1,721,015 research outputs found
Enhancing the observing capacity for the surface ocean by the use of Volunteer Observing Ship
No full textKnowledge of the surface ocean dynamics and the underlying controlling mechanisms is critical to understand the natural variability of the ocean and to predict its future response to climate change. In this paper, we highlight the potential use of Volunteer Observing Ship (VOS), as carrier for automatic underway measuring system and as platform for sample collection, to enhance the observing capacity for the surface ocean. We review the concept, history, present status and future development of the VOS-based in situ surface ocean observation. The successes of various VOS projects demonstrate that, along with the rapid advancing sensor techniques, VOS is able to improve the temporal resolution and spatial coverage of the surface ocean observation in a highly cost-effective manner. A sustained and efficient marine monitoring system in the future should integrate the advantages of various observing platforms including VOS
Seasonal and inter-annual variability in alkalinity in Liverpool Bay (53.5° N, 3.5° W) and in major river inputs to the North Sea
No full textA critical factor controlling changes in the acidity of coastal waters is the alkalinity of the water. Concentrations of alkalinity are determined by supply from rivers and by in situ processes such as biological production and denitrification. A 2-year study based on 15 cruises in Liverpool Bay followed the seasonal cycles of changing concentrations of total alkalinity (TA) and total dissolved inorganic carbon (DIC) in relation to changes caused by the annual cycle of biological production during the mixing of river water into the Bay. Consistent annual cycles in concentrations of nutrients, TA and DIC were observed in both years. At a salinity of 31.5, the locus of primary production during the spring bloom, concentrations of NO x decreased by 25?±?4 ?mol kg?1 and DIC by 106?±?16 ?mol kg?1. Observed changes in TA were consistent with the uptake of protons during primary biological production. Concentrations of TA increased by 33?±?8 ?mol kg?1 (2009) and 33?±?15 ?mol kg?1 (2010). The impact of changes in organic matter on the measured TA appears likely to be small in this area. Thomas et al. (2009) suggested that denitrification may enhance the CO2 uptake of the North Sea by 25%, in contrast we find that although denitrification is a significant process in itself, it does not increase concentrations of TA relative to those of DIC and so does not increase buffer capacity and potential uptake of CO2 into shelf seawaters. For Liverpool Bay historical data suggest that higher concentrations of TA during periods of low flow are likely to contribute in part to the observed change in TA between winter and summer but the appropriate pattern cannot be identified in recent low-frequency river data. On a wider scale, data for the rivers Mersey, Rhine, Elbe and Weser show that patterns of seasonal change in concentrations of TA in river inputs differ between river systems
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Phytoplankton and pigment studies in the Bay of Biscay and English Channel
Full text linkDuring the final year (2010) of the MV Pride of Bilbao (PoB) ferry operation between Portsmouth (UK) and Bilbao (Spain) a comprehensive phytoplankton data set was collected based on pigments and taxonomy measurements. The work was in support of the EU project ProTool (http://www.protool-project.eu) that aimed to develop an automated system for measuring primary productivity from ships of opportunity. Not unexpectedly, the biological patterns relate to the hydrographic conditions and in general, pigment distributions are indicative of the taxonomy. A predominately diatom bloom was observed in the Bay of Biscay in April, with a mixed population of diatoms, dinoflagellates and coccolithophores throughout the spring and summer, and a very distinctive bloom, which contained a large proportion of the dinoflagellate Karenia Mikimotoi, to the stratified side of the Ushant Front in mid-July
Seasonal variability of the carbonate system and coccolithophore Emiliania huxleyi at a Scottish Coastal Observatory monitoring site
No full textLack of information about carbonate chemistry in inshore waters is a ‘knowledge gap’ in assessing the impacts of changing carbonate chemistry on the marine environment. Assessing the response of calcifying phytoplankton to this changing carbonate chemistry requires a greater understanding of temporal variation. This study provides a description of the variability of carbonate parameters at a monitoring site in the eastern coast of Scotland. Four-years of monthly data were analysed to assess the diversity, abundance and morphometrics of coccolithophores in relation to carbonate chemistry and environmental variables. The seasonality in carbonate parameters reflected the seasonal cycle in phytoplankton activity, with higher total alkalinity concentrations and pH and lower dissolved inorganic carbon concentrations during the growing season. The dominant coccolithophore at the site was Emiliania huxleyi which showed a clear seasonal pattern, being more abundant in mid-summer when warmer and nutrient-depleted conditions restricted the annual diatom bloom. This study revealed the presence of three morphotypes of E. huxleyi, type A, type A overcalcified (type AO) and type B, which were seasonally distributed throughout the year. The less calcified form was mainly observed in spring while heavily calcified morphotypes overlapped during summer. Autumn and winter months were dominated by the most calcified form (type AO). These results indicate that the seasonal pattern of E. huxleyi morphotypes was not related to the carbonate concentration at the site. This study reflects the strong interannual variability in carbonate chemistry and the complexity associated with coccolithophore calcification, and highlights the need of long-term data to understand the potential impact of ocean acidification on calcifying phytoplankton
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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