Book reviews     

Rudnicki  John W.  Zheng  Gutuan  Koch  Manfred  Hanyga  Andrzej  Fujinawa  Yukio  Tabeart  Frazer  Kimbrough  David L.  Lovison-Golob  Lucía  Dore  Anthony  Blecki  Jan  Sroczynska-Kozuchowska  Magdalena 《Pure and Applied Geophysics》1993,140(3):537-556

Pure and Applied Geophysics -  相似文献   

Search for finite dimensional attractors in atmospheric turbulence   总被引：1，自引：0，他引：1  

Rudolf O. Weber  Peter Talkner  Gérard Stefanicki  Luc Arvisais 《Boundary-Layer Meteorology》1995,73(1-2):1-14

The question is investigated whether the dynamics of turbulent wind fields in the atmospheric boundary layer can be satisfactorily described by a low-dimensional deterministic system. Special emphasis is laid on the detection of a possibly existing, underlying strange attractor. Fast response wind measurements of an ultrasonic anemometer with a sampling rate of 21 Hz were carried out over periods of several days in the near surface boundary layer. The correlation dimension of the resulting time series, several million data points long, is estimated by means of the Grassberger-Procaccia algorithm. No sign of a low dimensional attractor can be detected. By comparison with different types of random noise, the existence of an attractor with dimension lower than six can be excluded in the present data sets.  相似文献   

A Road Map for the Generation of a Near-Infrared Guide Star Catalog for Thirty Meter Telescope Observations     

Smitha Subramanian  Annapurni Subramaniam  T. Sivarani  Luc Simard  G. C. Anupama  Kim Gillies  A. N. Ramaprakash  B. Eswar Reddy 《Journal of Astrophysics and Astronomy》2016,37(3):24

The near-infrared instruments in the upcoming Thirty Meter Telescope (TMT) will be assisted by a multi conjugate Adaptive Optics (AO) system. For the efficient operation of the AO system, during observations, a near-infrared guide star catalog which goes as faint as 22 mag in J_Vega band is essential and such a catalog does not exist. A methodology, based on stellar atmospheric models, to compute the expected near-infrared magnitudes of stellar sources from their optical magnitudes is developed. The method is applied and validated in JHKs bands for a magnitude range of J_Vega 16–22 mag. The methodology is also applied and validated using the reference catalog of PAN STARRS. We verified that the properties of the final PAN STARRS optical catalog will satisfy the requirements of TMT IRGSC and will be one of the potential sources for the generation of the final catalog. In a broader context, this methodology is applicable for the generation of a guide star catalog for any existing/upcoming near-infrared telescopes.  相似文献   

Neoproterozoic to Lower Palaeozoic successions of the Tandilia System in Argentina: implication for the palaeotectonic framework of southwest Gondwana     

Udo Zimmermann  Daniel G. Poir��  Luc��a G��mez Peral 《International Journal of Earth Sciences》2011,100(2-3):489-510

The Cryogenian to Uppermost Ediacaran successions of the Tandilia System (Sierras Bayas Group and Cerro Negro Formation) in central-eastern Argentina is exceptional because of its unmetamorphosed and nearly undeformed character, its sediment provenance trend and the absence of any identified glacial deposit and the deposition of warm water carbonates. We decipher a dramatic change in the basin evolution from small-scale depositional areas during the Neoproterozoic to a larger basin related to an active continental margin throughout the Uppermost Ediacaran. The base of the succession is represented by immature detritus of alkaline composition (Villa Mónica Formation), but towards the top of this formation, the material is sorted and reworked, nonetheless still reflecting in its detritus the local rocks. The clastic deposition is interrupted by diagenetic overprinted dolomites. The unconformable overlying quartz-arenitic Ediacaran Cerro Largo Formation reworked the Cryogenian Villa Mónica Formation and contains mainly felsic granitic and metamorphic basement material of slightly wider variety, while the dominant alkaline geochemical signature in rocks of the Villa Mónica Formation disappears. Based on diagenetic, petrographic and sedimentological data, we can interpret the unconformity representing a longer time of erosion. The Cerro Largo Formation shows a transition to mudstones and the heterolithic facies of the Olavarría Formation. The top of the Sierras Bayas Group is represented by limestones (Loma Negra Formation), which are discordantly overlain by the Uppermost Ediacaran Cerro Negro Formation. The latter displays detrital material derived from a continental arc, mafic and felsic sources. Several arc-related geochemical proxies (Th/Sc?<?0.8; Zr/Sc?<?10; La/Sc?<?2; Ti/Zr?>?20) are recorded in the sediment detritus, as are syn-depositional pyroclastites. The absence of volcanic material in the underlying rocks allows proposing that the Cerro Negro Formation is related to an active continental margin fringing Gondwana (??Terra Australis Orogen??) as a retro-arc or retro-arc foreland basin.  相似文献   

