The effective air quality management in the heavy polluted areas has to be based on high-quality monitoring with properly designed monitoring network and targeted measurements, which provided information required to source apportionment. The thesis aim was to apportion sources of atmospheric aerosol based on highly time resolved data of mass concentration of size segregated aerosol, its temporal and spatial variability, elemental composition, OC/EC and size distribution of carcinogenic polyaromatic hydrocarbons. Sampling campaigns went during winter and summer in small settlement Březno by Chomutov, residential area Ostrava - Radvanice a Bartovice and Mladá Boleslav in the years 2008 - 2010, 2012, 2013. We determined mass concentrations of PM10, PM1-10, PM1.15-10 and PM0.15-1.5 and their size fraction ratios. Based on the size ratios, the source apportionment of fine fraction (PM0.15-1.15) with focus on PM0.34-1.15 is crucial. We examined seasonal and spatial variability of PM10, PM.2.5, PM1 and PM1-10. Based on the examination, we obtained representative highly-time resolved data with regards to season and sampling locality. We analysed dynamic of size distribution of particle-bond eight carcinogenic polycyclic hydrocarbons. Based on the results the source apportionment of PM0.34-1.15 is crucial....

Este trabalho teve como objetivo investigar a relação entre produtos de atividades antropogênicas na Amazônia e sua influência no efeito indireto dos aerossóis no clima. Para isso, foi feita uma caracterização físico-química detalhada dos aerossóis naturais e de queimadas na Amazônia e procurou-se compreender como estes diferentes tipos de aerossóis se comportam como Núcleos de Condensação de Nuvens. Foi estudado também a influência dos aerossóis de queimadas na composição química da precipitação e no transporte de nutrientes. Visando atingir estes objetivos, foram feitas medidas em regiões distintas da Amazônia com relação ao impacto por atividades antropogênicas, principalmente queimadas. Foi possível observar em várias circunstâncias uma relação entre a composição do material particulado e da precipitação, o que nos permitiu concluir que as emissões antropogênicas influenciam significativamente a composição da precipitação. Foram identificadas as principais componentes que afetam a composição do material particulado em suspensão na Amazônia, e concluimos que o material particulado originado de emissões biogênicas é predominante em regiões preservadas, com pequena contribuição também de poeira de solo e transporte de aerossóis marinhos. Em regiões sob influência de atividades antropogênicas, observou-se que a composição dos aerossóis e da precipitação é afetada mesmo na estação úmida. No estudo das propriedades físicas e químicas das partículas de aerossol que são relevantes para o seu papel como Núcleos de Condensação de Nuvens, concluiu-se que a distribuição de tamanho é mais importante do que a composição química das partículas, devido ao fato das emissões de novas partículas por queimadas ocorrer predominantemente acima do diâmetro seco de ativação. A composição química só foi importante em valores de supersaturação baixos (< 0.2%), o que significa que esse efeito pode ser importante para nuvens estratiformes, onde o valor máximo de supersaturação é baixo, devido a baixa velocidade de ascensão das parcelas. A exportação de nutrientes devido ao transporte em larga escala de aerossóis de emissões de queimadas se mostrou particularmente crítica com relação às quantidades de fósforo que estão sendo perdidas irreversivelmente pela floresta amazônica, que foi cerca de 7 vezes maior do que a quantidade reposta por deposição úmida. Essa perda de fósforo pode ser crítica para o ecossistema em longo prazo. / The main objective of this study was to investigate the relationship between anthropogenic emissions in the Amazon basin and the indirect aerosol effect on climate. A detailed study of physical and chemical properties of natural and biomass burning aerosols was conducted, in order to understand how these completely different aerosols behave as Cloud Condensation Nuclei (CCN). It was also investigated the influence of biomass burning aerosols in chemical composition of precipitation, and transport of nutrients. The measurements were carried out in completely different regions respect to the impact of anthropogenic activities, especially biomass burning emissions. The analysis of aerosols and rainwater chemistry showed that anthropogenic emissions have a significant influence in the composition of precipitation. Factor analysis was applied to perform source identification, and the conclusion is that at remote and free of anthropogenic emission areas, the most important contribution was from biogenic emissions, with a small contribution of soil dust and marine aerosols advection. It was quite different at regions under influence of anthropogenic activities, where measurements showed a clear anthropogenic influence even during wet season both in aerosols and precipitation chemistry. In the study of hygroscopic properties of aerosol particles, the main conclusion was that size distribution of particles is the most important parameter to determine the ability of aerosols to act as CCN, because most of biomass burning emission are particles bigger than the activation diameter. Chemical composition was an important factor only if supersaturation is below 0.2%, because in this supersaturation range the activation diameter is extremely sensible to small changes in supersaturation. Transport of nutrients due to largescale transport of biomass burning aerosols was specially critical concerning phosphorus exportation, estimated as 7 times the apportionment through wet deposition. Continuous exportation of phosphorus can be a long term limitation to the forest ecosystem, if biomass burning activity maintain its present levels.

