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Vorhersage der Wassertemperatur von Seen und Talsperren über verschiedene Zeitskalen und Evaluierung der damit verbundenen Unsicherheiten und Vorhersagengüte
No full textFreshwater lakes are facing increasing stress due to climate change and the more frequent and intense extreme events. Therefore, we urgently need to develop workflows to forecast the long-term impacts of climate change under various emission scenarios and near-term forecasts to predict the response of the lake variables’ extreme events and inform decision-makers about mid and shortterm variabilities, enabling proactive and informed management. However, developing a forecasting workflow requires a proper understanding of the theoretical concepts and definitions of forecasts and projections, which are often not recognized correctly in the forecasting literature.
Forecasts should not only make predictions but also quantify uncertainties or skills to provide reliable information. This thesis aims at developing a general workflow focusing on lake temperature, which can be applied at different forecasting horizons. The workflow employs ensemble techniques, skill scoring, and uncertainty analysis, using state-of-the-art open-source climate data and lake models to provide robust forecasts. The workflows were applied at two sites: Lake Sevan, a large natural alpine lake, and the Wupper Reservoir, a highly flushed temperate reservoir.
The long-term end-of-the-century projections were conducted for Lake Sevan by employing a large multi-dimensional ensemble generated by forcing an ensemble of five hydrodynamic lake models with a multi-domain ensemble of CORDEX GCMs (General Circulation Models) and RCMs (Regional Climate Models) projections. The approach also included quantification of the contributions from the sources of uncertainty. The mid-term seasonal forecasts were conducted on the Wupper Reservoir by utilizing an integrated workflow of coupled Catchment-Lake and auxiliary inflow-temperature and outflow models, using the ECMWF SEAS-5 seasonal forecasts as forcing data. This project marked the first application of seasonal forecasts for lakes within a study that included multiple case studies and provided the corresponding forecast skills to address the probabilistic nature of the seasonal forecasts. The short-term forecasts employed a simplified version of the workflow used for seasonal forecasts but used the DWD ICON numerical weather predictions as first application of ICON for lakes.
The probabilistic nature of the climate projections poses challenges to the application, as predictability in some regions can be limited. However, the findings of this thesis confirm that the general concept is valid to address the probabilistic nature of climate and weather predictions, deliver forecasts for the targeted horizons, and include skills and uncertainty quantification to ensure reliability. This thesis identify when, where, and how these predictions can be relied on.Süßwasserseen stehen durch den Klimawandel und zunehmende und intensivere Extremereignisse unter wachsendem Stress. Es besteht daher ein dringender Bedarf an Workflows zur Vorhersage der langfristigen Auswirkungen des Klimawandels unter verschiedenen Emissionsszenarien und an kurzfristigen Vorhersagen der Reaktion von Seevariablen auf extreme Ereignisse. So können Entscheidungsträger über mittel- und kurzfristige Schwankungen informiert werden und ein proaktives Management ermöglicht werden. Die Entwicklung eines Prognose-Workflows erfordert jedoch ein angemessenes Verständnis der theoretischen Konzepte und Definitionen von Vorhersagen, die in der Prognoseliteratur oft nicht richtig erkannt werden.
Vorhersagen sollten nicht nur zukünftige Zustände abschätzen, sondern auch Unsicherheiten und die Vorhersagegüte quantifizieren, um zuverlässige Informationen zu liefern. Ziel dieser Arbeit ist die Entwicklung eines allgemeinen Workflow für Seetemperaturen, der für verschiedene Zeithorizonte anwendbar ist. Der Ansatz nutzt Ensembles, (skill)Gütemaß-Bewertungen und Unsicherheitsanalysen unter Verwendung moderne open-source Klimadaten und Seenmodelle, um robuste Vorhersagen zu liefern. Es wurde an zwei Standorten angewendet: Am Sewansee, einem großen natürlichen Alpensee, und an der Wuppertalsperre, einem Stausee der gemäßigten Zone mit kurzer Aufenthaltsdauer.
Für den Langzeithorizont wurden am Sevan-See Projektionen bis Ende des Jahrhunderts erstellt, indem fünf hydrodynamische Seenmodelle mit einem breiten Ensemble von CORDEX-GCM- und RCM-Klimaprojektionen angetrieben wurden. Dies erlaubte eine detaillierte Quantifizierung von Unsicherheitsquellen. Für die mittelfristigen saisonalen Vorhersagen in der Wuppertalsperre wurde ein integrierter Workflow aus gekoppelten Einzugsgebiets-See-Modellen und zusätzlichen Zufluss-Temperatur- und Abflussmodellen verwendet, die mit ECMWF SEAS-5 Daten gespeist wurden. Dies ist die erste Anwendung von saisonalen Vorhersagen für Seen in einer Studie mit mehreren Fallbeispielen und Vorhersagengüte, die den probabilistischen Charakter dieser Vorhersagen erfassen. Für die Kurzfristvorhersage wurde eine vereinfachte Version des saisonalen Workflows verwendet, diesmal mit der ICON-Wettervorhersage des DWD, der ersten ICON-Anwendung für Seen.
Dieser Ansatz der detaillierten Modellierung spezifischer Fallstudien unterstützt die Entwicklung von Arbeitsabläufen, die darauf abzielen, Prozesse genau darzustellen und somit Werkzeuge für das Seenmanagement bereitzustellen. Der probabilistische Charakter der Klimaprojektionen stellt eine Herausforderung für die Anwendung dar, da die Vorhersagbarkeit in einigen Regionen begrenzt sein kann. Die Ergebnisse dieser Arbeit bestätigen jedoch, dass das allgemeine Konzept gültig ist, um den probabilistischen Charakter von Klima- und Wettervorhersagen zu berücksichtigen, Vorhersagen für die angestrebten Horizonte zu liefern und Gütemaß und Unsicherheitsquantifizierung einzubeziehen, um Zuverlässigkeit zu gewährleisten. In dieser Arbeit wird ermittelt, wann, wo und wie man sich auf diese Vorhersagen verlassen kann
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Lake Sevan modeling data 2008- 2017 including inflows, outflow, temperature and model setup
No full textThis dataset is regarding the modeling work of Lake Sevan, the largest freshwater lake in the Caucasus titled (Shikhani et al., Simulating thermal dynamics of the largest lake in the Caucasus region: The mountain Lake Sevan). This data was used to drive the General Lake Model, calibrate the model, and validate it. It contains the inflows, the outflow, the lake bathymetry, water level observations, and the meteorology (average of observed stations), as well as the temperature profiles in both of the sampling points. Moreover, it contains the nml file of the settings of the GLM used for this manuscript. Between 2008 and 2017
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