bluuebunny/crossref_metadata_2025 huggingface dataset:
Querying a Static and Dynamic Learner Corpus
Authors: Heift Trude , Caws Catherine
Published: January 2018

This chapter discusses the cyclical process of collecting and recycling learner data within the E-Tutor CALL system and presents a study on student usage of its data-driven learning (DDL) tool. E-Tutor consists of a static and dynamic learner corpus for L2 learners of German. The static learner corpus has been constructed from approximately 5000 learners who used the system over a period of five years. These learners provided millions of submissions from a variety of activity types. In addition, all concurrent E-Tutor users contribute data to a dynamic corpus, which allows them to compare and examine their ongoing system submissions to those contained in the static corpus. The authors conducted a study with 84 learners and recorded their interaction with the DDL tool of E-Tutor over one semester. Study results on student usage suggest that investigating sample input of a large, unknown user group might be less informative and of less interest to language learners than their own data. For the DDL tool to be useful for all proficiency levels, training and scaffolding must also be provided.
Analysis of Role Stress in the Indian IT Industry
Authors: Rathore Shubhangini
Published: January 2018

Contemporary industries face new competition requiring employees to work for longer hours under competitive time-bound deadlines. Prolonged exposure to such stressful situations leads to a depletion and exhaustion of resources in the mind and body with dysfunctional effects on job performance and overall organizational effectiveness. The Indian IT industry is a fast-paced service industry that is characterized by such stressful work situations and related outcomes. This chapter analyses the various factors that contribute to organizational stress and the role of demographic factors on role stress among the professionals of the Indian IT industry. A sample of 250 employees has been collected from the Delhi NCR region. Role stress has been measured by using the ORS scale which comprises of 10 dimensions of the role of stress that are measured by 50 items. The results show that there is a considerable amount of work related stress along with a significant impact of demographic factors on the role of stress amongst the IT professionals.
Recruitment Trends in the Contemporary Era
Authors: Chhabra Anu , Ahuja Vandana
Published: January 2018

Recruitment is the process of identifying and hiring the right talent for a job in an organization, within a timeframe and by incurring the least expenses. The life cycle of the recruitment process starts from identification of an open position which needs to be filled to the candidate joining the organisation formally. On hearing the word recruitment, what flashes in an individual's mind is the process the HR group would follow to choose a candidate, get him interviewed, cross levels, offer, joining formalities completion, and to integrate the new joinee with the organization's philosophy. But, over a period, this process has evolved and it has transformed its existence from a simple process to a much more organized and digitally equipped one. The importance of a recruitment service though has remained the same, that is, the candidate should have the right skills, right knowledge, aptitude, and most importantly, attitude. But what has been the focus of improvement of the Human resources is the time duration and the cost effectiveness.
Employee Online Communities
Authors: Alavi Shirin
Published: January 2018

This chapter seeks to impart understanding of the role of employee online communities for enhanced employee engagement and retention in an organization. The highly engaged and motivated employees would contribute more towards accomplishing the organizations goals. The various research studies conducted in the past across the world identify job satisfaction as a major determinant of employee engagement and retention. The role of internal communication through employee online communities of organizations or intranets is theoretically suggested to be a major influencer for the enhancement of employee engagement efforts. This can help to enhance and support culture, corporate values, mission statement, and annual company goals. The purpose of this chapter is to investigate the role that the employee online communities of organizations play in order to support the twin objectives of employee retention and engagement. Engaging employees can be the catalyst for inducing positive change among employees and, as a result, boosting an organization's success.
High Involvement Work Processes
Authors: Joy Manu Melwin
Published: January 2018

The purpose of this chapter is to examine the effect of high involvement work processes on employee withdrawal behaviors in information technology sector in India. It draws from the structured questionnaire data from 300 software engineers working in Infosys, CTS, and HCL. Data was analyzed to find out details related to the relationship between high involvement work processes and employee withdrawal behaviors. It was found that high involvement work processes have a strong negative impact on withdrawal behaviors. The relationship was found to be stronger in the case of work withdrawal behaviors compared to that of job withdrawal behaviors.
Three New Directions for Time Banking Research
Authors: Valek Lukas
Published: January 2018

This chapter aims to highlight three viable fields of research within the domain of time banking (TB), a time-currency-based complementary economy system that has been implemented in various frameworks now for more than three decades. The areas of information management (IM), knowledge management (KM), and open source software (OSS) are almost totally unexplored within time banking. In information management, attention has mainly been devoted to IM frameworks. One link (among others) between knowledge management and open source software has been found in a core concept of the time bank called co-production. Finally, all three of these fields can be related directly to time banking and should have a place in further research, the results of which could also have applications in the field of complementary economic systems in general.
Existential Graphs and Cognition
Authors: Clivio Caterina , Danesi Marcel
Published: January 2018

