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Air Pollution from Natural and Anthropogenic Sources over Mediterranean Region: Assessment of an Online Coupled Meteorological and Air Quality Model
Get PDFNel presente elaborato viene proposto uno studio per comprendere e quantificare in modo migliore ed approfondito delle fonti di inquinamento atmosferico in Italia e nella regione mediterranea circostante. Sospette fonti di inquinanti includono attività umane, idrocarburi naturali da foreste (isoprene e terpeni) ed episodi di polvere minerale trasportata dal vento prevalentemente dal deserto del Sahara. Una profonda comprensione di queste fonti è fondamentale per lo sviluppo di azioni mirate a mitigare l’inquinamento atmosferico. Lo studio considera principalmente gli idrocarburi e la polvere naturali, utilizzando un modello di trasporto chimico all'avanguardia (“Weather Research and Forecasting with Chemistry”). Il modello ambientale WRF-Chem è un sistema di previsione a scala regionale "online" (meteorologia e chimica dell’atmosfera sono computati in maniera parallela e non in serie) progettato per simulare una vasta gamma di processi chimici, meteorologici, gas e aerosol dettagliati con un completo accoppiamento tra le diverse componenti e fasi. Il presente studio documenta due diverse applicazioni realizzate attraverso il modello WRF-Chem al fine di migliorare la sua rappresentazione dei processi chimici di gas e aerosol. La prima applicazione include la descrizione, l'esame e il test di una serie di aggiornamenti apportati al modello MEGAN versione 2.04 (“Model of Emission Gas and Aerosols from Nature”), modello per le emissioni biogeniche implementato in WRF-Chem, attraverso due diversi casi studio (ovvero il primo a livello europeo e il nella zona sud-est degli Stati Uniti). La seconda applicazione prevede l’applicazione del modello (WRF-Chem) per la valutazione delle intrusioni di polvere di sahariane nell'Europa meridionale e il loro confronto con le emissioni antropogeniche nell'arco di un intero anno (2017).
Lo studio di sensibilità del modello di emissioni biogeniche (MEGAN), a livello europeo, include quattro simulazioni. La prima è (1) quella di controllo: il database MEGAN è stato utilizzato senza alcuna modifica (Megan_V2.04); nella seconda (2) tutti i fattori di attività (γi) sono stati modificati seguendo gli aggiornamenti apportanti all’ultima versione del MEGAN (versione 2.10) (Megan_Gamma). La (3) terza simulazione aggiunge i PFT (Plant Functional Type – classificazione in base al tipo di vegetazione), i fattori di emissione variano al variare del tipo di pianta (Megan_GammaPFT); infine, l'ultima (4) calcola il fattore di emissione di isoprene all'interno dell'algoritmo di emissione MEGAN, invece di ricavarlo direttamente dal database di input come per tutte le altre simulazioni (Megan_GammaPFTISO). I risultati delle emissioni di isoprene e α-pinene dimostrano che l'aggiornamento del codice MEGAN aumenta notevolmente
le emissioni (ad esempio, nella città di Zagabria si ha un aumento di circa 100 mol/km2hr e a Kiev di circa 50 mol/km2h). Il confronto con l’inventario AIRBASE (rete europea per la qualità dell'aria e l'ambiente) ha mostrato che la distribuzione temporale e spaziale dell'ozono (O3) è ben rappresentata; la simulazione di controllo ha dimostrato i risultati migliori, dal momento che le simulazioni, considerando gli aggiornamenti effettuati al modello MEGAN, aumentano la concentrazione di ozono di circa 20-40 ppb. Gli altri gas considerati (NO2 e CO) sono risultati molto sottostimati, rispettivamente di un fattore 2 e 10, indipendentemente dalla simulazione considerata, poiché gli aggiornamenti apportate al modello MEGAN non influenzano tali composti.
D'altra parte, il caso studio statunitense include due simulazioni: quella di controllo (Megan_V2.04) e una simulazione considerando tutti gli aggiornamenti apportati al modello di emisione MEGAN (Megan_GammaPFTISO). Le simulazioni sono state effettuate in concomitanza con la campagna sperimentale NOMADSS (“Nitrogen, Oxidants, Mercury and Aerosol Distributions, Sources and Sinks”) (effettuata dal 1° giugno 00:00 UTC al 15 giugno 00:00 UTC, 2013) in modo da approvare gli aggiornamenti effettuati con tale set di dati. I valori modellati di O3 confermano il caso studio europeo, aggiornando le emissioni biogeniche, le concentrazioni di ozono aumentato del 10%; le concentrazioni di NOx sono sovrastimate, come il caso europeo, ma con migliori risultati. Infine, anche le concentrazioni di isoprene sovrastimano considerevolmente i dati sperimentali fino a un fattore 5 (la discrepanza media è di circa 7000 ppt).
