Environmental overview of Eckernförde Bay,northern Germany     

T. H. Orsi  F. Werner  D. Milkert  A. L. Anderson  W. R. Bryant 《Geo-Marine Letters》1996,16(3):140-147

This environmental overview of Eckernförde Bay (northern Germany) summarizes the results of previous studies relevant to the Office of Naval Research's Coastal Benthic Boundary Layer (CBBL) Baltic field exercise conducted during 1993–1994. Significant environmental characteristics include the following: (1) surface sediment distribution is related to water depth, dictated primarily by hydrodynamic reworking of older glacial deposits; (2) the origin and characteristics of small-scale sedimentary structures depend on storm-generated waves and currents; (3) the proximity of the sea surface and sediment —water interface results in a pelagic—benthic coupling that drives biogeochemical processes and produces organicrich, acoustically turbid sediments; and (4) the bay floor is complicated topographically by pockmarks and manmade sedimentary structures.  相似文献   

The influence of salinity on the heat-shock protein response of Potamocorbula amurensis (Bivalvia)   总被引：1，自引：0，他引：1  

Werner I 《Marine environmental research》2004,58(2-5):803-807

For biomarkers to be useful in assessing anthropogenic impacts in field studies involving aquatic organisms, they should not be affected by naturally occurring changes in environmental parameters such as salinity. This is especially important in estuarine environments and for relatively unspecific biomarkers like heat-shock proteins (hsps, stress proteins). In this study, the heat-shock protein response was measured in the euryhaline clam, Potamocorbula amurensis, after exposure to a range of salinities reflecting normal and extreme environmental conditions in Northern San Francisco Bay, California. The ability to raise cellular hsp70 levels in response to heat-shock was significantly impaired in P. amurensis collected from a low (0.5 ppt) salinity field site, and after 14 day exposure to low salinity in the laboratory.  相似文献   

Functional Molecular Biodiversity: Assessing the Immune Status of Two Sponge Populations (Suberites domuncula) on the Molecular Level     

Heinz C. Schröder  Vladislav A. Grebenjuk  Michael Binder  Alexander Skorokhod  Renato Batel  Hamdy Hassanein  & Werner E. G. Müller 《Marine Ecology》2004,25(2):93-108

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Estimating Deep Seafloor Interface and Volume Roughness Parameters Using the Multibeam-Hydrosweep System     

Bishwajit Chakraborty  Hans Werner Schenke  Vijay Kodagali  Rick Hagen 《Marine Geodesy》2002,25(1):19-26

Utilizing a hull-mounted, multinarrow beam echosounder onboard RV Polarstern, we measured variation of acoustic backscatter with incidence angles at two different sites in the Southern Oceans (Agulhas Plateau and the Riiser Larsen Sea). We modeled the data, using a composite roughness model, including water-sediment interface roughness and sediment volume roughness parameters. The model effectively uses the near normal incidence angle backscatter to determine the seafloor interface roughness parameters employing Helmholtz-Kirchhoff theory. Beyond 20° incidence angles, an application of Rayleigh-Rice theory is made by using a necessary splicing technique (combining both of the theories at 20° incidence angle). The estimated interface and volume roughness parameters are found to be in accordance with the known area geology.  相似文献   

A new bathymetric model for the central Fram Strait   总被引：1，自引：0，他引：1  

Klenke  Martin  Schenke  Hans Werner 《Marine Geophysical Researches》2002,23(4):367-378

Based on data from R/V Polarstern multibeam sonar surveys between 1984 and 1997 high resolution bathymetry has been generated for the central Fram Strait. The area insonified covers approx. 36,500 km² between 78–80°N and 0–7.5°E allowing the creation of a Digital Terrain Model (DTM) with 100 m grid spacing. The DTM was utilized for contouring and generation of a new series of bathymetric charts (AWI Bathymetric Charts of the Fram Strait, AWI BCFS) at a scale of 1:100,000. The paper starts with a brief introduction to the regional setting of the study area comprising information on the local links between bathymetry, sea ice transport and water mass exchange. The bathymetric feature names used in this article and how they were chosen is outlined. Next, the input data and processing applied are described. Thereafter the newly created grid and contour data are put into context with existing data sets. Finally the main bathymetric features of the area are characterized and the generated data products available for public disposal are specified.  相似文献   

