Дисертації з теми "Atmospheric aerosol formation"
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Tasoglou, Antonios. "Formation and Chemical Aging of Atmospheric Carbonaceous Aerosol." Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/757.
Повний текст джерелаWang, Shih-chen Flagan Richard C. "Aerosol formation and growth in atmospheric organic/NOx systems /." Diss., Pasadena, Calif. : California Institute of Technology, 1991. http://resolver.caltech.edu/CaltechETD:etd-01112007-152148.
Повний текст джерелаHennigan, Christopher James. "Properties of secondary organic aerosol in the ambient atmosphere sources, formation, and partitioning /." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26598.
Повний текст джерелаCommittee Chair: Weber, Rodney; Committee Co-Chair: Bergin, Michael; Committee Member: Mulholland, James; Committee Member: Nenes, Athanasios; Committee Member: Russell, Armistead. Part of the SMARTech Electronic Thesis and Dissertation Collection.
Lack, Daniel Anthony. "Modelling the formation of atmospheric aerosol from gaseous organic precursors." Thesis, Queensland University of Technology, 2003. https://eprints.qut.edu.au/15831/1/Daniel_Lack_Thesis.pdf.
Повний текст джерелаLack, Daniel Anthony. "Modelling the Formation of Atmospheric Aerosol From Gaseous Organic Precursors." Queensland University of Technology, 2003. http://eprints.qut.edu.au/15831/.
Повний текст джерелаMatsunaga, Aiko. "Secondary organic aerosol formation from radical-initiated reactions of alkenes development of mechanisms /." Diss., [Riverside, Calif.] : University of California, Riverside, 2009. http://proquest.umi.com/pqdweb?index=0&did=1899476651&SrchMode=2&sid=2&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1269361334&clientId=48051.
Повний текст джерелаIncludes abstract. Available via ProQuest Digital Dissertations. Title from first page of PDF file (viewed March 10, 2010). Includes bibliographical references. Also issued in print.
Barahona, Donifan. "On the representation of aerosol-cloud interactions in atmospheric models." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/41169.
Повний текст джерелаJames, Jonathan David. "Investigation into the composition and formation of atmospheric aerosol over the north-east Atlantic Ocean." Thesis, University of Birmingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324171.
Повний текст джерелаZhang, Xiaolu. "The sources, formation and properties of soluble organic aerosols: results from ambient measurements in the southeastern united states and the los angeles basin." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44894.
Повний текст джерелаMalloy, Quentin Gerald James. "Chemical and physical characterization of secondary organic aerosol formation from select agricultural emissions." Diss., UC access only, 2009. http://proquest.umi.com/pqdweb?index=33&did=1871857121&SrchMode=1&sid=2&Fmt=7&retrieveGroup=0&VType=PQD&VInst=PROD&RQT=309&VName=PQD&TS=1270140114&clientId=48051.
Повний текст джерелаMarks, Marguerite Colasurdo. "Incorporating Chemical Activity and Relative Humidity Effects in Regional Air Quality Modeling of Organic Aerosol Formation." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1511.
Повний текст джерелаCapouet, Manuel J. F. "Modeling the oxidation of alpha-pinene and the related aerosol formation in laboratory and atmospheric conditions." Doctoral thesis, Universite Libre de Bruxelles, 2005. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210935.
Повний текст джерелаGonser, Stefan Georg [Verfasser], and Andreas [Akademischer Betreuer] Held. "Ion dynamics and aerosol mass spectrometry during atmospheric new particle formation / Stefan Georg Gonser. Betreuer: Andreas Held." Bayreuth : Universität Bayreuth, 2014. http://d-nb.info/1060010216/34.
Повний текст джерелаPadro, Martinez Luz Teresa. "Towards an understanding of the cloud formation potential of carbonaceous aerosol laboratory and field studies /." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31780.
Повний текст джерелаCommittee Chair: Nenes, Athanasios; Committee Member: Huey, Greg; Committee Member: Meredith, Carson; Committee Member: Teja, Amyn; Committee Member: Weber, Rodney J. Part of the SMARTech Electronic Thesis and Dissertation Collection.
Clark, Jared M. "The Formation and Stability of Radical-Molecule and Radical-Radical Complexes and Their Importance in Atmospheric Processes." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2679.
Повний текст джерелаFoley, Theresa Anne. "Three Air Quality Studies: Great Lakes Ozone Formation and Nitrogen Dry Deposition; and Tucson Aerosol Chemical Characterization." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/265339.