When looked at cumulatively, it can be said that American pragmatist philosopher Charles Sanders Peirce strove to understand cognition via his sign theory and especially his notion of existential graphs. Peirce put forth ideas for a discipline that would incorporate notions of psychology and semiotics into a unified ontological and epistemological theory of mind. The connecting link was his system of diagrammatic logic, called “existential graphs.” For Peirce a graph was more powerful than language as a means of understanding because it showed how its parts resembled relations among the parts of cognitive acts. Existential graphs show that cognition cannot be extracted from a linear or hierarchical succession of structures, but the very process of thinking itself in actu. In fact, Peirce called his graphs “moving pictures of thought” because they allow us to see how are thoughts are unfolding. In short, as Kiryuschenko (2012) puts it, “Graphic language allows us to experience a meaning visually as a set of transitional states, where the meaning is accessible in its entirety at any given here and now during its transformation” (p. 122).
The Reincarnation of the Aura
Authors: Bigliardi Victoria
Published: January 2018

In 1935, Walter Benjamin introduced the aura as the abstract conceptualization of uniqueness, authenticity, and singularity that encompasses an original art object. With the advent of technological reproducibility, Benjamin posits that the aura of an object deteriorates when the original is reproduced through the manufacture of copies. Employing this concept of the aura, the author outlines the proliferation of plaster casts of sculptures in eighteenth- and nineteenth-century Europe, placing contextual emphasis on the cultural and prestige value of originals and copies. Theories of authenticity in both art history and material culture are used to examine the nature of the aura and to consider how the aura transforms when an original object is lost from the material record. Through an object biography of a fifteenth-century sculpture by Francesco Laurana, the author proposes that the aura does not disappear upon the loss of the original, but is reincarnated in the authentic reproduction.
Influence of Opinion Leaders on Purchase Intention Using Social Network Analysis
Authors: Chen Yi-Fen , Tsai Chia-Wen , Ann Yu-Fu
Published: January 2018

This article examines social network centralities to identify peer group's opinion leader with the aim of determining whether an opinion leader and perceived value influence purchase intention in the field of paid mobile apps. Social network analysis (SNA) and regression analysis are applied to examine the hypotheses within the theoretical framework. The experiment involved a peer group of college students with total of 46 subjects. Using SPSS to analyze the influences of perceived value and the group's opinion leader on purchase intention, the results showed that consumer purchase intention is positively influenced by both the perceived value of paid mobile apps and positive advices given by opinion leader. In addition, an analysis using Ucinet 6 to examine consulting network centrality, friendship network centrality, and information centrality of every member of the group revealed that based on group structure, the group member having the highest centrality has the group's potential to be the opinion leader.
Air Flow Straighteners’ Application to Reduce the Power Consumption of Exhaust Ventilation Schemes
Authors: Azarov Valery N. , Sergina Natalia M. , Stefanenko I.V.
Published: January 2018

It was proposed to use air flow screw straightened units in outlet pipe of the dust collectors to reduce the aerodynamic resistance of exhaust ventilation systems. It is allowed to decrease power consumption for their maintenance operation consequently. The article describes the results of experimental studies to evaluate its effectiveness by applying the tangential screw straightened unit within ventilation system. The obtained results showed that the use of this device allows reducing the aerodynamic resistance of the cyclone by 14.6%, and for counter-swirling flows’ dust collector (CSFC) by 17.2-23.6%. It was found that meanings of the aerodynamic resistance depend on value the share proportion of the flow entering into lower CSFC apparatus’ input.
Modelling of Dust Dispersion of Emissions from Expanded Clay Manufacturing in the Atmosphere
Authors: Menzelintseva N.V. , Karapuzova Natalia Yurevna , Vlasova O.S. , Redhwan A.M.
Published: January 2018

The manufacturing of expanded clay represents a certain hazard to the environment and human health. The emissions contain a significant amount of fine dust, and the enterprises are located in close proximity to residential areas. Fine dust particles can stay in the air for a long time, they are transported over long distances thereby increasing the contaminated zone. The OND-86 method (the Industry Regulatory Document) is used to calculate dust dispersion in the atmosphere, which does not take into account a series of factors that determine the dispersion parameters, for example, air humidity. The authors have obtained one-parameter regression equations between the concentration of expanded clay dust in atmospheric air and the influencing factors: air temperature, relative air humidity, distance from the source, wind speed. A strong correlation dependence between the concentration of expanded clay dust and the relative air humidity has been established. An adequate multiple correlation equation that establishes a relationship between the dust concentration and the factors listed has been obtained. The given equation was used in practice when performing dispersion calculations, including the forecasting ones. The authors give the forecast of pollution with expanded clay dust for 2018.
Study on Mechanical Alloying of TiB2 Particulate Reinforced Titanium Matrix Composites
Authors: Li Yue Ying , Zhu Fu Wen , Qiao Zhen Liang
Published: January 2018

TiB2 particulate reinforced titanium matrix composites were prepared by mechanical alloying and spark plasma sintering. Volume fraction of TiB2 powders in the composites are 5%, 10%, 15%. The effect of milling time and the volume fraction of reinforcement on microstructure and properties of the composites were studied. The results show that with increasing milling time, the size of powder particles decreases, quantity of them increases, and microstructure of the sintered samples becomes finer and more uniform. When milling time reaches 30h, the trend of powder agglomeration increases, the downward trend of the particle size becomes slowly. With the milling time, the density of titanium matrix composites is on the rise. The density of 10vol%TiB2 particulate reinforced titanium matrix composites can reach 4.799 g/cm3, with 30h milling time and sintering at 900°C. The density and hardness of the composites increase with increasing the volume fraction of TiB2. When the volume fraction of TiB2 is 15%, after milling 10h and sintered at 800°C, the density and hardness of the composites can reach 4.713g/cm3 and HV851.58.
Comparative Tribological and Mechanical Property Analysis of Nano-Silica and Nano-Rubber Reinforced Epoxy Composites
Authors: Kurdi Abdulaziz , Chang Li
Published: January 2018

