Rozprawy doktorskie na temat „Atmospheric chemistry”
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 50 najlepszych rozpraw doktorskich naukowych na temat „Atmospheric chemistry”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj rozprawy doktorskie z różnych dziedzin i twórz odpowiednie bibliografie.
Pinot, de Moira John C. "Laser studies of atmospheric chemistry". Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299100.
Pełny tekst źródłaSteiner, Allison L. "The influence of atmospheric chemistry and climate on atmosphere-biosphere interactions". Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/25751.
Pełny tekst źródłaDrummond, Benjamin. "The chemistry of hot exoplanet atmospheres : developing and applying chemistry schemes in 1D and 3D models". Thesis, University of Exeter, 2017. http://hdl.handle.net/10871/27993.
Pełny tekst źródłaSrithawirat, Thunwadee. "Atmospheric chemistry of saccharides and furfural". Thesis, University of East Anglia, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.551251.
Pełny tekst źródłaWittig, Ann Elizabeth. "Atmospheric hydrocarbon chemistry in central Texas /". Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
Pełny tekst źródłaHelmer, Magdalena. "Meteoric metal chemistry". Thesis, University of East Anglia, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318079.
Pełny tekst źródłaSurl, Luke. "Modelling the atmospheric chemistry of volcanic plumes". Thesis, University of East Anglia, 2016. https://ueaeprints.uea.ac.uk/59407/.
Pełny tekst źródłaClegg, S. L. "The atmospheric chemistry of extremely concentrated solutions". Thesis, University of East Anglia, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376080.
Pełny tekst źródłaSanderson, Michael George. "Experimental and modelling studies of atmospheric chemistry". Thesis, University of York, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259802.
Pełny tekst źródłaHorst, Sarah M. "Post-Cassini Investigations of Titan Atmospheric Chemistry". Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/145467.
Pełny tekst źródłaGunawardena, Rohith. "Atmospheric methyl iodide". Full text open access at:, 1985. http://content.ohsu.edu/u?/etd,91.
Pełny tekst źródłaBright, Vivien Bianca. "Street canyon atmospheric composition : coupling dynamics and chemistry". Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4414/.
Pełny tekst źródłaGiardina, Agata. "Atmospheric plasma chemistry for environmental and biological applications". Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3423160.
Pełny tekst źródłaLa Tesi riporta e discute i risultati ottenuti nell’applicazione di plasmi non termici per il trattamento ossidativo di inquinanti modello e ulteriori risultati relativi all’utilizzo del plasma in campo biomedico. L’apparato sperimentale impiegato è stato progettato e realizzato in collaborazione con il Dipartimento di Ingegneria Elettrica e produce una scarica a barriera di dielettrico (reattore DBD). Il sistema era già in uso nel periodo antecedente l’inizio della mia attività di dottorato. Le specie reattive che si generano a causa della scarica elettrica nell’aria umida sovrastante la fase liquida entrano in contatto con essa e possono reagire con l’inquinante organico in soluzione. Le specie reattive possono essere distinte in primarie, cioè generate direttamente dalla scarica per reazione del gas con gli elettroni energetici formando radicali, ioni e specie eccitate altamente reattive ed instabili, e secondarie prodotte per reazione delle stesse specie con le molecole del gas oppure con l’umidità presente. Il primo passo è stato quello di applicare tali scariche elettriche per il trattamento di diverse categorie di inquinanti emergenti allo scopo di valutare le potenziali applicazioni di questa tecnologia in relazione alle proprietà chimico fisiche degli inquinanti trattati. Sono stati selezionati i seguenti contaminanti organici persistenti: il sulfametossazolo, un antibiotico veterinario, il triclosan, un antibatterico, l’acido perfluoroacetico e tre erbicidi, l’irgarol, il metolachlor ed il mesotrione. Per tutti i composti in esame ho ottenuto profili esponenziali di degradazione in funzione del tempo di trattamento, da cui sono state ricavate le costanti cinetiche di pseudo-primo ordine. L’analisi HPLC-MS ha consentito l’identificazione degli intermedi e prodotti di degradazione, compatibili con possibili reazioni