Experimental and Numerical Study of Wind and Turbulence in a Near-Field Dispersion Campaign at an Inhomogeneous Site     

Xiao Wei  Eric Dupont  Eric Gilbert  Luc Musson-Genon  Bertrand Carissimo 《Boundary-Layer Meteorology》2016,160(3):475-499

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Sustainable groundwater extraction in coastal areas: a Belgian example   总被引：1，自引：0，他引：1  

Alexander Vandenbohede  Emmanuel Van Houtte  Luc Lebbe 《Environmental Geology》2009,57(4):735-747

Water extractions in coastal areas have to deal with salt water intrusion and lowering of hydraulic heads in valuable ecosystems. Therefore, sustainable management of fresh water resources in these areas is crucial. This is illustrated here with two water extractions in the western Belgian coastal plain which extract groundwater from a phreatic dune aquifer. One water extraction faced problems with salt water intrusion, while lowering of hydraulic heads was an issue for both. To remedy the salt water intrusion, it was found that decreasing the extraction rate was the only solution. To offset this and to increase hydraulic heads around both extractions, it was decided to artificially recharge the aquifer of the second extraction with tertiary treated wastewater. By taking these interventions, the combined production capacity of the water extractions was increased with 56% whereas 27% less water was extracted from the dune aquifer itself. Extraction history and the effects of interventions are illustrated for both water extractions with water quality data and fresh water head observations. A more detailed insight in groundwater flow and fresh–salt water distribution in the aquifer is provided by simulating the evolution of the water extractions with a 3D density dependent groundwater flow model.  相似文献   

Effects of sorption competition on caesium diffusion through compacted argillaceous rock     

Andreas Jakob  Wilfried Pfingsten  Luc Van Loon 《Geochimica et cosmochimica acta》2009,73(9):2441-2456

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Effect of reduced impact logging and small-scale mining disturbances on Neotropical stream fish assemblages     

Luc Allard  Manon Popée  Régis Vigouroux  Sébastien Brosse 《Aquatic Sciences - Research Across Boundaries》2016,78(2):315-325

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Institutional ambiguity in implementing the European Union Marine Strategy Framework Directive   总被引：1，自引：0，他引：1  

Judith van Leeuwen  Luc van HoofJan van Tatenhove 《Marine Policy》2012,36(3):636-643

This article addresses the institutional ambiguity that exists between the European, Regional and Member State levels in the implementation of the Marine Strategy Framework Directive (MSFD). The two main reasons for the emergence of institutional ambiguity are (1) the MSFD being a framework directive and (2) Member States are required to coordinate the implementation of the MFSD through the Regional Sea Conventions. Institutional ambiguity refers to the interference zone between different institutional settings that come together in new policy practices. New rules of the game are needed to bring these institutional settings together and the room to manoeuvre for the actors who negotiate these rules is a defining feature of institutional ambiguity. This article analyses the institutional ambiguity associated with MSFD implementation on the European and regional level for four European Seas: the North Sea, the Baltic Sea, the Mediterranean Sea and the Black Sea. The results indicate different levels of institutional ambiguity in each of the four regions, with the lowest level of ambiguity in the Baltic Sea and the highest in the Mediterranean Sea. Institutional ambiguity also exists on the European level, as coordination efforts have not resulted in clear directions for the implementation of the MSFD as yet. The level of institutional ambiguity is influenced by the relative number of EU member states bordering the particular sea and whether they consider implementation of the MFSD to be urgent. Member States bordering the Mediterranean and the Black Seas lack the support of Regional Sea Conventions in addition to receiving limited direction from the European level.  相似文献   

Source of error and uncertainty in sheet erosion rates estimated from dendrogeomorphology          下载免费PDF全文

José M. Bodoque  Juan A. Ballesteros‐Cánovas  Ana Lucía  Andrés Díez‐Herrero  José F. Martín‐Duque 《地球表面变化过程与地形》2015,40(9):1146-1157

Dendrogeomorphology has been used since the 1960s to estimate sheet erosion rates. To date, most efforts have focused on accurately determining the first year of root exposure. However, an adequate methodological approach that takes into consideration the microtopography of the ground surface when estimating sheet erosion rates using dendrogeomorphology has not been proposed. In this study, terrestrial laser scanning (TLS) was used for the first time to examine how changes in microtopography determine the level of certainty in estimates. To this end, highly accurate TLS‐based digital elevation models representing exposed roots and their immediate vicinity were analysed using geographic information system tools. The results indicate that erosion rates calculated using the standard dendrogeomorphic method have been underestimated by up to 29% because the method does not take into account changes to the microtopography caused by the axial and radial pressure of the roots. Another source of uncertainty, which we estimate to be 50%, was also found and is the result of changes in the ground surface microtopography caused by variations in soil roughness. These findings do not invalidate the usefulness of dendrogeomorphology for assessing soil erosion, although they do show the need for correct characterization of the microtopography to guarantee reliability. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献