Повний текст джерелаOfner, Johannes [Verfasser], and Cornelius [Akademischer Betreuer] Zetzsch. "Formation of secondary organic aerosol and its processing by atmospheric halogen species – A spectroscopic study / Johannes Ofner. Betreuer: Cornelius Zetzsch." Bayreuth : Universitätsbibliothek Bayreuth, 2011. http://d-nb.info/1015875475/34.
Повний текст джерелаToprak, Emre [Verfasser], and S. [Akademischer Betreuer] Norra. "Real Time Detection of Primary Biological Aerosol Particles (PBAP) in the context of atmospheric ice formation / Emre Toprak. Betreuer: S. Norra." Karlsruhe : KIT-Bibliothek, 2014. http://d-nb.info/105695597X/34.
Повний текст джерелаKatragkou, Eleni. "Aircraft based measurements of atmospheric sulfur dioxide and ground based measurements of gaseous sulfur (VI) in the simulated internal flow of an aircraft engine implications for atmospheric aerosol formation /." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969654588.
Повний текст джерелаAllen, Christopher J. T. "Atmospheric mechanisms of central Saharan dust storm formation in boreal summer : observations from the Fennec campaign." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:896c26f3-c7a5-4c93-9e53-69b69b28d1cb.
Повний текст джерелаVan, Eijck Anna [Verfasser]. "Atmospheric degradation of reactive biogenic VOCs and their role in aerosol formation: modelling activities, laboratory experiments and field studies in different vegetation zones / Anna Van Eijck." Mainz : Universitätsbibliothek Mainz, 2016. http://d-nb.info/1109819099/34.
Повний текст джерелаRiva, Matthieu. "Caractérisation d’une nouvelle voie de formation des aérosols organiques secondaires (AOS) dans l’atmosphère : rôle des précurseurs polyaromatiques." Thesis, Bordeaux 1, 2013. http://www.theses.fr/2013BOR14942/document.
Повний текст джерелаThis work deals with the secondary organic aerosol (SOA) formation from gas phase oxidation of volatile organic compounds in the presence of atmospheric oxidants (ozone, hydroxyl radical, chlorine and nitrate radical). Among them, polycyclic aromatic hydrocarbons (PAHs) have been proposed as an important potential source of anthropogenic SOA. The oxidation of 4 main gaseous PAHs (naphthalene, acenaphthylene, acenaphthene and phenanthrene) in the presence of main atmospheric oxidants has been performed in order to investigate the SOA formation. Characterization of both gas and particulate phases has been carried out using mass spectrometry and optical spectroscopy allowing the identification of products in both phases. Then, chemical mechanisms have been proposed in order to explain SOA formation. SOA yields have been also determined to evaluate the impact of the gas phase oxidation of PAHs in SOA formation. Experiments have been carried out using flow tube and atmospheric simulation chambers. SOA fate has been investigated to determine the different oxidation processes involved in SOA aging
Modini, Robin Lewis. "Investigation of the effect of organics on the water uptake of marine aerosols." Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/46884/1/Robin_Modini_Thesis.pdf.
Повний текст джерелаJaecker-Voirol, Anne. "Etude physico-chimique de la formation des aerosols : application aux pluies acides et a la stratosphere." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13222.
Повний текст джерелаGramotnev, Galina. "Analysis of dispersion and propagation of fine and ultra fine particle aerosols from a busy road." Thesis, Queensland University of Technology, 2007. https://eprints.qut.edu.au/16338/1/Galina_Gramotnev_Thesis.pdf.
Повний текст джерелаGramotnev, Galina. "Analysis of dispersion and propagation of fine and ultra fine particle aerosols from a busy road." Queensland University of Technology, 2007. http://eprints.qut.edu.au/16338/.
Повний текст джерелаCarter-Fenk, Kimberly Anne. "Structure, Adsorption Mechanisms, and Vibrational Exciton Formation at Proxy Marine Interfaces." The Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1617809603306859.
Повний текст джерелаJouan, Caroline. "Les nuages de glace en arctique : mécanismes de formation." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2013. http://tel.archives-ouvertes.fr/tel-00843520.
Повний текст джерелаPettibone, Alicia Stanier Charles O. "Toward a better understanding of new particle formation." [Iowa City, Iowa] : University of Iowa, 2009. http://ir.uiowa.edu/etd/420.