dovute all’azione dell’ozono e dei radicali ∙OH. Sono stati proposti inoltre i meccanismi di degradazione dei composti organici trattati. Lo scopo finale nell’uso di processi di degradazione avanzata è la completa conversione della componente organica a CO2. In seguito al trattamento al plasma, sono state riscontrate percentuali di mineralizzazione pari o maggiori al 93% per tutti gli inquinanti considerati, usati in concentrazione pari a 5 μM, fatta eccezione per l’acido perfluoroottanoico per cui la percentuale di mineralizzazione è stata considerevolmente più bassa (42%). Lo studio dei processi di degradazione al plasma è inoltre servito in alcuni casi da punto di partenza per ulteriori approfondimenti. È questo il caso dell’irgarol, in cui si è cercato di implementare l’effetto del plasma aggiungendo un fotocatalizzatore ampiamente utilizzato, TiO2. Non sono stati riscontrati tuttavia miglioramenti nell’effetto della scarica su tale inquinante indicando un trascurabile effetto fotocatalitico nelle condizioni sperimentali adottate. Un ulteriore avanzamento nelle ricerche in questo ambito è consistito nell’applicazione della scarica DBD su una miscela di inquinanti, il metolachlor e il mesotrione, solitamente utilizzati in combinazione in diverse formulazioni agricole. Gli studi cinetici effettuati hanno evidenziato che i due composti non si influenzano reciprocamente quando subiscono il trattamento al plasma in soluzioni miste in cui sono presenti in rapporto molare 1:1. Un importante parametro nella valutazione di una tecnica di depurazione consiste nell’analisi ecotossicologica del campione acquoso dopo il trattamento. A tale scopo, in collaborazione con il Prof. Giovanni Libralato del Dipartimento di Biologia dell’Università di Napoli, sono stati effettuati test tossicologici su campioni contenenti sulfametossazolo (SMZ), prima e dopo il trattamento nel reattore DBD. Allo scopo è stata utilizzata una batteria di test acuti e cronici per Vibrio Fischeri, Daphnia magna e Raphidocaelis subcapitata. I dati ottenuti a partire da una soluzione di SMZ 5·10-4 M hanno mostrato un elevato livello di tossicità della soluzione iniziale e la riduzione (V.fischeri) o l’azzeramento di tali effetti (D.magna e R.subcapitata) a seguito del trattamento nel reattore al plasma. Un nuovo reattore è stato inoltre ideato e realizzato in collaborazione con il Dr. Franco Bosi, del Dipartimento di Ingegneria Industriale dell’Università di Padova. La sorgente di plasma utilizza una scarica di tipo streamer ed è stata realizzata allo scopo di favorire un migliore trasporto delle specie reattive prodotte dalla scarica e ottimizzare la loro interazione con la soluzione da trattare. Il reattore è stato quindi caratterizzato in collaborazione con il Dr. Gabriele Neretti (Università di Bologna) e la Dr.ssa Barbara Zaniol (Consorzio RFX, Padova) e collaudato nel trattamento di due inquinanti organici, il fenolo ed il metolachlor. Infine nel corso di un periodo di quattro mesi di attività di ricerca presso il laboratorio della Prof.ssa Bandow dell’Università di Bochum (Germania) ho avuto modo di approfondire alcuni aspetti legati alle applicazioni del plasma atmosferico in campo biomedico. In particolare ho partecipato a studi sugli effetti di due diverse sorgenti al plasma su un enzima, gliceraldeide-3-fosfato deidrogenasi, in vitro e sul batterio E. coli. Il sito di attacco principale è risultato essere il sito attivo cisteina con conseguente ossidazione del gruppo -SH. Lo stesso approccio è stato applicato, in collaborazione con il Prof. Benedikt per lo studio degli effetti del plasma, in assenza e in presenza delle specie ioniche. I risultati ottenuti hanno evidenziato un effetto sinergico dovuto alla copresenza di specie neutre e ioniche.
Tang, Yi. "Atmospheric fate of various fluorocarbons". Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/10598.
Pełny tekst źródłaKindler, Thomas Paul. "The development of supercomputing tools in a global atmospheric chemistry model and its application on selected problems in global atmospheric chemistry modeling". Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/26283.
Pełny tekst źródłaMyton, David Michael. "Development and Applications of High Resolution Kinetic Atmospheric Pressure Ionization Mass Spectrometry in Atmospheric Chemistry". PDXScholar, 1991. https://pdxscholar.library.pdx.edu/open_access_etds/1209.
