 《Natural Hazards》2021,105(2):1765-1796

Natural Hazards - This contribution explores the conceptual and empirical linkages between population dynamics and natural hazard risk management (NHRM). Following a review of the international...  相似文献   

Ion microprobe evidence for the mechanisms of stable isotope retrogression in high-grade metamorphic rocks     

J. M. Eiler  J. W. Valley  C. M. Graham  L. P. Baumgartner 《Contributions to Mineralogy and Petrology》1995,118(4):365-378

Retrograde interdiffusion is widely proposed as the dominant factor in producing the stable isotopic fractionation among minerals in slowly cooled igneous and metamorphic rocks. Mineral zonation consistent with interdiffusion of stable isotopes has never been directly observed, however, leaving doubt as to the mechanism responsible for the bulk-mineral isotopic compositions commonly measured. Ion microprobe analyses of oxygen isotope ratios in magnetite were combined with conventional bulk mineral analyses and diffusion modeling to document the relationship between mineral zonation and the mechanism of retrogression inferred from bulk mineral data. Two samples of magnetitebearing, quartzo-feldspathic Lyon Mountain gneiss from the Adirondack mountains, N.Y. were studied in detail. Conventional stable isotope analysis of both samples indicates that isotope thermometers are discordant and were reset by as much as 200°C from the estimated peak temperature of 750°C. The relative order of apparent temperatures recorded by various thermometers differs between the two samples, however, with T _qtz-fsp≫T _mt-qtz and T _mt-fsp in one sample and T _qtz-fsp<T _mt-qtz and T _mt-fsp in the other. Diffusion modeling using the Fast Grain Boundary model shows that the former pattern of apparent temperatures is consistent with closed system interdiffusion during cooling, whereas the latter is not. The modeling predicts that 0.5 mm diameter magnetite grains common to this rock type will contain isotopic zonation of 1‰ (rims lower in δ¹⁸O than cores), and that the cores of smaller (0.1 mm) grains will be similarly lower than to the cores of large (0.5 mm) grains. Ion microprobe analysis reveals that the zoning patterns of magnetite grains from the first sample contain clear core to rim zonation in multiple grains (Δcore-rim=1.1±0.4‰) and predicted grain-size vs core composition variations, consistent with diffusion-controlled resetting of bulk mineral fractionations. In contrast, the second sample shows irregular inter-and intra-granular variations over an 8‰ range, consistent with open system alteration. These results provide direct documentation of the importance of interdiffusion in affecting stable isotope distributions in slowly cooled rocks. The correlations of bulk-mineral resetting with zonation show that bulk mineral data, when interpreted with detailed modeling, can be used to determinate what processes controlling retrogression.  相似文献   

Einfluß der Luftmassen auf den Jahresgang der Poliomyelitis in Mitteleuropa     

Dr. H. Abel  Prof. Dr. A. Baumgartner  Dr. W. Donle 《Theoretical and Applied Climatology》1974,22(1-2):169-196

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Elektrische Fernmessung der Luft- und Bodentemperatur in einem Bergwald     

A. Baumgartner  G. Hofmann 《Theoretical and Applied Climatology》1957,8(2):215-230

Zusammenfassung Im Rahmen einer forstmeteorologisch ausgerichteten klimatologischen Standortsuntersuchung wurden an einer Schneise am Westhang des Großen Falkensteins (Bayerischer Wald) Messungen der Luft- und Bodentemperaturen durchgeführt. Längs der etwa 3 km lange Meßstrecke, die einen Höhenunterschied von etwa 700 m erfaßte, waren an sechs Stellen jeweils im Boden (10 cm), im Stammraum (3 m), im unteren Kronenraum (20 m) und über den Wipfeln (45 m) Thermistore angebracht, deren Widerstand zentral mit Hilfe einer Brücke und einer Wähleinrichtung abgelesen wurde. Von den Ergebnissen im Sommer 1955 werden charakteristische Werte des Tagesganges, der Tagesschwankung, des Streubereichs und der Tagesmittel der Luft- und Bodentemperaturen mitgeteilt, die die Auswirkungen des Bestandes auf das Mikroklima kennzeichnen. Der Einfluß der Höhenlage auf die Temperaturschichtung im Bestand und die Dynamik des Hangluftkörpers werden besprochen. Abschließend werden die Thermistormessungen im Wald mit den Ergebnissen der Registrierungen in Klimahütten längs der Schneise vergleichen.