La seconda applicazione di WRF-Chem prevede due simulazioni con durata annuale (dal 1° gennaio 2017 00:00 UTC al 1° gennaio 2018 00:00 UTC): la prima considera solo l'emissione di polvere minerale (chem_opt = 401 - "DUSTONLY”), mentre la seconda considera tutti i tipi di emissioni (biogeniche, incendi e antropogeniche) (chem_opt = 201 - "MOZMOSAIC"); entrambe le simulazioni per le polveri desertiche utilizzano lo schema di emissione GOCART (Goddard Chemistry Aerosol Radiation and Transport). Le rianalisi NCEP/NCAR e la rete di stazioni superficiali archiviate dell'Università del Wyoming sono state utilizzate per valutare la risoluzione spaziale della temperatura, dell'umidità relativa e della velocità e direzione del vento, dimostrando una grande capacità del modello WRF-Chem di riprodurre i dati sperimentali. L'associazione tra la densità di massa della colonna di polvere modellata [kg/m2] e il campo con la relativa rianalisi MERRA-2 (“Modern-Era Retrospective Analysis for Research and Applications”) ha mostrato una evidente sovrastima del modello per il carico di polvere minerale nelle regioni maggiori del Nord
Africa (sovrastima di un fattore di 10 - MERRA-2 = 2x10-4 kg/m2; WRF-Chem = 2x10-3 kg/m2). La sovrastima del modello è confermata dal confronto di entrambe le simulazioni con i prodotti di AOD (Aerosol Optical Depth - 550 nm) della rete di rilevazione AERONET (Aerosol Robotic NETwork): le stazioni di Roma e Napoli analizzate riportano pressoché lo stesso andamento di AOD durante il periodo analizzato, anche i valori massimi di AOD vengono catturati, ma la massa di polveri minerali è sovrastimata da entrambe le simulazioni (nel mese di maggio - AODDUSTONLY = 0.9; AODMOZMOSAIC = 1.2; AODAERONET = 0.3).A study to better understand and quantify the source of air pollution in Italy and the surrounding Mediterranean region is proposed. Suspected sources of pollutants include human activities, natural hydrocarbons from forests (isoprene and terpenes) and episodes of wind-blown mineral dust from the Sahara Desert. A deep understanding of these sources is fundamental to developing science-based mitigation actions. The study addresses specifically the natural hydrocarbons and dust, using a state-of-the-art chemistry transport model (Weather Research and Forecasting with Chemistry). The WRF-Chem system is an “online” regional scale prediction model designed to simulate many detailed meteorological, gas and aerosol chemical processes, with full coupling between the different components and phases. This study documents two different applications, and their evaluation, that have been made using WRF-Chem model in order to improve its representation of gas and aerosol chemical processes. The first application includes the description, examination and test of a set of updates made to the MEGAN version 2.04 (Model of Emission Gas and Aerosols from Nature) model, one of the BVOC (biogenic volatile organic compound) emission model includes in WRF-Chem, by two different test cases (i.e. the first at European level, and the second, at United States level). The main objective of the second WRF- Chem application, involves the assessment of Sharan dust outbreaks to the southern Europe and how they compare to anthropogenic emissions over a whole year (2017).
The MEGAN sensitivity study, at European level, includes four simulations. The first one is (1) the control one: the MEGAN database has been used without any change (Megan_V2.04); on the (2) second one all the activity factors (γi) have been modified following the MEGAN version 2.10 (Megan_Gamma). The (3) third simulation adds the PFTs (Plant Functional Type) emission factors changes to the activity factors (Megan_GammaPFT); finally, the (4) last one calculates more the isoprene emission factor within the MEGAN emission algorithm, instead of reading it directly from the input database (Megan_GammaPFTISO). The simulations listed above, are applied to simulate an intense ozone event that took place over central Italy in August 13th, 2015. Results for isoprene and α-pinene emissions demonstrate the updating the MEGAN code the emissions increase considerably (i.e. Zagreb has an increase about 100 mol/km2hr and Kiev about 50 mol/km2 hr). The comparison with the AIRBASE (European Environment Agency air quality network) showed that only the temporal and spatial distribution of the O3 are well represented; the control simulation demonstrated the ozone better results, since the updates simulations increase
the ozone concentration of nearly from 20 to 40 ppb. The other trace gases considered (NO2 and CO) model results are very underestimate, respectively by a factor of 2 and 10 regardless of simulations considered, since the MEGAN updates does not affect that compounds.
On the other hands, the U.S. MEGAN sensitivity case of study, includes two simulations: the control one (Megan_V2.04) and a simulation with all code changes applied (Megan_GammaPFTISO). They are concurrently with the NOMADSS (Nitrogen, Oxidants, Mercury and Aerosol Distributions, Sources and Sinks) field campaign (from June 1th 00:00 UTC to June 15th 00:00 UTC, 2013), in order to validate the updates with that dataset. Isoprene concentrations overestimate the NOMADSS considerably up to a factor of 5 (average discrepancy is about 7000 ppt). The O3 modeled values confirm the European case of study, updating MEGAN ozone concentrations increase by 10 %; the NOx concentrations are overestimate, as European case, but with better agreement. The MEGAN updates do not take effects on the NOx concentrations.
Last WRF-Chem application has one-year time duration (from January 1st 2017 00:00 UTC to January 1st 2018 00:00 UTC) where two simulations are carried out: the first considering only the dust emission (chem_opt = 401 – “DUSTONLY” simulation) and the second one considering all the type of emissions (biogenic, biomass burning and anthropogenic) (chem_opt = 201 – “MOZMOSAIC” simulation); both of simulations use the GOCART (Goddard Chemistry Aerosol Radiation and Transport) dust emission scheme. The NCEP/NCAR reanalysis and the University of Wyoming surface stations network have been used to assess the spatial resolution of simulated temperature, relative humidity and wind speed and direction, showing a great capability of WRF- Chem model to reproduce the experimental data and its spatial trend. The association between the modeled dust column mass density [kg/m2] and the field with the corresponding MERRA-2 (Modern-Era Retrospective Analysis for Research and Applications) reanalysis showed an evident dust load overestimated over the North-Africa regions (i.e. by a factor of 10 - MERRA-2 = 2x10- 4 kg/m2; WRF-Chem = 2x10-3 kg/m2). The dust modeled overestimate is confirmed by the comparison of both simulations with the AERONET AOD (550 nm) products; i.e. Rome and Naples stations have nearly the same year trend, AOD peaks are captured as well, but the dust magnitude is overestimated from both simulations (e.g. May – AODDUSTONLY = 0.9; AODMOZMOSAIC = 1.2; AODAERONET = 0.3)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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