1,720,983 research outputs found
Processed CO2 measurements during the 2021-2022 Saildrone 1079 mission (Eastern Tropical Atlantic area)
No full textIn the framework of the EuroSea project (Task 7.3), a demonstration mission in the Tropical Atlantic has been conducted to enhance and optimize the network design of the Tropical Atlantic Observing System (TAOS) following an integrative multi-platform approach. One Gen6 Saildrone Explorer USV equipped with a CTD, wind, and carbon measurements systems sailed to the Cape Verde region where it acquired data between September 2021 and February 2023. Objectives for this mission include developing an integrated multi-platform approach to improving carbon monitoring, data quality, and regional upscaling from moored instrumentation, biogeochemical Argo floats, autonomous surface observation, and remote sensing products. The present dataset is also part of the SOCAT 2023 database
Dataset for research article: "Coastal marine carbon and air-sea fluxes quantified from pH sensors on an extended AUV deployment
No full textData supports: Hammermeister et al. Coastal Marine Carbon and Air-Sea Fluxes Quantified from pH Sensors on an Extended AUV Deployment. Journal of Geophysical Research: Oceans</span
Seasonal and multiannual dynamics of the carbonate system in the surface waters of the Mediterranean Sea
No full textThe Mediterranean Sea, which has a rapid water masses’ renewal time, undergoes numerous upheavals in response to the current climate change induced by anthropic activities. As a consequence, the oceanic pH decrease, the temperature increase, and the modification of air-sea CO2 exchanges are already visible. In this context, the study of the oceanic carbonate system and its short- and long-term variability in this basin is essential to estimate the impact of current and future changes on the oceanic carbon cycle. This thesis, carried out in the framework of the PERLE project and the National Observation Services MOOSE and SOMLIT, aims to describe the variability of the oceanic carbonate system in the surface waters of three distinct regions of the Mediterranean basin. With the complementary use of high-resolution data acquisition tools (Argo floats, underwater gliders, instrumented mooring lines), this work has contributed to better understand and quantify the processes responsible for the short (seasonal) and long (multiannual) term variability. Although thermal processes and variations in total inorganic carbon (CT ) concentrations are generally accepted as the factors governing seasonal variability, this work has highlighted the impact of total alkalinity (AT ) variations on seasonal oceanic pCO2 changes in the Eastern Mediterranean Sea. Thus, the estimated ratio of annual variations in AT to CT in the Eastern sub-basin shows the interest of this metric to estimate the sensitivity of the system to changes in AT , and highlights the uniqueness of this sub-basin compared to other oceanic regions, including the Western Mediterranean Sea. In the coastal environment, freshwater intrusion events and CO2 plumes emitted by urban areas have been identified as significant contributors to seasonal variability. Windy events and water renewal time also impact these dynamic environments. The long-term evolution of the mediterranean carbonate system parameters is firstly controlled by increasing atmospheric CO2 concentration. Distinct processes between the Eastern and Western sub-basins may modulate these trends. In the North Western Levantine basin, an increase in the AT content seems to affect the long-term evolution of carbonate system properties over the past 20 years. The influence of alkalinity on the buffering capacities of oceanic waters has been highlighted in this work. In the Ligurian Sea, this work raises the hypothesis that the long-term trends in this region can be attributed to the peculiar hydrological dynamic. The presence of the Northern Current, which modulates biological, physical, and chemical processes, seems to impact the trends observed at the ANTARES site. Thus, this work highlights the important differences in the dynamics of carbonate system parameters across the Mediterranean basin on seasonal and multi-year scales. Understanding these major findings on oceanic carbonate chemistry requires process studies based on the implementation of sampling strategies adapted to these objectives. This raises the interest of this study area for a more global understanding of the oceanic carbon cycle.La mer Méditerranée, qui présente un temps de renouvellement de ses eaux rapide, subit de nombreuses perturbations en réponse au changement climatique actuel induit par les activités anthropiques. En conséquence, la baisse du pH des eaux, l’augmentation de la température et la modification des échanges air-mer de CO2 y sont observables. Dans ce contexte, l’étude du système des carbonates océanique et de sa variabilité à court et long termes dans ce bassin est essentielle pour estimer l’impact des changements actuels et à venir sur le cycle du carbone océanique. Ces travaux de thèse, réalisés dans le cadre du projet PERLE et des Services Nationaux d’Observation MOOSE et SOMLIT, visent à décrire la variabilité du système des carbonates océanique dans les eaux de surface de trois régions distinctes du bassin méditerranéen. Avec l’utilisation complémentaire d’outils d’acquisition de données à haute résolution (flotteurs Argo, planeurs sous-marins, lignes de mouillage