Vários métodos de amostragem e análise de partículas em suspensão na atmosfera foram discutidos. Os métodos mais utilizados, gravimétrico e refletância foram testados comparativamente e quanto à correlação entre seus resultados em dois locais distintos. Os fatores intervenientes nos resultados obtidos foram estudados quanto à sua influência. Os métodos gravimétrico e reflectância foram analisados quanto a exatidão dos resultados fornecidos e quanto ao seu significado higiênico em função da correlação existente entre concentração de partículas na atmosfera e danos à saúde. A presente investigação levou o autor a concluir por uma significante diferença entre os resultados fornecidos pelos métodos em estudo, por uma correlação estratificada e variável de local para local entre eles, e por inadequacidade dos valores fornecidos por cada um dos métodos em estudo quanto ao fato de não fornecerem os valores de concentração de partículas na atmosfera mais correlacionados com danos à saúde. O autor sugere o uso ou o desenvolvimento de um método que pelo menos separe as partículas nas frações respirável e não respirável e que permita uma análise posterior de cada uma das frações. Sugere ainda que concomitantemente sejam efetuados estudos epidemiológicos de correlação entre os valores obtidos e danos à saúde para determinação de novos padrões de qualidade do ar para partículas em suspensão na atmosfera. / Various methods to evaluate concentrations of suspended particulate matter were discussed. The two most commonly ueed methods, gravimetric high volume sampler and DECD reflectance method were tested to compare and correlate their results in two different places. The interfering factors were studied to deter mine their influence on the results. The hivol and reflectance methods were analysed according to the accuracy of the results and according to the hygienic significance as they correlate with health effects. This investigation brought the author to the conclusion that there is a significant statistical difference between the results of the two methods. There are correlations between the methods, which are stratified and vary from one place to the other. Finally, however the results are not the best estimate of the concentratios of suspended particulate matter that correlates with health effects. The author suggests the use or the development of a new method that at least can separate the particles sampled into two fractions, one respirable and another non-respirable. Both fractions must be collected in such a way and in such quantities that allow for adequate analysis afterwards. It is suggested also, that epidemiological studies to correlate the results with health effects must be carried on et the same time in arder to set new air quality standards for suspended particute matter.

Vários métodos de amostragem e análise de partículas em suspensão na atmosfera foram discutidos. Os métodos mais utilizados, gravimétrico e refletância foram testados comparativamente e quanto à correlação entre seus resultados em dois locais distintos. Os fatores intervenientes nos resultados obtidos foram estudados quanto à sua influência. Os métodos gravimétrico e reflectância foram analisados quanto a exatidão dos resultados fornecidos e quanto ao seu significado higiênico em função da correlação existente entre concentração de partículas na atmosfera e danos à saúde. A presente investigação levou o autor a concluir por uma significante diferença entre os resultados fornecidos pelos métodos em estudo, por uma correlação estratificada e variável de local para local entre eles, e por inadequacidade dos valores fornecidos por cada um dos métodos em estudo quanto ao fato de não fornecerem os valores de concentração de partículas na atmosfera mais correlacionados com danos à saúde. O autor sugere o uso ou o desenvolvimento de um método que pelo menos separe as partículas nas frações respirável e não respirável e que permita uma análise posterior de cada uma das frações. Sugere ainda que concomitantemente sejam efetuados estudos epidemiológicos de correlação entre os valores obtidos e danos à saúde para determinação de novos padrões de qualidade do ar para partículas em suspensão na atmosfera. / Various methods to evaluate concentrations of suspended particulate matter were discussed. The two most commonly ueed methods, gravimetric high volume sampler and DECD reflectance method were tested to compare and correlate their results in two different places. The interfering factors were studied to deter mine their influence on the results. The hivol and reflectance methods were analysed according to the accuracy of the results and according to the hygienic significance as they correlate with health effects. This investigation brought the author to the conclusion that there is a significant statistical difference between the results of the two methods. There are correlations between the methods, which are stratified and vary from one place to the other. Finally, however the results are not the best estimate of the concentratios of suspended particulate matter that correlates with health effects. The author suggests the use or the development of a new method that at least can separate the particles sampled into two fractions, one respirable and another non-respirable. Both fractions must be collected in such a way and in such quantities that allow for adequate analysis afterwards. It is suggested also, that epidemiological studies to correlate the results with health effects must be carried on et the same time in arder to set new air quality standards for suspended particute matter.

