Flutuações Diárias na Concentração de Black Carbon na Atmosfera de São José dos Campos-SP

Flutuações diárias na concentração de Black carbon naatmosfera de São José dos Campos-S

Lidar Observations in South America. Part I - Mesosphere and Stratosphere

South America covers a large area of the globe and plays a fundamental function in its climate change, geographical features, and natural resources. However, it still is a developing area, and natural resource management and energy production are far from a sustainable framework, impacting the air quality of the area and needs much improvement in monitoring. There are significant activities regarding laser remote sensing of the atmosphere at different levels for different purposes. Among these activities, we can mention the mesospheric probing of sodium measurements and stratospheric monitoring of ozone, and the study of wind and gravity waves. Some of these activities are long-lasting and count on the support from the Latin American Lidar Network (LALINET). We intend to pinpoint the most significant scientific achievements and show the potential of carrying out remote sensing activities in the continent and show its correlations with other earth science connections and synergies. In Part I of this chapter, we will present an overview and significant results of lidar observations in the mesosphere and stratosphere. Part II will be dedicated to tropospheric observations

Lidar Observations in South America. Part II - Troposphere

In Part II of this chapter, we intend to show the significant advances and results concerning aerosols’ tropospheric monitoring in South America. The tropospheric lidar monitoring is also supported by the Latin American Lidar Network (LALINET). It is concerned about aerosols originating from urban pollution, biomass burning, desert dust, sea spray, and other primary sources. Cloud studies and their impact on radiative transfer using tropospheric lidar measurements are also presented

Transição vespertina da camada limite superficial acima do pantanal: diferenças entre as estações seca e úmida

É utilizada a escala de comprimento de flutuabilidade, lb, para investigar a evolução da estrutura da turbulência na camada limite superficial (CLS) acima do Pantanal (lb= ?w/N, onde ?w é o desvio padrão da flutuação de velocidade vertical e N, a frequência de Brunt-Väissälä). Teoricamente, lb é um indicador da maior escala vertical da turbulência na camada limite noturna (CLN) e detecta o grau de supressão de movimentos verticais devido à estabilidade estática. Duas classes de dados foram estabelecidas: (i) com a ocorrência de jato de baixos níveis (JBN); (ii) sem a ocorrência de JBN. Os resultados mostram notórias diferenças no valor de lb para cada uma das duas classes em questão. Para a classe (i) o valor de lb oscila entre 2m e 20m na transição vespertina, podendo atingir valores mais elevados, o que não é observado para a classe (ii), cujos valores de lb são menores que 5m e pouco variam ao longo da noite. ABSTRACT: The buoyancy length-scale, lb, is used to investigate the early evening transiction (EET) evolution of the surface boundary layer (SBL) structure above Pantanal (lb= σw/N, where σw is the standard-deviation of the vertical velocity fluctuation and N is the Brunt-Väissälä frequency). Theoretically, lb indicates which is the highest vertical turbulence length scale in the nocturnal stable boundary-layer and is related with the vertical motion suppression due to the static stability. Two SBL data classes have been defined: (i) with low level jet occurrence; (ii) without low level jet. The results show net differences in lb values for each one of analyzed classes. For the former i-class, the lb value oscillates between 2m and 20m during the EET and sometimes reaches higher values than 20m, what is not observed for ii-class data, whose values are lesser than 5m and do not vary strongly during night-time

Estimativa da altura da camada limite atmosférica acima do pantanal: estudo comparativo usando radiossondagens e sodar

Neste artigo são comparadas informações de sondagens verticais simultâneas da camada limite atmosférica (CLA) obtidas com radiossondagens (RS) e SODAR (SO). Os dados foram coletados durante a estação seca, em setembro de 1999, na Base de Estudos da UFMS no Pantanal (19\ub0 58' S; 57\ub0 02' O), quando da realização do Experimento IPE-2. Ao se comparar as alturas da CLA (Zi) estimadas com base em dados de RS e SO observa-se uma razoável correlação entre os mesmos (0,51 para 46 dados disponíveis). Entretanto, o grau de concordância entre as estimativas de Zi com base em RS e SO varia dependendo do período do dia em que é realizada a comparação. A pior concordância é verificada nos períodos em que a convecção térmica é mais intensa, durante os quais as estimativas de Zi pelo SODAR parecem ser incapazes de detectar a altura do topo da camada de mistura obtida com o perfil vertical de temperatura potencial virtual fornecido pela RS (método de referência). Estes resultados corroboram investigações de outros pesquisadores e são úteis para uma melhor compreensão das limitações inerentes ao SODAR na caracterização da estrutura vertical da CLA convectiva. ABSTRACT: Simultaneous radiossonde (RS) and SODAR (SO) vertical soundings of the atmospheric boundary layer (ABL) above Pantanal are compared. The data were collected in September 1999 at the UFMS Station in Pantanal (19\ub0 58' S; 57\ub0 02' W), during IPE-2 intensive campaign experiment. The atmospheric boundary layer (ABL) height (Zi) estimation with RS and SO present a reasonable agreement (0.51 correlation coefficient for 46 data points). However, this correlation coefficient, r, shows net changes depending on the day-time or night-time observation period. The lowest r-values are obtained during day-time periods with strong thermal convection, when Zi estimated with SO seems to be insensitive to thermal ABL structure depicted by RS potential virtual temperature profiles (reference method). The results agree with earlier investigations concerning the SO capability to detect the vertical structure of the convective boundary-layer