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Summary In the course of a forestry-climatological investigation measurements of air and soil temperature have been made in and near a deforested line at the western slope of the Grosser Falkenstein (Bavarian Forest). Along a stretch of 3 km, comprising a difference of height of about 700 m one has fixed at 6 places thermistores in the soil (10 cm), in the trunk region (3 m), in the lower top region (20 m) and above the tops of the trees (45 m); the resistance of the different thermistores was measured from one spot by means of a bridge and a selective device. Of the results of summer 1955 characteristic figures of the daily variation and amplitude, of the dispersion and daily means of air and soil temperatures, characterizing the effects of the forest on the microclimate, are communicated. The influence of altitude on the stratification of temperature in the forest and the dynamics of the air mass along the slope are discussed. Finally the thermistore measurements inside the forest are compared with the results of the records in thermometer screens along the deforested line.

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Résumé Au cours d'une étude climatologique forestière faite au bord d'une laie sur le versant ouest du Grand Falkenstein dans la Forêt de Bavière, on a procédé à des mesures de la température de l'air et du sol. Sur une longueur de 3 km environ, comprenant une dénivellation d'à peu près 700 m, on a fixé en 6 points de la pente des thermistores dans le sol (à 10 cm), dans la région des troncs (à 3 m), dans celle des houppes (à 20 m) et au-dessus des cimes des arbres (à 45 m); la résistance des différents thermistores a été mesurée depuis un seul point à l'aide d'un pont et d'un dispositif sélecteur. Des résultats de l'été 1955, on a représenté dans ce travail des valeurs caractéristiques des moyennes journalières, de la variation et de l'amplitude diurne ainsi que de la dispersion de la température du sol et de l'air, qui donnent un aperçu de l'influence de l'association forestière sur le micro-climat. On discute aussi l'influence de l'altitude sur la stratification de la température dans la forêt ainsi que la dynamique de la masse d'air du versant. Pour terminer, on compare les valeurs des mesures faites au milieu des arbres à l'aide des thermistores avec les enregistrements obtenus dans des abris météorologiques placés le long de la laie.

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The geologic history of the Caribbean-Cocos plate boundary with special reference to the Nicoya ophiolite complex (Costa Rica) and D.S.D.P. results (Legs 67 and 84 off Guatemala): A synthesis     

Jacques Bourgois  Jacques Azema  Peter O. Baumgartner  Jean Tournon  Alain Desmet  Jean Aubouin 《Tectonophysics》1984,108(1-2)

The Pre-Upper Senonian basement of Costa Rica crops out in the Santa Elena and Nicoya peninsulas. From south to north and from base to top the basement includes: the Esperanza, Matapalo and Santa Elena units. The Esperanza unit is Albian-Santonian in age and consists mainly of pillow basalt and massive basalt flows. The Matapalo unit includes Callovian to Cenomanian radiolarite and includes massive basalt flows, basalt, and dolerite basement. The Santa Elena unit contains ultramafic and mafic rocks in which harzburgite is the major component. The most important tectonic features of the Nicoya Complex are the large Santa Elena and Matapalo nappes. Nappe emplacement was from north to south during upper Santonian time. The sedimentary cover of the Nicoya Complex comprises:

1. (1) the Campanian El Viejo Formation that consists of shallow-water sediments in the north (Santa Elena Peninsula) and the Campanian-Maastrichtian Sabana Grande Formation of deep-water origin in the South (Nicoya Peninsula);

2. (2) Paleocene strata indicating deposition in a deep-water environment comprises the Rivas, Las Palmas and Samara Formations;

3. (3) a post-upper Eocene (?) sequence that consists of the shallow-water Barra Honda and Montezuma Formations.

