Formal definition and dating of the GSSP (Global Stratotype Section and Point) for the base of the Holocene using the Greenland NGRIP ice core,and selected auxiliary records     

Mike Walker  Sigfus Johnsen  Sune Olander Rasmussen  Trevor Popp  Jørgen‐Peder Steffensen  Phil Gibbard  Wim Hoek  John Lowe  John Andrews  Svante Björck  Les C. Cwynar  Konrad Hughen  Peter Kershaw  Bernd Kromer  Thomas Litt  David J. Lowe  Takeshi Nakagawa  Rewi Newnham  Jakob Schwander 《第四纪科学杂志》2009,24(1):3-17

The Greenland ice core from NorthGRIP (NGRIP) contains a proxy climate record across the Pleistocene–Holocene boundary of unprecedented clarity and resolution. Analysis of an array of physical and chemical parameters within the ice enables the base of the Holocene, as reflected in the first signs of climatic warming at the end of the Younger Dryas/Greenland Stadial 1 cold phase, to be located with a high degree of precision. This climatic event is most clearly reflected in an abrupt shift in deuterium excess values, accompanied by more gradual changes in δ¹⁸O, dust concentration, a range of chemical species, and annual layer thickness. A timescale based on multi‐parameter annual layer counting provides an age of 11 700 calendar yr b2 k (before AD 2000) for the base of the Holocene, with a maximum counting error of 99 yr. A proposal that an archived core from this unique sequence should constitute the Global Stratotype Section and Point (GSSP) for the base of the Holocene Series/Epoch (Quaternary System/Period) has been ratified by the International Union of Geological Sciences. Five auxiliary stratotypes for the Pleistocene–Holocene boundary have also been recognised. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Estimating minimum streamflow from measurements at ungauged sites in regions with streamflow‐gauging networks     

Christopher Konrad  Christine Rumsey 《水文研究》2019,33(15):2057-2067

Estimation of low flows in rivers continues to be a vexing problem despite advances in statistical and process‐based hydrological models. We develop a method to estimate minimum streamflow at seasonal to annual timescales from measured streamflow based on regional similarity in the deviations of daily streamflow from minimum streamflow for a period of interest. The method is applied to 1,019 gauged sites in the Western United States for June to December 2015. The gauges were clustered into six regions with distinct timing and magnitude of low flows. A gamma distribution was fit each day to the deviations in specific discharge (daily streamflow divided by drainage area) from minimum specific discharge for gauges in each region. The Kolmogorov–Smirnov test identified days when the gamma distribution was adequate to represent the distribution of deviations in a region. The performance of the gamma distribution was evaluated at gauges by comparing daily estimates of minimum streamflow with estimates from area‐based regression relations for minimum streamflow. Each region had at least 8 days during the period when streamflow measurements would provide better estimates than the regional regression equation, but the number of such days varied by region depending on aridity and homogeneity of streamflow within the region. Synoptic streamflow measurements at ungauged sites have value for estimating minimum streamflow and improving the spatial resolution of hydrological model in regions with streamflow‐gauging networks.  相似文献   

Buchbesprechungen     

F. Steinhauser  K. Cehak 《Theoretical and Applied Climatology》1974,22(4):393-400

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Buchbesprechungen     

F. Steinhauser  K. Cehak 《Theoretical and Applied Climatology》1970,18(3-4):397-400

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International cooperation in meteorology     

Konrad Cehak 《Geoforum》1973,4(2):62-67

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The source of ore metals     

Konrad B. Krauskopf 《Geochimica et cosmochimica acta》1971

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Die Aufnahme von Wasserdampf durch menschliche Haut,Pflanze und Erdboden     

Konrad J. K. Büttner 《Theoretical and Applied Climatology》1958,9(1):80-85

Zusammenfassung Laboratoriumsversuche und Feldbeobachtungen zeigen einen unerwartet starken Transport von Wasserdampf in die menschliche Haut, in getrocknete und in lebende Pflanzen und in trockenen Erdboden hinein. Diese Vorg?nge selbst beruhen offenbar auf Diffusion und Sorption. Dabei ist für menschliche Haut und für Pflanzen das Entstehen hoher osmotischer Drucke, d. h. niederer Wasserkonzentration, wahrscheinlich gemacht; doch sind die Ursachen dafür noch unbekannt.