O objetivo desse trabalho foi estudar a relação entre profundidade óptica de aerossóis (AOD), obtida por sensoriamento remoto, e a concentração de material particulado (MP10 e MP2,5) medida próximo à superfície sobre a Região Metropolitana de São Paulo (RMSP). A profundidade óptica foi derivada a partir de medidas de radiâncias fornecidas pelos sensores MODIS. Estes sensores estão posicionados a bordo dos satélites EOS-TERRA e EOS-AQUA, operados pela NASA. As concentrações de MP10 e MP2,5 foram obtidas nas estações da rede operacional da CETESB. Foram feitos alguns estudos de caso considerando diferentes situações atmosféricas, aos quais se aplicou a metodologia proposta por Castanho (2005) que busca reduzir as incertezas na determinação da profundidade óptica derivada do MODIS e identificar qual o modelo de aerossol é mais adequado para aplicação em estudos de qualidade do ar. Os valores de AOD calculados para as diferentes situações foram comparados com aqueles obtidos pela AERONET e com as concentrações anteriormente citadas, buscando uma validação dos mesmos. Valores médios de AOD foram calculados para áreas de 10 km x 10 km ao redor das estações de monitoramento do MP. Testes foram realizados para verificar os efeitos de sazonalidade, da quantidade de água na coluna atmosférica, da resposta da AOD por faixas de concentração de MP10, da geometria do sensor, da presença de nuvens e da presença de aerossol acima da Camada de Mistura (CM). Os resultados foram apresentados por estações com o objetivo de se visualizar diferentes condições sobre a região estudada. Alguns dos fatores relevantes observados durante a comparação entre a concentração de MP10 e a AOD foram: a influência do período do ano e da quantidade de água na coluna atmosférica. A geometria do sensor foi fator determinante para melhora das correlações, quando limitado o ângulo de espalhamento em 140°. Situações em que há ausência de nuvens, identificadas através de imagens do MODIS no visível, também apresentaram melhores resultados. Outro fator de extrema importância foi a estrutura vertical da CM. Através de medidas obtidas de um LIDAR foi verificado que a presença de aerossóis acima da CM, a qual é determinada principalmente pelas condições atmosféricas, é determinante para as correlações entre AOD e o MP. / The main purpose of this work was to study the relationship between the Aerosol Optical Depth (AOD), obtained by remote sensing, and the particulate material concentration (PM10 and PM2.5), near to the surface over the Metropolitan Area of Sao Paulo (MASP). The Aerosol Optical Depth was retrieved based on reflectance measurements provided by MODIS sensors. These sensors are carried aboard EOS-TERRA and EOS-AQUA satellites, which are operated by NASA. The PM10 and PM2.5 concentrations were obtained in the CETESB operational network. Case studies were performed, considering several atmospheric conditions, applying the methodology proposed by CASTANHO (2005), designed both to reduce the uncertainty in the determination of the MODIS derived Optical Depth and to identify which aerosol model is more appropriated for air quality studies. Some derived results were compared with AERONET data and with the previously mentioned concentrations as a cross-check test. Mean AOD values were calculated using 10 km x 10 km area ground around PM monitoring stations. Tests were performed to estimate the effects of seasonality, atmospheric column water content, AOD response to PM10 concentration, sensor geometry, clouds and aerosol concentration above the Mixing Layer (ML). To stress the different conditions of the studied region, the results were presented considering each station. Some of the relevant observed factors in the PM10 concentration and AOD comparison were the year period influence and the atmospheric column water content. The sensor geometry was an important factor to the improvement of the obtained correlations when the scattering angle was bounded to 140°. Cloudless situations, identified by MODIS true color images, also improved the results. Another important factor was the Mixing Layer vertical structure. Using LIDAR measurements it was verified that the presence of aerosols above the ML, which is determined mainly by atmospheric conditions, is crucial for the correlations between AOD and PM.

