bluuebunny/crossref_metadata_2025 huggingface dataset:
Composition and development of the clay fraction in danish soils. An overview / Composition et évolution de la fraction argileuse des sols danois. Un aperçu
Authors: Moberg Jens Peter
Published: June 2018

Composition et évolution de la fraction argileuse des sols danois. Un aperçu — Des études de la fraction argileuse des sols danois montrent que souvent le quartz et le feldspath constituent 20 à 30 pour cent de cette fraction, et que normalement la distribution des minéraux argileux en feuillets est la suivante : illite >> smectite > chlorite et autres minéraux argileux hydroxy-interstratifiés = kaolinite > vermiculite. Des oxyhydroxydes de Fe sont présents dans tous les sols, et la gibbsite est présente dans nombre de sols développés sur les dépôts d'âge glaciaire pré-Weichselien. Des hydroxydes d'Al et des oxyhydroxydes de Al-Si moins bien cristallisés ne se trouvent que dans les spodosols. Le quartz, le feldspath, la majorité de l'illite, la kaolinite et quelques-uns des autres minéraux argileux en feuillets peuvent être d'origine détritique, tandis qu'une fraction substantielle des minéraux argileux à silicate à feuillets 2 :1 peut avoir été néoformée dans le sol.
La tectonique polyphasée dans la boutonnière précambrienne de Bou Azzer (Anti-Atlas central, Maroc) : apports de l'imagerie spatiale Landsat-MSS et de l'analyse structurale de terrain / The Panafrican tectonic events in the eroded anticline of Bou Azzer (Central Anti-Atlas, Morocco), from Landsat-MSS imagery and field structural analysis
Authors: Emran Anas , Chorowicz Jean
Published: June 2018

L'analyse de l'image spatiale Landsat-MSS et l'étude de la déformation sur le terrain montrent les caractéristiques des phases de déformations successives dans la boutonnière précambrienne de Bou Azzer (Anti-Atlas, Maroc). L'évolution tectonique comprend : une phase panafricaine majeure (Bl), tangentielle, marquée par une compression orientée WNW-ESE ; une phase panafricaine tardive (B2), compressive, correspondant à un serrage orienté N020° à N030° ; une phase post-panafricaine précoce (PPi), décrochante à accidents N070° senestres, cri étant orienté N085° et cr3 N175° ; une phase post-panafricaine tardive (PP2), extensive, cri étant vertical et <r3 orienté NE-SW ; une phase hercynienne compressive, avec cri NNW-SSE et <r3 WSW-ENE. Nous mettons en évidence le caractère synsédimentaire des deux phases extensives PPi et PP2 et le lien avec le volcanisme du P3 et l'Adoudounien inférieur. La distension post-panafricaine s'est donc produite en deux temps : formation de fossés continentaux où s'accumule un matériel détritique grossier, installation d'un large bassin sédimentaire épicontinental.
Les mécanismes du dépoussiérage. The dedusting mechanims
Authors: Castel Bernard
Published: June 2018

Après une brève présentation des généralités sur les techniques de dépoussiérage, comprenant l'analyse des bilans matière et les définitions nécessaires, on présente un inventaire des outils de séparation solide/gaz : les chambres de sédimentation, les cyclones, les laveurs (dont le cas particulier du Venturi), les filtres et les séparateurs électrostatiques. Pour chaque outil, on fait état de son principe de fonctionnement et des paramètres permettant le contrôle et la conduite. Enfin, on propose un synoptique d'aide au choix d'un appareil, selon les caractéristiques du gaz, les performances à atteindre, les spécifications propres au procédé et les données économiques.
La flore de la zone de transition de l'Autunien supérieur de Lodève / The flora from the transition zone of the upper Autunian of the Lodève basin
Authors: Galtier Jean , Broutin Jean
Published: June 2018

Une flore provenant de la mine d'uranium (COGEMA) près de Lodève est décrite. Elle appartient à la zone de transition ou Autunien alternant rouge et gris. Quoique dominé par Antunia conferta et Walchia piriformis, cet assemblage montre une grande diversité de formes calliptéridiennes (sept espèces) en même temps que la présence d'«éléments stéphaniens» tels que Calamités et Annularia. Cette flore présente ainsi des caractères intermédiaires entre la célèbre flore des Tuilières de l'Autunien gris sous-jacent et d'autres flores de la même zone de transition précédemment décrites.
Géodynamique actuelle du bassin versant de l'Oued Tensift (Maroc) : érosion mécanique et bilan des transports solides fluviaux. / Present geodynamic of the Tensift drainage basin (Morocco) : mechanical erosion and fluvial transports of sediments
Authors: Haida Souad , Snoussi Maria , Latouche Claude , Probst J.L.
Published: June 2018

Present geodynamic of the Tensift drainage basin (Morocco) : mechanical erosion and fluvial transports of sediments

The aim of this study is to improve the knowledge on sediment mobilization in semi-arid climate through a global estimation of erosion-transport-sedimentation budget in the Tensift drainage basin (Morocco).

The lithological material which could be mobilized by erosion of the main formations has been estimated using simple models to a specific value of 373 t.km-2.an-1. Sediment discharge to Atlantic ocean is calculated using river transport measurements to 200 t.km-2.an-1. This last flux represents 69% of the total sediments potentially eroded in the Tensift basin. The remaining 31% could be attributed to sedimentary deposits in the alluvial plain.