This thesis examines the utility of mathematical complexity measures for the analysis of stratospheric dynamics. Through theoretical considerations and tests with artificial data sets, e.g., the iteration of the logistic map, suitable parameters are determined for the application of the statistical entropy measures sample entropy (SE) and Rényi entropy (RE) to methane (a long-lived stratospheric tracer) data from simulations of the SOCOL chemistry-climate model. The SE is shown to be useful for quantifying the variability of recurring patterns in a time series and is able to identify tropical patterns similar to those reported by previous studies of the ``tropical pipe'' region. However, the SE is found to be unsuitable for use in polar regions, due to the non-stationarity of the methane data at extra-tropical latitudes. It is concluded that the SE cannot be used to analyse climate complexity on a global scale. The focus is turned to the RE, which is a complexity measure of probability distribution functions (PDFs). Using the second order RE and a normalisation factor, zonal PDFs of ten consecutive days of methane data are created with a Bayesian optimal binning technique. From these, the RE is calculated for every day (moving 10-day window). The results indicate that the RE is a promising tool for identifying stratospheric mixing barriers. In Southern Hemisphere winter and early spring, RE produces patterns similar to those found in other studies of stratospheric mixing. High values of RE are found to be indicative of the strong fluctuations in tracer distributions associated with relatively unmixed air in general, and with gradients in the vicinity of mixing barriers, in particular. Lower values suggest more thoroughly mixed air masses. The analysis is extended to eleven years of model data. Realistic inter-annual variability of some of the RE structures is observed, particularly in the Southern Hemisphere. By calculating a climatological mean of the RE for this period, additional mixing patterns are identified in the Northern Hemisphere. The validity of the RE analysis and its interpretation is underlined by showing that qualitatively similar patterns can be seen when using observational satellite data of a different tracer. Compared to previous techniques, the RE has the advantage that it requires significantly less computational effort, as it can be used to derive dynamical information from model or measurement tracer data without relying on any additional input such as wind fields. The results presented in this thesis strongly suggest that the RE is a useful new metric for analysing stratospheric mixing and its variability from climate model data. Furthermore, it is shown that the RE measure is very robust with respect to data gaps, which makes it ideal for application to observations. Hence, using the RE for comparing observations of tracer distributions with those from model simulations potentially presents a novel approach for analysing mixing in the stratosphere.

This thesis examines the utility of mathematical complexity measures for the analysis of stratospheric dynamics. Through theoretical considerations and tests with artificial data sets, e.g., the iteration of the logistic map, suitable parameters are determined for the application of the statistical entropy measures sample entropy (SE) and Rényi entropy (RE) to methane (a long-lived stratospheric tracer) data from simulations of the SOCOL chemistry-climate model. The SE is shown to be useful for quantifying the variability of recurring patterns in a time series and is able to identify tropical patterns similar to those reported by previous studies of the ``tropical pipe'' region. However, the SE is found to be unsuitable for use in polar regions, due to the non-stationarity of the methane data at extra-tropical latitudes. It is concluded that the SE cannot be used to analyse climate complexity on a global scale. The focus is turned to the RE, which is a complexity measure of probability distribution functions (PDFs). Using the second order RE and a normalisation factor, zonal PDFs of ten consecutive days of methane data are created with a Bayesian optimal binning technique. From these, the RE is calculated for every day (moving 10-day window). The results indicate that the RE is a promising tool for identifying stratospheric mixing barriers. In Southern Hemisphere winter and early spring, RE produces patterns similar to those found in other studies of stratospheric mixing. High values of RE are found to be indicative of the strong fluctuations in tracer distributions associated with relatively unmixed air in general, and with gradients in the vicinity of mixing barriers, in particular. Lower values suggest more thoroughly mixed air masses. The analysis is extended to eleven years of model data. Realistic inter-annual variability of some of the RE structures is observed, particularly in the Southern Hemisphere. By calculating a climatological mean of the RE for this period, additional mixing patterns are identified in the Northern Hemisphere. The validity of the RE analysis and its interpretation is underlined by showing that qualitatively similar patterns can be seen when using observational satellite data of a different tracer. Compared to previous techniques, the RE has the advantage that it requires significantly less computational effort, as it can be used to derive dynamical information from model or measurement tracer data without relying on any additional input such as wind fields. The results presented in this thesis strongly suggest that the RE is a useful new metric for analysing stratospheric mixing and its variability from climate model data. Furthermore, it is shown that the RE measure is very robust with respect to data gaps, which makes it ideal for application to observations. Hence, using the RE for comparing observations of tracer distributions with those from model simulations potentially presents a novel approach for analysing mixing in the stratosphere.