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Todo o tipo de documentos relacionados com uma conferência; ex.: artigos de conferências, relatórios de conferências, palestras em conferências, artigos publicados em proceedings de conferências, relatórios de abstracts de artigos de conferência e posters de conferências.
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Browsing DCA - Comunicações a Conferências / ConferenceItem by Subject "Aerossol Atmosférico"
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- 7Be as a tracer on the investigation of upper tropospheric dispersion of Saharan dust during the mid-winter 2000 storm events (Azores).Publication . Rodrigues, A. F.; Holmes, Charles; Pio, Casimiro; Marot, Marci; Fialho, Paulo7Be is a nuclide that acts like a tracer of input from the stratosphere and upper troposphere, where it is produced by spallation processes of light atmospheric nuclei such as nitrogen 14, oxygen 16 and carbon 12, with protons and neutrons (Zanis et al. 2000). By measuring the activity of beryllium isotopes attached to submicrometer aerosol particles, information on the mechanisms of exchange between the stratosphere and troposphere is obtained. […].
- Aerosol Measurements in the Free Troposphere at the North Atlantic Pico Mountain Observatory in the Azores.Publication . Mazzoleni, Claudio; Fialho, Paulo; Gorkowski, Kyle; Owen, Robert; Dziobak, Michael P.; Hueber, Jacques; Dzepina, Katja; Kramer, Louisa; Olsen, Seth C.; Kumar, Sumit; Helmig, DetlevPico is a small island (447 km2) in the archipelago of the Azores, Portugal, in the North Atlantic Ocean. The island has a very steep inactive volcano. An atmospheric monitoring station (Pico Mountain Observatory) was established close to the summit of the volcano by the late Dr. Richard Honrath and colleagues in 2001. The station, far from persistent local sources, is located near the northern cliff of the summit caldera at an altitude of 2225 meters. The station altitude is typically well above the boundary layer during summertime, when average marine boundary-layer heights are below 1200 meters and rarely exceed 1300 meters. Air masses reaching the station are often transported from North America and seldom from Europe or North Africa. The station’s uniqueness and significance lie in its location that allows study of the transport and evolution of gases and aerosols from North America in the free troposphere. Until recently, the focus was on the measurement and analysis of trace gases (ozone, carbon monoxide, non-methane hydrocarbons, nitrogen oxides) and light-absorbing aerosol (black carbon and iron oxide). Aerosol light attenuation has been measured at the site since 2001 using a seven-wavelengths aethalometer. An optical particle sizer was installed at the site in 2010 and has been running in parallel to the aethalometer for two seasons. A three-wavelength nephelometer, to measure the aerosol total- and back-scattering, and aerosol samplers for morphological and chemical analysis will be installed at the site in 2012. Our goal is to enhance the observatory monitoring capabilities for aerosol research. The objectives of this new research program are to: (a) assess background as well as specific event tropospheric aerosol properties, (b) compare aerosol and gases measurements with model outputs, and (c) use the data collected to provide satellite validation. This research is anticipated to enhance our understanding of the interactions between tropospheric aerosols, clouds, and climate by allowing, for example, the analysis of North American outflows and seasonal changes, the assessment of different source regions, the estimation of aerosol radiative forcing above marine clouds and in clear sky, and the study of the relative contribution of anthropogenic versus biomass burning emissions. In this poster we present a preliminary analysis of the black carbon and aerosol size data in conjunction with retroplume model analysis.
- Amostragem de partículas em suspensão na atmosfera do Atlântico Norte.Publication . Rodrigues, A. F.; Fialho, Paulo; Pio, CasimiroOs aerossóis têm géneses e composições muito diferenciadas. Estes têm origem nas emissões naturais (por exemplo o spray marinho e as emissões vulcânicas) ou antropogénicas (por exemplo os processos de combustão). A caracterização física e química dos aerossóis é importante para compreender a relação entre: a sua origem; os mecanismos de transporte difusivo das massas de ar atmosférico; os processos de nucleação associados à formação de nuvens; e os mecanismos de transformação química. O Arquipélago dos Açores localizado numa zona remota (longe das emissões poluentes do continente Europeu e Americano e com emissões locais desprezáveis), é o local ideal para a caracterização física e química das massas de ar que o atravessam. A sua atmosfera "limpa" permite o estudo do transporte a longas distâncias de poluentes entre os continentes americano e europeu. Neste contexto efectuou-se a caracterização física do aerossol, recorrendo a um colector de partículas de grande volume (High-Volume - figura 1) com uma cabeça de pré-selecção de 10 μm. Os aerossóis foram separados em duas fracções, uma fina (diâmetros inferiores a 10 μm) essencialmente associada a contribuições antropogénicas, e outra grosseira (diâmetros entre 0,95 μm e 10 μm) maioritariamente relacionada com contribuições naturais. A massa de aerossol amostrada é determinada pela pesagem dos filtros onde este é recolhido, conjuntamente são efectuadas medidas de caudal volúmico e tempo de amostragem.
- Assessment of air quality on basis of particle matter (PM) measurement in the North Atlantic.Publication . Barata, Filipe; Fialho, Paulo; Pio, CasimiroThe European thematic strategy on air pollution and the accompanying proposal to revise the ambient air quality directive (1999/30/EC) would, for the first time, introduce controls on human expose to PM2.5 to complement the existing limits on coarse particulate matter (PM10) (EC, 2005).
- AZores Observation NETwork – AZONETPublication . Fialho, Paulo
- Calibration experiments for filter based absorption photometers during the EUSAAR-2009 photometer workshop.Publication . Müller, Thomas; Henzing, Bas; Sheridan, P. J.; Wiedensohler, Alfred; Virkkula, Aki; Mocnik, Grisa; Walker, J.; Fialho, Paulo; Eleftheriadis, Kostas; Filep, Agnes; Leeuw, Gerrit
- Calibration experiments for filter based absorption photometers during the EUSAAR-2009 photometer workshop.Publication . Müller, Thomas; Henzing, Bas; Sheridan, P.J.; Wiedensohler, Alfred; Virkkula, Aki; Mocnik, Grisa; Walker, J.; Fialho, Paulo; Eleftheriadis, Kostas; Filep, Agnes; Leeuw, GerritAerosol light absorption is an important parameter for the assessment of the radiation budget of the atmosphere. Filter based absorption photometers, e.g. the Aethalometer and the Particle Soot Absorption Photometer (PSAP) have been available for several years. Multiple scattering of light in the filter medium and the presence of scattering particles result in a measured attenuation coefficient, which is different from the absorption coefficient of airborne particles. