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151.
Werner Lohmann 《Astrophysics and Space Science》1973,24(2):531-533
The relative frequency of the fainter stars increases from the centre of the cluster to the boundary. 相似文献
152.
Werner Lohmann 《Astrophysics and Space Science》1974,29(1):61-62
According to the Bottlinger law the mass of M33 is determined with (1.29±0.23)×1010
M from measurements of the velocities of the neutral hydrogen by Warneret al. (1973).
Mitteilungen Serie A. 相似文献
Mitteilungen Serie A. 相似文献
153.
Werner Lohmann 《Astrophysics and Space Science》1976,45(1):27-29
The open star cluster M6 (NGC 6405) is investigated by strip counts on reproductions of the chart of Vleeming (1974). The results are collected in Part 3.
Mitteilungen Serie A. 相似文献
Mitteilungen Serie A. 相似文献
154.
Dr. Hans Hinrich Lohmann 《International Journal of Earth Sciences》1964,54(1):161-165
Zusammenfassung Im mittleren Silur ist das Zapla-Eis vom Pampeanischen Massiv und vom Altiplano-Massiv nach Nordosten geflossen. Die Gondwana-Vereisung lä\t sich in Bolivien nur im Karbon feststellen, sie wird von der unterpermischen marinen Copacabana-Gruppe überdeckt. Das Gondwana-Eis in Bolivien ist anscheinend nicht vom Brasilianischen Schild, sondern aus Nordwest-Argentinien abzuleiten.
Der staatlichen bolivianischen Erdölgesellschaft Y. P. F. B. danke ich für die Ermöglichung dieser Studien in den Jahren 1961 bis 1963, au\erdem vielen Kollegen für anregende Diskussionen. 相似文献
Resumen Durante el SilÚrico Médio el glaciár de Zapla se movía hacia el Noreste, partiendo del Macizo Pampeano y del Macizo Altiplánico. — Tilitas del Gondwana fuerón observadas en Bolivia sólamente en el Carbonífero; superpuésto se encuentran los sedimentos calcáreos marinos del grupo Copacabana de edad Pérmica inferior. La glaciación del Gondwana en Bolivia probablemente no se deriva del Escudo Brasileño, mas bien de la región de La Rioja en el Noroeste Argentino
Der staatlichen bolivianischen Erdölgesellschaft Y. P. F. B. danke ich für die Ermöglichung dieser Studien in den Jahren 1961 bis 1963, au\erdem vielen Kollegen für anregende Diskussionen. 相似文献
155.
Oliver Wetter Christian Pfister Johannes P. Werner Eduardo Zorita Sebastian Wagner Sonia I. Seneviratne Jürgen Herget Uwe Grünewald Jürg Luterbacher Maria-Joao Alcoforado Mariano Barriendos Ursula Bieber Rudolf Brázdil Karl H. Burmeister Chantal Camenisch Antonio Contino Petr Dobrovolný Rüdiger Glaser Iso Himmelsbach Andrea Kiss Oldřich Kotyza Thomas Labbé Danuta Limanówka Laurent Litzenburger Øyvind Nordl Kathleen Pribyl Dag Retsö Dirk Riemann Christian Rohr Werner Siegfried Johan Söderberg Jean-Laurent Spring 《Climatic change》2014,125(3-4):349-363
The heat waves of 2003 in Western Europe and 2010 in Russia, commonly labelled as rare climatic anomalies outside of previous experience, are often taken as harbingers of more frequent extremes in the global warming-influenced future. However, a recent reconstruction of spring–summer temperatures for WE resulted in the likelihood of significantly higher temperatures in 1540. In order to check the plausibility of this result we investigated the severity of the 1540 drought by putting forward the argument of the known soil desiccation-temperature feedback. Based on more than 300 first-hand documentary weather report sources originating from an area of 2 to 3 million km2, we show that Europe was affected by an unprecedented 11-month-long Megadrought. The estimated number of precipitation days and precipitation amount for Central and Western Europe in 1540 is significantly lower than the 100-year minima of the instrumental measurement period for spring, summer and autumn. This result is supported by independent documentary evidence about extremely low river flows and Europe-wide wild-, forest- and settlement fires. We found that an event of this severity cannot be simulated by state-of-the-art climate models. 相似文献
156.
Oliver Wetter Christian Pfister Johannes P. Werner Eduardo Zorita Sebastian Wagner Sonia I. Seneviratne Jürgen Herget Uwe Grünewald Jürg Luterbacher Maria-Joao Alcoforado Mariano Barriendos Ursula Bieber Rudolf Brázdil Karl H. Burmeister Chantal Camenisch Antonio Contino Petr Dobrovolný Rüdiger Glaser Iso Himmelsbach Andrea Kiss Oldřich Kotyza Thomas Labbé Danuta Limanówka Laurent Litzenburger Øyvind Nordli Kathleen Pribyl Dag Retsö Dirk Riemann Christian Rohr Werner Siegfried Johan Söderberg Jean-Laurent Spring 《Climatic change》2014,125(3-4):365-367
157.