Повний текст джерелаLamkaddam, Houssni. "Etude en atmosphère simulée de la formation d'Aérosol Organique Secondaire issue de la photooxydation du n-dodécane : impact des paramètres environnementaux." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1128/document.
Повний текст джерелаSecondary Organic Aerosol (SOA), the major fraction of the submicron aerosol, plays a key role on health, environment and climate. The evaluation of its impacts is a real challenge for the scientific community. Our current knowledge of SOA formation processes and chemical composition is still very deficient and limit the development of atmospheric models to quantify the impacts of SOA on air quality and climate system. Therefore, the aim of this work is to produce a set of experimental data to use to constrain and improve the models. To do that, the SOA formation has been studied from the photooxidation of a model precursor, n-dodecane, in the CESAM environmental chamber. The chemical composition has been investigated by spectrometric and chromatographic techniques which allowed us to identify the reaction products constituting the gaseous and particulate phases. In particular, new condensed phase mechanisms have been proposed to explain the formation of carboxylic acids and lactones, identified for the first time. These could be implemented in the models. A wide variety of environmental conditions, such as temperature, relative humidity and the presence/absence of preexisting particles, have been taken into account in this work. The study of the temperature influence has shown a low sensitivity of this parameter on the SOA production. While the study relative humidity effect has shown that adding water to the reaction system beyond 5% lowers SOA yields by almost a factor of 2 in comparison to dry conditions. The SOA formation potential, under these conditions, has been evaluated, and resulted in parameterizations which could be useful for modelers. Furthermore, a characterization of the wall effects in CESAM, i.e. gas and particulate phase wall losses, has been carried out
Lannuque, Victor. "Formation de l’aérosol organique secondaire dans les modèles de qualité de l’air : développement d’une paramétrisation sur la base de simulations explicites." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1129.
Повний текст джерелаThe gaseous oxidation of organic compounds emitted into the atmosphere leads to the formation of thousands of secondary organic compounds (SOC). A fraction of these SOC is low volatile, and can partition between the gaseous phase and the particulate phase, forming secondary organic aerosols (SOA). The SOA are a main component of the particles, representing between 20% and 80% of the total mass of fine aerosols. Therefore, SOA contribute to the impact of aerosols on the environment, in particular air quality and climate. The quantification of the SOA impacts is estimated using chemical-transport models (CTM). Comparisons with in situ measurements show that the spatial and temporal variations of SOA mass are not correctly simulated by CTM. In these models, the SOA formation is represented in a simplified way, using empirical parameterizations developed on the basis of observations performed in atmospheric simulation chambers. Improving the representation of organic aerosols in CTM is therefore required to diagnose the origin of air pollution by fine particles, improve the reliability of pollution episode prediction and assess the impact of aerosols on the environment. The objectives of this thesis are :• to explore the influence of environmental conditions on SOA formation and properties,• to develop a new parameterization of SOA formation based on a deterministic representation of atmospheric chemistry,• to evaluate this parameterization in CTM by comparison with in-situ measurements. Deterministic models represent the non-linearity of SOA formation processes. The model GECKO-A (Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere) is a numerical modelling tool that integrates the elementary data (kinetics and thermodynamics) from laboratory studies. In this thesis, oxidation scenarios representative of various environmental conditions were developed and GECKO-A was used to study the impact of environmental factors (temperature, NOx concentrations, solar radiations, etc.) on the formation and the properties of the SOA. On the basis of these simulations, a new parameterization for SOA formation was developed: VBS-GECKO. The evaluation of the VBS-GECKO in box model has shown a good reproduction of the organic aerosol (OA) concentrations with RMSE lesser than 20%.The VBS-GECKO was integrated into the CHIMERE CTM to simulate summer concentrations of OA over Europe. Simulated OA are significantly improved compared to the reference parameterization used in CHIMERE. The VBS-GECKO was also used to study (i) the sources and properties of SOA and (ii) different representations of emissions of semi-volatile and intermediate volatility organic compounds by road traffic
Huang, Xiaofeng. "Formation mechanisms of water-soluble organic compounds in atmospheric aerosols /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?AMCE%202005%20HUANG.
Повний текст джерелаGérard, Violaine. "Surfactants in atmospheric aerosols and their role on cloud formation." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1216/document.
