bluuebunny/crossref_metadata_2025 huggingface dataset:
Superimposed auriferous structural events along the Llewellyn-Tally Ho deformation corridor in southern Yukon and northwest British Columbia
Authors: Ootes L , Castonguay S , Friedman R , Devine F
Published: March 2019

The Llewellyn-Tally Ho deformation zone in northwest British Columbia and southern Yukon demarcates the eastern limit of the Nisling terrane and the western limit of the Stikine terrane and has spatially related epithermal, mesothermal, and intrusion-related gold
deposits and occurrences. The Llewellyn fault is a southeast-striking, steeply dipping brittle dextral strike-slip structure that overprints 'early' penetrative fabrics and ductile deformation. The Tally Ho shear zone, in the Yukon, represents an early ductile deformation zone, comprising one
penetrative foliation (Smain) and mylonite zones that are overprinted by late brittle faulting, analogous to the Llewellyn fault. Previous work and this study demonstrate that brittle strike-slip deformation along the Llewellyn fault occurred between ca. 56 and 50 Ma. Two granodiorite intrusions
(ca. 75 Ma) crosscut the early ductile deformation fabrics. In the Tally Ho shear zone, Smain crosscuts a granodiorite pluton and porphyry dyke, which have yielded preliminary U-Pb zircon dates of ca. 98 and 95 Ma, respectively. As such, we infer that the early ductile fabrics formed before ca. 75
Ma and after ca. 95 Ma. This study further demonstrates that the early ductile and late brittle deformation are separated by at least ca. 20 Ma, indicating the various styles of gold mineralization developed during temporally distinct tectonic events: an 'early' late Cretaceous ductile event typical
of the Tintina gold belt; and a 'later' Eocene brittle event matching the timing and structural framework of the Juneau gold camp.
Volcanology, geochemistry and petrogenesis of the Expo-Raglan magmatic system in the eastern Cape Smith Belt, Nunavik, northern Quebec
Authors: McKevitt D J , Lesher C M , Houlé M G
Published: March 2019

The Paleoproterozoic volcano-sedimentary Cape Smith Belt in Nunavik (northern Quebec) contains a variety of mafic-ultramafic units classifiable by position in sequence, geometry, lithology, degree of differentiation and mineralization style. Non-differentiated to
differentiated mafic flows/sills comprise the majority of the section as essentially non-mineralized massive-pillowed basalts, conformable gabbroic units and differentiated pyroxenite/gabbro/basalt flows. Differentiated mafic-ultramafic sills intrude sedimentary strata of the lower and upper
Povungnituk Group and host reef-style PGE-(Cu)-(Ni) mineralization (e.g. Delta). Poorly differentiated ultramafic-mafic bladed dykes along the Expo Trend in the Povungnituk Group commonly host Cu-Ni-(PGE) sulphides along their margins (e.g. Expo-Ungava, Méquillon) and reach up to 35 weight
% MgO in the most magnesian olivine pyroxenitic parts and up to 16 weight % MgO in their chilled melanogabbroic margins. Poorly differentiated ultramafic lava channels along the Raglan Trend at the base of the Chukotat Group host Ni-Cu-(PGE) mineralization at or near their lower contacts,
and reach MgO contents of nearly 44 weight % in the most magnesian peridotitic parts and up to 20 weight % in their chilled pyroxenitic margins. Recent dating indicates a temporal overlap between the Expo and Raglan parts of the system; however, field and geochemical data suggest that the
Expo dykes are derived from less magnesian magmas and formed mineralization with higher Cu/Ni ratios than the lava channels in in the Raglan Trend. The Expo dykes may have fed other parts of the system, but do not appear to represent direct feeders to the mineralized lava channels in the Raglan
parts.
Measuring Reliability of Movement With Accelerometry: Fitbit® Versus ActiGraph®
Authors: Rowe Veronica T. , Neville Marsha
Published: March 2019

OBJECTIVE. We sought to determine the reliability of the Fitbit® Flex™ compared with the ActiGraph® Bluetooth® Smart wGT3X-BT wireless activity monitor and to contribute to the clinical utility of accelerometry measurement of upper extremity (UE) movement.

METHOD. Two studies were conducted at different sites with healthy adult participants. In Study 1, participants wore both accelerometers on both wrists during everyday activities for a 24-hr period. In Study 2, participants wore both accelerometers on the dominant wrist for 4 hr during an active period of the day. All participants wore the accelerometers during regular daily activities.

RESULTS. Data recorded from the Fitbit and the ActiGraph showed a high positive correlation; however, the Fitbit recorded significantly fewer movements than the ActiGraph.

