Ein Verfahren zur Berechnung von Gezeitenstrom- und Gefällsellipsen     

Harry Sendner 《Ocean Dynamics》1952,5(4):199-204

Zusammenfassung Bei der im Folgenden beschriebenen Methode zur Berechnung der Stromellipsenelemente werden die Summen und Differenzen der Hauptachsen bzw. ihrer Richtungen und Phasen als Beträge bzw. Richtungen zweier Vektoren bestimmt. Die Komponenten dieser Vektoren sind wieder Summen und Differenzen von vier Konstanten, die man bei der harmonischen Analyse der Stromkomponenten bezüglich der betreffenden Tide gewinnt. Eine andere Berechnungsmethode geht von den harmonischen Konstanten der Stromkomponenten aus und benutzt trigonometrische Funktionen komplexen Arguments. Zum Schluß werden Beziehungen zwischen den Elementen der Stromellipse und denen der Gefällsellipse aufgestellt unter der Voraussetzung, daß der Zusammenhang zwischen horizontalen und vertikalen Gezeiten sich durch die linearisierten hydrodynamischen Grundgleichungen darstellen läßt.

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A method of calculating tidal stream and gradient ellipses

Summary In the following paper a method of calculating the elements of tidal stream ellipses is described by which the sums and differences of the major axes or their directions and phases are determined as the scalar quantities or directions of two vectors. The components of these vectors, on their turn, are sums and differences of four constants obtained by the harmonic analysis of the stream components with regard to the respective tide. Another calculating method proceeds from the harmonic constants of the stream components and employs trigonometric functions of complex arguments. Finally, on the supposition that the relation between horizontal and vertical tides may be represented by the linearized fundamental hydrodynamic equations, relations are established between the elements of the tidal stream ellipse and those of the gradient ellipse.

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Mode de calcul des ellipses du courant de marée et du gradient

Résumé Le mode de calcul des éléments des ellipses du courant expliqué ci-dessous demande que les sommes et les différences des grandaxes ou leurs directions et leurs phases soient déterminées comme grandeurs scalaires ou comme directions de deux vecteurs. Les composantes de ces vecteurs sont, de leur part, les sommes ou les différences de quatre constantes qui résultent de l'analyse harmonique des composantes de courant de la marée en question. Une autre méthode de calcul part des constantes harmoniques des composantes de courant et emploie des fonctions trigonométriques à l'argument complexe. Enfin, pourvu que la relation entre les composantes horizontales et verticales puisse être représentée à l'aide des équations hydrodynamiques fondamentales linéarisées, des relations entre les éléments de l'ellipse du courant et ceux de l'ellipse du gradient sont établies.

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Determining the age of water and long-term transport timescale of the Chesapeake Bay   总被引：5，自引：0，他引：5  

Jian Shen  Harry V. Wang 《Estuarine, Coastal and Shelf Science》2007,74(4):585-598

The concept of age of water (AW) is applied to the Chesapeake Bay to investigate the long-term transport properties for dissolved substances. A real-time calibrated hydrodynamic Chesapeake Bay model in 3 Dimensions (CH3D), employing a boundary-fitted curvilinear grid, is used for the study. The long-term transport properties, represented by AW, are investigated under the conditions of low river inflow of 1995 and high river inflow of 1996, as well as for constant mean inflows. The influences of freshwater, density-induced circulation, and wind-induced transport on age distribution have been investigated. Model results show that river inflows, wind stress, and density-induced circulation play important roles in controlling the long-term transport in the Bay. The model results shows that it requires 120–300 days for a marked change in the characteristics of the pollutant source discharged into the Bay from the Susquehanna River to affect significantly the conditions near the mouth under different hydrodynamic conditions. An increase of river discharge results in increases of downstream residual current and gravitational circulation, and thus reduces AW. The density-induced circulation contributes to the transport substantially. The dissolved substances discharged into the Bay are transported out of the Bay more rapidly when the estuary becomes more stratified. Southeasterly and southwesterly winds have strong impacts on the transport compared to the northeasterly and northwesterly winds. The former increases lateral and vertical mixing significantly. Consequently, the gravitational circulation is reduced and the transport time is increased by 50%. The model results provide useful information for understanding the long-term transport processes in the Bay.  相似文献   