Os processos de remoção de espécies químicas da atmosfera têm sido estudados atualmente utilizando modelos numéricos, na tentativa de compreender melhor, os processos de transferências de gases e material particulado (sejam elas naturais ou antropogênicas) intra-reservatórios na atmosfera e seus efeitos na dinâmica do tempo e clima. Neste estudo, foi utilizado o modelo RAMS para simular a estrutura vertical das nuvens que se desenvolvem na região amazônica, em conjunto ao modelo de remoção B. V. 2, para os processos de remoção úmida que ocorrem tanto dentro quanto abaixo da nuvem, além das condições atmosféricas locais da região da Bacia Amazônica para, assim, simular a transferência das espécies químicas da atmosfera para a hidrosfera dentro do escopo do projeto LBA. Dentro deste projeto, foram realizadas campanhas intensivas de medições, como a LBA/DRY-TO-WET e LBA/SMOCC (setembro a novembro de 2002) na região de Rondônia. No período das campanhas, foram realizadas medições das concentrações dos gases amônia, ácido nítrico e dióxido de enxofre, além das espécies inorgânicas solúveis em água, como amônio, nitrato e sulfato, entre outros. Estas concentrações de gases e partículas, bem como os parâmetros meteorológicos obtidos durante as campanhas, realizadas durante o período de transição entre as estações seca e chuvosa na região, foram utilizados como dados de entrada para ambos os modelos, onde foram escolhidos alguns eventos específicos. Com intuito de melhor representar o espectro de gotículas de nuvens no modelo de remoção, foram utilizadas a função de distribuição de Levine & Schwartz, 1982 e funções gama ajustadas aos dados observados em distribuição de gotículas de nuvem obtidas em vôos efetuados durante o experimento. Conseqüentemente, este trabalho visou à simulação da concentração na água de chuva de três espécies químicas (SO42-, NO3- e NH4+) removidas da atmosfera pelo evento de precipitação, comparando-as às composições químicas da água de chuva observadas experimentalmente, em dois eventos selecionados (9 e 10 de outubro de 2002). Simulações atmosféricas com o RAMS apresentaram resultados bastante satisfatórios conseguindo representar aspectos microfísicos das nuvens que se desenvolvem na região amazônica com bastante fidelidade. Os resultados da modelagem dos processos de remoção mostraram uma boa concordância com os observados, principalmente para o sulfato (que em alguns casos a quantidade encontrada na água de chuva pela simulação foi 97% da observada) em ambos os eventos, quando a altura da nuvem foi considerada mais realista para região (16 km). Além disso, observou-se que o espectro de gotículas de nuvem utilizado foi um parâmetro importante nos resultados. Os resultados mostraram ainda, uma predominância dos processos que ocorrem dentro da nuvem, sendo estes responsáveis por cerca de 80% a 97% da concentração da espécie química encontrada na água de chuva, corroborando a literatura. Com isso, ficou evidente a complexidade das interações e transferências entre os reservatórios atmosfera / hidrosfera através dos processos de remoção de poluentes, ressaltando assim, a importância dos estudos sobre este assunto. / The scavenging processes of chemical species have been studied using numerical modeling in order to understand the gases and particulate matter intra-reservoir transferences (natural or anthropogenic) which affect weather and climate. In this study RAMS model was used in turn to simulate cloud vertical structure formed over Amazonian area working together to B.V.2 scavenging model. The last model was used to simulate the in- and below-cloud scavenging processes, besides the local atmospheric conditions within the LBA Project. In this Project, there were evaluated many measurements of LBA/DRY-TO-WET and LBA/SMOCC (September to November) Campaigns at Rondonia State. During the Campaigns, ammonia, nitric acid and sulfur dioxide gases were evaluated and their respective particulate matter, ammonium, nitrate and sulfate, among others, as well as rainwater chemistry. These concentrations and meteorological parameters were also obtained, during the transition from dry to wet season, and used as input data to the both modeling, where some events were chosen. With the intention of modeling improvement, cloud droplet spectra were used from Levine & Schwartz, 1982 and gamma functions, according to each case and based on the droplet distribution obtained from flight collected data during the field Campaign. Consequently, this work simulated the rainwater concentrations of three chemical species (SO42-, NO3- e NH4+) scavenged from atmosphere by the precipitation event and compared to the observed data of two selected events (9 and 10 October 2002). RAMS atmospheric simulations presented satisfactory results which showed detailed cloud microphysics processes of Amazonian region. The modeling results show good agreement of observed data, mainly to sulfate, reaching 97% of the observed sulfate for both events, when the cloud height was considered more realistic for the region (16 km). Besides, the cloud droplet spectra were an important parameter to the modeling. The results also showed that the in-cloud process is responsible by 80% to 97% of the chemical species found in rainwater. Additionally, it was clear that the complexity of the interaction and intra-reservoir transferences through the scavenging processes and their importance.