CONCLUSION. Although the Fitbit and the ActiGraph measure UE activity similarly, the Fitbit was not as sensitive as the ActiGraph. This study provides informative data on the clinical utility of the Fitbit compared with the ActiGraph.
Rekrutering via Sociale MediaEen Kwalitatief Onderzoek Bij Hr-managers En Medewerkers
Authors: Carpentier Marieke , Stockman Sara , Van Hoye Greet
Published: March 2019

De meerderheid van de werkzoekenden is actief op sociale media. Deze platformen zijn daarom veelbelovende tools voor rekrutering en employer branding. Organisaties kunnen sociale media aanwenden om huidige vacatures in te vullen, maar ook om een aantrekkelijk employer brand te creëren
met het oog op toekomstige aanwervingen. Ondanks dat meer en meer organisaties sociale media gebruiken voor rekrutering, is er nog weinig onderzoek over hoe en waarom sociale media worden gebruikt in een rekruteringscontext en welke problemen zich hierbij kunnen stellen. Deze kwalitatieve
studie onderzoekt de ervaringen van HR-managers en medewerkers. Hierbij ligt enerzijds de focus op sociale media als rekruteringstool in het algemeen. Anderzijds wordt gekeken naar één specifieke manier waarop sociale media als rekruteringstool kunnen worden ingezet, met name
via het betrekken van medewerkers. Op basis van de resultaten adviseren wij HR-professionals in de praktijk om een systematische samenwerking met de departementen marketing en communicatie uit te bouwen, en om te investeren in HR-metrics. Ook strekt het tot de aanbeveling om medewerkers meer
te informeren over wat ze kunnen doen met sociale media gericht op rekrutering, en daarbij beter in te spelen op wat medewerkers motiveert om positieve informatie over hun werkgever te verspreiden. Tenslotte wijzen we op het belang van een lange termijn strategie voor rekrutering waarop alle
activiteiten worden afgestemd.Due to the widespread use of social media, these platforms are promising tools for recruitment and employer branding. Organizations can employ social media not only for filling in vacancies, but also to create an attractive employer brand to serve future needs. However, almost no research has investigated recruiting through social media. Hence, this qualitative study examines the experiences of both HR managers and employees to understand why and how social media are used in a recruitment context and which problems occur. We focus on social media as recruitment tools in general and on how and why employees are stimulated to share vacancies and messages on these platforms as well. Based on the study results, we recommend that organizations set up a collaboration between the different departments involved in the use of social media, invest in HR metrics and analytics, improve the communication to employees with regard to what they can do, how and why, understand why employees want to share information about the organization as an employer and create communication to trigger these motives, and, finally, invest in a long term strategy and align all recruitment activities with this strategy.
Hrm En Arbeidsverhoudingen: Historische Achtergronden Van Een Ongemakkelijke Relatie En Perspectieven Voor De Toekomsti
Authors: Looise Jan Kees
Published: March 2019

HRM en arbeidsverhoudingen hebben een ongemakkelijke relatie. Nadat ze begin 20e eeuw onder invloed van het bureaucratische kapitalisme beide tot wasdom zijn gekomen, zijn ze daarna steeds verder uit elkaar gegroeid. Vanaf de jaren `30 werd dit vooral veroorzaakt door de groeiende
dominantie van de arbeidsverhoudingen op nationaal niveau en vanaf de jaren `80 door de overname van die dominantie door het HRM op organisatieniveau. Het gevolg is een flinke kloof tussen beide die de laatste tijd alleen nog maar breder en dieper lijkt te worden. In deze bijdrage wordt
een poging gedaan de achtergronden van de gegroeide afstand tussen HRM en arbeidsverhoudingen te verklaren en na te gaan of hier in de toekomst verbetering kan worden gebracht en zo ja, op welke manier. Daartoe wordt gebruik gemaakt van een historisch benadering. Kijken naar het verleden biedt
geen garantie voor betere analyses en voorspellingen voor de toekomst, maar het stelt ons wel in staat langere ontwikkelingslijnen te kennen en te begrijpen en daarmee beter in schatten waar we nu staan en naartoe gaan.Although they regard the same topic, namely the employment relations or the relations between employer(s) and employee(s), HRM and industrial relations have a difficult connection. Since both have matured as a result of the development of bureaucratic capitalism in the beginning of the 20th century, they have developed in different directions. From the 1930’s on this was caused by the growing dominance of industrial relations at societal level, while from the 1980s on this dominance has been taken over by HRM, in both cases leaving the other in a rather dependent position. As a result no mature relationship between HRM and industrial relations has developed but a growing gap that seems to widen even more last decades. By using a historical approach this contribution aims to contribute to a better understanding of the development of both HRM and industrial relations and their mutual relations in the past and future. Looking to the past offers no guarantee for better analyses and predictions of the future, but it helps us to better understand `long development lines’ and so come to a more comprehensive view on the future.
International Agricultural Concepts through the Eyes of School-Based Agriculture Education Students
Authors: Conner Nathan W. , Greer Sarah , Stripling Christopher T.
Published: March 2019