Повний текст джерелаClouds are essential components of the Earth’s hydrological system and climate but some aspects of their formation are still not completely understood. In particular, although Köhler theory predicts that surfactants should enhance cloud droplet activation, current models consider this role negligible. At the time of this PhD work, a few studies had started to demonstrate the contrary but atmospheric evidence for the role of these compounds was still missing and very little was known about their atmospheric concentrations, sources, and mechanism of action. The objective of this PhD work was to investigate these aspects. A method was developed to quantify surfactant concentrations in aerosols. Its application led to the first absolute atmospheric surfactants’ surface tension curves, in coastal PM2.5 aerosols in Sweden, and to the identification of the ratio C/CMC as the key parameter controlling the cloud-forming efficiency of aerosols. A second study revealed strong correlations between cloud occurrence and intrinsic surfactant properties in boreal PM1 aerosols in Finland, demonstrating for the first time the role of surfactants in cloud formation from direct atmospheric observations. The results predicted Cloud Condensation Nuclei numbers four times larger on average than when neglecting surfactant effects, showing the importance of including surfactant effects in cloud predictions models. The role of surfactants inferred from macroscopic measurements was confirmed by laboratory experiments on individual micron-sized droplets showing an increase of droplet growth in the presence of surfactants. Finally, observations from the different field studies indicated a biological origin for the surfactants present in atmospheric aerosols
Zuberi, Bilal 1976. "Microphysics of atmospheric aerosols : phase transitions and cloud formation mechanisms." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/17654.
Повний текст джерелаVita.
Includes bibliographical references (leaves 134-148).
Clouds play an extremely important role in our atmosphere, from controlling the local weather, air pollution and chemical balance in the atmosphere to affecting long-term climatic changes at local, regional and global scales. The mechanisms through which tropospheric clouds form are still not fully understood, leading to gross uncertainties in understanding the effect of atmospheric aerosols on the environment. Using laboratory measurements, microphysical properties of typical micro-meter size atmospheric aerosols are investigated in this study. Upper tropospheric ice clouds (cirrus) form when ice is nucleated either homogeneously or heterogeneously in aqueous aerosols. We have investigated the homogeneous and heterogeneous ice nucleation in aqueous particles. Our results for homogeneous nucleation in aqueous ammonium nitrate particles show that the current thermodynamic models do not correctly predict water activities in these particles under super-saturated conditions. High super-saturations are required for ice to nucleate homogeneously in aqueous ammonium nitrate particles. We have also investigated the role of crystallized salt cores, such as solid ammonium sulfate and letovicite, in the heterogeneous nucleation of ice in saturated aqueous ammonium sulfate particles. Our results show that the surface morphology and defects on microcrystals could result in the creation of active sites, leaving the crystallized salt cores as potent ice nuclei under certain conditions. We have also investigated the role of mineral dust and soot, major components of insoluble particulates in the atmosphere, as ice-nuclei. We have found mineral dust to be an effective ice nuclei but both fresh and aged soot do not promote ice nucleation in aqueous particles.
(cont.) Soot is the most ubiquitous aerosol in the atmosphere. The lifetime and microphysics of nano-porous soot has a large impact on earth's radiative budget, heterogeneous chemistry, urban and regional air pollution and human health. We have investigated the hydrophilic properties of both fresh and aged soot as a function of relative humidity. Our results show that fresh hydrophobic soot oxidized (aged) by OH/0₃/UV in the presence of water vapor or by exposure to concentrated HNO₃ becomes hydrophilic and exhibits a greater affinity for water. Due to this increased hydrophilicity, aged soot can be easily entrained inside existing liquid cloud droplets, and even activate as cloud condensation nuclei at high super-saturations, thus influencing its heterogeneous chemistry, radiative properties and atmospheric lifetime.
by Bilal Zuberi.
Ph.D.
Liu, Jiumeng. "Chemical and optical properties of organic aerosols in the atmosphere over continental US: formation, partitioning, and light absorption." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50370.
Повний текст джерелаGarbarienė, Inga. "Origin, chemical composition and formation of submicron aerosol particles in the atmosphere." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140520_134625-72680.
