1,720,967 research outputs found
Extreme precipitation in the south and south-east Mediterranean climate structure and predictability
No full textAs part of a Global Flood project, we assess the conditions that lead to the changing frequency and spatial structure of extreme daily precipitation events in this region for the 6 month winter period from Oct-March. Spatial and temporal trends in the ECA&D data for this region are analyzed in the precipitation frequency and intensity for events exceeding the 99th percentile of daily precipitation. The associated climatic conditions (SST, atmospheric circulation patterns, canonical moisture sources and moisture transport patterns) are analyzed using re-analysis data to establish the concurrent and season ahead conditions associated with the leading space and time patterns. Analogs of these patterns are investigated for GCM integrations for future climate (seasonal forecasts as well as IPCC scenarios) to assess potential predictability and outcomes
21st Projections of precipitation extremes in the Mediterranean from a medium resolution GCM
No full textPrecipitation extremes simulated by a medium resolution GCM ( INMCM3.0) are analyzed for
the Mediterranean region. A structured analysis of low frequency variability in the control
and forced ( corresponding to the IPCC scenarios) model runs is performed. The preliminary
results of the analysis of rainfall patterns under global warming conditions, during the
extended winter ONDJFM season, show an increase of rainfall extremes in both frequency
and intensity in northern Europe and a decrease in the most part of Mediterranean. In the
latter region an increase of dry conditions is also observed. The change in the rainfall patterns
can be explained by a northward shift of the North Atlantic winter storm track. This
shift is related changes in meridional and zonal surface temperature gradients ( Equator-
Pole and Ocean-Land contrast, respectively) due to anthropogenic forcing. Changes in the
inter-annual and multi-decadal natural variability are also noted
GCM projection of precipitation extremes in the mediterranean: changes ansd low frequency characteristic
No full textPrecipitation extremes simulated a medium by resolution GCM ( INMCM3.0) as are analyzed
for the Mediterranean region. A structured analysis of low frequency variability in the
control and forced ( corresponding to the IPCC scenarios) model runs is performed. The
preliminary results of the analysis of rainfall patterns under global warming conditions,
during the extended winter ONDJFM season, show an increase of rainfall extremes in
both frequency and intensity in northern Europe and a decrease in the most part of Mediterranean.
In the latter region an increase of dry conditions is also observed. The change in
the rainfall patterns can be explained by a northward shift of the North Atlantic winter
storm track. This shift is related changes in meridional and zonal surface temperature gradients
( Equator- Pole and Ocean-Land contrast, respectively) due to anthropogenic forcing.
Changes in the inter-annual and multi-decadal natural variability are also noted
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
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
Mid Latitude Extreme Precipitation under future changed climate
No full textPrecipitation patterns under global warming scenario are statistically analyzed for the Mediterranean and North Europe areas. Simulation data from the global coupled atmosphere-ocean model INMCM.3 are used and compared with obervations.
Changes in intensity, frequency, duration and amount of precipitation due to different IPCC scenarios are investigated.
Furthermore we analyze the precipitation patterns for the better understanding of the hydrologic cycle, including a statistical analysis of precipitation extreme events
- …