Ship hull drag reduction using bottom air injection   总被引：1，自引：0，他引：1  

Robert Latorre Dr. 《Ocean Engineering》1997,24(2):161-175

The idea of bottom air injection to reduce ship hull resistance is not new. Early patents envisioned planing hull applications. Recent planing hull tests speed realized an increase of 7–12 knots. River barges and ship fitted with an air injection system results are presented to show a 10–15% reduction in the frictional resistance. Graphs for making initial estimates for displacement hulls with bottom air injection are presented. It is clear from these results that improvements in high speed planing catamarans and full form hull resistance can be realized by using bottom air injection.  相似文献   

Les coraux (Scléractiniaires et Hydro-coralliaires) de 'atoll de Takapoto, îles Tuamotu: Aspects écologiques     

Dietrich H.H.  Kühlmann  Jean-Pierre  Chevalier 《Marine Ecology》1986,7(1):75-104

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Baltic cod recruitment - the impact of climate variability on key processes   总被引：3，自引：0，他引：3  

Koster  Friedrich W.; Mollmann  Christian; Hinrichsen  Hans-Harald; Wieland  Kai; Tomkiewicz  Jonna; Kraus  Gerd; Voss  Rudiger; Makarchouk  Andrei; MacKenzie  Brian R.; St. John  Michael A.; Schnack  Dietrich; Rohlf  Norbert; Linkowski  Tomasz; Beyer  Jan E. 《ICES Journal of Marine Science》2005,62(7):1408-1425

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Particle size distribution and dissolution properties of metals in cyclone fly ash   总被引：1，自引：0，他引：1  

H. Rönkkömäki Ph.D.  R. Pöykiö Ph.D.  H. Nurmesniemi Ph.D.  K. Popov D.Sc.  E. Merisalu Dr.  T. Tuomi PhD  I. Välimäki M.Sc. 《International Journal of Environmental Science and Technology》2008,5(4):485-494

The particles in the examined cyclone fly ash were all smaller than 0.25 mm. in diameter, and particles smaller than 0.075 mm. in diameter accounted for 88.4 % of the ash weight. This result indicates that cyclone fly ash consists of particles with a small diameter. The metals in the cyclone fly ash were enriched in small particles. The highest concentrations for zinc, copper, lead, cadmium and molybdenum in the cyclone fly ash were found in the smallest particle size fraction (< 0.075 mm.) and for Barium, chromium, nickel, Vanadium and Cobalt in the second to smallest particle size fraction (0.075-0.125 mm.). From an environmental and toxicological standpoint, the smallest particles are of the greatest concern when ash is handed at landfill disposal sites (transport and disposal especially in stormy weather conditions), and some studies have reported risks to workers from prolonged exposure to ash. The results of the comparison of various dissolution methods for metals showed that the digestion procedures with nitric acid alone (USEPA 3051) or with a mixture of nitric acid + hydrogen peroxide (USEPA 3050B) slightly underestimated the metal concentrations in the cyclone fly ash. Although the use of hydrofluoric acid is often necessary for the determination of a number of elements associated with siliceous minerals, its use can result in loss of trace elements during dissolution.  相似文献   

Total ozone variations in the tropical belt: An application for quality of ground based measurements     

Dr R. D. Bojkov  V. E. Fioletov 《Meteorology and Atmospheric Physics》1996,58(1-4):223-240

Summary The study of the regime of ozone variations in the huge tropical belt (25° S to 25° N), which are, in general, very small and zonally nearly symmetric, permits to establish a statistical model for estimating the ozone deviations using Total Ozone Mapping Spectrometer (TOMS) data. The equatorial stratospheric winds at 25 and 50hPa and the solar flux at 10.7 cm are used as major predictors and the linear trend was also estimated. The 10m/sec stratospheric wind change is related to1.2% ozone change at the equator, to practically no change in the 8–15° belts and up to 1.4% change with opposite phase over the tropics in spring but nearly zero change in fall. The solar cycle related amplitude is about 1.4% per 100 units of 10.7 cm solar flux. The ozone trends are negative: not significant over the equator and about –2% per decade (significant at 95% level) over the tropics. The latter could have been enforced by the 2 to 4% lower ozone values during 1991–1993, part of which might be related to the effects of the Mt. Pinatubo eruption, but might also be due to the strong QBO. The estimated deviations are verified versus reliable observations and the very good agreement permits applying the model for quantitative quality control of the reported ozone data from previous years. The standard deviation of the difference between observed ozone deviations and those estimated from the model is only 0.9–1.6% for yearly mean, that means instruments used for total ozone observations in the tropical belt should have systematic error of less than 1%. Cases when the discrepancies between the model and reported observations at a given station exceed 2–3% for time interval of 2 or more years should be verified.With 17 Figures  相似文献