1,720,975 research outputs found

    Influence of high latitude anomalies on tropical climate phenomena and global climate

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    The tropical ocean and atmosphere are a highly active and very important region of the globe. Climate phenomena such as El Ni˜no (Philander, 1990), the Tropical Atlantic Dipole, and the Indian Ocean Dipole, play an important role in global climate variability. The tropical atmospheric boundary layer is very sensitive to even small changes in the sea surface temperature (SST). Small SST anomalies in the tropics can lead to shifts in the large scale convection cells and result in atmospheric heating. There is potential for positive feedback between the tropical ocean and atmosphere.Ocean waves are capable of propagating long distances very fast. Barotropic waves (adjustments in free surface height) can propagate round the globe within days. Baroclinic waves, propagating along the thermocline are able to cross the equatorial Atlantic in 2 – 3 months. This work shows the potential for ocean wave propagation to influence global climate, by linking high latitude anomalies to tropical climate phenomena.The first part of this thesis is a detailed examination of the “Tropical Atlantic Dipole” (TAD). Analysis of model data shows a dipole pattern in the SST, with strong cross-equatorial asymmetry in the surface mixed layer. Below the mixed layer the pattern becomes symmetric, and Kelvin and Rossby wave like adjustment can be seen to occur. However, the timeseries is not sufficiently long to provide confidence in resolving the power spectrum, and as such the results are inconclusive. The complexity of the model makes it difficult to identify the mechanism(s) which are responsible for driving the dipole. An idealised basin model is used to examine high latitude anomalies which create equatorward propagating coastal Kelvin waves as a possible driving mechanism for the TAD. The results show that coastal Kelvin wave propagation can quickly transmit a signal from the high latitude anomaly to the equator, and equatorial Kelvin and Rossby wave propagation can quickly influence the entire tropical ocean. This suggests that forcing of the TAD may come from higher latitudes, although it is still not fully understood how a symmetric sub-surface signal can become asymmetric at the surface. Restoring surface boundary conditions limit the response of the model, restricting the formation of a TAD. A similar experiment, using an idealised coupled model configuration is suggested, but not possible in the time available.The second part of this thesis looks in detail at the role of the ocean in rapidly transmitting a high latitude response to the equator, using an existing coupled climate model configured with realistic land geometry and bottom topography. Simulations of a salinity anomaly in the Southern Ocean show that it is possible to create an equatorial response in SST within a month, with SST anomalies of 2.5± after 6 months. Barotropic Kelvin and Rossby wave propagation is shown to be important in creating such a rapid equatorial response. Two points that are identified from this experiment are examined in further detail using an idealised basin model. Firstly, a mechanism for energy exchange within the equatorial waveguide is tested. Results suggest that it is not the mechanism responsible for the signals seen in the coupled climate model. Secondly, idealised model integrations confirm that transmission of signals along topographic ridges is possible. Signals strong enough to excite equatorward coastal Kelvin wave propagation are able to use topography to cross the Southern Ocean and reach the coast of Australia

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

    Dispelling the Myths Behind First-author Citation Counts

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used

    Author Under Sail The Imagination of Jack London, 1893-1902

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    In Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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