Nano-filler reinforced epoxy composites has been investigated in this study subjected to various mechanical and pin-on-disk tribological tests. Two different types of nano-filler were used namely, rigid nano-silica (SiO2) particles and soft nano-rubber particles. Incorporation of nano-filler in polymer matrix enhance mechanical properties. In addition, tribological response of composites are also better compared to neat epoxy polymer. However, the effect of nano-silica addition is much more pronounced than that of nano-rubber due to the high rigidity of nano-silica reinforced epoxy composite. This was mainly attributed to transfer film layer (TFL) formation. The TFL was further investigated by electron microscope and nanoindentor. The best set of tribological properties was achieved at 8 wt. % nano-silica addition. This was due to better reinforcement dispersion and continuous transfer film layer formation which eventually control the overall friction and wear mechanism.
Designing of Outriggers for the Needs of the Vehicles Stability Testing
Authors: Kryaskov Victor , Vashurin Andrey , Tumasov Anton , Vasiliev Alexey
Published: January 2018

This paper is dedicated to the issues of designing of outriggers for avoidance of vehicle tilting during its stability tests. An analysis of existing types of outriggers was done by authors as well as legislative requirements on them. The reliable and well-timed operation of outriggers largely depends on the height of their positioning on a vehicle. In order to determine this important parameter a special methodic of determining the tipping angle of the vehicle with the use of computer-aided design (CAD) was composed by authors. The article also contains some main principles of strength analysis of the structure a very important part of which became the necessity of determination of coefficient of friction between the outrigger sliders and the supporting surface. This coefficient has a direct impact on the value of transverse forces appearing at the ends of outrigger beams.
Editorial
Authors: Marambe Buddhi
Published: January 2018

No abstract available
Raw rubber properties and mechanical properties of smoked sheet rubber made from natural rubber latex preserved using ammonia
Authors: Rathnayake S. , Dharmathilaka P. , Warnajith D. , Wekumbura C. , Siriwardena S.
Published: January 2018

A study was carried out to understand the processing behaviour of smoked sheet rubber manufactured using natural rubber field latex (NRFL) preserved using ammonia at different concentrations. The NRFL preserved with sodium sulphite was used as a control together with un-preserved NRFL. The NRFL preserved using different ammonia concentrations were kept for different time intervals before further processing. Sheet rubber was manufactured using the preserved latex according to the standard manufacturing procedures. Preservation ability, acid requirement for coagulation, drying characteristics, and the raw rubber properties and mechanical properties of sheet rubber were evaluated. The results revealed that the ammonia concentration should exceed 0.15% to keep the latex for more than a day without pre-coagulation. As the ammonia concentration is higher, the acid requirement was higher. Sheet rubber manufactured using ammoniated latex takes marginally longer time to reach complete dryness. The ammonia concentration and time of preservation has a significant effect on raw rubber properties other than un-aged rapid plasticity number. There was no significant effect (p>0.05) on the mechanical properties other than aged-tensile, tear properties and rebound resilience at aged state.
Ciclos económicos e inmigración: trabajadoras latinoamericanas en Estados Unidos durante la Gran Recesión
Authors: Ariza Marina
Published: January 2018

A pesar de haber afectado más a los hombres trabajadores que a las mujeres, la primera crisis global del siglo XXI es un escenario adecuado para analizar la compleja relación entre ciclos económicos, fuerza de trabajo femenina e inmigración. Con base en metodologías cuantitativas se emprende una evaluación del impacto de la Gran Recesión sobre la fuerza de trabajo inmigrante latinoamericana en Estados Unidos, contrastando su situación respecto de las nativas y el resto de las inmigrantes en tres momentos analíticos: 2007 (precrisis), 2009 (recesión) y 2014 (recuperación). Los resultados resaltan tanto el carácter mayormente contracíclico (de amortiguación) de las trabajadoras inmigrantes (en particular latinoamericanas) a lo largo del ciclo económico —mediado por la estructura segregada de los mercados de trabajo—, como los perdurables efectos negativos del fuerte período recesivo sobre sus posibilidades de empleo a varios años de iniciada la recuperación económica.
Las ciudades en la gobernanza global multinivel: una aproximación teórica
Authors: Lara Pacheco Ray Freddy
Published: January 2018

La actuación de las ciudades como fuerza política eficaz e influyente en la gobernanza global multinivel cobra cada vez más relevancia a partir del nuevo milenio. Una de las manifestaciones del potencial de la ciudad está, por ejemplo, en la provisión de soluciones a problemas locales que pueden ser escalables globalmente, y viceversa. De ahí el oportuno planteamiento de una agenda de investigación más allá de las establecidas por la paradiplomacia y la ciudad global que identifique categorías/variables clave que ayuden en la propuesta de trabajos de corte empírico, como puede ser la imagen, la agencia e identidad, tan necesarios para asentar y confirmar los presupuestos en torno a la ciudad en la gobernanza global multinivel.
El rol de la paradiplomacia en las entidades binacionales: análisis del accionar de las provincias argentinas y regiones chilenas en los casos de EBITAN y EBIFETRA
Authors: Álvarez Mariano
Published: January 2018