As demands to participate in a global economy increase, American students, who have limited knowledge of international agriculture concepts, must be better educated in terms of international awareness and understanding. The purpose of this study was to identify the attitudes, beliefs, understanding, and desired instructional methods of Tennessee school-based agricultural education students in regards to international agriculture. A descriptive questionnaire comprised of 46 items, which measured four constructs, was used to collect data. The summated means of all students for attitudes, beliefs, understanding, and instruction were
3.81 (SD = .46), 3.81 (SD = .57), 3.76 (SD = .51), and 3.76 (SD = .47), respectively. Findings indicated students hold positive attitudes and beliefs toward international agricultural concepts. In an effort to remain a global leader in science and innovation and to meet the needs of the agricultural employers, State Departments of Education should consider providing resources for the development, testing, and implementation of internationalized curricula. If not currently internationalized, other countries should also consider internationalizing their curricula and determine how best to equip students with the skills and knowledge necessary to work in a globalized economy.
United States and Latin American Undergraduate Students’ Knowledge, Attitudes and Perception of Global Agricultural Issues
Authors: Morales Sarahi , Brashears M. Todd , Akers Cindy , Malaga Jaime , Wingenbach Gary
Published: March 2019

Global trends are demanding agricultural students have a broader perspective of agriculture and competitiveness and they become responsible global citizens. This study compared United States and Latin American undergraduate students’ knowledge, attitudes, and beliefs regarding international agricultural issues, as well as their attitudes about global citizenship. Overall, students’ results indicated a lack of knowledge regarding international agricultural issues, with only 3.6% obtaining a score above 60%. Students’ recorded positive attitudes and beliefs about international agricultural issues but had mixed feelings regarding global citizenship attitudes. Scores on all constructs were found to be significantly different
between the studied academic institutions (p < .05). The stepwise multiple linear regression indicated the predictors of university of enrollment and students’ attitudes and beliefs about international agricultural issues were significantly related to their global citizenship attitudes: F (3, 1194) = 83.04, p = .01, explaining 17% of the variance in the model. The obtained results suggest students hold positive and open-minded attitudes and beliefs regarding international agricultural issues. These attitudes should be balanced by academic institutions with the knowledge needed by students to meet the demands of the agricultural industry. A global understanding can potentially enable future professionals to succeed in both local and global settings, and furthermore, help them become global citizens.
Competency Assessment as a Way of Determining Training and Educational Needs of Extension Professionals in Nepal
Authors: Ghimire Ramjee P. , Suvedi Murari , Kaplowitz Michael , Richardson Robert
Published: March 2019

This study examines the level of and gaps in core competencies among agricultural extension professionals in Nepal. The study population was composed of agricultural extension professionals in governmental extension offices and agriculture-based, non-governmental organizations. During August-September 2015, 349 extension professionals completed selfadministered surveys. The design for the data collection instrument was based on a literature review and on focus group recommendations. Data were analyzed using descriptive and inferential statistics. The findings revealed that respondents perceived themselves to be moderately competent in extension core competencies -- program planning, program implementation, communication skills, educational and informational technology, program evaluation, personal and professional development, diversity, and technical subject matter expertise. Respondents’ perceived levels of competency differed by their current position, undergraduate college attended, and level of education, although not much by their age and experience in extension. Office chiefs and foreign-educated respondents perceived themselves as
having higher levels of competency than their counterparts -- subject matter specialists and technical officers, and in-country-educated professionals. The perceived levels of the importance of all core competencies were significantly higher than the professionals’ perceived levels of their own competency, indicating gaps in extension core competencies among Nepalese extension professionals. The findings imply that that there is a need for in-service training of extension professionals in all core competency areas. Preservice extension education curricula need to be reviewed and updated, incorporating the core competencies highlighted in this study.
A Case Study of Indonesian Journalists’ Participation in a Cochran Fellowship Program focused on Biotechnology and Journalism
Authors: Leggette Holli R. , Hall Samuel Thomas , Murphrey Theresa Pesl
Published: March 2019

This case study describes the participation of Indonesian journalists in a two-week Cochran Fellowship Program designed to teach about biotechnology and the process of disseminating scientific information. The purpose of this case study was to examine the experience of Indonesian journalists who participated in science communication training in an effort to document practices that improve journalistic writing skills and encourage positive perceptions of biotechnology. Therefore, we collected pre- and post-training reflections, photo reflections, and project debriefing session reflections from six Indonesian journalists who specialized in various types of journalism and worked for private or government-owned news organizations. The reflections revealed changes in comfort level with journalistic writing, thoughts and behaviors, and understanding of the biotechnology process. The journalists showed the most change in comfort level for explaining communication tools; using, evaluating, and choosing communication mediums; and translating science related to biotechnology. They described biotechnology as a highly debated, multi-step process affecting food security and noted that they gained valuable information about science journalism and biotechnology. Training journalists and understanding their voices could enable agriculturalists to more effectively communicate about scientific issues and develop impactful capacity-building activities. Because journalists
have the power to inform and influence, programs, like this one, can have far-reaching, beneficial impacts on the adoption of biotechnology. However, researchers should investigate future programs using a longitudinal study to determine if programs influence the stories published in the years following the training
Communicating Agriculture and Nutrition: Opportunities for Agricultural Extension-Communication and Advisory Services in Nepal
Authors: Rodriguez Lulu , Andrade Juan
Published: March 2019

