Trajectory Studies of Polar Stratospheric Cloud Lidar Observations at Sodankylä (Finland) During SESAME: Comparison with Box Model Results of Particle Evolution     

V. Rizi  G. Redaelli  G. Visconti  F. Masci  C. Wedekind  B. Stein  F. Immler  B. Mielke  P. Rairoux  L. Woste  M. Del Guasta  M. Morandi  F. Castagnoli  S. Balestri  L. Stefanutti  R. Matthey  V. Mitev  M. Douard  J.P. Wolf  E. Kyro  M. Rummukainen  R. Kivi 《Journal of Atmospheric Chemistry》1999,32(1):165-181

Polar stratospheric clouds (PSC) were observed with the multi-wavelength lidar of the MOANA project (Modelling and Observations of Aerosols in the Northern Atmosphere) during SESAME (Second European Stratospheric Arctic and Mid-latitude Experiment). The physical state, liquid or solid, of the cloud particles can be inferred from the lidar data. Using isentropic back-trajectories to obtain the thermal history of the sampled air masses, it is possible to reconcile most of the observations with current ideas on PSC formation and evolution. When the cloud particles were identified as liquid, changes in the size distribution of the droplets along the trajectory were calculated using a micro-physical box model. Backscatter ratios calculated from the size distributions are in broad agreement with the lidar data, giving confidence in current understanding of the evolution of ternary solution (H2SO4, HNO3 and H2O) droplets.Results from two soundings are shown which bear on the problem of the formation of solid particles. In the first, solid particles were detected. The air mass had cooled to the frost point 12 hours earlier. In the second no solid particles were detected although the air temperature was below the nitric acid trihydrate existence point, and had decreased by 12K in the previous 14 hours.  相似文献   

Clay-mineral and grain-size distributions in surface sediments of the White Sea (Arctic Ocean): indicators of sediment sources and transport processes   总被引：1，自引：1，他引：0  

Cornelia Saukel  Rüdiger Stein  Christoph Vogt  Vladimir P. Shevchenko 《Geo-Marine Letters》2010,30(6):605-616

In this study, the grain-size and clay-mineral compositions of 73 surface sediment samples collected in a variety of environmental settings in the White Sea are presented to characterize recent sedimentation processes, reconstruct transport pathways, and identify potential source areas of the terrigenous components. Areas >100 m deep are invariably characterized by silty clay, whereas areas <100 m deep exhibit more heterogeneous grain-size compositions plausibly explained by coastal erosion and (re-)distribution mechanisms, particularly tidal currents. The dominance of sand in the estuarine areas of the Onega and Dvina rivers as well as toward the Gorlo Strait connecting the White Sea with the Barents Sea is attributed to increased current speeds. Illite and smectite are the dominant clay minerals in recent sediments of the southwestern and eastern White Sea sectors, respectively. Their distribution patterns largely depend on the geology of the source areas, and mirror surface circulation patterns, especially in Dvina Bay. Smectite is a key clay mineral in White Sea surface sediments, as it reveals the dominating influence of the Northern Dvina’s runoff on sedimentation and water circulation throughout the basin. In comparison to other Eurasian shelf seas, the White Sea is characterized by a greater diversity of clay-mineral assemblages, which range from illite- to smectite-dominated sectors containing variable amounts of chlorite and kaolinite.  相似文献   

Gedenktage     

Walter Stein 《Ocean Dynamics》1965,18(3):130-132

  相似文献   

Geochemistry, tectonic setting and geodynamic significance of late orogenic dikes in the Melibocus Massif, Bergsträsser Odenwald     