The comparison between the fluvial transports of different floods during the same year exhibits the importance of the hydrological processes in the mechanical erosion control. Moreover, a survey of three hydrological years (dry. mean and humid) allows to follow the present interannual geodynamic evolution of this basin. The sediment budget shows that the climatic factor controls the fluvial transport for the different lithologies. Topography and lithology represent complementary factors, mainly in mountainous part of the drainage basin. Replaced in the whole Maghreb context, the mean values calculated for the Tensift river are in good agreement with those already obtained by various authors (Snoussi et al., 1989 et 1990 ; Probst et Amiotte Suchet, 1992) regarding moroccan. algerian and tunisian rivers. This study confirms the importance of the mechanical erosion and fluvial sediment transports in semi-arid climatic area such as the Tensift draining basin. The sediment yield measured in this region are for example much more higher (1 to 2 order of magnitude) than those observed in tropical Africa.
Light Scattering by Fractal Dust Aggregates. II. Opacity and Asymmetry Parameter
Authors: Tazaki Ryo , Tanaka Hidekazu
Published: June 2018

Optical properties of dust aggregates are important at various astrophysical environments. To find a reliable approximation method for optical properties of dust aggregates, we calculate the opacity and the asymmetry parameter of dust aggregates by using a rigorous numerical method, the T-Matrix Method, and then the results are compared to those obtained by approximate methods: the Rayleigh–Gans–Debye (RGD) theory, the effective medium theory (EMT), and the distribution of hollow spheres method (DHS). First of all, we confirm that the RGD theory breaks down when multiple scattering is important. In addition, we find that both EMT and DHS fail to reproduce the optical properties of dust aggregates with fractal dimensions of 2 when the incident wavelength is shorter than the aggregate radius. In order to solve these problems, we test the mean field theory (MFT), where multiple scattering can be taken into account. We show that the extinction opacity of dust aggregates can be well reproduced by MFT. However, it is also shown that MFT is not able to reproduce the scattering and absorption opacities when multiple scattering is important. We successfully resolve this weak point of MFT, by newly developing a modified mean field theory (MMF). Hence, we conclude that MMF can be a useful tool to investigate radiative transfer properties of various astrophysical environments. We also point out an enhancement of the absorption opacity of dust aggregates in the Rayleigh domain, which would be important to explain the large millimeter-wave opacity inferred from observations of protoplanetary disks.
The Absolute Magnitude of the Sun in Several Filters
Authors: Willmer Christopher N. A.
Published: June 2018

This paper presents a table with estimates of the absolute magnitude of the Sun and the conversions from vegamag to the AB and ST systems for several wide-band filters used in ground-based and space-based observatories. These estimates use the dustless spectral energy distribution (SED) of Vega, calibrated absolutely using the SED of Sirius, to set the vegamag zero-points and a composite spectrum of the Sun that coadds space-based observations from the ultraviolet to the near-infrared with models of the Solar atmosphere. The uncertainty of the absolute magnitudes is estimated by comparing the synthetic colors with photometric measurements of solar analogs and is found to be ∼0.02 mag. Combined with the uncertainty of ∼2% in the calibration of the Vega SED, the errors of these absolute magnitudes are ∼3%–4%. Using these SEDs, for three of the most utilized filters in extragalactic work the estimated absolute magnitudes of the Sun are M

B
 = 5.44, M

V
 = 4.81, and M

K
 = 3.27 mag in the vegamag system and M

B
 = 5.31, M

V
 = 4.80, and M

K
 = 5.08 mag in AB.
An updated checklist of the Tenebrionidae sec. Bousquet et al. 2018 of the Algodones Dunes of California, with comments on checklist data practices
Authors: Johnston M. Andrew , Aalbu Rolf , Franz Nico
Published: June 2018

Generating regional checklists for insects is frequently based on combining data sources ranging from literature and expert assertions that merely imply the existence of an occurrence to aggregated, standard-compliant data of uniquely identified specimens. The increasing diversity of data sources also means that checklist authors are faced with new responsibilities, effectively acting as filterers to select and utilize an expert-validated subset of all available data. Authors are also faced with the technical obstacle to bring more occurrences into Darwin Core-based data aggregation, even if the corresponding specimens belong to external institutions. We illustrate these issues based on a partial update of the Kimsey et al. 2017 checklist of darkling beetles - Tenebrionidae sec. Bousquet et al. 2018 - inhabiting the Algodones Dunes of California. Our update entails 54 species-level concepts for this group and region, of which 31 concepts were found to be represented in three specimen-data aggregator portals, based on our interpretations of the aggregators' data. We reassess the distributions and biogeographic affinities of these species, focusing on taxa that are precinctive (highly geographically restricted) to the Lower Colorado River Valley in the context of recent dune formation from the Colorado River. Throughout, we apply taxonomic concept labels (taxonomic name according to source) to contextualize preferred name usages, but also show that the identification data of aggregated occurrences are very rarely well-contextualized or annotated. Doing so is a pre-requisite for publishing open, dynamic checklist versions that finely accredit incremental expert efforts spent to improve the quality of checklists and aggregated occurrence data.
Discovering New Fungal Species to Kick-Start a Passion for Science
Authors: Padamsee Mahajabeen , Buchanan Peter , Weir Bevan , Petterson Megan
Published: June 2018

Our recent project supported through Unlocking Curious Minds funding from New Zealand’s Ministry of Business Innovation and Employment enabled us to introduce school students to the fascinating, yet frequently forgotten, fungal kingdom. In this project, we demystified the science of species discovery. We collaborated with students at three schools and initially introduced the fungal kingdom to students that ranged in age from 8–17. We then set out to find, discriminate, and describe a species new to science with each school.