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Summary Laboratory experiments and field observations show surprisingly high amounts of transfer of water vapor into human skin, into dry and living plants, and into dry soil. The processes involved seem to be based on diffusion and sorption. These results may be explained by assuming the existence of high osmotic pressures in skin and in plants; the reason for this concentration is not yet known.

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Résumé Des essais de laboratoire et dans la nature montrent un transport inattendu de vapeur d'eau dans la peau humaine, dans des plantes séchées et vivantes ainsi que dans le sol sec. Les phénomènes reposent apparemment sur la diffusion et sur la sorption. En ce qui concerne la peau humaine et les plantes, il est donc probable qu'elles entretiennent des pressions osmotiques élevées; mais la cause en est encore inconnue.

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Contribution Number 32 of the Department of Meteorology and Climatology, University of Washington.

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Herrn Dr.Anders K. ?ngstr?m zu seinem 70. Geburtstag gewidmet.  相似文献   

Acceptance Speech for the V. M. Goldschmidt Medal     

Konrad B. Krauskopf 《Geochimica et cosmochimica acta》1983,47(5):982-983

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Martian Seasonal CO₂ Ice in Polygonal Troughs in Southern Polar Region: Role of the Distribution of Subsurface H₂O Ice     

Konrad J. KossackiWojciech J. Markiewicz 《Icarus》2002,160(1):73-85

The Mars Orbiter Camera onboard the Mars Global Surveyor has obtained several images of polygonal features in the southern polar region. In images taken during the end of the southern spring, when the surrounding surface is free of the seasonal frost, CO₂ ice still appears to be present within the polygonal troughs. In Earth's polar regions, polygons such as these are indicative of water ice in the ground below. We analyzed the seasonal evolution of the thermal state and the CO₂ content of these features. Our 2-D model includes condensation and sublimation of the CO₂ ice, a self consistent treatment of the variations of the thermal properties of the regolith, and the seasonal variations of the local atmospheric pressure which we take from the results of a general circulation model. We find that the residence time of seasonal CO₂ ice in troughs depends not only on atmospheric opacity and albedo of the CO₂ ice, but also and most significantly on the distribution of water ice in the regolith. Optical properties of the atmosphere and surface CO₂ ice can be independently obtained from observations. To date this is not true about the distribution of water ice below the surface. Our analysis quantifies the dependence of the seasonal cycle of the CO₂ ice within the troughs on the assumed distribution of the water ice below the surface. We show that presence of water ice in the ground at a depth smaller than the depth of the troughs reduces winter condensation rate of CO₂ ice. This is due to higher heat flux conducted from the water ice rich regolith toward the facets of the troughs.  相似文献   

Intramonthly Indices of the Pacific/North American Teleconnection Pattern and Temperature Regimes over the United States     

C. E. Konrad 《Theoretical and Applied Climatology》1998,60(1-4):11-19

Summary Previous work has examined relationships between the planetary scale Pacific North American (PNA) teleconnection pattern and regional scale mean temperature over portions of the United States, but analyses have been restricted to monthly values of these two variables. It is not clear if this is the most appropriate scale for relating PNA patterns to temperature. In this study, PNA indices are related to various aspects of temperature over a range of time scales spanning one month. To carry this out, standardized PNA indices are calculated for 6 time intervals ranging from 5 to 30 days over a period of 27 winter seasons. Standardized regional scale temperature anomalies are assessed over various regions of the United States and used to compute mean, maximum, and minimum temperature anomalies over the same 6 time intervals. Correlation matrices are then constructed to provide relationship characteristics between the PNA indices and temperature measures within the intramonthly time scale. Only the southeastern and northwestern regions of the United States display significant relationships between the PNA indices and temperature. Over the Southeast, temperature anomalies on short time scales relate most strongly to PNA indices computed over time intervals of 25 to 30 days; this is especially the case for the minimum temperature anomaly. The strongest relationships, however, are observed between the PNA index and temperature anomalies computed on a 20–25 day time interval. Over the Northwest, the relationships are not as strong and somewhat more varied. Most notably, moderate connections are found between the 30 day PNA index and minimum temperature anomalies computed over a 25 day period. Received August 18, 1997Revised November 28, 1997  相似文献