U. Altenberger  R. Oberhänsli  E. Stein  M. Moghni 《Mineralogy and Petrology》2001,72(1-3):209-228

Summary The Melibocus Massif forms a tonalite pluton in the W’ Bergstr?sser Odenwald, which is interpreted as part of a magmatic arc of Devonian to Carboniferous age. Dikes of various compositions intrude frequently this tonalite. Different dike-lithologies are associated with different strike directions. Most dikes show evidence of high-temperature shearing. A probable maximum paleostress direction of ca. 060° can be estimated, i.e. nearly parallel to the known Variscan subduction zone in the Northwest. Due to their ductile deformation under conditions around the Ar-closing temperature of amphibole, intrusion likely occurred during the Carboniferous (Mississippian). The gabbroic to dioritic dikes (malchites) have calc-alkaline composition. Comparison with modern analogues suggests subduction-related arc magmatism. Rare earth element distributions indicate more than 5% partial melting of the mantle source with limited amounts of residual garnet. In contrast to the tonalite pluton the granitoid dikes (alsbachites) are of S-type origin, as indicated by primary muscovite and chemical composition. This requires involvement of continental material in the dike’s source rather than in the tonalite host rock’s source. The trace element chemistry of these dikes indicates magma formation in a convergent plate tectonic situation, i.e. a magmatic arc regime. Therefore, the dikes are probably the late part of the same subduction-related magmatism, which produced the tonalitic and other plutons of the Bergstr?sser Odenwald. In contrast to the large pluton-forming magmas, formation of the dikes during late or post-collisional extension or transtension followed by a phase of compression or transpression is probable.

---

Zusammenfassung Geochemie, tektonische Stellung und geodynamische Signifikanz sp?torogener G?nge im Melibocus Massiv, Bergstr?sser Odenwald Der Melibokus Tonalit-Pluton geh?rt zum Bergstr?sser Odenwald, der als Teil eines devonisch-karbonischen magmatischen Bogens interpretiert wird. In diesem Pluton treten sehr h?ufig magmatische G?nge unterschiedlicher Zusammensetzung auf. Die Arbeit zeigt, dass die G?nge unterschiedlicher Zusammensetzung unterschiedliche Streichrichtungen haben. Die meisten der untersuchten G?nge zeigen Hochtemperatur-Schergefüge. Aus der Lage der zerscherten G?nge l?sst sich eine Pal?ostressrichtung mit 060° für Sigma 1 ableiten. Diese Richtung weicht nur unwesentlich von der bekannten variskischen Subduktionszone im Nordwesten ab. Aufgrund ihrer Hochtemperatur-Gefüge, die im Bereich der Schlie?ungstemperatur von Ar in Hornblenden gebildet wurden, ist das Alter der G?nge wahrscheinlich ebenfalls als Karbon (Mississippian) einzustufen. Die gabbroiden bis dioritischen G?nge (Malchite) haben eine kalkalkaline Zusammensetzung. Der Vergleich mit rezenten Magmatiten deutet auf eine Entstehung in einem magmatischen Bogen (Kontinentalrand) hin. Die Seltenerdelementverteilung der G?nge zeigt einen wahrscheinlichen Aufschmelzungsgrad der Mantelquellregion von über 5% bei einem geringen Anteil von residualem Granat an. Im Gegensatz zu den tonalitischen Nebengesteinen zeigen die granitoiden G?nge anhand ihrer modalen (Muskovit) als auch chemischen Zusammensetzung S-Typ-Charakter. Dies bedeutet eine h?here Beteiligung krustaler Komponente in der Magmenquelle als dies für den Tonalit angenommen werden darf. Die Spurenelementchemie der granitoiden G?nge zeigt ebenfalls eine Bildung in einem konvergenten plattentektonischen Regime, d.h. innerhalb eines magmatischen Bogens. Die G?nge stellen somit vermutlich das Produkt eines sp?ten Abschnittes des subduktionsbezogenen Magmatismus, der auch die Tonalite und andere Plutone im zentralen Bergstr?sser Odenwald geschaffen hat, dar. Im Gegensatz zu dem Magmatismus der die Plutone erzeugt hat, sind die G?nge wahrscheinlich gegen Ende der Kollision oder nachfolgend auf diese in eine sich dehnende Kruste intrudiert und in einem nachfolgenden kompressiven Regime deformiert worden.

---

---

Received August 31, 1999; revised version accepted October 9, 2000  相似文献   

The magnetic effects of brecciation and shock in meteorites: III. The achondrites     

Aviva Brecher  Miriam Fuhrman  Judy Stein 《Earth, Moon, and Planets》1979,20(3):265-279

We present results of a magnetic survey of achondritic meteorites, representing the aubrites (A), diogenites (D), Irowardites (H), and eucrites (E) groups and relate their magnetic behavior to respective class characteristics and models of origin.Magnetic susceptibility (x) values cluster well within each group and decrease systematically between groups (from 2 to 0.1×10^–3GOe^–1 cm^–3), with the average metal contents, (from 1 to <0.1 wt%) in the above order. The natural remanent magnetization (NRM) values range broadly within each group, but group averages decrease roughly as above. However, the considerable within-sample and intra-group variability in NRM level and its demagnetization characteristics attest to inhomogeneous and localized brecciation effects. Although petrological-chemical studies resolve a primary component of magmatic differentiation on the planetoid of origin, no clear magnetic record of such event has been preserved. The magnetization of achondrites is mainly the product of their complex, multi-stage impact brecciation and metamorphism history, in accord with other lines of evidence.The magnetic behavior of achondrites is remarkably similar to that characteristic of lunar breccias and impact-melt rocks and reinforces their analogous mode of genesis, as brought out by chemical and petrographic analyses.  相似文献   