Повний текст джерелаDisertacija skirta smulkiosios aerozolio dalelių frakcijos šaltinių, fizikinių ir cheminių savybių įvertinimui kompleksiškai apjungiant įvairius tyrimo metodus. Darbe susieti elementinės ir organinės anglies koncentracijų pokyčiai su tolimąja oro masių pernaša, įvertinta regiono bei vietinių šaltinių įtaka bendrai aerozolio dalelių taršai. Aprašyti anglies turinčių aerozolio dalelių pasiskirstymai pagal dydį foninėse vietovėse ir miesto aplinkoje. Naudojant aerozolio masių spektrometrą Preilos atmosferos užterštumo tyrimų stotyje buvo identifikuotas biogeninis organinių medžiagų šaltinis, kuris vidutiniškai sudaro 15 % nuo organinių medžiagų masės, tačiau Šiaurės Atlanto oro masėje biogeninių medžiagų indėlis siekia net 50 %. Atlikus kompleksinę aerozolio ir stabiliųjų anglies izotopų masių spektrometrinę analizę buvo nustatyta, kad pirminis anglies turinčio aerozolio dalelių šaltinis mieste yra autotransportas, o Rūgšteliškio foninėje vietovėje – biomasės deginimas. Taip pat buvo nustatyta, kad Vilniuje dominavo antropogeninės antrinės organinės medžiagos (76 %), o Rūgšteliškyje vyravo biogeninės antrinės organinės medžiagos (apie 50%). Vertinant tolimosios oro masių pernašos įtaką vietinės kilmės aerozolio dalelių formavimuisi ir kaitai, buvo nustatyta, kad vulkaninės kilmės aerozolio dalelės turi įtakos submikroninės aerozolio dalelių frakcijos koncentracijai, cheminei sudėčiai ir pasiskirstymui pagal dydį.
Saunders, Russell W. "Laboratory studies of aerosol formation in the Earth's lower and upper atmosphere." Thesis, University of East Anglia, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433795.
Повний текст джерелаTargino, Admir Créso. "Regional studies of the optical, chemical and microphysical properties of atmospheric aerosols : Radiative impacts and cloud formation." Doctoral thesis, Stockholm University, Department of Meteorology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-740.
Повний текст джерелаAtmospheric particles are ubiquitous in the Earth’s atmosphere and have potential to influence atmospheric chemistry, visibility, global climate and human health, particularly downwind from major pollution sources. The main objective of this thesis was to investigate questions pertaining to the microphysical, chemical and optical properties of aerosol particles by using in situ data collected during four experiments carried out in different regions of the Northern Hemisphere.
The first two papers of this thesis reports on airborne measurements of the aerosol optical properties performed over the North Atlantic and the Los Angeles basin. Airmasses from Europe and North Africa are usually advected in over the North Atlantic, alternating with the background marine conditions. The results showed that the aerosols are not uniformly distributed in the area and variability in the aerosol fields occurs at sub-synoptic scales. It was also observed that the single scattering coefficient varied as the polluted plumes aged, suggesting a relationship between this quantity and transport time. The measurements performed around the Los Angeles basin showed that the area’s complex topography and local meteorological circulations exert a strong control on the distribution of the aerosol in the basin. Large spatio-temporal gradients in the aerosol optical properties were observed along a transect flown from the shore towards the mountains. Profiles flown over sites located on the mountains displayed a stratified configuration with elevated aerosol layers.
Airborne data of residual particles collected in orographic wave clouds over Scandinavia were analyzed using a single particle analysis technique. Mineral dust, organic aerosols and sea salt were the main group of particles identified. Residuals composed predominantly of mineral dust were found in glaciated clouds while organic residuals were found in liquid clouds. The results suggest that organic material may inhibit freezing and have considerable influence on supercooled clouds that form through heterogeneous pathways.
The partitioning of the aerosol particles between cloud droplets and interstitial air has been addressed in terms of their microphysical properties using data obtained at a mountain-top site in Sweden during a stratocumulus event. The results showed that the scavenging efficiency varied during the cloud event, and Aitken-mode particles were also efficiently scavenged in addition to accumulation-mode particles. It is hypothesized that alterations of the aerosol chemical composition occurred during the measurement period, modifying the hygroscopic nature of the particles and decreasing their activation diameter.
Alvarado, Matthew James. "Formation of ozone and growth of aerosols in young smoke plumes from biomass burning." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45606.
Повний текст джерелаThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 272-291).