Molecular identification of ascaridoid nematodes from the deep-sea onion-eye grenadier (Macrourus berglax) from the East Greenland Sea   总被引：2，自引：0，他引：2  

Esra Kellermanns  Sven Klimpel  Harry Wilhelm Palm 《Deep Sea Research Part I: Oceanographic Research Papers》2007,54(12):2194-2202

Macrourus berglax from the East Greenland Sea was studied for the presence of ascaridoid nematodes in 2001, 2002 and 2003. The fishes were collected between 278 and 413 m water depth using a benthopelagic net. Based on the amplification of the internal transcribed spacer ITS-1, 5.8S, ITS-2 and flanking sequences (=ITS+), three ascaridoid nematode species were identified. The prevalence of infestation during the 3 years ranged from 42.9% to 62.9% and 22.9% to 40.0% for the anisakids Anisakis simplex (s.s.) and Pseudoterranova decipiens (s.s.), respectively, and from 28.6% to 60.0% for the raphidascarid Hysterothylacium aduncum. A total of 18 specimens, two of each species and examination year, revealed no sibling species, suggesting a limited distribution of other ascaridoid siblings into the deep sea. The ITS-1, 5.8S and ITS-2 sequences of A. simplex (s.s.) from the East Greenland Sea did not differ from previously published sequence data (GenBank) from other regions in the Atlantic and Pacific oceans. The sequences of P. decipiens (s.s.) corresponded most closely to those of specimens from Richardson Bay, western Pacific, and differed in four positions (0.5%). They corresponded least to those of specimens from Japan (1.5%). The sequence data for H. aduncum differed in two positions in the ITS-1 (0.2%) and three positions in the ITS-2 (0.3%) from sequences from Japan. A high genetic similarity between the regions can be explained by (a) extensive final host migration in the case of A. simplex (s.s.), (b) an overlapping distribution of final host populations along the continental shelves for P. decipiens (s.s.) and (c) a low host specificity and large population size in the intermediate and final hosts for H. aduncum. The occurrence of the identified species in the macrourid fish underlines the potential of cosmopolitan ascaridoid nematodes to distribute not only horizontally but also vertically in the deep sea.  相似文献   

Sedimentary development of the Louisiana continental shelf related to sea level cycles: Part II—seismic response     

James M. Coleman  Harry H. Roberts 《Geo-Marine Letters》1988,8(2):109-119

Cyclic sequences occur worldwide in nearly every stratigraphic sequence; they are particularly well-developed in fluvial and deltaic sediments that have been influenced by high-frequency eustatic sea-level fluctuations. The large data base for this study (including 471 deep foundation borings, thousands of line kilometers of high-resolution seismic, and sedimentological and dating analyses) represents the most complete information on high-resolution chronostratigraphy and lithostratigraphy that is available on any modern continental shelf/upper slope. These data are used to document sedimentological characteristics and high-resolution seismic responses during three complete sea-level cycles over the entire continental shelf/upper slope of offshore Louisiana. Examination of high-resolution seismic records indicates that well-defined, high-amplitude, laterally continuous reflectors correlate with rising and high stand condensed sedimentary sequences and that the deposits laid down during falling and low-stand periods (expanded sections) are characterized by a wide range of acoustic responses. Discontinuous reflectors with high-amplitude variability, continuous parallel reflectors, and chaotic and amorphous zones are common acoustic responses. The association between a particular lithofacies and a specific acoustic response on 3.5-kHz records was found to be very poor.  相似文献   