Meeting the dual goal of improving income and enhancing the nutrition status of Nepal’s rural residents is the mandate of the Integrating Gender and Nutrition within Agricultural Extension Services (INGENAES) project, which is supported by the United States Agency for International Development’s (USAID) Feed the Future initiative. A landscape study that provided an overview of Nepal’s agriculture and the status of the country’s agricultural extension system (AES) threshed out a primary target audience—rural women. How can they be reached with nutrition information through the existing AES? The landscape study also identified 11 organizations as INGENAES collaborators. What opportunities do they offer to advance INGENAES objectives?
Following Rice and Foote’s (2001) systems-theoretical approach, this formative evaluation study drew from the insights of project and program managers and coordinators, communication officers, representatives of non-government organizations (NGOs), extension officers, and editors and journalists of farm publications who work in the intersection of agriculture and nutrition in Nepal. Data were gathered from a survey of the chief communication and/or extension officers of these 11 partner agencies. Additional data were collected from evaluation questionnaires completed by project managers and communication officers of 12 government and non-government agencies who participated in a seminar-workshop on how to improve gender and nutrition communication. These two methods brought to light opportunities that can be used to enhance the communication and/or extension of nutrition-enriched agricultural information, especially to rural women. Recommendations for future communications work are offered.
College of Agricultural, Food, and Life Sciences International Education: Students’ Preferred Location of Travel and Perceptions of Benefits and Barriers
Authors: Edgar Leslie D. , Edgar Don W. , Hansen Maggie Jo
Published: March 2019

The University of Arkansas has a campus-wide goal of 25 percent of students participating in an international program prior to graduation. This created concern because only three percent of Dale Bumpers College of Agricultural, Food and Life Sciences (Bumpers College) students participated in an international program prior to 2012. For five years, the Bumpers College International Programs Office (IPO) has assessed students to determine their perceived benefits, barriers, and needs in an effort to design international programs of interest and increase student participation. In this study, Bumpers College students were surveyed to determine perceived benefits and barriers to participating in an international program and identify the countries of interest in visiting. Instruments were administered via paper form to 1,165 students enrolled in large section courses in fall 2016. Using a six-point Likert-type scale, students’ believed international program participation “looks good on a resume” with a mean of 5.46 (SD = 0.77). The least important statement was “increased employability” with a mean of 4.92 (SD = 1.00). Students slightly agreed or agreed to all questionnaire benefit statements. The barrier statement “costs too high” was identified as the most important with a mean of 4.79 (SD = 1.12). The least important statement was “an international program will not have an impact on my future career” with a mean of 2.12 (SD = 1.21). About 72% of students were willing to participate in an international experience in a European country. Recommendations for practice and research are discussed and identified limitations are provided.
Barrier Analysis as a Tool to Inform Extension Activity Planning: Insights from Guatemala
Authors: Seiler-Martinez Alene , Murphrey Theresa Pesl , Wingenbach Gary , Lombardini Leonardo
Published: March 2019

Over the past decade, renewed emphasis has been placed on extension services in developing countries to reduce rural poverty and improve food security. Despite this emphasis, complex physical, political, and socioeconomic environments in developing countries pose significant difficulties to extension agents’ success rates of adoption of new practices and/or behavior change among rural populations. In addition, agents have meager resources at their disposal. Development programs in the health sector have had success with employing behavior change theories for program design, driven by the Barrier Analysis as a method for gathering data about target populations. Theory and research suggest this method provides key information about why a target population might adopt new practices. If extension agents in developing countries such as Guatemala had access to such information, they might intentionally design interventions that lead to adoption. This paper provides an examination of examples from the field in Guatemala that illuminate ways in which extension agents can gain formative data that when analyzed, may shape how they encourage adoption of new practices. The implications of this paper suggest that using formative data gathering for planning interventions can lead to the behavior change extension agents and their governments seek.
U.S. International Agricultural Development: What Events, Forces, Actors, and Philosophical Perspectives Presaged Its Approach?
Authors: Raczkoski Brandon M. , Edwards M. Craig
Published: March 2019

The philosophical perspectives, including significant actors, events, and forces, that influenced and presaged the United States’ approach to international agricultural development are somewhat unclear. The purpose of this historical narrative, therefore, was to understand the key drivers responsible for forging the U.S. framework for technical agricultural assistance abroad, especially in its formative years. The study’s findings were reported by answering two questions. The first question explored historical events, including federal legislative acts and statutes, which precipitated the U.S. approach to international agricultural development. The second research question addressed the philosophical primers imbued in the U.S. approach to international agricultural development, including significant actors responsible for championing it. We assert the environmental pragmatism of Liberty Hyde Bailey and its other proponents was the philosophical foundation and worldview that informed many of the pioneers who guided the U.S. approach to offering agricultural assistance as part of the nation’s international development efforts. As such, we recommend the inclusion of certain aspects of environmentalism in agricultural and extension educator preparation with implications for international and domestic development, including long-term sustainability initiatives.
Social Capital of Faculty within Haiti’s Agricultural Education and Training System
Authors: Albert Bertrhude , Roberts T. Grady , Harder Amy
Published: March 2019