Toxicopathic liver lesions in English sole and chemical contaminant exposure in Vancouver Harbour,Canada     

Stehr CM  Myers MS  Johnson LL  Spencer S  Stein JE 《Marine environmental research》2004,57(1-2):55-74

The prevalence of toxicopathic liver lesions in English sole (Pleuronectes vetulus) was determined along a presumed gradient of chemical contamination in Vancouver Harbour, Canada. Fish were captured from five sites in or near Vancouver Harbour, British Columbia, Canada. No toxicopathic lesions were observed in fish examined at the reference site (Howe Sound outside Vancouver Harbour), or at the outer harbour site. In contrast, 20-23% of the fish from three sites located in the central harbour, Indian Arm and Port Moody Arm had one or more types of toxicopathic lesions. Likewise, aromatic hydrocarbon (AH) metabolites measured in bile exhibited a gradient in levels from lower concentrations at the reference site to significantly higher levels in fish from Indian Arm and Port Moody Arm harbour sites. The occurrence of toxicopathic liver lesions was statistically associated with concentrations of AHs measured in sediment and AH metabolite levels measured in bile.  相似文献   

In situ target strength and behaviour of northern krill (Meganyctiphanes norvegica)     

Klevjer  Thor A.; Kaartvedt  Stein 《ICES Journal of Marine Science》2006,63(9):1726-1735

  相似文献   

Isolation and characterization of benzo[a]pyrene metabolites formed in vivo by juvenile and adult english sole     

Usha Varanasi  John E. Stein  Marc Nishimoto  Tom Hom 《Marine environmental research》1984,14(1-4)

  相似文献   

Latest Pleistocene to Holocene changes in glaciomarine sedimentation in Scoresby Sund and along the adjacent East Greenland Continental Margin: Preliminary results     

R. Stein  H. Grobe  H. Hubberten  P. Marienfeld  S. Nam 《Geo-Marine Letters》1993,13(1):9-16

Based on preliminary results of sedimentological and organic geochemical investigations, distinct changes in the composition of siliciclastic and biogenic components occured in sediments from the East Greenland Continental Slope and Shelf and Scoresby Sund during the latest Pleistocene to Holocene times. These changes probably reflect the (? early/) late Weichselian glacial to Holocene interglacial transition, i.e., the decay of continental ice masses and sea-ice cover, causing major changes in supply of terrigenous matter and surface-water productivity. Flux rates of coarse-grained ice-rafted debris (IRD) distinctly decreased on the continental slope/shelf during the deglaciation interval. During the last 10,000 years, major amounts of IRD were trapped in the Scoresby Sund system. In comparison to modern interglacial conditions, surface-water productivity was significantly lower during the last glacial.  相似文献   

The differential impact of physical disorder and collective efficacy: a geographically weighted regression on violent crime   总被引：1，自引：0，他引：1  

Rachel E. Stein  Jamison F. Conley  Clinton Davis 《GeoJournal》2016,81(3):351-365

While much of the research on neighborhood crime considers the neighborhood as a whole, this study utilizes spatial analysis techniques to examine how the presence of disorder and collective efficacy create unique pockets of opportunities for criminal behavior within neighborhoods. This spatial perspective reveals how the effect of disorder and efficacy upon crime patterns itself varies across a neighborhood. Physical disorder is measured through systematic social observations and the level of collective efficacy is evaluated through survey responses of neighborhood residents. The indices of disorder and efficacy are compared to crime data from police call logs using geographically weighted regression. Our findings demonstrate a complex spatial relationship between disorder and efficacy. The effects of disorder and efficacy are not consistent across an entire neighborhood, but rather display local variations in small geographical areas within neighborhoods, including some pockets of the neighborhood where the relationships between disorder, efficacy, and crime were contrary to the expected relationships. Based upon these findings, we conclude opportunity is central to understanding crime, and emphasize the role of informal social control in neighborhoods.  相似文献