Dissolved carbon and 33-133-133-1anomalies in the water column caused by hydrocarbon seeps on the northwestern Gulf of Mexico slope     

Paul Aharon  Ellen R. Graber  Harry H. Roberts 《Geo-Marine Letters》1992,12(1):33-40

Alkalinity, dissolved inorganic carbon (DIC), and ¹³C profiles from seep sites on the northwestern Gulf of Mexico upper slope show anomalously negative ¹³C values of up to –4.5 PDB, increased levels of DIC of up to 2.45 mmole/liter, and slight alkalinity rises of up to 2.54 meq/liter, relative to water column profiles from a seep-free site (0.63, 2.04 mmole/liter, and 2.39 meq/liter). The observed DIC enrichments coupled with the¹³C-depletions are attributed to the release of CO₂ by microbial oxidation of crude oil in the seep environment, and its migration into the water column. The ¹³C composition of the migrating CO₂ is estimated to be –26.0 on the basis of dissolved carbon inventory. Manifestation of DIC and ¹³C anomalies in the water column caused by hydrocarbon seepage holds promise to be useful for hydrocarbon reconnaissance surveys over large offshore tracts on account of the simplicity of sampling acquisition, and rapidity of analytical techniques in the laboratory.  相似文献   

IN-SITU observations of irregular ionospheric structure associated with the plasmapause     

Harry A. Taylor  Guy R. Cordier 《Planetary and Space Science》1974,22(9):1289-1296

Additional studies of the ion composition results obtained from the OGO-6 satellite support earlier observations of irregularities in the distribution of H⁺ and He⁺ within the light ion trough near L = 4, which has been associated with the plasmapause. These irregularities are in the form of sub-troughs superimposed upon the major mid latitude decrease of the light ions. In the sub-troughs, ionization depletions and recoveries of as much as an order of magnitude are observed within a few degrees of latitude, usually exhibited in a pattern which changes significantly with longitude as the Earth rotates beneath the relatively fixed satellite orbit. The location and properties exhibited by these sub-troughs appear to be consistent with the concept of a plasmasphere distortion in the form of “plasmatails” resulting from the combined effects of magnetospheric convection plus corotation. Like the light ion trough, the “plasmatail” irregularity in H⁺ may be obscured on the day side by the dominant topside distribution of O⁺. Consequently, these light ion irregularities are seen as an important factor for studies of plasmapause-trough relationships.  相似文献   

Hydrogeology and sustainable future groundwater abstraction from the Agua Verde aquifer in the Atacama Desert,northern Chile   总被引：1，自引：0，他引：1  

Javier Urrutia  Jorge Jódar  Agustín Medina  Christian Herrera  Guillermo Chong  Harry Urqueta  José A. Luque 《Hydrogeology Journal》2018,26(6):1989-2007

The hyper-arid conditions prevailing in Agua Verde aquifer in northern Chile make this system the most important water source for nearby towns and mining industries. Due to the growing demand for water in this region, recharge is investigated along with the impact of intense pumping activity in this aquifer. A conceptual model of the hydrogeological system is developed and implemented into a two-dimensional groundwater-flow numerical model. To assess the impact of climate change and groundwater extraction, several scenarios are simulated considering variations in both aquifer recharge and withdrawals. The estimated average groundwater lateral recharge from Precordillera (pre-mountain range) is about 4,482 m³/day. The scenarios that consider an increase of water withdrawal show a non-sustainable groundwater consumption leading to an over-exploitation of the resource, because the outflows surpasses inflows, causing storage depletion. The greater the depletion, the larger the impact of recharge reduction caused by the considered future climate change. This result indicates that the combined effects of such factors may have a severe impact on groundwater availability as found in other groundwater-dependent regions located in arid environments. Furthermore, the scenarios that consider a reduction of the extraction flow rate show that it may be possible to partially alleviate the damage already caused to the aquifer by the continuous extractions since 1974, and it can partially counteract climate change impacts on future groundwater availability caused by a decrease in precipitation (and so in recharge), if the desalination plant in Taltal increases its capacity.  相似文献   