The purpose of this research was to identify how teaching at multiple institutions impacts social capital of faculty within the Haitian AET system. Putnam’s social capital framework was used in the current study. Social capital is developed based on relationships with others. Bonding social capital is homogenous; bridging social capital is heterogonous; linking social capital connects an individual with external resources. A mixed methods approach was used in order to accomplish the study’s objectives. Results from the quantitative portion of this research showed a low positive association between teaching at multiple institutions and bonding social capital. Similarly, a moderate positive association between teaching at multiple institutions and linking social capital was found. Conversely, data showed a negligible negative association between
linking social capital and teaching at multiple institutions. The qualitative portion of this research showed that most educators were optimistic about teaching at various institutions; however, faculty indicated teaching at multiple institutions did not translate directly into an increase in their social capital. In fact, teaching at multiple institutions only increased the demands on their time caused by having multiple appointments. It is recommended that universities invest in platforms and strategies to increase faculty’s social capital. From a
theoretical perspective, this research applies social capital theory in a new context. This research may also have value to development researchers working with higher education faculty in other countries.
Determinants of Student Persistence in Completing BS Agriculture Degrees in the University of the Philippines
Authors: Ortega-Dela Cruz Ruth A. , Quimbo Maria Ana T.
Published: March 2019

The study used descriptive research design to identify factors that explain persistence of BS Agriculture (BSA) students in the University of the Philippines Los Baños during their first year of college as they moved on to the next year level towards degree completion. In addition to selfadministered questionnaire, Key Informant interviews were also conducted. Findings reveal that institution-related factor particularly the institution’s commitment to academic excellence constitutes most to the experiences of agriculture students. Analysis of Variance reveals a significant difference in the persistence of BS Agriculture students across year levels. The results of the study point out that, as per responses of the students as well as the faculty and administrators interviewed, the University has not gone far enough to ensure that BSA students are supported in an efficient manner. The University of the Philippines, being the National University has much opportunity to make positive changes in persistence of these special populations of agriculture students. Thus, it needs to take steps toward making more of a commitment to student success.
Critical Action Inquiry for the Establishment of a Global Food Security Graduate Certificate in Latin America and the Caribbean at Texas Tech University
Authors: Millares Forno Carla Andrea , Brashears Todd , Boren-Alpizar Amy E. , Baker Matt , Carpio Carlos
Published: March 2019

The purpose of the study was to determine the topics and courses of a graduate certificate focusing on Global Food Security (GFS) for Latin America and the Caribbean (LAC) through critical action inquiry. GFS is a major issue worldwide that will continue to expand in years to come. Almost 795 million people are estimated to have suffered from chronic hunger globally in 2014-2016. Studies have shown the strong relationship between education and food security and we do not argue for causation, merely association. For this reason, curricula focused on teaching GFS to graduate students will enable professionals in international settings to manage the complexities of food security more effectively. For this critical action inquiry study, identification of the content was the result of a three-round Delphi study performed with experts from LAC and its comparison with the result of the Texas Tech University (TTU) professors survey to determine the topics and courses. Of the 91-originally-idenified topics, 40 reached experts’ consensus. The topics were then grouped into 23 courses. Faculty from TTU also ranked the courses. In the end, seven courses emerged from the research. The curriculum was approved and directed toward professionals in Latin America and the Caribbean. The courses for the online and face-to-face delivery of this multidisciplinary graduate certificate comprise the four pillars of food security and cross-cutting topics.
Exploring the Influence of Innovation Characteristics on the Adoption of a Water and Input Saving Technology in the Jordan Valley: Implications for Community Extension Workers
Authors: Rodriguez Mary T. , Roberts T. Grady , Harder Amy
Published: March 2019

As the world’s population is set to increase to an estimated 9.6 billion people, the greater the strain becomes on the food system to meet people’s food and nutrition needs (United Nations, 2013). The MENA region is expected to increase in population by double by 2050 further straining their water and food resources (IFPRI, 2010). Improved innovations to increase production have been encouraged to address those issues. Fertigation, and in particular the more effective hydraulic injector, was introduced in the Jordan Valley to help manage the amount of fertilizer application, reduce run-off in irrigated agriculture, and improve water use efficiency. However, despite its advantages, the hydraulic injector fertigation technology has not been widely adopted. This study sought to better understand this phenomena through the use of mixed methods research on the impact of innovation characteristics, as defined by Rogers (2003), on adoption of the technology. Results found complexity to have a statistically significant impact on adoption and to be a significant predictor of adoption. While not specifically a component of Roger’s innovation characteristics, affordability was a key factor in non-adoption.
Enhancement of secondary organic aerosol formation and its oxidation state by SO2 during photooxidation of 2-methoxyphenol
Authors: Liu Changgeng , Chen Tianzeng , Liu Yongchun , Liu Jun , He Hong , Zhang Peng
Published: March 2019