We communicated with the students through social media and traditional means at each step of the discovery process, which culminated with the students visiting us at Manaaki Whenua-Landcare Research in Auckland. The students were given a tour of our two nationally significant collections, the New Zealand Fungarium and the International Collection of Microorganisms from Plants. During this visit we revealed the genus of the fungus that the students had discovered and the students chose the species epithets for each new fungal species. These new species were published in scientific papers in which the names of the students, and their main teachers, from each school were included. Our project enabled us not only to educate students about Fungi, which are often overlooked in school curricula, but also to introduce students to the importance of species discovery, taxonomy, and the role of collections.
A Collaborative Effort toward an Integrative Web Portal at the University of Wisconsin-Madison
Authors: Leith Elizabeth
Published: June 2018

The University of Wisconsin (UW) Madison's five main natural history collections (Anthropology, Entomology, Geology, Herbarium, and Zoology) have joined together to begin digitizing our collections and disseminating information online via an integrated web portal. This two-year project, currently beginning its second year, is the result of a UW2020 grant, "Development of the Wisconsin Integrated Biodiversity, Human, and Environmental Specimen Portal."

The first objective of the grant is to initiate, or assist with current, digitizing efforts within each collection. This step includes photographing, inventorying, and/or cataloging specimens and either entering new records or updating existing records in collection-specific databases. The remaining objective is to design and implement a web presence (in the planned format of a web portal) to allow the ability to search a limited number of fields from all of the collections' databases. This step, currently still in the planning stages, involved hiring a temporary employee to liaise between all of the collections, perform the web design, and write the background scripts to pull needed data from each collection's database program. This presentation will outline the grant goals and progress to date by each collection, although the primary focus will be on the successes and limitations in the Anthropology collection.
Les intellectuels argentins face à la Grande Guerre
Authors: Molinaro Natalia
Published: June 2018

Résumé Malgré la politique de neutralité adoptée par l’Argentine pendant la Grande Guerre, celle-ci ne fut pas sans conséquences pour le pays, que ce soit sur le plan économique, politique, social ou culturel. Les débats générés au sein de l’opinion par le conflit et la ligne adoptée par les gouvernements successifs se radicalisèrent à partir de 1917, après l’accumulation d’incidents diplomatiques remettant en cause les relations de l’Argentine avec l’Allemagne et suite à l’entrée en guerre des États-Unis, aux côtés de plusieurs pays latino-américains. Cet article propose un aperçu des positionnements des intellectuels argentins face à la Grande Guerre et une synthèse des travaux menés par l’historiographie récente dans ce domaine.
Libertad cristiana y sumisión política en el pensamiento luterano
Authors: Utrera García Juan Carlos
Published: June 2018

Este trabajo pretende mostrar la trascendencia de la noción de «libertad cristiana» para la reflexión política de Lutero, en tanto permite desvelar directamente los fundamentos de sus doctrinas eclesiológicas e, indirectamente, indagar las bases últimas sobre las que elabora su teoría de la autoridad civil. Esto conduce a señalar la centralidad de determinados elementos de la teología voluntarista luterana que dan unidad a su pensamiento y, en definitiva, conforman un modelo teológico político de indudable influencia sobre la modernidad.
Paz religiosa, libertad religiosa: la apuesta por el pacifismo de Pedro Ximénez en el Dialogus de pace (1579)
Authors: García Pinilla Ignacio J.
Published: June 2018

Pedro Ximénez (Petrus Ximenius, 1524-1595) es un personaje muy poco conocido actualmente, a pesar del gran prestigio del que gozó en vida. La reciente identificación del anónimo Dialogus de pace como obra suya permite estudiar su avanzada postura ante el habitual uso de la coerción para imponer la unidad religiosa, en concreto en el marco de la conferencia de paz de 1579 en Colonia. En esta obra, marcadamente pacifista, incide en los conceptos de amnistía, consenso y restitución, con un desarrollo que puede ponerse en parangón con las aportaciones de otros españoles sobre el mismo asunto, como las de Fadrique Furio Ceriol.
El Commentaire Philosophique de Pierre Bayle: una interpretación alternativa
Authors: Bahr Fernando
Published: June 2018

El Commentarie philosophique sur ces paroles de Jésus-Christ «Contrain-les d’entrer» del calvinista francés Pierre Bayle constituye uno de los capítulos más interesantes en la elaboración moderna del concepto de tolerancia civil. En este artículo se pasa revista a algunas de las ideas desarrolladas en esa obra y se analizan particularmente las dificultades para concilliar los criterios racionalistas presentados en la Parte I con los razonamientos escépticos que dominan en la Parte II. Al respecto, con el apoyo de pasajes hasta aquí poco reconocidos, se ofrece una lectura alternativa, a saber, que Bayle no habría querido elaborar en el Commentaire philosophique una teoría de la tolerancia sino recopilar argumentos contrarios a la persecución religiosa, argumentos que podrían demostrar su eficacia en situaciones específicas.
Notas para el estudio de la secularización de la cultura: dos iniciativas irénicas de Leibniz
Authors: De Salas Jaime
Published: June 2018