Desde fines de los ochenta, Argentina y Chile han comenzado un proceso de integración que se vio favorecido con el regreso a la democracia. Dentro del mismo, el componente subestatal se ha ido incorporando, especialmente a partir del Tratado de Maipú de 2009, entregando mayores oportunidades de participación a los gobiernos no centrales. No obstante, es necesario explorar si, más allá del reconocimiento por parte de los Estados, las provincias argentinas y regiones chilenas han sabido aprovechar los canales de participación que se les presentan. A tal fin se analizan comparativamente las entidades binacionales creadas para los proyectos Túnel Internacional de Agua Negra (EBITAN) y Ferrocarril Trasandino Central (EBIFETRA).
Total Nonnegativity and Stable Polynomials
Authors: Purbhoo Kevin
Published: January 2018

We consider homogeneous multiaffine polynomials whose coefficients are the Plücker coordinates of a point V of the Grassmannian. We show that such a polynomial is stable (with respect to the upper half plane) if and only if V is in the totally nonnegative part of the Grassmannian. To prove this, we consider an action of matrices on multiaffine polynomials. We show that a matrix A preserves stability of polynomials if and only if A is totally nonnegative. The proofs are applications of classical theory of totally nonnegative matrices, and the generalized Pólya–Schur theory of Borcea and Brändén.
Верхние оценки хроматических чисел евклидовых пространств
с запрещенными рамсеевскими множествами
Authors: Prosanov Roman Igorevich
Published: January 2018

Хроматическое число евклидова пространства $\mathbb R^n$
с запрещенным конечным множеством точек $C$ -
это минимальное число цветов, в которые можно так раскрасить
точки этого пространства, чтобы не нашлось одноцветного множества,
конгруэнтного $C$. В работе приводятся новые верхние оценки
для этой величины.
Библиография: 27 названий.
Ограниченность в пределе по Пуассону решений
систем дифференциальных уравнений и функции Ляпунова
Authors: Lapin Kirill Sergeevich
Published: January 2018

В работе введены понятия различных видов ограниченности по Пуассону
решений систем дифференциальных уравнений.
Получены достаточные условия введенных в работе различных видов
ограниченности решений по Пуассону.
Библиография: 9 названий.
Ортогональные комплексные структуры в $\mathbb{R}^4$
Authors: Chirka Evgenii Mikhailovich
Published: January 2018

Комплексные ортогональные структуры в областях в $\mathbb{R}^4$ исследуются методами многомерного комплексного анализа. Доказываются новые теоремы об устранимых особенностях таких структур. Исследуются простейшие многозначные ортогональные комплексные структуры. Приводится классификация квадрик в $\mathbb{CP}_3$ относительно действия конформной группы и описываются дискриминантные множества твисторных проекций модельных квадрик.
Библиография: 39 названий.
Существование и единственность слабого решения нелокального уравнения агрегации с вырождающейся диффузией общего вида
Authors: Vildanova Venera Fidarisovna
Published: January 2018

Единственность слабого решения нелокального уравнения агрегации с вырождающейся диффузией доказана методом энергетических оценок. Существование решения доказано комбинированием методов итераций и сжимающих отображений с использованием энергетических оценок. Исследуемые уравнения возникают в моделях биологической агрегации.
Библиография: 23 названия.
Sveti Maksim Grek (cca. 1470–1556): med rokopisi, knjigami in knjižnicami v zgodnjerenesančnem obdobju
Authors: Zajc Neža
Published: January 2018

Usoda sv. Maksima Greka (Mihail Trivolis, ok. 1470, Arta – Maksim Grek, 1556, Moskva) predstavlja značilno ljubezen do znanja, ki je usmerjala zgodnjerenesančnega individuuma. Čeprav je Mihaela Trivolisa, ki je v severni Italiji doživel mnogo bogatih intelektualnih izkušenj, pozneje v moskovski Rusiji doletela krivična obsodba na cerkvenih zborih (1525, 1531), njegova dejavnost priča o njegovem duhovnem vzpenjanju. Kot učenec filologa in prevajalca iz grščine v latinščino Joannisa Laskarisa ter sodelavec Alda Manuzia v njegovi tiskarni v Benetkah, je Mihael Trivolis pridobil znanje o rokopisih, inkunabulah ter o tehniki spreminjanja človeške pisave v tiskano obliko. A mislec, ki je na gradu Mirandola učil grščino nečaka slavnega Pica, je našel duševni mir šele na sveti gori Atos, v samostanu Vatopedion, kjer je z imenom Maksim sprejel meništvo. Tam je nadaljeval z rokopisnim in knjižnim delom ter ustvarjal svoj molitveni opus. Na povabilo ruskega velikega kneza Vasilija III, da naj z Atosa pošljejo prevajalca, je leta 1518 odpotoval v Moskvo, kjer je bil kmalu po krivem obtožen heretičnih napak pri prevajanju in obsojen skoraj na dosmrtno kazen. Vendar je v času priprtja v samostanskih ječah napisal veliko število osebnih spisov, ki so hranjeni v rokopisih. Njegova ustvarjalnost je posebej nazorna v njegovi literarni dejavnosti. Umrl je leta 1556, cenjen in spoštovan. Še za časa svojega življenja je bil prepoznan za svetnika, uradno pa ga je ruska pravoslavna cerkev za svetega proglasila šele leta 1988.
Knjižnica kot (tretji) prostor: družbeni učinki prostorskih praks
Authors: Vogrinčič Čepič Ana
Published: January 2018