Recent instrument development for aerosol measurement has focussed on small-scale, on-line measurements that can be incorporated into miniaturised sensor nodes as part of ambient or personal air quality monitoring networks. As a result, optical particle counters (OPCs) have risen in popularity given their ability to consistently size and count individual particles. OPCs have limitations, however, in their inability to detect ultrafine particles (considered the most influential to human health) or to measure particle mass directly (the standard metric for air quality). The growing field of microelectromechanical systems (MEMS) offers a potential alternative by implementing microresonators as mass sensors. MEMS resonators have high mass sensitivities and have recently seen implementation as particulate matter (PM) monitors. The field of MEMS PM instruments is still limited with a variety of implemented resonator topologies and sampling mechanisms. In general, however, they offer real-time, high sensitivity measurements at low flow rates. The aim of this thesis was to further examine the viability of implementing MEMS resonators for PM measurement with a focus on practical considerations for real-world applications. To this end, a new microresonator-based impactor was developed - the MEMS Impactor Stage (MIS) - capable of accommodating various nozzle and resonator combinations. Square lateral bulk acoustic resonators were the primary topology, but the results within the thesis are widely applicable. A series of laboratory studies covered the resonator lifetime, reusability, detection limits, and response to environmental changes. The resonator displayed a high sensitivity throughout, capable of detecting ultrafine particles, but is vulnerable to misinterpretation. Beyond mass measurement, studies introduced possible extensions to hygroscopicity and compositional applications. Ambient particle measurements with the MIS, simulating a real-world application to air quality monitoring, showed the capabilities as a PM instrument while highlighting concerns to be addressed for future instrument design. A microresonator-based impactor has potential as an alternative to OPCs, but its cross sensitivity to deposition patterns and environmental effects must be accounted for prior to implementation as PM monitor.

O objetivo deste trabalho foi estudar o papel dos aerossóis em modificar o desenvolvimento das nuvens e da precipitação. Esta tem sido uma das mais intrigantes questões no estudo das mudanças climáticas. Medidas da concentração de núcleos de condensação de nuvens (CCN) e distribuições de gotículas de nuvem durante o Experimento de Grande Escala da Biosfera-Atmosfera na Amazônia (LBA) revelaram características distintas entre condições atmosféricas limpas e poluídas. As medidas foram conduzidas no Sudoeste da Região Amazônica durante os meses de setembro e outubro de 2002, focando a transição do final da estação seca para o início da estação chuvosa. Durante a transição, a análise da concentração de CCN dentro da camada limite revelou um decréscimo geral, de valores acima de 1200 cm-3 para menos de 300 cm-3. A comparação entre áreas limpas e poluídas mostrou concentrações de CCN cerca de 5 vezes maiores em áreas poluídas. As diferenças não foram tão grandes nos níveis acima da camada limite. As medidas também mostraram um ciclo diurno acompanhando a atividade de queima de biomassa. Distribuições de tamanho de gotículas medidas em duas regiões com concentrações de aerossóis extremamente diferentes foram analisadas. Em condições poluídas pela queima de biomassa foi encontrada alta concentração de gotículas, com diâmetro médio e conteúdo de água de nuvem aumentando muito pouco com a altura, em comparação com regiões limpas. A função gama foi usada para ajustar as distribuições de gotículas e o parâmetro de forma da função foi usado como critério para definir adequadamente a melhor representação das distribuições de gotículas. De acordo com os valores encontrados, distribuições gama estreitas (parâmetro de forma em torno de 5) são mais bem indicadas para representar condições poluídas enquanto que aquelas mais largas se ajustam melhor em condições limpas (parâmetro de forma em torno de 2). Com base nesses resultados, experimentos numéricos foram conduzidos com o Brazilian Regional Atmospheric Modeling System (BRAMS) para investigar os efeitos da concentração de CCN e do parâmetro de forma das distribuições de gotículas no desenvolvimento da precipitação em nuvens convectivas tropicais. Os resultados mostraram uma grande sensibilidade devido às mudanças nesses parâmetros. Altas concentrações de CCN e distribuições de gotículas estreitas (parâmetros de forma maiores), típicas de dias poluídos, produziram baixos valores médios para água líquida integrada na coluna e precipitação acumulada na superfície. Por outro lado, tendência oposta a este efeito foi encontrada em condições limpas (baixos valores para ambos, a concentração de CCN e o parâmetro de forma). O parâmetro de forma se mostrou ser mais importante que a concentração de CCN. Os efeitos da concentração de CCN e do parâmetro de forma também influenciaram a distribuição espacial dos campos de nuvem e precipitação. Embora o valor médio desses campos tenha diminuído em condições poluídas, o valor máximo aumentou. Como conseqüência da menor dispersão nas nuvens em condições poluídas, mais radiação solar esteve disponível na superfície. Isto é oposto aos resultados dos modelos globais que mostram redução na radiação solar como conseqüência do segundo efeito indireto dos aerossóis. Da mesma forma, este estudo encontrou que as diferenças são reduzidas quando é incluído o efeito direto dos aerossóis em absorver ou refletir a radiação solar. Sobretudo, os resultados sugerem que um maior número de modelos com tratamento explícito dos processos