El artículo se aproxima a dos iniciativas irénicas en las que Leibniz intervino en los años centrales de su carrera: la de Cristóbal de Rojas que buscaba la reconciliación de católicos y protestantes y la que Leibniz y Molano sostuvieron con D. E. Jablonsky dentro de las relaciones de las cortes luterana y calvinista de Hannover y Berlín. Estudia particularmente la dual dimensión desde la que interviene Leibniz: como miembro de la Corte de Hannover y como autor de una metareflexión que subraya la importancia moral de esta iniciativa, para la cual son de interés la distinción orteguiana entre ideas y creencias, así como la atención a la forma.
La crítica de la teología política en Toland
Authors: Espinosa Fco. Javier
Published: June 2018

Toland (1670-1722) fue un pensador que tenía como objetivos luchar por la libertad, la tolerancia religiosa y la sucesión protestante al trono de Gran Bretaña. Quería demostrar que no hay nada en el cristianismo contrario a la razón y que, por tanto, todas las ideas eran accesibles a todos, incluso a los pobres y a los ignorantes. Así intentaba acabar con el poder de las jerarquías religiosas. Frente a los intentos conservadores de utilización política de la religión, defendía «la unidad sin uniformidad».
Mandeville: la cultura del sentimiento religioso
Authors: Seoane Pinilla Julio
Published: June 2018

Mandeville es un autor que con claridad apostó por la tolerancia religiosa y por una religión de Estado con la que el «hábil político» era capaz de lograr la cohesión social y el progreso económico. Mi trabajo muestra esta evidencia como punto de partida pero quiere presentar un hecho curioso: una vez que el trabajo de organización político y social se ha realizado con materiales meramente humanos (no religiosos), Mandeville considera que es necesario plantearse preguntas de cariz religioso que tratan a Dios como un amigo que nos da esperanza para poder vivir en un mundo de escala humana.
La mirada del filósofo y la mirada del historiador. Las reflexiones de Hume sobre la Reforma protestante
Authors: López Sastre Gerardo
Published: June 2018

Para Hume no pueden demostrarse ni la existencia de Dios ni la inmortalidad del alma. Las creencias religiosas son, por tanto, irracionales; pero en tanto que operan en muchas sociedades hay que estudiar qué efectos producen. En el caso de la Reforma protestante dio pábulo a los proyectos políticos más descabellados, pero también desarrolló un ideal de libertad. Sentados estos puntos, analizaremos las propuestas políticas que Hume pensaba que podían obtenerse de este análisis histórico con vistas a minimizar los males sociales que las religiones provocaban.
Los obispos de Cartagena de Indias durante el siglo XVIII: criollos y regalismo
Authors: Serrano García Manuel
Published: June 2018

El obispado de Cartagena de Indias presenta las características propias de la Iglesia americana durante el siglo XVIII, a saber, criollismo e importancia del clero secular. No obstante, las particularidades de la ciudad de Cartagena permiten establecer nuevos puntos de vista sobre estos aspectos. La importancia del sector comercial en el patriciado urbano, condiciona el auge del criollismo en la ciudad que favoreció el número de obispos criollos. Al mismo tiempo, a pesar de la escasez de rentas y de ser un obispado de segundo orden, el periodo de vacantes se vio reducido respecto a otras zonas del virreinato, conllevando una mejora en la administración diocesana.
Celebraciones teresianas en el Siglo de Oro
Authors: Arellano Ignacio
Published: June 2018

El artículo estudia, a partir de las relaciones de fiestas y otra documentación, las celebraciones por la beatificación y canonización de Santa Teresa, examinando la estructura de la fiesta y sus elementos: procesiones, función de las alegorías, técnicas emblemáticas, certámenes poéticos, escenografía y representaciones teatrales… para mostrar el doble objetivo de exaltación hagiográfica doctrinal y diversión popular de estos eventos festivos.
El archivo del Monasterio Cisterciense de Nuestra Señora de Belmonte (Asturias, España) en la historiografía moderna (1572-1807)
Authors: Fernández Ortiz Guillermo
Published: June 2018

En la Edad Moderna los archivos de las instituciones religiosas van a ser frecuentados por eruditos e historiadores para componer sus trabajos de carácter histórico. El objetivo del presente trabajo es estudiar, a través de un estudio de caso, cómo los historiadores de los siglos XVI a XIX acceden a un archivo monástico (el archivo del monasterio de Belmonte, Asturias, España), la accesibilidad a este archivo privado y el celo mostrado por los monjes del monasterio.
Misiones interiores y cambio social en la España de Franco. Una visión a través de la actividad misionera de la Asesoría Eclesiástica de Sindicatos
Authors: Bernal García Francisco
Published: June 2018

El objetivo de este artículo es evaluar el impacto religioso y social de las misiones que la Asesoría Eclesiástica de Sindicatos llevó a cabo en España entre 1949 y 1972. Para ello, analizaremos cinco aspectos fundamentales. Primeramente, estudiaremos los esfuerzos realizados por los misioneros para localizar a personas no bautizadas o que no hubiesen recibido la primera comunión, con la finalidad de administrarles tales sacramentos. En segundo lugar, analizaremos el uso de las misiones como instrumento para lograr una restauración de la moral. En tercer lugar, expondremos las dificultades que el mensaje misional encontró para adaptarse a los cambios sociales y culturales derivados del crecimiento económico de la década de 1960. En cuarto lugar, subrayaremos los obstáculos que los misioneros encontraron para lograr que su mensaje fuera escuchado por la clase obrera y enfatizaremos la persistencia de fenómenos de «oposición a la misión». Y en quinto y último lugar, realizaremos una evaluación de los datos de asistencia a algunas misiones, como forma de determinar hasta qué punto éstas produjeron una verdadera recatolización. En conjunto, estos cinco aspectos pretenden constituir una aportación significativa al estudio de las misiones interiores en la España de la época de Franco.
Perceptions of young men at the Free State School of Nursing with regards to teenage pregnancy
Authors: Madlala Siphiwe T. , Sibiya Maureen N. , Ngxongo Thembelihle S.P.
Published: June 2018