Abstract. 2-Methoxyphenol (guaiacol) is derived from the lignin pyrolysis
and taken as a potential tracer for wood smoke emissions. In this work, the
effect of SO2 at atmospheric levels (0–56 ppbv) on secondary organic
aerosol (SOA) formation and its oxidation state during guaiacol
photooxidation was investigated in the presence of various inorganic seed
particles (i.e., NaCl and (NH4)2SO4). Without SO2 and seed
particles, SOA yields ranged from (9.46±1.71) % to (26.37±2.83) % and could be well expressed by a one-product model. According to
the ratio of the average gas-particle partitioning timescale (τ‾g-p) over the course of the experiment to the vapor wall deposition
timescale (τg−w), the determined SOA yields were
underestimated by a factor of ∼2. The presence of
SO2 resulted in enhancing SOA yield by 14.04 %–23.65 %. With
(NH4)2SO4 and NaCl seed particles, SOA yield was enhanced by
23.07 % and 29.57 %, respectively, which further increased
significantly to 29.78 %–53.43 % in the presence of SO2,
suggesting that SO2 and seed particles have a synergetic contribution to
SOA formation. The decreasing trend of the τ‾g-p/τg-w ratio in the presence of seed particles and SO2
suggested that more SOA-forming vapors partitioned into the particle phase,
consequently increasing SOA yields. It should be noted that SO2 was
found to be in favor of increasing the carbon oxidation state (OSC) of
SOA, indicating that the functionalization or the partitioning of
highly oxidized products into particles should be more dominant than
the oligomerization. In addition, the average N∕C ratio of SOA was
0.037, which revealed that NOx participated in the photooxidation
process, consequently leading to the formation of organic N-containing
compounds. The experimental results demonstrate the importance of SO2 on
the formation processes of SOA and organic S-containing compounds and are also
helpful to further understand SOA formation from the atmospheric
photooxidation of guaiacol and its subsequent impacts on air quality and
climate.
Dual-wavelength radar technique development for snow rate estimation: a case study from GCPEx
Authors: Huang Gwo-Jong , Bringi Viswanathan N. , Newman Andrew J. , Lee Gyuwon , Moisseev Dmitri , Notaroš Branislav M.
Published: March 2019

Abstract. quantitative precipitation estimation (QPE) of snowfall has generally been
expressed in power-law form between equivalent radar reflectivity factor
(Ze) and liquid equivalent snow rate (SR). It is known that
there is large variability in the prefactor of the power law due to changes
in particle size distribution (PSD), density, and fall velocity, whereas the
variability of the exponent is considerably smaller. The dual-wavelength
radar reflectivity ratio (DWR) technique can improve SR
accuracy by estimating one of the PSD parameters (characteristic diameter),
thus reducing the variability due to the prefactor. The two frequencies
commonly used in dual-wavelength techniques are Ku- and Ka-bands. The basic
idea of DWR is that the snow particle size-to-wavelength ratio is
falls in the Rayleigh region at Ku-band but in the Mie region at
Ka-band. We propose a method for snow rate estimation by using NASA D3R radar DWR and
Ka-band reflectivity observations collected during a long-duration synoptic
snow event on 30–31 January 2012 during the GCPEx (GPM Cold-season
Precipitation Experiment). Since the particle mass can be estimated using
2-D video disdrometer (2DVD) fall speed data and hydrodynamic theory, we
simulate the DWR and compare it directly with D3R radar measurements. We also use
the 2DVD-based mass to compute the 2DVD-based SR. Using three different mass
estimation methods, we arrive at three respective sets of Z–SR and
SR(Zh, DWR) relationships. We then use these relationships with D3R
measurements to compute radar-based SR. Finally, we validate our method by
comparing the D3R radar-retrieved SR with accumulated SR directly measured by a
well-shielded Pluvio gauge for the entire synoptic event.
Effects of Gas-Wall Interactions on Measurements of Semivolatile Compounds and Small Polar Molecules
Authors: Liu Xiaoxi , Deming Benjamin , Pagonis Demetrios , Day Douglas A. , Palm Brett B. , Talukdar Ranajit , Roberts James M. , Veres Patrick R. , Krechmer Jordan E. , Thornton Joel A. , de Gouw Joost A. , Ziemann Paul J. , Jimenez Jose L.
Published: March 2019