instrumentées), ces travaux ont contribué à mieux comprendre et quantifier les processus responsables de la variabilité à court (saison) et long (pluriannuelle) termes. Bien que les processus thermiques et les variations des concentrations en carbone inorganique total (CT ) soient généralement admis comme étant les facteurs régissant la variabilité saisonnière, ces travaux ont mis en lumière l’impact des variations de l’alcalinité totale (AT ) sur les changements saisonniers de la pCO2 océanique en Méditerranée orientale. Ainsi, le rapport des variations annuelles de l’AT par rapport au CT estimé dans le sous-bassin oriental montre l’intérêt de cette métrique pour estimer la sensibilité du système aux changements de l’AT , et souligne la singularité de ce sous-bassin par rapport aux autres régions océaniques, y compris la Méditerranée occidentale. En milieu côtier, les événements d’intrusion d’eaux douces et les panaches de CO2 émis par les agglomérations urbaines ont été mis en évidence comme des contributeurs notables de la variabilité saisonnière. Les épisodes venteux et le temps de renouvellement des eaux impactent également ces environnements dynamiques. L’évolution à long terme des paramètres du système des carbonates en Méditerranée est contrôlée au premier ordre par l’augmentation de la concentration en CO2 atmosphérique. Des processus distincts entre les sous-bassins orientaux et occidentaux peuvent moduler ces tendances. Dans le Nord-Ouest du Levantin, une augmentation du contenu en AT semble affecter l’évolution à long terme des propriétés du système des carbonates au cours des 20 dernières années. L’influence de l’alcalinité sur les capacités tampons des eaux océaniques a été soulignée dans ces travaux. En mer Ligure, ces travaux soulèvent l’hypothèse que les tendances à long terme dans cette région peuvent être attribuées à la dynamique hydrologique particulière. La présence du Courant Nord, qui module les processus biologique, physique, et chimique, semble impacter les tendances observées au site ANTARES. Ainsi, ces travaux de thèse soulignent les différences de dynamique des paramètres du système des carbonates à travers le bassin méditerranéen aux échelles saisonnière et pluriannuelle. La compréhension de ces résultats majeurs sur la chimie des carbonates océanique nécessite des études de processus basées sur la mise en place de stratégies d’échantillonnage adaptées à ces objectifs. Ceci soulève l’intérêt de cette zone d’étude pour la compréhension plus globale du cycle du carbone océanique
Wind measurements and platform characteristics during the 2021-2022 Saildrone 1079 mission (Eastern Tropical Atlantic area)
No full textIn the framework of the EuroSea project (Task 7.3), a demonstration mission in the Tropical Atlantic has been conducted to enhance and optimize the network design of the Tropical Atlantic Observing System (TAOS) following an integrative multi-platform approach. One Gen6 Saildrone Explorer USV equipped with a CTD, wind, and carbon measurements systems sailed to the Cape Verde region where it acquired data between September 2021 and February 2023. Objectives for this mission include developing an integrated multi-platform approach to improving carbon monitoring, data quality, and regional upscaling from moored instrumentation, biogeochemical Argo floats, autonomous surface observation, and remote sensing products
CTD measurements during the 2021-2022 Saildrone 1079 mission (Eastern Tropical Atlantic area)
No full textIn the framework of the EuroSea project (Task 7.3), a demonstration mission in the Tropical Atlantic has been conducted to enhance and optimize the network design of the Tropical Atlantic Observing System (TAOS) following an integrative multi-platform approach. One Gen6 Saildrone Explorer USV equipped with a CTD, wind, and carbon measurements systems sailed to the Cape Verde region where it acquired data between September 2021 and February 2023. Objectives for this mission include developing an integrated multi-platform approach to improving carbon monitoring, data quality, and regional upscaling from moored instrumentation, biogeochemical Argo floats, autonomous surface observation, and remote sensing products
CO2 measurements during the 2021-2022 Saildrone 1079 mission (Eastern Tropical Atlantic area)
No full textIn the framework of the EuroSea project (Task 7.3), a demonstration mission in the Tropical Atlantic has been conducted to enhance and optimize the network design of the Tropical Atlantic Observing System (TAOS) following an integrative multi-platform approach. One Gen6 Saildrone Explorer USV equipped with a CTD, wind, and carbon measurements systems sailed to the Cape Verde region where it acquired data between September 2021 and February 2023. Objectives for this mission include developing an integrated multi-platform approach to improving carbon monitoring, data quality, and regional upscaling from moored instrumentation, biogeochemical Argo floats, autonomous surface observation, and remote sensing products.
The ASVCO2 system (pCO2 sensor type) on the SailDrone is equipped with on-board reference gas containers to calibrate itself before and after each measurement, and readings of zero gas and reference gas values (that span the ocean pCO2 values of the location where the system is deployed) are made immediately before the calibration
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
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