Air-quality assessment of Pico-mountain environment (Azores) by using chemometric and trajectory analyses
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This article illustrates the use of chemometrics in the interpretation of aerosol data collected by a seven-wavelength aethalometer at the PICO-NARE observatory, in Pico island, Azores, Portugal. Samples were assessed through k 0-standardized, instrumental neutron activation analysis (k 0-INAA), and concentrations of up to 20 airborne elements were determined. The chemometric analysis by self-organizing maps (SOM) tried to identify groups of similarity for sampling events and chemical tracers, discriminating in this way each group of similarity thus obtained. Additionally, synoptic back trajectories for each of the sampling days distributed into four clusters were calculated, in order to associate the classified groups with possible pollution sources.
KeywordsAerosol monitoring Chemometrics Self-organizing maps HYSPLIT models
One of the authors (V. Simeonov) would like to express his sincere gratitude to the Executive Committee of NAMLS-9 and personally to Dr. M. C. Freitas for financial and moral support. The authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and/or READY website (http://www.arl.noaa.gov/ready.html) used in this publication. The authors are also indebted to Prof. Paulo Fialho and Dr. Filipe Barata (Group of Chemistry and Physics of the Atmosphere, Department of Agricultural Sciences, University of Azores, Portugal), respectively, for filter availability and spot identification.
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