Two unconformities are significant geological features of the upper-Senonian to Tertiary history of Costa Rica. The lower one is at the base of the Sabana Grande Formation and marks a major change in the geologic conditions (basalt is scarce in the Campanian-Tertiary series); the upper unconformity at the base of the Barra Honda and Montezuma Formations is not as major as the lower one. During post-Campanian time, normal faulting occurred in two stages separated by a strong erosional phase.The geology of the landward slope of the adjacent Middle America Trench is outlined by interpreting multifold seismic reflection records off the west coast of Costa Rica and the DSDP Legs 67 and 84 transects off Guatemala. The western Caribbean plate boundary may have been under extensional stress for the last 75 m.y. The strong landward-dipping reflectors of the Middle America Trench landward slope off Guatemala could be equivalent to the on-land pre-Campanian overthrusts of Costa Rica. The available data are consistent with the Convergent Extensional margin concept.  相似文献   

Development of the HEFT and NuSTAR focusing telescopes     

Fiona A. Harrison  Finn E. Christensen  William Craig  Charles Hailey  Wayne Baumgartner  C. M. H. Chen  James Chonko  W. Rick Cook  Jason Koglin  Kristin-Kruse Madsen  Michael Pivavoroff  Steven Boggs  David Smith 《Experimental Astronomy》2005,20(1-3):131-137

Hard X-ray/soft gamma-ray astrophysics is on the verge of a major advance with the practical realization of technologies capable of efficiently focusing X-rays above 10 keV. Hard X-ray focusing telescopes can achieve orders of magnitude improvements in sensitivity compared to the instruments based on coded apertures and collimated detectors that have traditionally been employed in this energy band. Compact focal planes enable high-performance detectors with good spectral resolution to be employed in efficient, low-background configurations. We have developed multilayer coated grazing incidence optics and solid state Cadmium Zinc Telluride focal plane systems for the High Energy Focusing Telescope (HEFT) balloon-borne experiment, and for the Nuclear Spectroscopic Telescope Array (NuSTAR) Small Explorer satellite. In this paper we describe the technologies, telescope designs, and performance of both experiments.  相似文献   

Problems associated with luminescence dating of Late Quaternary glacial sediments in the NW Scottish Highlands   总被引：2，自引：0，他引：2  

Sven Lukas  Joel Q.G. Spencer  Ruth A.J. Robinson  Douglas I. Benn   《Quaternary Geochronology》2007,2(1-4):243-248

Linking the timing of glacial episodes and behaviour to climatic shifts that are documented in ice and marine sedimentary archives is key to understanding ocean-land interactions. In the NW Scottish Highlands a large number of closely spaced (‘hummocky’) moraines formed at retreating glacier margins. Independent age control on one palaeo-glacier limit is consistent with the timing of Younger Dryas (YD) glaciation in the area, but adjacent glacier lobes have remained undated due to the lack of sites and material for ¹⁴C dating. Direct dating of ice-marginal moraines using optically stimulated luminescence (OSL) techniques has never been attempted before in Scotland, but if successful, they may be the most appropriate methods for constraining the age of sediment deposition in the absence of organic material. Coarse-grained quartz and K-feldspar minerals from supraglacial sheet flow deposits and glacilacustrine sediments within ice-marginal moraines were analysed using the single-aliquot regenerative-dose (SAR) protocol. Independent age control and clear geomorphological relationships indicate that all samples should yield YD or post-Last Glacial Maximum (LGM) ages. Quartz OSL shine down curves showed low luminescence sensitivity, significant medium-to-slow components, a weak fast component, and scattered SAR data; Linearly Modulated-OSL (LM-OSL) measurements confirmed that the fast component was weak or absent. In contrast, feldspar infrared stimulated luminescence (IRSL) was highly sensitive with excellent SAR data. However, SAR data from 3 mm diameter aliquots of feldspar (200 grains) give higher than expected equivalent doses (D_e) by an order of magnitude. SAR measurements of small clusters of feldspar grains (ranging from 1–8) considerably broaden the apparent D_e distribution, but even the lowest value is about 2–3 times the expected D_e. Two possibilities arise to explain the quartz and feldspar data: (1) that glacial sequences in the NW Highlands re-work inherited (older) glacial deposits and that some of the pre-Devensian existing glacial landforms have only been modified during Devensian glaciation; or (2) that the sedimentary processes operating in these ice-marginal environments are not conducive to adequate bleaching of quartz and feldspar grains. Our study implies that ice-proximal supraglacial sediments from this region in NW Scotland reflect older ages of deposition, but dating YD sediments has not been possible.  相似文献   