Prispevek obravnava družbene učinke heterogene rabe prostora v izposojevalnih knjižnicah (t. i. circulating libraries) 18. stoletja in v sodobnih splošnih javnih knjižnicah in na tej osnovi preizprašuje ustreznost koncepta tretji prostor, ki se vsaj zadnjih deset let v knjižničnem diskurzu pojavlja kot deskriptivna stalnica. Skozi analizo ugotavlja, da je stroka premalo kritično posvojila razumevanje referenčne Oldenburgove definicije, saj ta v resnici zgreši osrednjo namembnost javnih knjižnic. V premislek zato ponudi reinterpretacijo koncepta za sodobno knjižnično prakso. Članek zaključuje širša refleksija o tem, kako sploh misliti knjižnico v 21. stoletju.
Origin of elemental carbon in snow from western Siberia and northwestern European Russia during winter–spring 2014, 2015 and 2016
Authors: Evangeliou Nikolaos , Shevchenko Vladimir P. , Yttri Karl Espen , Eckhardt Sabine , Sollum Espen , Pokrovsky Oleg S. , Kobelev Vasily O. , Korobov Vladimir B. , Lobanov Andrey A. , Starodymova Dina P. , Vorobiev Sergey N. , Thompson Rona L. , Stohl Andreas
Published: January 2018

Abstract. Short-lived climate forcers have been proven important both for the climate
and human health. In particular, black carbon (BC) is an important climate
forcer both as an aerosol and when deposited on snow and ice surface because
of its strong light absorption. This paper presents measurements of elemental
carbon (EC; a measurement-based definition of BC) in snow collected from
western Siberia and northwestern European Russia during 2014, 2015 and 2016.
The Russian Arctic is of great interest to the scientific community due to
the large uncertainty of emission sources there. We have determined the major
contributing sources of BC in snow in western Siberia and northwestern
European Russia using a Lagrangian atmospheric transport model. For the first
time, we use a recently developed feature that calculates deposition in
backward (so-called retroplume) simulations allowing estimation of the
specific locations of sources that contribute to the deposited mass. EC concentrations in snow from western Siberia and northwestern European
Russia were highly variable depending on the sampling location. Modelled BC
and measured EC were moderately correlated (R=0.53–0.83) and a systematic
region-specific model underestimation was found. The model underestimated
observations by 42 % (RMSE = 49 ng g−1) in 2014, 48 % (RMSE = 37 ng g−1)
in 2015 and 27 % (RMSE = 43 ng g−1) in 2016. For EC
sampled in northwestern European Russia the underestimation by the model was
smaller (fractional bias, FB > −100 %). In this region, the
major sources were transportation activities and domestic combustion in
Finland. When sampling shifted to western Siberia, the model underestimation
was more significant (FB < −100 %). There, the sources included
emissions from gas flaring as a major contributor to snow BC. The accuracy
of the model calculations was also evaluated using two independent datasets
of BC measurements in snow covering the entire Arctic. The model
underestimated BC concentrations in snow especially for samples collected in
springtime.
Principal component analysis of summertime ground site measurements in the Athabasca oil sands: Sources of IVOCs
Authors: Tokarek Travis W. , Odame-Ankrah Charles A. , Huo Jennifer A. , McLaren Robert , Lee Alex K. Y. , Adam Max G. , Willis Megan D. , Abbatt Jonathan P. D. , Mihele Cristian , Darlington Andrea , Mittermeier Richard L. , Strawbridge Kevin , Hayden Katherine L. , Olfert Jason S. , Schnitzler Elijah G. , Brownsey Duncan K. , Assad Faisal V. , Wentworth Gregory R. , Tevlin Alex G. , Worthy Douglas E. J. , Li Shao-Meng , Liggio John , Brook Jeffrey R. , Osthoff Hans D.
Published: January 2018

Abstract. In this paper, measurements of air pollutants made at a ground site near Fort McKay in the Athabasca oil sands region as part of a multi-platform campaign in the summer of 2013 are presented. The observations included measurements of selected volatile organic compounds (VOCs) by a gas chromatograph &ndash ion trap mass spectrometer (GC-ITMS). This instrument observed a large, analytically unresolved hydrocarbon peak (with retention index between 1100 and 1700) associated with intermediate volatility organic compounds (IVOCs). However, the activities or processes that contribute to the release of these IVOCs in the oil sands region remain unclear. Principal component analysis (PCA) with Varimax rotation was applied to elucidate major source types impacting the sampling site in the summer of 2013. The analysis included 28 variables, including concentrations of total odd nitrogen (NOy), carbon dioxide (CO2), methane (CH4), ammonia (NH3), carbon monoxide (CO), sulfur dioxide (SO2), total reduced sulfur compounds (TRS), speciated monoterpenes (including α- and β-pinene and limonene), particle volume calculated from measured size distributions of particles less than 10 µm and 1 µm in diameter (PM10-1 and PM1), particle-surface bound polycyclic aromatic hydrocarbons (pPAH), and aerosol mass spectrometer composition measurements, including refractory black carbon (rBC) and organic aerosol components. The PCA was complemented by bivariate polar plots showing the joint wind speed and direction dependence of air pollutant concentrations to illustrate the spatial distribution of sources in the area. Using the 95 % cumulative percentage of variance criterion, ten components were identified and categorized by source type. These included emissions by wet tailings ponds, vegetation, open pit mining operations, upgrader facilities, and surface dust. Three components correlated with IVOCs, with the largest associated with surface mining and is likely caused by the unearthing and processing of raw bitumen.
Combining airborne in situ and ground-based lidar measurements for attribution of aerosol layers
Authors: Nikandrova Anna , Tabakova Ksenia , Manninen Antti , Väänänen Riikka , Petäjä Tuukka , Kulmala Markku , Kerminen Veli-Matti , O'Connor Ewan
Published: January 2018

