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Zusammenfassung Die vulkanischen Gesteine des Rotliegenden des Niedecker Gebietes sind untersucht worden. Die petrographische Untersuchung erlaubt uns, diese Formationen als Ignimbrite zu bezeichnen. Die Anwesenheit eines Minerals der Montmorin-Gruppe, inmitten des Gesteines, ist mit der Ignimbritbildung, die durch die paleomagnetischen Messungen bestätigt wird, vereinbar. Die chemische Entwicklung wird skizziert. 相似文献
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Corentin Faucher Antoine Saucier Denis Marcotte 《Stochastic Environmental Research and Risk Assessment (SERRA)》2014,28(8):2027-2050
This paper presents a new stochastic simulation method that improves on our unilateral patchwork simulation method (Faucher et al., Stoch Environ Res Risk Assess, 27:253–273, 2012) by eliminating anisotropy biases. As in our unilateral method, images are built by assembling patterns together while controlling the local-mean histogram. The patterns, which are square image-pieces, are picked in a reference image. The reference image is used as a data bank holding the statistical informations about the random field to simulate. In contrast with the unilateral method, the path followed by our new simulation is random and guided by local errors. The new method, called corrective pattern-matching simulation, proceeds iteratively by making local corrections to the simulated image. For several types of images, it is shown that our simulations respect conditioning data and reproduce faithfully the reference image visual appearance. It is shown that the control of the local-mean histogram allows to control one-point statistics and multi-point statistics. 相似文献
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Jun Takahashi Tatsuo Suzuki Igor V Polyakov Kohei Mizobata Moto Ikeda Fancois J.Saucier Markus Meier 《极地研究(英文版)》2008,19(2):159-167
This study investigates the Arctic Ocean warming episodes in the 20th century using both a high-resolution coupled global climate model and historical observations. The model, with no flux adjustment, reproduces well the Atlantic Water core temperature （AWCT） in the Arctic Ocean and shows that four largest decadalscale warming episodes occurred in the 1930s, 70s, 80s, and 90s, in agreement with the hydrographic observational data. The difference is that there was no pre-warming prior to the 1930s episode, while there were two pre-warming episodes in the 1970s and 80s prior to the 1990s, leading the 1990s into the largest and prolonged warming in the 20th century. Over the last century, the simulated heat transport via Fram Strait and the Barents Sea was estimated to be, on average, 31.32 TW and 14.82 TW, respectively, while the Bering Strait also provides 15.94 TW heat into the west- ern Arctic Ocean. Heat transport into the Arctic Ocean by the Atlantic Water via Fram Strait and the Barents Sea correlates significantly with AWCT （ C = 0.75 ） at 0- lag. The modeled North Atlantic Oscillation （NAO） index has a significant correlation with the heat transport （ C = 0.37 ）. The observed AWCT has a significant correlation with both the modeled AWCT （ C =0.49） and the heat transport （ C =0.41 ）. However, the modeled NAO index does not significantly correlate with either the observed AWCT （ C = 0.03 ） or modeled AWCT （ C = 0.16 ） at a zero-lag, indicating that the Arctic climate system is far more complex than expected. 相似文献
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CO2 and H2O eddy-flux measurements derived from airborne vertical wind and concentration data are examined to determine the accuracy of the eddy-flux estimate in moderately unstable conditions within the surface layer. Integral scale estimation is used to determine the minimum length of a sample required to achieve a given accuracy. Cospectral analysis is used to examine the scales responsible for the transport of water vapour and carbon dioxide in the surface layer. Cospectra are found to broaden as the sampling altitude increases, a well known result. At low altitudes, the cospectrum is found to become negative for large scales. A significant fraction of the flux is carried by this range of scales, which suggests that scales larger than the boundary-layer height may play an important role in the transport at low altitudes. 相似文献
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F. J. Saucier S. Senneville S. Prinsenberg F. Roy G. Smith P. Gachon D. Caya R. Laprise 《Climate Dynamics》2004,23(3-4):303-326