Matrix‐dependent garnet growth in polymetamorphic rocks of the Sesia zone,Italian Alps     

M. Robyr  B. Darbellay  L.P. Baumgartner 《Journal of Metamorphic Geology》2014,32(1):3-24

Mushroom‐ and atoll‐shaped garnet crystals were found in high‐pressure quartz‐rich pelitic layers from the Monte Mucrone area (Western Alps, Italy). These garnet crystals are characterized by a peninsula‐shaped core surrounded by a partially crystallized, dodecahedral external rim. Textural observations and thermodynamic modelling point towards growth of the atoll garnet from the Monte Mucrone area during two distinct orogenic cycles. The core region and the inner part of the ring forming the edge of the atoll grew under Barrovian metamorphic conditions of likely Hercynian age, while the outer rim of the atoll structure developed under Alpine high‐pressure conditions. Electron backscatter diffraction analyses indicate that the atoll‐shaped structure has one single crystallographic orientation, despite its complex compositional zoning. Thermodynamic modelling reveals marked changes in equilibrium assemblage leading to changes in stoichiometry of the garnet‐forming reaction, which in turn explain the characteristic garnet morphology. Small amounts of quartz are consumed during the earlier stage of garnet growth history, whereas the production of garnet requires a much larger amount of quartz during the final stage of its growth. This leads to a change from initial poikiloblastic to non‐poikiloblastic textures. This change is responsible for the formation of atoll‐shaped garnet. Finally, garnet in intercalated mica‐rich layers forms idiomorphic crystals, continuous from the centre to rim. This study highlights the importance of the difference between the local matrix composition and the aggregate composition of the reactants needed for the garnet‐forming reaction. Finally, we show that interaction between matrix and reaction stoichiometry can lead to porphyroblast precipitation inside the already grown porphyroblast.  相似文献   

Aalenian to Cenomanian Radiolaria of the Bermeja Complex (Puerto Rico) and Pacific origin of radiolarites on the Caribbean Plate     

Alexandre N. Bandini  Peter O. Baumgartner  Kennet Flores  Paulian Dumitrica  Cyril Hochard  G��rard M. Stampfli  Sarah-Jane Jackett 《Swiss Journal of Geoscience》2011,104(3):367-408

The study of the radiolarian ribbon chert is a key in determining the origins of associated Mesozoic oceanic terranes and may help to achieve a general agreement regarding the basic principles on the evolution of the Caribbean Plate. The Bermeja Complex of Puerto Rico, which contains serpentinized peridotite, altered basalt, amphibolite, and chert (Mariquita Chert Formation), is one of these crucial oceanic terranes. The radiolarian biochronology presented in this work is mainly based by correlation on the biozonations of Baumgartner et al. (1995) and O??Dogherty (1994) and indicates an early Middle Jurassic to early Late Cretaceous (late Bajocian?Cearly Callovian to late early Albian?Cearly middle Cenomanian) age. The illustrated assemblages contain about 120 species, of which one is new (Pantanellium karinae), and belonging to about 50 genera. A review of the previous radiolarian published works on the Mariquita Chert Formation and the results of this study suggest that this formation ranges in age from Middle Jurassic to early Late Cretaceous (late Aalenian to early?Cmiddle Cenomanian) and also reveal a possible feature of the Bermeja Complex, which is the younging of radiolarian cherts from north to south, evoking a polarity of accretion. On the basis of a currently exhaustive inventory of the radiolarite facies s.s. on the Caribbean Plate, a re-examination of the regional distribution of Middle Jurassic sediments associated with oceanic crust, and a paleoceanographic argumentation on the water currents, we come to the conclusion that the radiolarite and associated Mesozoic oceanic terranes of the Caribbean Plate are of Pacific origin. Eventually, a discussion on the origin of the cherts of the Mariquita Formation illustrated by Middle Jurassic to middle Cretaceous geodynamic models of the Pacific and Caribbean realms bring up the possibility that the rocks of the Bermeja Complex are remnants of two different oceans.  相似文献