Background: Teenage pregnancy is a socio-economic challenge and a serious public health problem for communities in South Africa. It is, therefore, imperative that effective interventions and programmes be implemented to address this problem. A number of research studies have been conducted on teenage pregnancy in South Africa, but their focus was mainly on teenage girls excluding young men’s involvement in teenage pregnancy.Aim: The aim of the study was to determine the perceptions of young men between the ages of 18 and 23 years towards teenage pregnancy.Methods: A qualitative, explorative semi-structured interview descriptive design was used toconduct the study. The study was guided by the Johnson’s Behavioral System Model. Purposive sampling was used to select 10 participants with whom semi-structured interviews were conducted. Thematic analysis of data were performed.Setting: The study was conducted in Free State School of Nursing’s two main campuses.Results: The findings of this study revealed that young men were not involved in reproductive health programmes aiming to prevent teenage pregnancies. Father and son’s poor communication on issues related to sex and teenage pregnancy contributes to unprotected sexual intercourse resulting in teenage pregnancy. Cultural and traditional practices such as the withdrawal method, not using contraceptives, and misleading teachings at the initiation schools contribute to risk factors of teenage pregnancy.Conclusion: There is still a gap in reproductive health that needs to be filled by involving young men to reduce teenage pregnancies. Involving young men in reproductive health programmes could lead to a decreased number of teenage pregnancies. Factors, such as cultural and traditional practices, and father and son sexual health education, need to be taken into consideration to prevent teenage pregnancies.
Squeak Noise Prediction for Systems with Dry Friction Damping
Authors: Weisheit Konrad , Marburg Steffen
Published: June 2018

Squeak noise is a phenomenon which is often categorized as BSR, i.e. buzz, squeak and rattle. It arises from stick-slip movement between parts in contact. In a vehicle cabin, this noise is undesirable and has to be prevented. Simulation methods are used to find critical contact conditions in the construction at an early stage of development. For accurate predictions, these methods have to take nonlinear behavior into account. In this paper, the Harmonic Balance Method is applied to a three-dimensional finite element model in order to calculate vibrations of systems with dry friction contacts. The system’s sensitivity to different contact formulations is investigated. For a reference, a test rig has been built. It consists of a beam with harmonic excitation. The beam is clamped at one end. At the other end it is in dry friction contact with a plate. Different excitation levels, frequencies, normal contact forces and material pairs are evaluated. The system’s response in time and frequency domain is compared to corresponding simulation results. The contact definition is updated to achieve accuracy in calculated dynamic responses. Results of calculation can be used to estimate the radiated noise, e.g. by determining the Equivalent Radiated Power.
Adult training in the digital age
Authors: Bode Eckhardt , Gold Robert
Published: June 2018

Digital technologies will both create new jobs and replace existing ones. To cope with increasing labor market dynamics in the digital age, workers will have to become more mobile across jobs, occupations, and industries. The relative importance of their job-specific skills will decrease while that of their general skills applicable to various occupations will increase. The G20 should establish national adult training programs that focus on improving workers’ general skills, specifically their theoretical, non-cognitive, and digital skills. These general skills will enable workers to work with technology instead of competing with it, thereby increasing their job mobility and employability.
Recent decrease trend of atmospheric mercury concentrations in East China: the influence of anthropogenic emissions
Authors: Tang Yi , Wang Shuxiao , Wu Qingru , Liu Kaiyun , Wang Long , Li Shu , Gao Wei , Zhang Lei , Zheng Haotian , Li Zhijian , Hao Jiming
Published: June 2018

Abstract. Measurements of gaseous elemental mercury (GEM), other air pollutants, including SO2,
NOx, O3, PM2.5, and CO, and meteorological
conditions were carried out at Chongming Island in East China from 1 March
2014 to 31 December 2016. During the sampling period, GEM
concentrations significantly decreased from 2.68 ± 1.07 ng m−3 in
2014 (March to December) to 1.60 ± 0.56 ng m−3 in 2016 (March to
December). Monthly mean GEM concentration showed a significant decrease, at
a rate of -0.60±0.08 ng m−3 yr−1 (R2=0.64,
p < 0.01 significance level). Combining the analysis of the potential
source contribution function (PSCF), principle component analysis (PCA), and
the emission inventory, we found that the Yangtze River Delta (YRD) region was the
dominant source region of GEM in Chongming Island and the main source
industries included coal-fired power plants, coal-fired industrial boilers,
and cement clinker production. We further quantified the effect of emission
change on the air Hg concentration variations at Chongming Island through a
coupled method of trajectory clusters and air Hg concentrations. It was
found that the reduction of domestic emissions was the main driver of GEM
decline in Chongming Island, accounting for 70 % of the total decline. The
results indicated that air pollution control policies targeting SO2,
NOx, and particulate matter reductions had significant co-benefits on
GEM.
Multivariate analysis of Kelvin wave seasonal variability in ECMWF L91 analyses
Authors: Blaauw Marten , Žagar Nedjeljka
Published: June 2018