microfísicos de nuvem são necessários. Esses modelos permitem comparações, podendo mostrar o melhor tratamento numérico a ser usado na representação dos efeitos dos aerossóis no processo de precipitação como um todo. Estes resultados são importantes porque melhoram a compreensão de como o clima será afetado como conseqüência das mudanças futuras. / The objective of this work was to study the role of aerosols in modifying clouds and precipitation. This is one of the most difficult aspects in the study of climate changes. Field measurements of cloud condensation nuclei (CCN) and cloud size distributions performed during the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) campaign revealed distinct characteristics between clean and polluted atmospheric conditions. Measurements were conducted over the southwestern Amazon region during September-October 2002 focusing the transition from dry to wet seasons. During this period, analysis of CCN concentrations in the boundary layer revealed a general decreasing trend from mean values higher than 1200 cm-3 to values lower than 300 cm-3. The comparison between clean and polluted areas showed CCN concentrations 5 times higher than in polluted areas. These differences were not so strong above the boundary layer. Measurements also showed a diurnal cycle following the biomass burning activity. Cloud droplet size distributions at two regions with extremely different aerosols loading were also analyzed. During biomass-burning conditions, at high concentrations of cloud droplets, the mean diameter and liquid water content increased very little with altitude when compared with unpolluted conditions. A gamma distribution was used to fit the measured droplet spectra and the shape parameter was used as a criterion to define the best choice of spectra representation. According to the found values, narrow gamma distributions optimally fit polluted conditions (shape parameter around 5), while broad distributions are best fits for unpolluted conditions (shape parameter around 2). Based on these results, numerical experiments were carried out using the Brazilian Regional Atmospheric Modeling System (BRAMS) to investigate the effects of CCN concentrations and shape parameters of droplet spectra on the development of precipitation in tropical convective clouds. The results showed large sensitivity due to changes in these parameters. It was observed that high CCN concentrations and narrower cloud droplet distributions (high values for shape parameter), typical of the polluted days, produced low mean values of liquid water path and accumulated surface precipitation. On the other hand, an opposite trend to this effect was found under clean conditions (low CCN concentration and shape parameter values). Shape parameter showed to be much more important than CCN concentration. The effects of CCN concentration and shape parameter also influenced the spatial distribution of cloud and precipitation fields. Although mean values of these fields decreased under polluted conditions, maximum values were increased. Consequently, the less dispersion in clouds under polluted conditions, the more surface solar radiation was found. This is opposite to the results of global climate models, which predict reduction in solar radiation as a consequence of the second aerosol indirect effect. Also, it was found that the differences were reduced when the aerosols direct effect to absorb or reflect solar radiation is included. Moreover, the results suggest that additional models with explicit microphysics process treatment are necessary in order to allow further comparisons, which could show the best numerical treatment to be used in representing the aerosol effects on precipitation process. The importance of these results is to improve the understanding of future climate changes.

Spatial distribution of diurnal variations of aerosol properties in South Korea, both long term and short term, is studied by using 9 AERONET sites from 1999 to 2017 for long-term averages and from an additional 10 sites during the KORUS-AQ field campaign. The extent to which WRF-Chem model and the GOCI satellite retrieval can describe these variations is also analyzed. In daily average, Aerosol Optical Depth (AOD) at 550 nm is 0.386 and shows a diurnal variation of +20 to -30% in inland sites, respectively larger than the counterparts of 0.308 and ± 20% in coastal sites. Both the inland and coastal sites have their diurnal variation peaks in the early morning and in the evening with noontime and early afternoon valleys. In contrast, Angstrom exponent values in all sites are between 1.2 and 1.4 with the exception of the inland rural sites having smaller values near 1.0 during the early morning hours. All inland sites experience a pronounced increase of Angström Exponent from morning to evening, reflecting overall decrease of particle size in daytime. To statistically obtain the climatology of diurnal variation of AOD, a minimum of requirement of ~2 years of observation is needed in coastal rural sites, twice more than the urban sites, which suggests that diurnal variation of AOD in urban setting is distinct and persistent. AERONET, GOCI, WRF-Chem, and observed PM2.5 data consistently show dual peaks for both AOD and PM2.5, one at ~ 10 KST and another ~14 KST. While Korean GOCI satellite is able to consistently capture the diurnal variation of AOD, WRF-Chem clearly has the deficiency to describe the relatively change of peaks and variations between the morning and afternoon, suggesting further studies for the diurnal profile of emissions. Overall, the relative small diurnal variation of PM2.5 is in high contrast with large AOD diurnal variation, which suggests the need to use AOD from geostationary satellites for constrain either modeling or analysis of surface PM2.5 for air quality application.