Pełny tekst źródłaZangmeister, Chistopher Douglas. "Chemistry of alkali halide and ice surfaces: Characterization of reactions relevant to atmospheric chemistry". Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/284312.
Pełny tekst źródłaHan, Dawei. "Atmospheric Hydrocarbon Analysis". PDXScholar, 1993. https://pdxscholar.library.pdx.edu/open_access_etds/4588.
Pełny tekst źródłaLi, Xin. "Applications of Molecular Dynamics in Atmospheric and Solution Chemistry". Doctoral thesis, KTH, Teoretisk kemi och biologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-33309.
Pełny tekst źródłaQC 20110511
Edwards, Gavin D. "Aircraft studies of atmospheric chemistry over the North Atlantic". Thesis, University of Leicester, 2000. http://hdl.handle.net/2381/30044.
Pełny tekst źródłaSmith, Stuart James. "Atmospheric chemistry : laboratory studies of kinetics of important reactions". Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.330031.
Pełny tekst źródłaAllen, Nicholas David Causier. "Observation of trace gases from the atmospheric chemistry experiment". Thesis, University of York, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.546834.
Pełny tekst źródłaWilliams, Jonathan M. J. "A study of the atmospheric chemistry of alkyl nitrates". Thesis, University of East Anglia, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241517.
Pełny tekst źródłaBaggott, Sarah Louise. "Numerical modelling of atmospheric chemistry in the West Midlands". Thesis, University of Birmingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275667.
Pełny tekst źródłaMathews, Sussen. "Study of systems relevant to combustion and atmospheric chemistry". Thesis, University of Aberdeen, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322537.
Pełny tekst źródłaSayer, Robert Michael. "Atir flow cell developments and studies in atmospheric chemistry". Thesis, University of York, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250623.
Pełny tekst źródłaNakano, Yukio. "Kinetic study of reactive halogen species in atmospheric chemistry". 京都大学 (Kyoto University), 2003. http://hdl.handle.net/2433/148869.
Pełny tekst źródłaHaigh, Theodore Alan. "Theoretical and experimental evaluation of hysteresis in atmospheric chemistry". PDXScholar, 1992. https://pdxscholar.library.pdx.edu/open_access_etds/4318.
Pełny tekst źródłaHall, I. W. "Kinetic studies of atmospheric reactions". Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236263.
Pełny tekst źródłaGrange, Andrew H. "Medium resolution atmospheric pressure ionization mass spectrometry /". Full text open access at:, 1988. http://content.ohsu.edu/u?/etd,158.
Pełny tekst źródłaCapps, Shannon. "Advanced sensitivity analysis techniques for atmospheric chemistry models: development and application". Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/51755.
Pełny tekst źródłaTremblay, André 1948. "A three dimensional cloud chemistry model /". Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=73980.
Pełny tekst źródłaMohr, Karen Irene. "An investigation of land/atmosphere interactions : soil moisture, heat fluxes, and atmospheric convection /". Digital version:, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p9992875.
Pełny tekst źródłaTraub, Michael Andreas. "Lagrangian transport evaluation of atmospheric chemistry in the Mediterranean region". [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=975874489.
Pełny tekst źródłaHorseman, Andrew Mark. "Modelling cirrus cloud fields for climate and atmospheric chemistry studies". Thesis, Lancaster University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.652029.
Pełny tekst źródłaHickson, Kevin Michael. "A study of several reactions relevant to atmospheric ozone chemistry". Thesis, University of Birmingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343854.
Pełny tekst źródłaHinneburg, Detlef, i Nicole Mölders. "A mesoscale atmospheric model combining meteorology, chemistry, biology, and heterogeneity". Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-213743.