Abstract. This paper presents a multivariate analysis of the linear Kelvin waves (KWs)
represented by the operational 91-level ECMWF analyses in the 2007–2013 period,
with a focus on seasonal variability. The applied method simultaneously filters
KW wind and temperature perturbations in the continuously stratified
atmosphere on the spherical Earth. The spatial filtering of the three-dimensional
KW structure in the upper troposphere and lower stratosphere is
based on the Hough harmonics using several tens of linearized shallow-water
equation systems on the spherical Earth with equivalent depths ranging from 10 km to a
few metres. Results provide the global KW energy spectrum. It shows a clear seasonal cycle with the KW activity
predominantly in zonal wavenumbers 1–2, where up to 50 % more energy is observed during the solstice seasons
in comparison with boreal spring and autumn. Seasonal variability in KWs in the upper troposphere and lower stratosphere is examined in
relation to the background wind and stability.
A spectral bandpass filtering is used to decompose variability into three period ranges:
seasonal, intra-seasonal and intra-monthly variability components.
Results reveal a slow seasonal KW component with a robust dipole structure in the upper troposphere with its position
determined by the location of the dominant convective outflow throughout the seasons. Its maximal strength occurs
during boreal summer when easterlies in the eastern hemisphere are strongest. The two other components
represent vertically propagating KWs and are observed throughout the year with seasonal variability mostly
found in the wave amplitudes being dependent on the seasonality of the background easterly winds and static stability.
High–Arctic aircraft measurements characterising black carbon vertical variability in spring and summer
Authors: Schulz Hannes , Bozem Heiko , Zanatta Marco , Leaitch W. Richard , Herber Andreas B. , Burkart Julia , Willis Megan D. , Hoor Peter M. , Abbatt Jonathan P. D. , Gerdes Rüdiger
Published: June 2018

Abstract. The vertical distribution of black carbon (BC) particles in the Arctic atmosphere is one of the key parameters controlling its radiative forcing. Hence, this work investigates the presence and properties of BC over the high Canadian Arctic. Airborne campaigns were performed as part of the NETCARE project and provided insights into the variability of the vertical distributions of BC particles in summer 2014 and spring 2015. The observation periods covered evolutions of cyclonic disturbances to the polar dome that caused and changed transport of air pollution into the High–Arctic, as otherwise the airmass boundary largely impedes entrainment of pollution from lower latitudes. A total of 48 vertical profiles of refractory BC (rBC) mass concentration and particle size, extending from 0.1 to 5.5 km altitude, were obtained with a Single–Particle Soot Photometer (SP2). Generally, the rBC mass concentration decreased from spring to summer by a factor 10. Such depletion was associated with a decrease of the mean rBC particle diameter, from approximately 200 nm to 130 nm at low altitude. Due to the very low number fraction, rBC particles did not substantially contribute to the total aerosol population in summer. Profiles analysed with potential temperature as vertical coordinate revealed characteristic variability patterns due to different balances of supply and removal of rBC in specific levels of the stable atmosphere. Kinematic back–trajectories were used to investigate transport pathways into these levels. The lower polar dome was influenced by low–level transport from sources within the cold central and marginal Arctic. During the spring campaign, a cold air outbreak over eastern Europe additionally caused northward transport of air from a corridor over western Russia to Central Asia that was affected by emissions from gas flaring, industrial activity and wildfires. This caused rBC concentrations between about 500 to 1800 m altitude to gradually increase from 32 to 49 ng m−3. The temporal development of transport to the level above, at around 2500 m, caused the initially low concentration to increase from
Ice core evidence for decoupling between mid-latitude atmospheric water cycle and Greenland temperature during the last deglaciation
Authors: Landais Amaëlle , Capron Emilie , Masson-Delmotte Valérie , Toucanne Samuel , Rhodes Rachael , Popp Trevor , Vinther Bo , Minster Bénédicte , Prié Frédéric
Published: June 2018

Abstract. The last deglaciation represents the most recent example of natural global warming associated with large-scale climate changes. In addition to the long-term global temperature increase, the last deglaciation onset is punctuated by a sequence of abrupt changes in the Northern Hemisphere. Such interplay between orbital- and millennial-scale variability is widely documented in paleoclimatic records but the underlying mechanisms are not fully understood. Limitations arise from the difficulty in constraining the sequence of events between external forcing, high- and low- latitude climate and environmental changes. Greenland ice cores provide sub-decadal-scale records across the last deglaciation and contain fingerprints of climate variations occurring in different regions of the Northern Hemisphere. Here, we combine new ice d-excess and 17O-excess records, tracing changes in the mid-latitudes, with ice δ18O records of polar climate. Within Heinrich Stadial 1, we demonstrate a decoupling between climatic conditions in Greenland and those of the lower latitudes. While Greenland temperature remains mostly stable from 17.5 to 14.7 ka, significant change in the mid latitudes of northern Atlantic takes place at ~ 16.2 ka, associated with warmer and wetter conditions of Greenland moisture sources. We show that this climate modification is coincident with abrupt changes in atmospheric CO2 and CH4 concentrations recorded in an Antarctic ice core. Our coherent ice core chronological framework and comparison with other paleoclimate records suggests a mechanism involving two-step freshwater fluxes in the North Atlantic associated with a southward shift of the intertropical convergence zone.
Water and sediment fluxes in Mediterranean mountainous regions: comprehensive dataset for hydro-sedimentological analyses and modelling in a mesoscale catchment (River Isábena, NE Spain)
Authors: Francke Till , Foerster Saskia , Brosinsky Arlena , Sommerer Erik , Lopez-Tarazon Jose A. , Güntner Andreas , Batalla Ramon J. , Bronstert Axel
Published: June 2018