The overall goal of this doctoral dissertation is to develop a prototype instrument, a Portable Aerosol Collector and Spectrometer (PACS), that can continuously measure aerosol size distributions by number, surface area and mass concentrations over a wide size range (from 10 nm to 10 µm) while also collecting particles with impactor and diffusion stages for post-sampling chemical analyses. To achieve the goal, in the first study, we designed, built and tested the PACS hardware. The PACS consists of a six-stage particle size selector, a valve system, a water condensation particle counter to measure number concentrations and a photometer to measure mass concentrations. The valve system diverts airflow to pass sequentially through upstream stages of the selector to the detectors. The stages of the selector include three impactor and two diffusion stages, which resolve particles by size and collect particles for chemical analysis. Particle penetration by size was measured through each stage to determine actual performance and account for particle losses. The measured d50 of each stage (aerodynamic diameter for impactor stages and geometric diameter for diffusion stages) was similar to the design. The pressure drop of each stage was sufficiently low to permit its operation with portable air pumps. In the second study, we developed a multi-modal log-normal (MMLN) fitting algorithm to leverage the multi-metric, low-resolution data from one sequence of PACS measurements to estimate aerosol size distributions of number, surface area, and mass concentration in near-real-time. The algorithm uses a grid-search process and a constrained linear least-square (CLLS) solver to find a tri-mode (ultrafine, fine, and coarse), log-normal distribution that best fits the input data. We refined the algorithm to obtain accurate and precise size distributions for four aerosols typical of diverse environments: clean background, urban and freeway, coal power plant, and marine surface. Sensitivity studies were conducted to explore the influence of unknown particle density and shape factor on algorithm output. An adaptive process that refined the ranges and step sizes of the grid-search reduced the computation time to fit a single size distribution in near-real-time. Assuming standard density spheres, the aerosol size distributions fit well with the normalized mean bias (NMB) of -4.9% to 3.5%, normalized mean error (NME) of 3.3% to 27.6%, and R2 values of 0.90 to 1.00. The fitted number and mass concentration biases were within ± 10% regardless of uncertainties in density and shape. With this algorithm, the PACS is able to estimate aerosol size distributions by number, surface area, and mass concentrations from 10 nm to 10 µm in near-real-time. In the third study, we developed a new algorithm–the mass distribution by composition and size (MDCS) algorithm–to estimate the mass size distribution of various particle compositions. Then we compared the PACS for measuring multi-mode aerosols to three reference instruments, including a scanning mobility particle sizer (SMPS), an aerodynamic particle sizer (APS) and a nano micro-orifice uniform deposit impactor (nanoMOUDI). We used inductively coupled plasma mass spectrometry to measure the mass of collected particles on PACS and nanoMOUDI stages by element. For the three-mode aerosol, the aerosol size distributions in three metrics measured with the PACS agreed well with those measured with the SMPS/APS: number concentration, bias = 9.4% and R2 = 0.96; surface area, bias = 17.8%, R2 = 0.77; mass, bias = -2.2%, R2 = 0.94. Agreement was considerably poorer for the two-mode aerosol, especially for surface area and mass concentrations. Comparing to the nanoMOUDI, for the three-mode aerosol, the PACS estimated the mass median diameters (MMDs) of the coarse mode well, but overestimated the MMDs for ultrafine and fine modes. The PACS overestimated the mass concentrations of ultrafine and fine mode, but underestimated the coarse mode. This work provides insight into a novel way to simultaneously assess airborne aerosol size, composition, and concentration by number, surface area and mass using cost-effective handheld technologies.