Caracterizacao do clima da cidade de Sao Jose dos Campos

This work analyses the climatological features of air temperature, specific humidity and rainfall totals from the meteorological station located in São José dos Campos Airport, SP, using the 1974 to 1998 data period. The results show that according to the Köppen classification, São José dos Campos has an Aw climate type. Thus, the winter is relatively dry with mean monthly rainfall totals less than 50 mm and rainy summer with monthly rainfall totals above 148 mm. It is shown that in average rains 120 days per year, 19 days in January, 17 days in December, 16 days in February, 15 days in March and only 6 days in July. Analysis of the year-to-year variability of rainfall shows that during El Niño and La Niña years, the rainfall is above than normal year values. Analysis of air temperature shows that maximum values vary between 23,3 oC in July and 30,2 oC in February. On the other hand, the minimum temperatures range between 11,7 oC in June and 19,8 oC in February. During some El Niño and La Niña events (e.g. 1977, 1994), the annual mean air temperature is above than average values. On the other hand, the analysis of specific humidity shows that typically the highest values occurs during summer time and the smallest ones during the winter period. This variable shows small interanual variability.Pages: 724-72

Aerosols observations by elastic lidar system over the city of Sao Paulo, Brazil

São Paulo (23°33'5, 46\ub044'W, 780 m ASL) is one of the most polluted cities in the world, Tegardirlg atmospheric air quality, (CO, suspended aerosol particles). In this paper, we present the first aerosols obscrvations perfomed by an elastic back.scatter lidar sysltm, over the city of São Paulo. The lidar- measurements concerned the retrieval of the vertical profile or the aerosol backscatter coefficient at 532 nm, using the Klett inversion technique. in the Planetary Boundary Layér (PBL) and me adjacent lower free troposphere. Systematic aerosols observations to be performed during the year 2001, wiIl enable the characterization of the various tropospheric layers, ând hclp to dcsign an efficient air pollution abatement strategy in thc city of São Paulo.Pages: 8407-840

Low temperature thermal diffusivity of LiKSO4 obtained using the photoacoustic phase lag method

This paper describes the determination of the thermal diffusivity of LiKSO photoacoustic phase lag method, in the 77 K to 300 K temperature interval. This method is quite simple and fast and when it is coupled to a specially designed apparatus, that includes a resonant photoacoustic cell, allows for the determination of the thermal diffusivity at low temperatures. The thermal diffusivity is an important parameter that depends on the temperature, and no values of this parameter for LiKSO 4, at low temperature, have yet been reported. The LiKSO 4is a crystal with many phase transitions which can be detected via the anomalies in the variation of the thermal diffusivity as a function of the temperature.Pages: 39-4

Association between micronuclei frequency in pollen mother cells of Tradescantia and mortality due to cancer and cardiovascular diseases: A preliminary study in Sao Jose dos Campos, Brazil

The present study was designed to explore the correlation between the frequency of micronuclei in Trad-MN, measured across 28 biomonitoring stations during the period comprised between 11 of May and 2 of October, 2006, and adjusted mortality rates due to cardiovascular, respiratory diseases and cancer in Sao Jose dos Campos, Brazil, an area with different sources of air pollution. For controlling purposes, mortality rate due to gastrointestinal diseases (an event less prone to be affected by air pollution) was also considered in the analysis. Spatial distribution of micronuclei frequency was determined using average interpolation. The association between health estimators and micronuclei frequency was determined by measures of Pearson`s correlation. Higher frequencies of micronuclei were detected in areas with high traffic and close to a petrochemical pole. Significant associations were detected between micronuclei frequency and adjusted mortality rate due to cardiovascular diseases (r = 0.841, p = 0.036) and cancer (r = 0.890, p = 0.018). The association between mortality due to chronic obstructive pulmonary diseases was positive but did not reach statistical significance (r = 0.640, p = 0.172), probably because of the small number of events. Gastrointestinal mortality did not exhibit significant association with micronuclei frequency. Because the small number of observations and the nature of an ecological study, the present findings must be considered with caution and considered as preliminary. Further studies, performed in different conditions of contamination and climate should be done before considering Trad-MN in the evaluation of human health risk imposed by air pollutants. (C) 2009 Elsevier Ltd. All rights reserved.CNPq (Brazilian Council of Research)LIM-HCFMUSP (institute of the Laboratories of Medical Investigation, Clinical Hospital, School of Medicine, University of Sao Paulo

Resonant photoacoustic cell for low temperature measurements

This paper describes a resonant photoacoustic cell for low temperature measurements. It has the shape of the Helmholtz resonator, with the microphone separated from the sample by a resonant tube. In this way the microphone is kept at room temperature while the sample temperature is lowered. When the sample is placed in a liquid nitrogen tank it is possible to change its temperature from 77 K to 300 K, with the aid of a furnace, which surrounds the sample holder. Two optical fibres lead the laser light to both sides of the sample, making possible the determination of the thermal diffusivity in all temperature intervals, by using the photoacoustic phase-lag method. (C) 1999 Elsevier Science Ltd. All rights reserved.Pages: 193-19