Temperature assimilation into a coastal ocean-biogeochemical model: assessment of weakly and strongly coupled data assimilation     

Goodliff  Michael  Bruening  Thorger  Schwichtenberg  Fabian  Li  Xin  Lindenthal  Anja  Lorkowski  Ina  Nerger  Lars 《Ocean Dynamics》2019,69(10):1217-1237

Ocean Dynamics - Satellite data of both physical properties as well as ocean colour can be assimilated into coupled ocean-biogeochemical models with the aim to improve the model state. The physical...  相似文献   

Trends and variation in concentration of dissolved metals (Cd, Cu, Pb, and Zn) in the North Sea (1980-1989)     

Scholten  M. C. Th.; Kramer  K. J. M.; Laane  R. W. P. M. 《ICES Journal of Marine Science》1998,55(5):825-834

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Routine analysis of sediment pore water of high ionic strength     

Peter Herzsprung  Elke Bozau  Olaf Büttner  Anja Duffek  Kurt Friese  Matthias Koschorreck  Martin Schultze  Wolf v. Tümpling  Katrin Wendt‐Potthoff 《洁净——土壤、空气、水》2006,34(6):593-607

Pore water of sediments plays an important role in aquatic systems as mediator and as the reactive zone between the sediment and surface water. Sediment pore waters with high ionic strength from acidified pit lakes were investigated to obtain information about the influence on the lake water quality. The analysis of soluble reactive phosphorus, nitrate, ammonium, silica, dissolved organic carbon, ferrous iron, sulfate, chloride, sodium, potassium, calcium, magnesium, manganese, and total dissolved iron was predetermined as the dataset required for evaluation of water quality. The data collection procedure was optimised by designing a methodology for stabilisation, dilution of pore water samples and adaptation of analytical methods. The developed methodology was evaluated with respect to the effort required in the laboratory under routine conditions. In the first round of analyses, 72% of 638 individual analyses from a random selection of pore water profiles were found to be within the calibration ranges. Remedial actions to handle the remaining 28% of invalid analytical results are exemplified. Differences between comparative analyses of some ions by continuous flow analysis, ion chromatography, and atomic emission spectroscopy were evaluated. The majority of results measured by ion chromatography differed on a highly significant level from results measured by atomic emission spectroscopy. Possible reasons, originating from the extreme sample matrix, are discussed. Finally, the designed methodology and the results of the method comparison are used to recommend the selection of analytical methods under specific conditions.  相似文献   

The response of the subglacial Lake Vostok, Antarctica, to tidal and atmospheric pressure forcing   总被引：1，自引：0，他引：1  

Anja Wendt  Reinhard Dietrich  Jens Wendt  Mathias Fritsche  Valery Lukin  Alexander Yuskevich  rey Kokhanov  Anton Senatorov  Kazuo Shibuya  Koichiro Doi 《Geophysical Journal International》2005,161(1):41-49

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Submillimetre continuum images of the NGC 2024 star-forming ridge     

Anja E. Visser  John S. Richer  Claire J. Chandler  & Rachael Padman 《Monthly notices of the Royal Astronomical Society》1998,301(2):585-592

We present 450- and 800-μm images, made with the James Clerk Maxwell Telescope, of the NGC 2024 molecular ridge. The seven previously known compact cores, FIR1–7, have been detected, and FIR5 has been resolved into a compact object and an associated extended source to the east. The estimated masses of the dense cores vary between 1.6 and 5.1 M⊙ per 14-arcsec beam, assuming a dust temperature of 30 K and a dust opacity of κ_800 μm = 0.002 m² kg⁻¹. A spectral index map made from the 450- and 800-μm images shows spatial variations, with the spectral index, α ( F _ν ∝ ν^α), being systematically lower towards the dense cores. We interpret this as evidence for a lower value of the frequency dependence of the dust opacity, β, towards the denser cores relative to the surrounding molecular material. This may indicate that grain growth is occurring in the cores, prior to planetesimal formation. By comparing the high-resolution 450-μm image with interferometer maps of the integrated CS(2–1) emission, the previously reported discrepancy between dust continuum emission and molecular line emission is found to be very localized. Depletion and temperature variations are discussed as possible explanations.  相似文献   

Sublimation of ice through sediment in Beacon Valley, Antarctica     

R.C.A. Hindmarsh  F.M. van der Wateren  Anja L.L.M. Verbers 《Geografiska Annaler: Series A, Physical Geography》1998,80(3-4):209-219

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How special are brightest group and cluster galaxies?     

