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A dendrochronological series of Araucaria angustifolia was analyzed for a better understanding of the climatic factors that operate in Campos do Jordão city, São Paulo state, Brazil. The dendroclimatic analysis was carried out using 45 samples from 16 Araucaria angustifolia trees to reconstruct the precipitation and the temperature over the 1803–2012 yearly interval. To this end, Pearson’s correlation was calculated between mean chronology and the climatic time series using a monthly temporal resolution to calibrate our models. We obtained correlations as high as r=0.22(α=0.1) for precipitation (February), and r=0.21(α=0.1) for temperature (March), both corresponding to the end of the summer season. Our results show evidence of temporal instabilities because the correlations for the halves of 1963–2012 were very different, as well as for the full period. To overcome this problem, the dendrochronological series and the climatic data were investigated using the wavelet techniques searching for time-dependent cause–effect relationships. From these analyses, we find a strong influence of the region’s precipitation and temperature on the growth of tree ring widths.

Este trabalho utiliza amostras da espécie Imbuia, (Ocotea porosa (Nees & Mart) Barroso), coletadas na cidade de General Carneiro, região Sudeste do Estado do Paraná (26º24’01 25"S 51º24’03 91"O), Brasil, para gerar a série dendrocronológica desta região. As amostras selecionadas para este estudo foram obtidas por meio de Análise de Clusters, que classifica objetos (amostras) com base em suas semelhanças. Com a finalidade de obter a série dendrocronológica, aplicou-se o método estatístico Análise de Componentes Principais (do inglês Principal Component Analysis- PCA). Obtidas as Componentes Principais (Principal Componentes - PCs), reconstruiu-se as séries sem a 1ª PC, sendo uma estimativa da tendência que melhor representa o crescimento natural de todas as árvores do local. A média das séries sem a 1ª PC é a série dendrocronológica. O método de PCA traz diversas vantagens sobre o método tradicional de obtenção da série cronológica como o processamento rápido de dados, uma forma automatizada de remover a tendência natural de crescimento em todas as amostras ao mesmo tempo, e também, o fato de integrar uma ferramenta poderosa, o método dos mínimos quadrados alternados (do inglês Alternating Least Squares – ALS), para estimar ou recuperar falhas de dados.

We report a study of the particulate matter emissions related to the 2015 fire outbreak at a fuel tank storage facility located at Santos, a coastal city in Brazil. The facility, managed by the company Ultracargo, had oil tanks (filled with gasoline and ethanol) destroyed by fire that lasted more than a week, between 2nd and 9th April. In this article, we present the atmospheric concentration analysis of particulate matter (PM10) measured over the entire month of April 2015 by the 2 closest stations that integrate the air quality monitoring system of the São Paulo State Environmental Company (CETESB). The results were compared with similar data from the same period of the yesteryear (April 2014). The results were also complemented by the air masses trajectories over the region (obtained with HYSPLIT/NOAA software). Our results do indicate a subtle increase in the particulate concentration during the days of the fire, followed by a fast dissipation over the subsequent weeks. The observed plume dispersion discussion is made considering the meteorological patterns of the region and other environmental and health reported impacts related to the accident.