Abstract. A comprehensive hydro-sedimentological dataset for the Isábena catchment, northeastern
(NE) Spain, for the period 2010–2018 is presented to analyse water and
sediment fluxes in a Mediterranean mesoscale catchment. The dataset includes
rainfall data from 12 rain gauges distributed within the study area
complemented by meteorological data of 12 official meteo-stations. It
comprises discharge data derived from water stage measurements as well as
suspended sediment concentrations (SSCs) at six gauging stations of the River
Isábena and its sub-catchments. Soil spectroscopic data from 351
suspended sediment samples and 152 soil samples were collected to
characterize sediment source regions and sediment properties via
fingerprinting analyses. The Isábena catchment (445 km2) is located
in the southern central Pyrenees ranging from 450 m to 2720 m a.s.l.;
together with a pronounced topography, this leads to distinct temperature and
precipitation gradients. The River Isábena shows marked discharge
variations and high sediment yields causing severe siltation problems in the
downstream Barasona Reservoir. The main sediment source is badland areas
located on Eocene marls that are well connected to the river network. The
dataset features a comprehensive set of variables in a high spatial and
temporal resolution suitable for the advanced process understanding of water
and sediment fluxes, their origin and connectivity and sediment budgeting and
for the evaluation and further development of hydro-sedimentological models
in Mediterranean mesoscale mountainous catchments. The dataset is available at http://doi.org/10.5880/fidgeo.2018.011.
Thickness of marine Holocene sediment in the Gulf of Trieste (northern Adriatic Sea)
Authors: Trobec Ana , Busetti Martina , Zgur Fabrizio , Baradello Luca , Babich Alberto , Cova Andrea , Gordini Emiliano , Romeo Roberto , Tomini Isabella , Poglajen Sašo , Diviacco Paolo , Vrabec Marko
Published: June 2018

Abstract. We use various geophysical datasets (multibeam and singlebeam echosounder
data, sub-bottom profiling Chirp and sonar data and very high-resolution
boomer seismic data) along with published sedimentological data and depth
data from nautical charts in order to create models of the depth of the
seafloor and the base of Holocene marine sediment in the Gulf of Trieste. The
two models are later used in order to calculate the thickness of marine
Holocene sediment which has been depositing on the Late Pleistocene alluvial
plain since the Holocene transgression in the Italian and Slovenian parts of
the gulf. Thicker Holocene marine sedimentary sequences averaging at around
5 m are characteristic for the southeastern part of the gulf. In other parts
of the gulf the Holocene marine sedimentary cover is very thin or even
absent, except in close proximity to the shoreline and fluvial sediment
sources, in the area of the Trezza Grande paleodelta and above topographic
depressions of the Late Pleistocene base. The presented datasets available
from the OGS SNAP data repository (http://doi.org/cpz2) represent a
valuable reference for a wide variety of research disciplines dealing with
the dynamic Earth system in the Gulf of Trieste and could be used as a
valuable tool for designing sampling and geophysical campaigns in the studied
area.
Dynamics of the Askja caldera July 2014 landslide, Iceland, from seismic signal analysis: precursor, motion and aftermath
Authors: Schöpa Anne , Chao Wei-An , Lipovsky Bradley P. , Hovius Niels , White Robert S. , Green Robert G. , Turowski Jens M.
Published: June 2018

Abstract. Landslide hazard motivates the need for a deeper understanding of the events
that occur before, during, and after catastrophic slope failures. Due to the
destructive nature of such events, in situ observation is often difficult or
impossible. Here, we use data from a network of 58 seismic stations to
characterise a large landslide at the Askja caldera, Iceland, on 21 July
2014. High data quality and extensive network coverage allow us to analyse
both long- and short-period signals associated with the landslide, and
thereby obtain information about its triggering, initiation, timing, and
propagation. At long periods, a landslide force history inversion shows that
the Askja landslide was a single, large event starting at the SE corner of
the caldera lake at 23:24:05 UTC and propagating to the NW in the following
2 min. The bulk sliding mass was 7–16 × 1010 kg, equivalent
to a collapsed volume of 35–80 × 106 m3. The sliding
mass was displaced downslope by 1260 ± 250 m. At short periods, a
seismic tremor was observed for 30 min before the landslide. The tremor is
approximately harmonic with a fundamental frequency of 2.3 Hz and shows
time-dependent changes of its frequency content. We attribute the seismic
tremor to stick-slip motion along the landslide failure plane. Accelerating
motion leading up to the catastrophic slope failure culminated in an aseismic
quiescent period for 2 min before the landslide. We propose that precursory
seismic signals may be useful in landslide early-warning systems. The 8 h
after the main landslide failure are characterised by smaller slope failures
originating from the destabilised caldera wall decaying in frequency and
magnitude. We introduce the term “afterslides” for this subsequent,
declining slope activity after a large landslide.
Development of high-precision distributed wireless microseismic acquisition stations
Authors: Qiao Shuaiqing , Duan Hongmei , Zhang Qisheng , Zhang Qimao , Li Shuhan , Liu Shenghui , Liu Shiyang , Wang Yongqing , Yan Shichu , Li Wenhao , Guo Feng
Published: June 2018