Pełny tekst źródłaEin mesoskaliges nicht-hydrostatisches Atmosphärenmodell ist um ein Chemie-TransportModul (CTM) zur Berücksichtigung der Triaden-Komponenten NO, N02 und 03 sowie um ein Verfahren zur verfeinerten Auflösung der topographischen Unterlage (explicit surface-subgrid modul ESSM) erweitert worden. CTM: Die simulierten zeitabhängigen Konzentrationsfelder sind das Resultat folgender modellierter Prozesse: Anthropogene Emission in verschiedenen Höhenschichten, biogene Emission, trockene Deposition (Rezeption), die speziellen chemischen Umwandlungen, turbulente Diffusion und passiver Transport. Da der Schwerpunkt der Prozesse und die höchsten Konzentrationsgradienten innerhalb der bodennahen ersten Modellschicht vorliegen, werden die Berechnungen in dieser Schicht auf einem verfeinerten vertikalen Untergitter durchgeführt. ESSM: Unabhängig von den Eigenheiten des CTM wird für alle untergrundbezogenen meteorologischen Größen ein regelmäßiges horizontales Untergitter zwecks Berücksichtigung des subskalig aufgelösten topographischen Untergrundes eingeführt. Auf diesem Untergitter werden in den bisherigen Näherungen alle Oberflächenflüsse für Impuls, fühlbare und latente Wärme, langwellige Strahlung, der Bodenwärmefluß, die Bodenfeuchte sowie die Energiebilanz am Boden berechnet. Die über die Untergitterzellen gemittelten Werte dienen den weiteren Berechnungen im normalen Modellgitter als die erforderlichen Randwerte. Innerhalb des CTM führt die ESSM-Methode zu einer Überlagerung des vertikalen CTM-Untergitters mit dem horizontalen Untergitter des ESSM. Erste Simulationsergebnisse, die dem derzeitigen Stand in der Realisierung des ESSM entsprechen, erbringen teilweise stark veränderte Depositionsraten infolge der Berücksichtigung der horizontal feiner aufgelösten Topographie
Hinneburg, Detlef, i Nicole Mölders. "A mesoscale atmospheric model combining meteorology, chemistry, biology, and heterogeneity". Wissenschaftliche Mitteilungen des Leipziger Instituts für Meteorologie ; 12 = Meteorologische Arbeiten aus Leipzig ; 4 (1999), S. 44-58, 1999. https://ul.qucosa.de/id/qucosa%3A15094.
Pełny tekst źródłaEin mesoskaliges nicht-hydrostatisches Atmosphärenmodell ist um ein Chemie-TransportModul (CTM) zur Berücksichtigung der Triaden-Komponenten NO, N02 und 03 sowie um ein Verfahren zur verfeinerten Auflösung der topographischen Unterlage (explicit surface-subgrid modul ESSM) erweitert worden. CTM: Die simulierten zeitabhängigen Konzentrationsfelder sind das Resultat folgender modellierter Prozesse: Anthropogene Emission in verschiedenen Höhenschichten, biogene Emission, trockene Deposition (Rezeption), die speziellen chemischen Umwandlungen, turbulente Diffusion und passiver Transport. Da der Schwerpunkt der Prozesse und die höchsten Konzentrationsgradienten innerhalb der bodennahen ersten Modellschicht vorliegen, werden die Berechnungen in dieser Schicht auf einem verfeinerten vertikalen Untergitter durchgeführt. ESSM: Unabhängig von den Eigenheiten des CTM wird für alle untergrundbezogenen meteorologischen Größen ein regelmäßiges horizontales Untergitter zwecks Berücksichtigung des subskalig aufgelösten topographischen Untergrundes eingeführt. Auf diesem Untergitter werden in den bisherigen Näherungen alle Oberflächenflüsse für Impuls, fühlbare und latente Wärme, langwellige Strahlung, der Bodenwärmefluß, die Bodenfeuchte sowie die Energiebilanz am Boden berechnet. Die über die Untergitterzellen gemittelten Werte dienen den weiteren Berechnungen im normalen Modellgitter als die erforderlichen Randwerte. Innerhalb des CTM führt die ESSM-Methode zu einer Überlagerung des vertikalen CTM-Untergitters mit dem horizontalen Untergitter des ESSM. Erste Simulationsergebnisse, die dem derzeitigen Stand in der Realisierung des ESSM entsprechen, erbringen teilweise stark veränderte Depositionsraten infolge der Berücksichtigung der horizontal feiner aufgelösten Topographie.
Jöckel, Patrick. "Cosmogenic 14 CO as tracer for atmospheric chemistry and transport". [S.l. : s.n.], 2001. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB8986380.