Auf der Grundlage von Sonnenphotometermessungen an drei Messstationen (AWIPEV/ Koldewey in Ny-Ålesund (78.923 °N, 11.923 °O) 1995–2008, 35. Nordpol Driftstation – NP-35 (84.3–85.5 °N, 41.7–56.6 °O) März/April 2008, Sodankylä (67.37 °N, 26.65 °O) 2004–2007) wird die Aerosolvariabilität in der europäischen Arktis und deren Ursachen untersucht. Der Schwerpunkt liegt dabei auf der Frage des Zusammenhanges zwischen den an den Stationen gemessenen Aerosolparametern (Aerosol optische Dicke, Angström Koeffizient, usw.) und dem Transport des Aerosols sowohl auf kurzen Zeitskalen (Tagen) als auch auf langen Zeitskalen (Monate, Jahre). Um diesen Zusammenhang herzustellen, werden für die kurzen Zeitskalen mit dem Trajektorienmodell PEP-Tracer 5-Tage Rückwärtstrajektorien in drei Starthöhen (850 hPa, 700 hPa, 500 hPa) für die Uhrzeiten 00, 06, 12 und 18 Uhr berechnet. Mit Hilfe der nicht-hierarchischen Clustermethode k-means werden die berechneten Rückwärtstrajektorien dann zu Gruppen zusammengefasst und bestimmten Quellgebieten und den gemessenen Aerosol optischen Dicken zugeordnet. Die Zuordnung von Aerosol optischer Dicke und Quellregion ergibt keinen eindeutigen Zusammenhang zwischen dem Transport verschmutzter Luftmassen aus Europa oder Russland bzw. Asien und erhöhter Aerosol optischer Dicke. Dennoch ist für einen konkreten Einzelfall (März 2008) ein direkter Zusammenhang von Aerosoltransport und hohen Aerosol optischen Dicken nachweisbar. In diesem Fall gelangte Waldbrandaerosol aus Südwestrussland in die Arktis und konnte sowohl auf der NP-35 als auch in Ny-Ålesund beobachtet werden. In einem weiteren Schritt wird mit Hilfe der EOF-Analyse untersucht, inwieweit großskalige atmosphärische Zirkulationsmuster für die Aerosolvariabilität in der europäischen Arktis verantwortlich sind. Ähnlich wie bei der Trajektorienanalyse ist auch die Verbindung der atmosphärischen Zirkulation zu den Photometermessungen an den Stationen in der Regel nur schwach ausgeprägt. Eine Ausnahme findet sich bei der Betrachtung des Jahresganges des Bodendruckes und der Aerosol optischen Dicke. Hohe Aerosol optische Dicken treten im Frühjahr zum einen dann auf, wenn durch das Islandtief und das sibirische Hochdruckgebiet Luftmassen aus Europa oder Russland/Asien in die Arktis gelangen, und zum anderen, wenn sich ein kräftiges Hochdruckgebiet über Grönland und weiten Teilen der Arktis befindet. Ebenso zeigt sich, dass der Übergang zwischen Frühjahr und Sommer zumindest teilweise bedingt ist durch denWechsel vom stabilen Polarhoch im Winter und Frühjahr zu einer stärker von Tiefdruckgebieten bestimmten arktischen Atmosphäre im Sommer. Die geringere Aerosolkonzentration im Sommer kann zum Teil mit einer Zunahme der nassen Deposition als Aerosolsenke begründet werden. Für Ny-Ålesund wird neben den Transportmustern auch die chemische Zusammensetzung des Aerosols mit Hilfe von Impaktormessungen an der Zeppelinstation auf dem Zeppelinberg (474m ü.NN) nahe Ny-Ålesund abgeleitet. Dabei ist die positive Korrelation der Aerosoloptischen Dicke mit der Konzentration von Sulfationen und Ruß sehr deutlich. Beide Stoffe gelangen zu einem Großteil durch anthropogene Emissionen in die Atmosphäre. Die damit nachweisbar anthropogen geprägte Zusammensetzung des arktischen Aerosols steht im Widerspruch zum nicht eindeutig herstellbaren Zusammenhang mit dem Transport des Aerosols aus Industrieregionen. Dies kann nur durch einen oder mehrere gleichzeitig stattfindende Transformationsprozesse (z. B. Nukleation von Schwefelsäurepartikeln) während des Transportes aus den Quellregionen (Europa, Russland) erklärt werden. / On the base of sun photometer measurements conducted at three different research stations (AWIPEV/Koldewey in Ny-Ålesund (78.923 °N, 11.923 °E) 1995-2008, 35. Northpole Drifting Station – NP-35 (84.3–85.5 °N, 41.7–56.6 °E) March/April 2008, Sodankylä (67.37 °N, 26.65 °E) 2004-2007) the aerosol variability in the european Arctic and their cause is analyzed. The main focus is to quantify the correlation between the measured aerosol parameters (aerosol optical depth, Angström coefficient, etc.) and the transport of aerosol from Europe and Russia on short timescales (days) as well as on long timescales (months, years). For the short timescales 5-day backward trajectories were calculated with the trajectory model PEP-Tracer at three different starting heights (850 hPa, 700 hPa, 500 hPa) four times the day (00:00, 06:00, 12:00, 18:00 UTC). Afterwards the non-hierarchical cluster method k-means is used to group the backward trajectories in differend aerosol source regions and allocate to the respective sun photometer measurements. This allocation of aerosol source region and sun photometer measurements does not show a correlation between polluted air mass of european or russian/asian origin and enhanced aerosol optical depth. However, in one case (March 2008) a clear influence of anthropogenic aerosol on the photometer measurements