Abstract. Understanding the distribution of aerosol layers is important for determining long range transport and aerosol radiative forcing. In this study we combine airborne in situ measurements of aerosol with data obtained by a ground-based High Spectral Resolution Lidar (HSRL) and radiosonde profiles to investigate the temporal and vertical variability of aerosol properties in the lower troposphere. The HSRL was deployed in Hyytiälä, Southern Finland, from January to September 2014 as a part of the US DoE ARM (Atmospheric Radiation Measurement) mobile facility during the BAECC (Biogenic Aerosols – Effects on Cloud and Climate) Campaign. Two flight campaigns took place in April and August 2014 with instruments measuring the aerosol size distribution from 10 nm to 10 µm at altitudes up to 3800 m. Two case studies from the flight campaigns, when several aerosol layers were identified, were selected for further investigation: one clear sky case, and one partly cloudy case. During the clear sky case, turbulent mixing ensured low temporal and spatial variability in the measured aerosol size distribution in the boundary layer whereas mixing was not as homogeneous in the boundary layer during the partly cloudy case. The elevated layers exhibited greater temporal and spatial variability in aerosol size distribution, indicating a lack of mixing. New particle formation was observed in the boundary layer during the clear sky case, and nucleation mode particles were also seen in the elevated layers that were not mixing with the boundary layer. Interpreting local measurements of elevated layers in terms of long-range transport can be achieved using back trajectories from Lagrangian models, but care should be taken in selecting appropriate arrival heights, since the modelled and observed layer heights did not always coincide. We conclude that higher confidence in attributing elevated aerosol layers with their air mass origin is attained when back trajectories are combined with lidar and radiosonde profiles.
Long-term observation of mid-latitude quasi 2-day waves by a water vapor radiometer
Authors: Lainer Martin , Hocke Klemens , Kämpfer Niklaus
Published: January 2018

Abstract. A mesospheric water vapor data set obtained by the middle atmospheric water vapor radiometer (MIAWARA) close to Bern, Switzerland (46.88° N, 7.46° E) during October 2010 to September 2017 is investigated to study the long-term evolution and variability of quasi 2-day waves (Q2DWs). We present a climatological overview and an insight on the dynamical behavior of these waves with the occurring spectrum of periods as seen from a mid-latitude observation site. Such a large and nearly continuous measurement data set as ours is rare and of high scientific value. The core results of our investigation include that the activity of the Q2DW manifests in burst-like events and is higher during winter months (November–February) than during summer months (May–August) for the altitude region of the mesosphere (up to 0.02 hPa in winter and up to 0.05 hPa in summer) that is accessible for the instrument. Single Q2DW events reach at most about 0.8 ppm in the H2O amplitudes. Further, monthly mean Q2DW amplitude spectra are presented and reveal a high frequency variability between different months. A large fraction of identified Q2DW events (20 %) develop periods between 38–40 h. Further, we show the temporal evolution of monthly mean Q2DW oscillations continuously for all months and separated for single months over 7 years. The analysis of autobicoherence spectra gives evidence that the Q2DW occasionally is to a high degree phase coupled to diurnal oscillations and to waves with a period close to 18 h.
Revisiting internal gravity waves analysis using GPS RO density profiles: comparison with temperature profiles and application for wave field stability study
Authors: Pisoft Petr , Sacha Petr , Miksovsky Jiri , Huszar Peter , Scherllin-Pirscher Barbara , Foelsche Ulrich
Published: January 2018