Anja von der Linden  Philip N. Best  Guinevere Kauffmann  Simon D. M. White 《Monthly notices of the Royal Astronomical Society》2007,379(3):867-893

We use the Sloan Digital Sky Survey (SDSS) to construct a sample of 625 brightest group and cluster galaxies (BCGs) together with control samples of non-BCGs matched in stellar mass, redshift and colour. We investigate how the systematic properties of BCGs depend on stellar mass and on their privileged location near the cluster centre. The groups and clusters that we study are drawn from the C4 catalogue of Miller et al. but we have developed improved algorithms for identifying the BCG and for measuring the cluster velocity dispersion. Since the SDSS photometric pipeline tends to underestimate the luminosities of large galaxies in dense environments, we have developed a correction for this effect which can be readily applied to the published catalogue data. We find that BCGs are larger and have higher velocity dispersions than non-BCGs of the same stellar mass, which implies that BCGs contain a larger fraction of dark matter. In contrast to non-BCGs, the dynamical mass-to-light ratio of BCGs does not vary as a function of galaxy luminosity. Hence BCGs lie on a different Fundamental Plane than ordinary elliptical galaxies. BCGs also follow a steeper Faber–Jackson relation than non-BCGs, as suggested by models in which BCGs assemble via dissipationless mergers along preferentially radial orbits. We find tentative evidence that this steepening is stronger in more massive clusters. BCGs have similar mean stellar ages and metallicities to non-BCGs of the same mass, but they have somewhat higher α/Fe ratios, indicating that star formation may have occurred over a shorter time-scale in the BCGs. Finally, we find that BCGs are more likely to host radio-loud active galactic nuclei than other galaxies of the same mass, but are less likely to host an optical active galactic nucleus (AGN). The differences we find are more pronounced for the less massive BCGs, i.e. they are stronger at the galaxy group level.  相似文献   

High-resolution Enceladus atlas derived from Cassini-ISS images     

Th. Roatsch  M. Wählisch  A. Hoffmeister  F. Scholten  R. Wagner  P. Helfenstein 《Planetary and Space Science》2008,56(1):109-116

The Cassini Imaging Science Subsystem (ISS) acquired 377 high-resolution images (<1 km/pixel) during three close flybys of Enceladus in 2005 [Porco, C.C., et al., 2006. Cassini observes the active south pole of Enceladus. Science 311, 1393-1401.]. We combined these images with lower resolution Cassini images and four others taken by Voyager cameras to produce a high-resolution global controlled mosaic of Enceladus. This global mosaic is the baseline for a high-resolution Enceladus atlas that consists of 15 tiles mapped at a scale of 1:500,000. The nomenclature used in this atlas was proposed by the Cassini imaging team and was approved by the International Astronomical Union (IAU). The whole atlas is available to the public through the Imaging Team's website (http://ciclops.org/maps).  相似文献   

Sediment loads due to fluvial transport and debris flows during the 2005 flood events in Switzerland   总被引：1，自引：0，他引：1  

Dieter Rickenmann  Anja Koschni 《水文研究》2010,24(8):993-1007

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Dietary greenhouse gas emissions of meat-eaters,fish-eaters,vegetarians and vegans in the UK   总被引：2，自引：1，他引：1  

Peter Scarborough  Paul N. Appleby  Anja Mizdrak  Adam D. M. Briggs  Ruth C. Travis  Kathryn E. Bradbury  Timothy J. Key 《Climatic change》2014,125(2):179-192

The production of animal-based foods is associated with higher greenhouse gas (GHG) emissions than plant-based foods. The objective of this study was to estimate the difference in dietary GHG emissions between self-selected meat-eaters, fish-eaters, vegetarians and vegans in the UK. Subjects were participants in the EPIC-Oxford cohort study. The diets of 2,041 vegans, 15,751 vegetarians, 8,123 fish-eaters and 29,589 meat-eaters aged 20–79 were assessed using a validated food frequency questionnaire. Comparable GHG emissions parameters were developed for the underlying food codes using a dataset of GHG emissions for 94 food commodities in the UK, with a weighting for the global warming potential of each component gas. The average GHG emissions associated with a standard 2,000 kcal diet were estimated for all subjects. ANOVA was used to estimate average dietary GHG emissions by diet group adjusted for sex and age. The age-and-sex-adjusted mean (95 % confidence interval) GHG emissions in kilograms of carbon dioxide equivalents per day (kgCO₂e/day) were 7.19 (7.16, 7.22) for high meat-eaters (?>?=?100 g/d), 5.63 (5.61, 5.65) for medium meat-eaters (50-99 g/d), 4.67 (4.65, 4.70) for low meat-eaters (?<?50 g/d), 3.91 (3.88, 3.94) for fish-eaters, 3.81 (3.79, 3.83) for vegetarians and 2.89 (2.83, 2.94) for vegans. In conclusion, dietary GHG emissions in self-selected meat-eaters are approximately twice as high as those in vegans. It is likely that reductions in meat consumption would lead to reductions in dietary GHG emissions.  相似文献