Abstract. Recent work has quantified the delay times in measurements of volatile organic compounds (VOCs) caused by the partitioning between the gas phase and the surfaces of the inlet tubing and instrument itself. In this study we quantify wall partitioning effects on time responses and transmission of multi-functional, semivolatile and intermediate-volatility organic compounds (S/IVOCs) with saturation concentrations (C*) between 100 and 104 µg m−3. The instrument delays of several chemical ionization mass spectrometer (CIMS) instruments increase with decreasing C*, ranging from seconds to tens of minutes, except for the NO3−-CIMS where it is always on the order of seconds. Six different tubing materials were tested. Teflon, including PFA, FEP, and conductive PFA, performs better than metals and Nafion in terms of both delay time and transmission efficiency. Analogous to instrument responses, tubing delays increase as C* decreases, from less than a minute to > 100 min. The delays caused by Teflon tubing vs. C* can be modeled using the simple chromatography model of Pagonis et al. (2017). The model can be used to estimate the equivalent absorbing mass concentration (Cw) of each material, and to estimate delays under different flow rates and tubing dimensions. We also include time delay measurements from a series of small polar organic and inorganic analytes in PFA tubing measured by CIMS. Small polar molecules behave differently than larger organic ones, with their delays being predicted by their Henry’s law constants instead of their C*, suggesting the dominance of partitioning to small amounts of water on sampling surfaces as a result of their polarity and acidity properties. PFA tubing has the best performance for gas-only sampling, while conductive PFA appears very promising for sampling S/IVOCs and particles simultaneously. The observed delays and low transmission both affect the quality of gas quantification, especially when no direct calibration is available. Improvements in sampling and instrument response are needed for fast atmospheric measurements of a wide range of S/IVOCs (e.g., by aircraft or for eddy covariance). These methods and results are also useful for more general characterization of surface/gas interactions.
On the validity of foraminifera-based ENSO reconstructions
Authors: Metcalfe Brett , Lougheed Bryan C. , Waelbroeck Claire , Roche Didier M.
Published: March 2019

Abstract. A complete understanding of past El Niño-Southern Oscillation (ENSO) fluctuations is important for the future predictions of regional climate using climate models. Reconstructions of past ENSO dynamics use carbonate oxygen isotope ratios (δ18Oc) and trace metal geochemistry (Mg / Ca) recorded by planktonic foraminifera to reconstruct past spatiotemporal changes in upper ocean conditions. We investigate whether planktonic foraminifera-based proxies offer sufficient spatiotemporal continuity with which to reconstruct past ENSO dynamics. Concentrating upon the period of the instrumental record, we use the Foraminifera as Modelled Entities model to statistically test whether or not δ18Oc and the Temperature signal (Tc) in planktonic foraminifera directly records the ENSO cycle. Our results show that it is possible to use δ18Oc from foraminifera to disentangle the ENSO signal only in certain parts of the Pacific Ocean. Furthermore, a large proportion of these areas coincide with sea-floor regions exhibiting a low sedimentation rate and/or water depth below the carbonate compensation depth, thus precluding the extraction of a temporally valid palaeoclimate signal using long-standing palaeoceanographic methods.
Meeting climate targets by direct CO2 injections:
What price would the ocean have to pay?
Authors: Reith Fabian , Koeve Wolfgang , Keller David P. , Getzlaff Julia , Oschlies Andreas
Published: March 2019

Abstract. We investigate the climate mitigation potential and collateral effects of direct injections of captured CO2 into the deep ocean as a possible means to close the gap between an intermediate CO2 emissions scenario and a specific temperature target, such as the 1.5 °C target aimed for by the Paris Agreement. For that purpose, a suite of approaches for controlling the amount of direct CO2 injections at 3000 m water depth are implemented in an Earth System Model of intermediate complexity. Following the representative concentration pathway RCP4.5, which is a medium mitigation CO2 emissions scenario, cumula-tive CO2 injections required to meet the 1.5 °C climate goal are found to be 390 Gt C by the year 2100 and 1562 Gt C at the end of simulations, by the year 3020. The latter includes a cumulative leakage of 602 Gt C that needs to be re-injected in order to sustain the targeted global mean temperature. CaCO3 sediment and weathering feedbacks reduce the required CO2 injections that comply with the 1.5 °C target by about 13 % in 2100 and by about 11 % at the end of the simulation. With respect to the injection-related impacts we find that average pH values in the surface ocean are increased by about 0.13 to 0.18 units, when compared to the control run. In the model, this results in significant increases in potential coral reef habi-tats, i.e., the volume of the global upper ocean (0 to 130 m depth) with omega aragonite > 3.4 and ocean temperatures be-tween 21 °C and 28 °C, compared to the control run. The potential benefits in the upper ocean come at the expense of strongly acidified water masses at depth, with maximum pH reductions of about −2.37 units, relative to preindustrial, in the vicinity of the injection sites. Overall, this study demonstrates that massive amounts of CO2 would need to be injected into the deep ocean in order to reach and maintain the 1.5 °C climate target in a medium mitigation scenario on a millennium timescale, and that there is a trade-off between injection-related reductions in atmospheric CO2 levels accompanied by reduced upper-ocean acidification and adverse effects on deep ocean chemistry, particularly near the injection sites.
Using nowcasting technique and data assimilation in a
meteorological model to improve very short range hydrological
forecasts
Authors: Poletti Maria Laura , Silvestro Francesco , Davolio Silvio , Pignone Flavio , Rebora Nicola
Published: March 2019