Abstract. We revise selected findings regarding the utilization of Global
Positioning System radio occultation (GPS RO) density profiles for
the analysis of internal gravity waves (IGW), introduced by
Sacha et al. (2014). Using various GPS RO datasets, we show that the
differences in the IGW spectra between the dry-temperature and
dry-density profiles that were described in the previous study as
a general issue are in fact present in one specific data version
only. The differences between perturbations in the temperature and
density GPS RO profiles do not have any physical origin, and there is
not the information loss of IGW activity that was suggested in
Sacha et al. (2014). We investigate the previously discussed question
of the temperature perturbations character when utilizing GPS RO
dry-temperature profiles, derived by integration of the hydrostatic
balance. Using radiosonde profiles as a proxy for GPS RO, we provide
strong evidence that the differences in IGW perturbations between
the real and retrieved temperature profiles (which are based on the
assumption of hydrostatic balance) include a significant
nonhydrostatic component that is present sporadically and might be
either positive or negative. The detected differences in related
spectra of IGW temperature perturbations are found to be mostly
about ±10 %. The paper also presents a detailed study on the utilization of GPS
RO density profiles for the characterization of the wave field
stability. We have analyzed selected stability parameters derived
from the density profiles together with a study of the vertical
rotation of the wind direction. Regarding the Northern Hemisphere
the results point to the western border of the Aleutian high, where
potential IGW breaking is detected. These findings are also
supported by an analysis of temperature and wind velocity
profiles. Our results confirm advantages of the utilization of the
density profiles for IGW analysis.
Latitude-dependent delay in the responses of the equatorial electrojet and Sq currents to X-class solar flares
Authors: Nogueira Paulo A. B. , Abdu Mangalathayil A. , Souza Jonas R. , Denardini Clezio M. , Barbosa Neto Paulo F. , Serra de Souza da Costa João P. , Silva Ana P. M.
Published: January 2018

Abstract. We have analyzed low-latitude ionospheric current responses to two
intense (X-class) solar flares that occurred on 13 May 2013 and
11 March 2015. Sudden intensifications, in response to solar flare radiation
impulses, in the Sq and equatorial electrojet (EEJ) currents, as detected by
magnetometers over equatorial and low-latitude sites in South America, are
studied. In particular we show for the first time that a 5 to 8 min time delay is
present in the peak effect in the EEJ, with respect that of Sq current
outside the magnetic equator, in response to the flare radiation enhancement.
The Sq current intensification peaks close to the flare X-ray peak, while the
EEJ peak occurs 5 to 8 min later. We have used the Sheffield University
Plasmasphere-Ionosphere Model at National Institute for Space Research
(SUPIM-INPE) to simulate the E-region conductivity enhancement as caused by
the flare enhanced solar extreme ultraviolet (EUV) and soft X-rays flux. We propose that the flare-induced enhancement in neutral wind occurring with a time delay (with respect
to the flare radiation) could be responsible for a delayed zonal electric
field disturbance driving the EEJ, in which the Cowling conductivity offers
enhanced sensitivity to the driving zonal electric field. Keywords. Ionosphere (equatorial ionosphere)
Webcam network and image database for studies of phenological changes of vegetation and snow cover in Finland, image time series from 2014 to 2016
Authors: Peltoniemi Mikko , Aurela Mika , Böttcher Kristin , Kolari Pasi , Loehr John , Karhu Jouni , Linkosalmi Maiju , Tanis Cemal Melih , Tuovinen Juha-Pekka , Arslan Ali Nadir
Published: January 2018

Abstract. In recent years, monitoring of the status of ecosystems using low-cost web (IP) or time lapse cameras has received wide interest. With broad spatial coverage and high temporal resolution, networked cameras can provide information about snow cover and vegetation status, serve as ground truths to Earth observations and be useful for gap-filling of cloudy areas in Earth observation time series. Networked cameras can also play an important role in supplementing laborious phenological field surveys and citizen science projects, which also suffer from observer-dependent observation bias. We established a network of digital surveillance cameras for automated monitoring of phenological activity of vegetation and snow cover in the boreal ecosystems of Finland. Cameras were mounted at 14 sites, each site having 1–3 cameras. Here, we document the network, basic camera information and access to images in the permanent data repository (http://www.zenodo.org/communities/phenology_camera/). Individual DOI-referenced image time series consist of half-hourly images collected between 2014 and 2016 (https://doi.org/10.5281/zenodo.1066862). Additionally, we present an example of a colour index time series derived from images from two contrasting sites.
Parametric decadal climate forecast recalibration (DeFoReSt 1.0)
Authors: Pasternack Alexander , Bhend Jonas , Liniger Mark A. , Rust Henning W. , Müller Wolfgang A. , Ulbrich Uwe
Published: January 2018

Abstract. Near-term climate predictions such as decadal climate forecasts are
increasingly being used to guide adaptation measures. For near-term
probabilistic predictions to be useful, systematic errors of the
forecasting systems have to be corrected. While methods for the
calibration of probabilistic forecasts are readily available, these
have to be adapted to the specifics of decadal climate forecasts
including the long time horizon of decadal climate forecasts,
lead-time-dependent systematic errors (drift) and the errors in the
representation of long-term changes and variability. These features
are compounded by small ensemble sizes to describe forecast
uncertainty and a relatively short period for which typically pairs
of reforecasts and observations are available to estimate
calibration parameters. We introduce the Decadal Climate Forecast
Recalibration Strategy (DeFoReSt), a parametric approach to
recalibrate decadal ensemble forecasts that takes the above
specifics into account. DeFoReSt optimizes forecast quality as
measured by the continuous ranked probability score (CRPS). Using a
toy model to generate synthetic forecast observation pairs, we
demonstrate the positive effect on forecast quality in situations
with pronounced and limited predictability. Finally, we apply
DeFoReSt to decadal surface temperature forecasts from the MiKlip
prototype system and find consistent, and sometimes considerable,
improvements in forecast quality compared with a simple calibration
of the lead-time-dependent systematic errors.
A large set of potential past, present and future hydro-meteorological time series for the UK
Authors: Guillod Benoit P. , Jones Richard G. , Dadson Simon J. , Coxon Gemma , Bussi Gianbattista , Freer James , Kay Alison L. , Massey Neil R. , Sparrow Sarah N. , Wallom David C. H. , Allen Myles R. , Hall Jim W.
Published: January 2018