The combustion of biomass is a major source of atmospheric trace gases and aerosols. Regional and global-scale models of atmospheric chemistry and climate take estimates for these emissions and arbitrarily "mix" them into grid boxes with horizontal scales of 10-200 km. This procedure ignores the complex non-linear chemical and physical transformations that take place in the highly concentrated environment of the young smoke plumes. In addition, the observations of the smoke plume from the Timbavati savannah fire [Hobbs et al., 2003] show much higher concentrations of ozone and secondary aerosol matter (nitrate, sulfate, and organic carbon [OC]) in the smoke plume than are predicted by current atmospheric chemistry models. To address these issues, we developed a new model of the gas- and aerosol-phase chemistry of biomass burning smoke plumes called ASP (Aerosol Simulation Program). Here we use ASP to simulate the gas-phase chemistry and particle dynamics of young biomass burning smoke plumes and to estimate the errors introduced by the artificial mixing of biomass burning emissions into large-scale grid boxes. This work is the first known attempt to simultaneously simulate the dynamics, gas-phase chemistry, aerosol-phase chemistry, and radiative transfer in a young biomass burning smoke plume. We simulated smoke plumes from three fires using ASP combined with a Lagrangian parcel model. We found that our model explained the formation of ozone in the Otavi and Alaska plumes fairly well but that our initial model simulation of the Timbavati smoke plume underestimated the formation of ozone and secondary aerosol matter. The initial model simulation for Timbavati appears to be missing a source of OH. Heterogeneous reactions of NO2 and SO2 could explain the high concentrations of OH and the rapid formation of ozone, nitrate and sulfate in the smoke plume if the uptake coefficients on smoke aerosols are large [O(10-3) and O(10-4), respectively]. Uncharacterized organic species in the smoke plume were likely responsible for the rapid formation of aerosol OC. The changes in the aerosol size distribution in our model simulations were dominated by plume dilution and condensational growth, with coagulation and nucleation having only a minor effect.
(cont.) We used ASP and a 3D Eulerian model to simulate the Timbavati smoke plume. We ran two test cases. In the reference chemistry case, the uncharacterized organic species were assumed to be unreactive and heterogeneous chemistry was not included. In the expanded chemistry case, the uncharacterized organic compounds were included, as were heterogeneous reactions of NO2 and SO2 with uptake coefficients of 10-3 and 2x10-4, respectively. The 3D Eulerian model matched the observed plume injection height, but required a large minimum horizontal diffusion coefficient to match the observed horizontal dispersion of the plume. Smoke aerosols reduced the modeled photolysis rates within and beneath the plume by 10%-20%. The expanded chemistry case provided a better match with observations of ozone, OH, and secondary aerosol matter than the reference chemistry case, but still underestimated the observed concentrations. We find that direct measurements of OH in the young smoke plumes would be the best way to determine if heterogeneous production of HONO from NO2 is taking place, and that these measurements should be a priority for future field campaigns. Using ASP within an Eulerian box model to evaluate the errors that can be caused by the automatic dilution of biomass burning emissions into global model grid boxes, we found that even if the chemical models for smoke plume chemistry are improved, the automatic dilution of smoke plume emissions in global models could result in large errors in predicted concentrations of O3, NOx and aerosol species downwind of biomass burning sources. The thesis discusses several potential approaches that could reduce these errors, such as the use of higher resolution grids over regions of intense biomass burning, the use of a plume-in-grid model, or the use of a computationally- efficient parameterization of a 3D Eulerian plume chemistry model.
by Matthew James Alvarado.
Ph.D.
Pistikopoulos, Panayotis. "Comportement physiochimique des hydrocarbures aromatiques polycycliques, particulaires et gazeux, dans l'atmosphere : mode de formation des aerosols, transport a meso-echelle, adaptation d'un modele-recepteur a des composes reactifs." Paris 7, 1988. http://www.theses.fr/1988PA077140.
Повний текст джерелаAsa-Awuku, Akua Asabea. "The effect of solute dissolution kinetics on cloud droplet formation." Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-11112005-141441/.
Повний текст джерелаBarsanti, Kelley Claire. "A general theoretical method for evaluating the formation of high-molecular weight/low-volatility compounds and their contribution to atmospheric organic particulate matter /." Full text open access at:, 2006. http://content.ohsu.edu/u?/etd,6.
Повний текст джерелаD'Auria, Raffaella. "A study of ionic clusters in the lower atmosphere and their role in aerosol formation." Diss., Restricted to subscribing institutions, 2005. http://proquest.umi.com/pqdweb?did=888854191&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Повний текст джерелаTargino, Admir Creso. "Regional studies of the optical, chemical and microphysical properties of atmospheric aerosols : radiative impacts and cloud formation /." Stockholm : Dept. of meteorology, Stockholm university, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-740.