Dag Hongve 《Journal of Paleolimnology》2003,30(1):75-93
Cores of recent sediments were sampled along a depth gradient in a 23 m deep kettle lake with stagnant deep waters containing exceptionally high concentrations of dissolved iron and manganese. Sediment cores were taken on two occasions, in 1978 and 1997, before and after an incidence of full circulation. The aims of this study are to see how oxic and anoxic conditions in the water column influence stratigraphy and sediment focusing and, to compare cores from 1979 and 1998 to see how measured element fluxes and external events are reflected in the chemical stratigraphy. Element analyses show characteristic stratigraphic patterns that depend on the ability to undergo redox transformations, sorptive properties and chemical equilibria in the anoxic deep waters and porewaters. In sediments from the oxic part of the lake Al, Cr, Co, Ni, Zn Cu, Cd, and Pb were well correlated. Positive correlations are seen between elements associated with primary production and sulphur. In the anoxic part of the lake most metals were positively correlated with carbonate. Phosphorus correlated positively with iron in sediments from oxic waters and negatively with manganese and iron deep-water sediments. Porewater analyses indicate that recycling from the deep-water sediments was negligible. The stratigraphy of lead agrees with the historic variation in atmospheric input and is used as a chronological marker. Assessed deposition rates agree with measurements in sediment traps. Most elements more than double their rates of deposition towards the deepest point of the lake, while sulphur, manganese and carbonate had maxima around the depth of the redoxcline in the water. Variations in the external loading and variable redox conditions in the deep waters explain variations in the chemical composition of recent sediments. 相似文献
158.
Dag O. Hessen JoLynn Carroll Berit Kjeldstad Anton A. Korosov Lasse H. Pettersson Dmitry Pozdnyakov Kai Sørensen 《Estuarine, Coastal and Shelf Science》2010
Spectral light attenuation profiles and concentrations of total and dissolved carbon (C), nutrients and chlorophyll a (Chla) were studied along transects running from the river mouth to the Kara Sea during late summer 2003 for the Yenisey and fall 2005 for the Ob estuaries. Earth Observation data were used to generate composite images of water color and Chla distribution over the estuaries and the Kara Sea to reveal the spatial impact of the river efflux in terms of optical properties. 相似文献
159.
Charles N. Alpers David L. Dettman Kyger C. Lohmann Dragan Brabec 《Journal of Geochemical Exploration》1990,38(1-2)
Stable isotope ratios of oxygen and carbon were determined for CO2 in soil gas in the vicinity of the massive sulfide deposit at Crandon, Wisconsin with the objective of determining the source of anomalously high CO2 concentrations detected previously by McCarthy et al. (1986). Values of δ13C in soil gas CO2 from depths between 0.5 and 1.0 m were found to range from −12.68‰ to −20.03‰ (PDB). Organic carbon from the uppermost meter of soil has δ13C between −24.1 and −25.8‰ (PDB), indicating derivation from plant species with the C3 (Calvin) type of photosynthetic pathway. Microbial decomposition of the organic carbon and root respiration from C3 and C4 (Hatch-Slack) plants, together with atmospheric CO2 are the likely sources of carbon in soil gas CO2. Values of δ18O in soil-gas CO2 range from 32 to 38‰ (SMOW). These δ18O values are intermediate between that calculated for CO2 gas in isotopic equilibrium with local groundwaters and that for atmospheric CO2. The δ18O data indicate that atmospheric CO2 has been incorporated by mixing or diffusion. Any CO2 generated by microbial oxidation of organic matter has equilibrated its oxygen isotopes with the local groundwaters.The isotopic composition of soil-gas CO2 taken from directly above the massive sulfide deposit was not distinguishable from that of background samples taken 1 to 2 km away. No enrichment of the δ13C value of soil-gas CO2 was observed, contrary to what would be expected if the anomalous CO2 were derived from the dissolution of Proterozoic marine limestone country rock or of Paleozoic limestone clasts in glacial till. Therefore, it is inferred that root respiration and decay of C3 plant material were responsible for most CO2 generation both in the vicinity of the massive sulfide and in the “background” area, on the occasion of our sampling. Interpretation of our data is complicated by the effects of rainfall, which significantly reduced the magnitude of the CO2 anomaly. Therefore, we cannot rule out the possible mechanism of carbonate dissolution driven by pyrite oxidation, as proposed by Lovell et al. (1983) and McCarthy et al. (1986). Further work is needed on seasonal and daily variations of CO2 concentrations and stable isotope ratios in various hydrogeologic and ecologic settings so that more effective sampling strategies can be developed for mineral exploration using soil gases. 相似文献
160.
Along the margins of continental ice sheets, lakes formed in isostatically depressed basins during glacial retreat. Their shorelines and extent are sensitive to the ice margin and the glacial history of the region. Proglacial lakes, in turn, also impact the glacial isostatic adjustment due to loading, and ice dynamics by posing a marine-like boundary condition at the ice margin. In this study we present a tool that efficiently identifies lake basins and the corresponding maximum water level for a given ice sheet and topography reconstruction. This algorithm, called the LakeCC model, iteratively checks the whole map for a set of increasing water levels and fills isolated basins until they overflow into the ocean. We apply it to the present-day Great Lakes and the results show good agreement (∼1−4%) with measured lake volume and depth. We then apply it to two topography reconstructions of North America between the Last Glacial Maximum and the present. The model successfully reconstructs glacial lakes such as Lake Agassiz, Lake McConnell and the predecessors of the Great Lakes. LakeCC can be used to judge the quality of ice sheet reconstructions. © 2019 The Authors Journal of Quaternary Science Published by John Wiley & Sons Ltd. 相似文献