Pełny tekst źródłaHerek, Jennifer Lynn Zewail Ahmed H. Zewail Ahmed H. "Femtochemistry and reactive intermediates : application to atmospheric and organic chemistry /". Diss., Pasadena, Calif. : California Institute of Technology, 1996. http://resolver.caltech.edu/CaltechETD:etd-04082008-084916.
Pełny tekst źródłaZhang, Qi. "Chemistry of organic nitrogen in atmospheric waters and fine particles /". For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.
Pełny tekst źródłaSheehy, Philip M. (Philip Michael). "Laboratory measurements and modeling of trace atmospheric species". Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32491.
Pełny tekst źródłaVita.
Includes bibliographical references (p. 129-145).
Trace species play a major role in many physical and chemical processes in the atmosphere. Improving our understanding of the impact of each species requires a combination of laboratory exper- imentation, field measurements, and modeling. The results presented here focus on spectroscopic and kinetic laboratory measurements and photochemical box modeling. Laboratory experiments were conducted using IntraCavity Laser Absorption Spectroscopy (ICLAS), a high-resolution, high sensitivity spectroscopic method that had been used primarily for static cell measurements in the Steinfeld Laboratory at MIT. Several modifications and improvements have been made to expand its versatility. Firstly, a discharge flow tube was coupled with the ICLA Spectrometer, and the formation kinetics of nitrosyl hydride, HNO, were measured as a means to test the system. Secondly, a novel edge-tuner was introduced as a means to expand the spectral range of the ICLA Spectrometer. An experiment for the detection of the hydroperoxyl radical employing the edge-tuner in the ICLA Spectrometer is discussed and proposed. The results from the laboratory measurements are followed by the presentation of a near-explicit kinetic box model designed to improve our understanding of the oxidative capacity of the urban troposphere in the Mexico City Metropolitan Area (MCMA). The box model was constructed using the Master Chemical Mechanism and was constrained using a large dataset of field measurements collected during the 2003 MCMA field campaign.
(cont.) The modeling is focused on the hydroxy and hydroperoxyl radicals (OH and HO₂), with an emphasis on the role of volatile organic compounds (VOCs) in the formation of both species.
by Philip M. Sheehy.
Ph.D.
Wild, James Oliver Felix. "Some problems in the numerical modelling of tropospheric chemistry". Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388385.
Pełny tekst źródłaYoung, Paul John. "The influence of biogenic isoprene emissions on atmospheric chemistry : a model study for present and future atmospheres". Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611914.
Pełny tekst źródłaGreen, Sarah A. "Applications of fluorescence spectroscopy to environmental chemistry". Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/13167.
Pełny tekst źródłaClemitshaw, K. C. "Mechanistic studies of atmospheric photo-oxidation reactions". Thesis, University of East Anglia, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372814.
Pełny tekst źródłaBanham, S. F. "Ionisation and solvation as key processes in heterogeneous stratospheric chemistry". Thesis, University of East Anglia, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296344.
Pełny tekst źródłaTeama, Doaa Galal. "A 30-Year Record of the Isotopic Composition of Atmospheric Methane". Thesis, Portland State University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3557627.
Pełny tekst źródłaMethane (CH4) is one of the most important greenhouse gases after water vapor and carbon dioxide due to its high concentration and global warming potential 25 times than that of CO2(based on a 100 year time horizon). Its atmospheric concentration has more than doubled from the preindustrial era due to anthropogenic activities such as rice cultivation, biomass burning, and fossil fuel production. However, the rate of increase of atmospheric CH4 (or the growth rate) slowed from 1980 until present. The main reason for this trend is a slowdown in the trend of CH 4sources. Measuring stable isotopes of atmospheric CH4 can constrain changes of CH4sources. The main goal of this work is to interpret the CH4 trend from 1978-2010 in terms of its sources using measurements of CH4 mixing ratio and its isotopes.