Повний текст джерелаPushpawela, Buddhi G. "The formation and characteristics of new particles in the atmosphere." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/122854/2/__qut.edu.au_Documents_StaffHome_StaffGroupH%24_halla_Desktop_Buddhi_Pushpawela_Thesis.pdf.
Повний текст джерелаSchulz, Christiane [Verfasser]. "Secondary organic aerosol in the pristine Amazonian atmosphere: chemical properties, formation pathways, and interactions with clouds / Christiane Schulz." Mainz : Universitätsbibliothek Mainz, 2019. http://d-nb.info/1185711856/34.
Повний текст джерелаAsa-Awuku, Akua Asabea. "The effect of solute dissolution kinetics on cloud droplet formation." Thesis, Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10456.
Повний текст джерелаLanzafame, Grazia Maria. "Understanding organic aerosol formation processes in atmosphere using molecular markers : a combined measurements-model approach." Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS519.
Повний текст джерелаOrganic aerosols (OA) account for a large fraction of ambient air particulate matter and have strong impacts on air quality and climate. As their sources and atmospheric formation processes, notably for secondary OA (SOA), are still not fully understood, their concentrations are often underestimated by air quality models. This work aimed at improving OA modelling by implementing specific organic molecular marker emissions and formation processes into the chemistry-transport model CHIMERE. It was based on the comparison of model outputs with measurements from field studies performed in the Paris region (suburban site of SIRTA, 25 km SW of Paris) over 2015 and 10 French urban locations in winter 2014-2015. 25 biogenic and anthropogenic SOA markers have been quantified in both, particulate and gas phases and the formation pathways of 10 have been developed and simulated using CHIMERE. The evolution of levoglucosan concentrations (biomass burning marker) has been also modeled. The results obtained showed that sources and precursor emissions (missing or underestimated), radical concentrations (NO, HO2 and RO2) and the lack of formation pathways, are key parameters for the simulation of SOA markers. Gas/particle partitioning seemed poorly linked to the T°C while the inclusion of hydrophilic non-ideal partitioning, usually neglected, seemed essential. Levoglucosan was well simulated, even if some underestimations existed in some regions. A significant theoretical gaseous fraction was also highlighted. The model/measurements comparison of molecular markers is a powerful tool to evaluate precursor emissions, physicochemical processes and in the end, to estimate OA sources
Niakan, Negar. "Effects of Molecular Structure of the Oxidation Products of Reactive Atmospheric Hydrocarbons on the Formation of Secondary Organic Particulate Matter, Including the Effects of Water." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/617.
Повний текст джерелаRoveretto, Marie. "Formation et vieillissement des aérosols : impact de la photochimie hétérogène." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1346.
Повний текст джерелаInterfaces are ubiquitous in the environment, and in addition many key atmospheric processes, such as gas deposition, aerosol and cloud formation are, at one stage or the other, strongly affected by physical and chemical processes occurring at interfaces. Unfortunately, these heterogeneous reactions are not fully understood to date and limit our ability to simulate and quantify the impact of aerosols due to large uncertainties in their formation and their evolution in the troposphere. This thesis aims to improve our knowledge about photochemical reactions at the air/liquid interfaces, which could be crucial for the assessment of their atmospheric impacts. Firstly, the reactivity of stearic acid at the air/water interface under irradiation was studied in different matrices thanks to a very sensitive tool, the Langmuir trough. We observed that monolayers of stearic acid undergo degradation under irradiation, even in the absence of photosensitizers. Experiments with monolayers in different surface states indicate that surface pressure influences this reactivity. APCI-Orbitrap coupling was used to detect and identify halogenated compounds produced from an irradiated solution containing a photosensitizer, 4-benzoylbenzoic acid. The effects of octanol as a surfactant and citric acid as a proton donor on these photosensitized reactions were also examined. In addition, the formation of secondary aerosols and their aging in the marine environment (at Cape-Verde) were studied in different conditions. The experiments clearly demonstrate the existence of photosensitized processes at the air/sea interface as a source of marine secondary aerosols. Finally, work on the photochemistry of organic matter from phytoplanktons gave information on their reactivity in the liquid phase. Overall, the results obtained during this thesis show that the photochemistry studied here can have a significant impact on the superficial microlayer of the oceans and, by extension, on marine aerosols