The seasonal cycle of water masses and sea ice in the Hudson Bay marine system is examined using a three-dimensional coastal ice-ocean model, with 10 km horizontal resolution and realistic tidal, atmospheric, hydrologic and oceanic forcing. The model includes a level 2.5 turbulent kinetic energy equation, multi-category elastic-viscous-plastic sea-ice rheology, and two layer sea ice with a single snow layer. Results from a two-year long model simulation between August 1996 and July 1998 are analyzed and compared with various observations. The results demonstrate a consistent seasonal cycle in atmosphere-ocean exchanges and the formation and circulation of water masses and sea ice. The model reproduces the summer and winter surface mixed layers, the general cyclonic circulation including the strong coastal current in eastern Hudson Bay, and the inflow of oceanic waters into Hudson Bay. The maximum sea-ice growth rates are found in western Foxe Basin, and in a relatively large and persistent polynya in northwestern Hudson Bay. Sea-ice advection and ridging are more important than local thermodynamic growth in the regions of maximum sea-ice cover concentration and thickness that are found in eastern Foxe Basin and southern Hudson Bay. The estimate of freshwater transport to the Labrador Sea confirms a broad maximum during wintertime that is associated with the previous summers freshwater moving through Hudson Strait from southern Hudson Bay. Tidally driven mixing is shown to have a strong effect on the modeled ice-ocean circulation. 相似文献
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Rezaee Hassan Marcotte Denis Tahmasebi Pejman Saucier Antoine 《Stochastic Environmental Research and Risk Assessment (SERRA)》2015,29(3):893-913
Stochastic Environmental Research and Risk Assessment - This study presents a new approach of generating a set of alternative training images (ATI) to use in patch-based multiple-point simulation.... 相似文献
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Native North American Indians built and maintained water control and irrigation facilities, especially in the southwestern United States. However, the use of human-made structures to manage water for agriculture and personal use is rarely documented in the Southeast. Excavations at the protohistoric period Jordan site in Louisiana demonstrate the use of earthworks, ponds, and ditches to channel and direct surface water for drainage and irrigation. The Jordan site is remarkable for its preservation, as well as for having evidence for sophisticated hydraulic engineering, but it is unlikely that it is unique in the Southeast in regard to the degree and kind of earthmoving related to water management. Archaeological and geological contexts provide the background for understanding the Jordan site features. Results of geoarchaeological subsurface investigations demonstrate the scale and nature of the site's aboriginal constructions and provide evidence that they were part of a deliberate plan to make the site area habitable during the immediate post-contact era in the Mississippi Valley. 相似文献
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Acta Geotechnica - The modal decomposition method (MDM) is used to analyse the grain size distribution curve (GSDC) of a soil that was likely to produce internal erosion according to old criteria,... 相似文献
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Fiammetta Straneo Franois Saucier 《Deep Sea Research Part I: Oceanographic Research Papers》2008,55(8):926-946
This study describes the first year round observations of the outflow from Hudson Strait as obtained from a moored array deployed mid-strait from August 2004–2005, and from a high-resolution hydrographic section conducted in September 2005. The outflow has the structure of a buoyant boundary current spread across the sloping topography of its southern edge. The variability in the flow is dominated by the extreme semi-diurnal tides and by vigorous, mostly barotropic, fluctuations over several days. The fresh water export is seasonally concentrated between June and March with a peak in November–December, consistent with the seasonal riverine input and sea-ice melt. It is highly variable on weekly timescales because of synchronous salinity and velocity variations. The estimated volume and liquid fresh water transports during 2004–2005 are, respectively, of 1–1.2 Sv and 78–88 (28–29) mSv relative to a salinity of 34.8 (33). This implies that the Hudson Strait outflow accounts for approximately 15% of the volume and 50% of the fresh water transports of the Labrador Current. This larger than previously estimated contribution is partially due to the recycling, within the Hudson Bay System, of relatively fresh waters that flow into Hudson Strait, along its northern edge. It is speculated that the source of this inflow is the outflow from Davis Strait. 相似文献