The current work presents the measurements and analysis of CH4 and its isotopes (δ13C and δD) of four air archive sample sets collected by the Oregon Graduate Institute (OGI). CH4 isotope ratios (δ13C and δD) were measured by a continuous flow isotope ratio mass spectrometer technique developed at PSU. The first set is for Cape Meares, Oregon which is the oldest and longest set and spans 1977-1999. The integrity of this sample set was evaluated by comparing between our measured CH4 mixing ratio values with those measured values by OGI and was found to be stable. Resulting CH4 seasonal cycle was evaluated from the Cape Meares data. The CH4 seasonal cycle shows a broad maximum during October-April and a minimum between July and August. The seasonal cycles of δ13C and δD have maximum values in May for δ13C and in July for δD and minimum values between September-October for δ13C and in October for δD. These results indicate a CH4 source that is more enriched January-May (e.g. biomass burning) and a source that is more depleted August-October (e.g. microbial). In addition to Cape Meares, air archive sets were analyzed from: South Pole (SPO), Samoa (SMO), Mauna Loa (MLO) 1992-1996. The presented δD measurements are unique measured values during these time periods at these stations.
To obtain the long-term in isotopic CH4 from 1978-2010, other datasets of Northern Hemisphere mid-latitude sites are included with Cape Meares. These sites are Olympic Peninsula, Washington; Montaña de Oro, California; and Niwot Ridge, Colorado. The seasonal cycles of CH4 and its isotopes from the composite dataset have the same phase and amplitudes as the Cape Meares site. CH4 growth rate shows a decrease over time 1978-2010 with three main spikes in 1992, 1998, and 2003 consistent with the literature from the global trend. CH4 lifetime is estimated to 9.7 yrs. The δ13C trend in the composite data shows a slow increase from 1978-1987, a more rapid rate of change 1987-2005, and a gradual depletion during 2005-2010. The δD trend in the composite data shows a gradual increase during 1978-2001 and decrease from 2001-2005. From these results, the global CH4 emissions are estimated and show a leveling off sources 1982-2010 with two large peak anomalies in 1998 and 2003. The global average δ13C and δD of CH 4 sources are estimated from measured values. The results of these calculations indicate that there is more than one source which controls the decrease in the global CH4 trend. From 1982-2001, δ13C and δD of CH4 sources becomes more depleted due to a decrease in fossil and/or biomass burning sources relative to microbial sources. From 2005-2010, δ 13C of CH4 sources returns to its 1981 value. There are two significant peaks in δ13C and δD of CH 4 sources in 1998 and 2003 due to the wildfire emissions in boreal areas and in Europe.
Yu, Pengfei. "A sectional aerosol model| With applications from the ground to the lower stratosphere". Thesis, University of Colorado at Boulder, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3721913.
Pełny tekst źródłaA sectional aerosol model (CARMA) has been developed and coupled with the Community Earth System Model (CESM1). Aerosol microphysics, radiative properties and interactions with clouds are simulated. The model described here uses 20 particle size bins for each aerosol component including freshly nucleated sulfate particles, as well as mixed particles containing sulfate, primary organics, black carbon, dust and sea salt. In this thesis, CESM1/CARMA is firstly constrained by a variety of observations, and then utilized to investigate several scientific topics including aerosol layers in the upper troposphere and lower stratosphere as well as forest fire smoke in the lower troposphere.
Recent studies reveal layers of enhanced aerosol scattering in the upper troposphere and lower stratosphere over Asia (ATAL) and North America (NATAL). The observed aerosol extinction enhancement is reproduced by CESM1/CARMA. Both model and observations indicate a strong gradient of the sulfur-to-carbon ratio from Europe to the Asia on constant pressure surfaces. We found that the ATAL is mostly composed of sulfates, surface-emitted organics and secondary organics; the NATAL is mostly composed of sulfates and secondary organics. The model also suggests emission increases in Asia between 2000 and 2010 led to an increase of aerosol optical depth of the ATAL by 0.002 on average, which is consistent with observations.
The Rim Fire of 2013, the third largest area burned by fire recorded in California history, is simulated by CESM1/CARMA. Modeled aerosol mass, number, effective radius, and extinction coefficient are within variability of data obtained from multiple airborne measurements. Simulations suggest Rim Fire smoke may block 4-6% of sunlight reaching the surface, with a cooling efficiency around 120-150 W m-2 per unit aerosol optical depth. This study shows that exceptional events like the 2013 Rim Fire can be simulated by a climate model with one-degree resolution, though that resolution is still not sufficient to resolve the smoke peak near the source region.
Davidson, Nicholas Mark. "Atmospheric processing of aerosols". Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8298/.
Pełny tekst źródła