Residential Location,Ambient Air Lead Pollution And Lead Absorption In Children*     

Raphael J. Caprio  Harry L. Margulis  Morris M. Joselow 《The Professional geographer》1975,27(1):37-42

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Resolving climate change in the period 15–23 ka in Greenland ice cores: a new application of spectral trend analysis     

Mat G. G. De Jong  Djin S. Nio  Alain R. Böhm  Harry C. Seijmonsbergen  Leo W. S. de Graaff 《地学学报》2009,21(2):137-143

Northern Hemisphere climate history through and following the Last Glacial Maximum is recorded in detail in ice cores from Greenland. However, the period between Greenland Interstadials 1 and 2 (15–23 ka), i.e. the period of deglaciation following the last major glaciation, has been difficult to resolve in great detail. We here offer a new subdivision of this in the NGRIP, GRIP and GISP2 ice cores, by newly introducing spectral trend analysis to the study of climate-related data series from ice cores. This analysis reveals patterns of change and discontinuity in the waveform properties of a data series, relating to the environmental (including climatic) history of accumulation of the rock or ice record. The application allows high-resolution correlation between the ice cores, and a greatly improved subdivision of the study interval. Nine climatic phases are recognized, within which more identifiable events can also be correlated between the three locations.  相似文献   

Velocity potential formulations of highly accurate Boussinesq-type models     

Harry B. Bingham  Per A. Madsen  David R. Fuhrman 《Coastal Engineering》2009

The highly accurate Boussinesq-type equations of Madsen et al. (Madsen, P.A., Bingham, H.B., Schäffer, H.A., 2003. Boussinesq-type formulations for fully nonlinear and extremely dispersive water waves: Derivation and analysis. Proc. R. Soc. Lond. A 459, 1075–1104; Madsen, P.A., Fuhrman, D.R., Wang, B., 2006. A Boussinesq-type method for fully nonlinear waves interacting with a rapidly varying bathymetry. Coast. Eng. 53, 487–504); Jamois et al. (Jamois, E., Fuhrman, D.R., Bingham, H.B., Molin, B., 2006. Wave-structure interactions and nonlinear wave processes on the weather side of reflective structures. Coast. Eng. 53, 929–945) are re-derived in a more general framework which establishes the correct relationship between the model in a velocity formulation and a velocity potential formulation. Although most work with this model has used the velocity formulation, the potential formulation is of interest because it reduces the computational effort by approximately a factor of two and facilitates a coupling to other potential flow solvers. A new shoaling enhancement operator is introduced to derive new models (in both formulations) with a velocity profile which is always consistent with the kinematic bottom boundary condition. The true behaviour of the velocity potential formulation with respect to linear shoaling is given for the first time, correcting errors made by Jamois et al. (Jamois, E., Fuhrman, D.R., Bingham, H.B., Molin, B., 2006. Wave-structure interactions and nonlinear wave processes on the weather side of reflective structures. Coast. Eng. 53, 929–945). An exact infinite series solution for the potential is obtained via a Taylor expansion about an arbitrary vertical position z = zˆ. For practical implementation however, the solution is expanded based on a slow variation of zˆ and terms are retained to first-order. With shoaling enhancement, the new models obtain a comparable accuracy in linear shoaling to the original velocity formulation. General consistency relations are also derived which are convenient for verifying that the differential operators satisfy a potential flow and/or conserve mass up to the order of truncation of the model. The performance of the new formulation is validated using computations of linear and nonlinear shoaling problems. The behaviour on a rapidly varying bathymetry is also checked using linear wave reflection from a shelf and Bragg scattering from an undulating bottom. Although the new models perform equally well for Bragg scattering they fail earlier than the existing model for reflection/transmission problems in very deep water.  相似文献