1,720,970 research outputs found
Investigating the predictability link between heatwaves and severe convective outbreaks in Europe
Get PDFRecent summers in Europe were accompanied by significant convective storm outbreaks with widespread large hail, flash floods and severe wind phenomena. Particularly severe outbreaks have occurred at the breaking point of multi-day heatwaves, leading to considerable compound hazards from heat and drought meeting severe thunderstorms. The decay of blockings and heatwaves remains one of the largest forecast uncertainties and shows ties to the onset of widespread convection. Utilizing reanalysis data, we investigate the link between blocking patterns, heat anomalies and the decay of blockings with respect to severe convective environments. This analysis reveals that severe thunderstorm environments across Europe are preceded by multi-day heat anomalies and a slow-moving upper-level wave pattern. With the predictability of blockings and heatwaves extending to several weeks, improved understanding of their evolution and following convective outbreaks is imperative to advance the predictive skill of severe convection. Advancing the understanding of links between large-scale processes and meso-scale convective clusters sheds light on the reasons for current limits in forecasting convective outbreaks and highlights possible windows of forecast opportunity, where predictability can be extended
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Lightning-Fast Thunderstorm Warnings: Predicting Severe Convective Environments with Global Neural Weather Models
No full textThe recently released suite of neural weather models can produce multi-day, medium-range forecasts within seconds, with a skill on par with state-of-the-art operational forecasts. Traditional neural model evaluation predominantly targets global scores on single
levels. Specific prediction tasks, such as severe convective environments, require much
more precision on a local scale and with the correct vertical gradients in between levels.
With a focus on the convective season of global hotspots in 2020, we assess the skill of
three top-performing neural weather models (Pangu-Weather, GraphCast, FourCastNet)
for two variables used to assess convective activity (Convective Available Potential Energy - CAPE, and Deep Layer Shear - DLS) at lead-times of up to 10 days against the
ERA-5 reanalysis and the IFS operational numerical weather prediction model. Looking
at the example of a US tornado outbreak on April 12 and 13, 2020, all models predict
elevated CAPE and DLS values multiple days in advance. The spatial structures in the
neural weather models are smoothed in comparison to IFS and ERA-5. The models show
differing biases in the prediction of CAPE values, with GraphCast capturing the value
distribution the most accurately and FourCastNet showing a consistent underestimation.
In seasonal analyses around the globe, we generally see the highest performance by Graph Cast and Pangu-Weather, which match or even exceed the performance of IFS. CAPE
derived from vertically coarse pressure levels of neural weather models nonetheless lacks
the precision of CAPE derived from the vertically fine resolution of numerical models.
The promising results here indicate that a direct prediction of CAPE in neural weather
models is likely to be skillful. This would open unprecedented opportunities for fast and
inexpensive predictions of severe weather phenomena. By advancing the assessment of
large neural weather models towards process-based evaluations we lay the foundation for
hazard-driven applications of artificial-intelligence-based weather forecasts
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe 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
- …