occurs. In March 2008, aerosol originating at forest fires in southeast Russia was transported into the Arctic and detected over NP-35 as well as Ny-Ålesund. Furthermore, the EOF method is used to verify if large-scale atmospheric circulation patterns determine the arctic aerosol variability. However, the connection to the sun photometer measurements is very weak except for seasonal variability. It is shown, that in spring-time due to the Iclandic low and the Siberian high, air masses from Europe and Russia as well as a strong high pressure system at Greenland and most parts of the Arctic cause higher aerosol optical depths in Ny-Ålesund. The transition from spring to summer aerosol concentration can at least partially be assigned to the replacement of the stable polar high in winter and spring by low pressure systems in summer. In addition to the transport pattern, chemical composition of the scattering aerosol in Ny-Ålesund was deduced from measurements by the Zeppelin station at the Zeppelin mountain (474m above sea level) near Ny-Ålesund. A clear positive correlation between sulfate and black carbon concentration was found. Both chemicals are mostly emitted through anthropogenic processes (e.g. combustion). The verifiable anthropogenic influence on the composition of arctic aerosols disagree with the missing linkage of transport from industrial regions to aerosol optical depth. It can only be explained by one or more transformation processes (e.g. nucleation of sulfuric acid) during the transport from the source regions (Europe, Russia) to the Arctic.

Defence Research and Development Canada - Atlantic is currently under a project arrangement with Sweden and Holland to investigate new or emerging fire suppression technologies in naval applications. One possible outcome of this project arrangement could be the identification of a safe and effective Halon 1301 replacement suppression agent within the respective navies. The subject area Canada has agreed to investigate is aerosol fire extinguishing agent technologies. Although aerosols have been shown to be effective in suppressing demonstration fires, to date there has been little systematic scientific research into fire suppression using aerosol particulates. Therefore, there is a need for more in depth investigation of some of the commercial aerosol products available on the market to determine their fire suppression efficacy in naval applications, as well as any potential negative impacts that the aerosol may have on personnel, equipment and the environment. Aerosol suppression systems range from small handheld grenade extinguishers to large fitted and remotely activated aerosol dispersal units. The fire research and testing presented in this thesis looks specifically at the efficacy and safe use of two variants of the small handheld aerosol extinguishers, while also assessing aerosol agent suppression technologies overall. The Royal Canadian Navy (RCN) currently uses a two tiered response to fire, consisting of first response by a Rapid Response Team (RRT), followed by full response by an Attack Team (AT). A Rapid Attack Team (RAT) has been introduced as an intermediate response team. To enhance efficiency of the RRTs or RATs, handheld aerosol units, in this evaluation the Dry Sprinkler Powder Aerosol (DSPA) and StatX fire knock down aerosol extinguishers, could potentially be stored throughout the ship or transported by the teams to a fire scene and used to control, suppress or even extinguish a fire prior to the AT arriving on the scene, particularly in the case of smaller enclosure fires. To fully evaluate their potential for use in this capacity, it is important to carefully study the suppression efficacy of these units under conditions similar to those in which they would be deployed, as well as to better understand their impact on a fire environment in terms of important parameters such as compartment temperature reduction, visibility, oxygen concentration, aerosol particulate dwell time, and toxicity. In terms of operational issues related to deployment of these pyrotechnic tools onboard RCN vessels, it is critical to assess the requirements for extinguisher safe storage and to gain an understanding of the incendiary potential of the units, as well as post suppression overhaul, smoke/agent clearing and compartment gas free certification. The thesis includes a description of the experimental design, measurement techniques, and key results and conclusions for each of the 26 full-scale simulated marine enclosure live fire tests that were conducted. In general, handheld aerosol extinguishers have proven to be effective for fire control and even suppression under certain circumstances. They can improve the fire safety of RCN vessels when used correctly. Experimental data measured that relate to the consequences of accidental discharge and incendiary potential can also be used to ensure naval applications are safe and effective.