Abstract. In recent years, owing to the shortage of oil and gas resources and increased difficulty in mining, traditional (wired) microseismic monitoring equipment has been unable to meet the needs of energy exploitation. Therefore, it is necessary to develop new high-precision seismic exploration and data acquisition systems. In this study, we combined advance acquisition systems with wireless technology to develop a new wireless microseismic acquisition system. The hardware circuit of the acquisition system mainly included a data acquisition board and a main control board. High-precision analog-to-digital conversion and digital filtering technologies were used to provide data with high signal-to-noise ratios, resolution, and fidelity to the acquisition stations. Key technologies were integrated into the ARM of the main control board. Reliable GPS technology was employed to realize synchronous acquisitions among various acquisition stations, and WIFI technology was used to achieve wireless data communication between acquisition stations and the central station, thus improving the data transmission speed and accuracy. After conducting a series of evaluation tests, it was found that the system was stable, convenient to use, and had high data accuracy, therefore providing significant support for the solution to problems encountered in current oil and gas exploration processes, such as the complicated environment and inconvenient construction.
Three-dimensional methane distribution simulated with FLEXPART 8-CTM-1.1 constrained with observation data
Authors: Groot Zwaaftink Christine D. , Henne Stephan , Thompson Rona L. , Dlugokencky Edward J. , Machida Toshinobu , Paris Jean Daniel , Sasakawa Motoki , Segers Arjo , Sweeney Colm , Stohl Andreas
Published: June 2018

Abstract. A Lagrangian particle dispersion model (FLEXPART CTM) is used to simulate global three-dimensional fields of trace gas abundance. These fields are constrained with surface observation data through nudging, a data assimilation method which relaxes model fields to observed values. Such fields are of interest to a variety of applications, such as inverse modelling, satellite retrievals and estimating global growth rates of greenhouse gases. Here, we apply this method to methane using 6 million model particles filling the global model domain. For each particle methane mass tendencies due to emissions based on several inventories, loss by reaction with OH, Cl, and O(1D), as well as observation data nudging were calculated. Model particles were transported by mean, turbulent and convective transport driven by 1° × 1° ERA Interim meteorology. Nudging is applied at 79 surface stations, which are mostly included in the WDCGG database or JR-STATION network in Siberia. For simulations of one year (2013), we perform a sensitivity analysis to show how nudging settings affect modelled concentration fields. These are evaluated with a set of independent surface observations and with vertical profiles in North America (NOAA/ESRL) and Siberia (YAK-AEROSIB and NIES). FLEXPART CTM results are also compared to simulations from the global Eulerian model, TM5, based on optimized fluxes. Results show that nudging strongly improves modelled methane near the surface, not only at the nudging locations, but also at independent stations. Mean bias at all surface locations could be reduced from over 20 ppb to less than 5 ppb through nudging. Near the surface, FLEXPART CTM, including nudging, appears better able to capture methane molar mixing ratios than TM5 with optimized fluxes, based on a larger bias of over 13 ppb in TM5 simulations. The vertical profiles indicate that nudging affects model methane at high altitudes, yet leads to very little improvement in the model results there. Averaged from 19 aircraft profile locations in North America and Siberia, root-mean square error (RMSE) changes only from 16.3 to 15.7 ppb through nudging, while the mean absolute bias increases from 5.3 to 8.2 ppb. The performance for vertical profiles is thereby similar to TM5 simulations based on TM5 optimized fluxes where we found a bias of 5 ppb and RMSE of 15.9 ppb. With this rather simple model setup, we thus provide three-dimensional methane fields suitable for use as boundary conditions in regional inverse modelling, as prior information for satellite retrievals, and for more accurate estimation of mean mixing ratios and growth rates. The method should also be applicable to other long-lived trace gases.
Evaluation of Monte Carlo tools for high energy atmospheric physics II: relativistic runaway electron avalanches
Authors: Sarria David , Rutjes Casper , Diniz Gabriel , Luque Alejandro , Ihaddadene Kevin M. A. , Dwyer Joseph R. , Østgaard Nikolai , Skeltved Alexander B. , Ferreira Ivan S. , Ebert Ute
Published: June 2018

Abstract. The emerging field of High Energy Atmospheric Physics studies events producing high energy particles and associated with thunderstorms, such as terrestrial gamma-ray flashes and gamma-ray glows. Understanding these phenomena requires appropriate models of the interaction of electrons, positrons and photons with air and electric fields. This work is made as a continuation of Rutjes et al. (2016), now including the effects of electric fields. We investigated results of three codes used in the community (Geant4, GRRR and REAM), for simulating the process of Relativistic Runaway Electron Avalanches. From analytical considerations, we show that the avalanche is mainly driven by electric fields and the ionisation and scattering processes determining the minimum energy of electrons that can runaway. To investigate this point further, we used a first simulation set-up to estimate the probability to produce a RREA from a relevant range of electron energies and electric field magnitudes. We found that the stepping methodology is important, and the stepping parameters have to be set up very carefully for Geant4. For example, a too large step size can lead to an avalanche probability reduced by a factor of 10, or a 40 % over-estimation of the average electron energy. Furthermore, the probability for the particles below 10 keV to accelerate and participate in the penetrating radiation is actually negligible for the full range of electric field we tested (E