Abstract. Forecasting flash floods with anticipation of some hours is still a challenge especially in environments made by a collection of small catchments. Hydrometeorological forecasting systems generally allow to predict the possibility of having very intense rainfall events on quite large areas with good performances even with 12–24 hours of anticipation. However, they are not able to predict exactly rainfall location if we consider portions of territory of 10 to 103 km2 as order of magnitude. The scope of this work is to exploit both observations and modeling sources to improve the discharge prediction in small catchments with time horizon of 2–8 hours. The models used to achieve the goal are essentially three i) a probabilistic rainfall nowcasting model able to extrapolate the rainfall evolution from observations; ii) a non hydrostatic high-resolution numerical weather prediction (NWP) model; iii) a distributed hydrological model able to provide a streamflow prediction in each pixel of the studied domain. These tools are used, together with radar observations, in a synergistic way, exploiting the information of each element in order to complement each other: observations are used in a frequently updated data assimilation framework to drive the NWP system, whose output is in turn used to improve the information in input to a nowcasting technique; finally nowcasting and NWP outputs are blended, generating an ensemble of rainfall scenarios used to feed the hydrological model and produce a prediction in terms of streamflow. The flood prediction system is applied to three major events occurred on Liguria Region (Italy) first to produce a standard analysis on predefined basin control sections, then using a distributed approach that exploit the capabilities of the employed hydrological model. The results obtained for these three analyzed events show that the use of the present approach is promising. Even if not in all the cases, the blending technique clearly enhances the prediction capacity of the hydrological nowcasting chain with respect to the use of input coming only from the nowcasting technique; moreover, a worsening of the performance is rarely observed and it is nevertheless ascribable to the critical transition between the nowcasting and the NWP model rainfall field.
EXCESSIVE FERTILIZER USAGE DRIVES AGRICULTURE GROWTH BUT DEPLETES WATER QUALITY
Authors: Kondraju T. T. , Rajan K. S.
Published: March 2019

Abstract. By 2050 most parts of India will be water stressed zones as most of the water resources are under heavy stress due to increasing nutrient contamination in their waters. In this scenario, studying the changes occurring in the freshwater nutrient contamination levels over a temporal scale is extremely important. This study focuses on monitoring the changes occurring in the nutrient contamination levels over a decade in a large reservoir known as Nagarjuna Sagar (NS) using remote sensing data. In this study, Landsat (5 & 8) data for the year 2005, 2009, 2015 and Sentinel (2A and 2B) data for the years 2016 and 2018 is used to study nutrient contamination in NS. The spatial spread of chlorophyll - a (chl-a) area is used as a proxy to estimate the extent of nutrient contamination in NS. In this study, only October images of NS are used as they exhibit the maximum spatial spread of Chl-a and hence help assess the contamination levels over the period 2005–2018. The analysis shows that during this period, chl-a spatial spread area has increased from 21 Km2 to 205 Km2, indicating a decrease in water quality in the reservoir. The study shows that this is accompanied by an increase in the agricultural land use area by 1000 Km2 in addition to a steep increase in the use of agricultural inputs, primarily fertilisers like urea, P and K. Thus, while the combined effect of excessive usage of fertilizers with agricultural intensification has increased crop yields, it has also contributed to damaging the freshwater resources.
A FIT-FOR-PURPOSE ALGORITHM FOR ENVIRONMENTAL MONITORING BASED ON MAXIMUM LIKELIHOOD, SUPPORT VECTOR MACHINE AND RANDOM FOREST
Authors: Jamali A.
Published: March 2019

Abstract. Due to concerns of recent earth climate changes such as an increase of earth surface temperature and monitoring its effect on earth surface, environmental monitoring is a necessity. Environmental change monitoring in earth sciences needs land use land cover change (LULCC) modelling as a key factor to investigate impact of climate change phenomena such as droughts and floods on earth surface land cover. There are several free and commercial multi/hyper spectral data sources of Earth Observation (EO) satellites including Landsat, Sentinel and Spot. In this paper, for land use land cover modelling (LULCM), image classification of Landsat 8 using several mathematical and machine learning algorithms including Support Vector Machine (SVM), Random Forest (RF), Maximum Likelihood (ML) and a combination of SVM, ML and RF as a fit-for-purpose algorithm are implemented in R programming language and compared in terms of overall accuracy for image classification.
GROUND PENETRATING RADAR DATA INTERPRETATION USING ELECTROMAGNETIC FIELD ANALYSIS FOR SEA ICE THICKNESS MEASUREMENT
Authors: Matsumoto M. , Yoshimura M. , Naoki K. , Cho K. , Wakabayashi H.
Published: March 2019

Abstract. Observation of sea ice thickness by remote sensing is one of key issues to understand an effect of global warming. However, ground truth must be necessary to discuss this kind of approach. Although there are several methods to acquire ice thickness, Ground Penetrating Radar (GPR) can be good solution because it can discriminate snow-ice and ice-sea water interface thanks to comparative higher spatial resolution than the other methods. In this paper, we carried out GPR measurement in brackish lake and an electromagnetic field analysis in order to interpret the GPR data. The simulation model was assumed considering the actual snow and ice thickness acquired in field measurement. From the simulation results, although it seems difficult to identify the reflection at snow and ice interface due to a thin layer thickness and a low dielectric constant, snow and ice thickness may be estimated by using multiple reflection components.