Abstract. Hydro-meteorological extremes such as drought and heavy precipitation can
have large impacts on society and the economy. With potentially increasing
risks associated with such events due to climate change, properly assessing
the associated impacts and uncertainties is critical for adequate adaptation.
However, the application of risk-based approaches often requires large sets
of extreme events, which are not commonly available. Here, we present such a
large set of hydro-meteorological time series for recent past and future
conditions for the United Kingdom based on weather@home 2, a modelling
framework consisting of a global climate model (GCM) driven by observed or
projected sea surface temperature (SST) and sea ice which is downscaled to
25 km over the European domain by a regional climate model (RCM). Sets of
100 time series are generated for each of (i) a historical baseline
(1900–2006), (ii) five near-future scenarios (2020–2049) and
(iii) five far-future scenarios
(2070–2099). The five scenarios in each future time slice all follow the
Representative Concentration Pathway 8.5 (RCP8.5) and sample the range of sea
surface temperature and sea ice changes from CMIP5 (Coupled Model Intercomparison Project Phase 5) models. Validation of the
historical baseline highlights good performance for temperature and potential
evaporation, but substantial seasonal biases in mean precipitation, which are
corrected using a linear approach. For extremes in low precipitation over a
long accumulation period (>3 months) and shorter-duration high
precipitation (1–30 days), the time series generally represents past
statistics well. Future projections show small precipitation increases in
winter but large decreases in summer on average, leading to an overall
drying, consistently with the most recent UK Climate Projections (UKCP09) but
larger in magnitude than the latter. Both drought and high-precipitation
events are projected to increase in frequency and intensity in most regions,
highlighting the need for appropriate adaptation measures. Overall, the
presented dataset is a useful tool for assessing the risk associated with
drought and more generally with hydro-meteorological extremes in the UK.
Mean transit times in headwater catchments: insights from the Otway Ranges, Australia
Authors: Howcroft William , Cartwright Ian , Morgenstern Uwe
Published: January 2018

Abstract. Understanding the timescales of water flow through catchments and the sources of stream water at different flow conditions is critical for understanding catchment behaviour and managing water resources. Here, tritium (3H) activities, major ion geochemistry and streamflow data were used in conjunction with lumped parameter models (LPMs) to investigate mean transit times (MTTs) and the stores of water in six headwater catchments in the Otway Ranges of southeastern Australia. 3H activities of stream water ranged from 0.20 to 2.14 TU, which are significantly lower than the annual average 3H activity of modern local rainfall, which is between 2.4 and 3.2 TU. The 3H activities of the stream water are lowest during low summer flows and increase with increasing streamflow. The concentrations of most major ions vary little with streamflow, which together with the low 3H activities imply that there is no significant direct input of recent rainfall at the streamflows sampled in this study. Instead, shallow younger water stores in the soils and regolith are most likely mobilised during the wetter months. MTTs vary from approximately 7 to 230 years. Despite uncertainties of several years in the MTTs that arise from having to assume an appropriate LPM, macroscopic mixing, and uncertainties in the 3H activities of rainfall, the conclusion that they range from years to decades is robust. Additionally, the relative differences in MTTs at different streamflows in the same catchment are estimated with more certainty. The MTTs in these and similar headwater catchments in southeastern Australia are longer than in many catchments globally. These differences may reflect the relatively low rainfall and high evapotranspiration rates in southeastern Australia compared with headwater catchments elsewhere. The long MTTs imply that there is a long-lived store of water in these catchments that can sustain the streams over drought periods lasting several years. However, the catchments are likely to be vulnerable to decadal changes in land use or climate. Additionally, there may be considerable delay in contaminants reaching the stream. An increase in nitrate and sulfate concentrations in several catchments at high streamflows may represent the input of contaminants through the shallow groundwater that contributes to streamflow during the wetter months. Poor correlations between 3H activities and catchment area, drainage density, land use, and average slope imply that the MTTs are not controlled by a single parameter but a variety of factors, including catchment geomorphology and the hydraulic properties of the soils and aquifers.
Stochastic generation of multi-site daily precipitation focusing on extreme events
Authors: Evin Guillaume , Favre Anne-Catherine , Hingray Benoit
Published: January 2018

Abstract. Many multi-site stochastic models have been proposed for the generation of daily precipitation, but they generally focus on the reproduction of low to high precipitation amounts at the stations concerned. This paper proposes significant extensions to the multi-site daily precipitation model introduced by Wilks, with the aim of reproducing the statistical features of extremely rare events (in terms of frequency and magnitude) at different temporal and spatial scales. In particular, the first extended version integrates heavy-tailed distributions, spatial tail dependence, and temporal dependence in order to obtain a robust and appropriate representation of the most extreme precipitation fields. A second version enhances the first version using a disaggregation method. The performance of these models is compared at different temporal and spatial scales on a large region covering approximately half of Switzerland. While daily extremes are adequately reproduced at the stations by all models, including the benchmark Wilks version, extreme precipitation amounts at larger temporal scales (e.g., 3-day amounts) are clearly underestimated when temporal dependence is ignored.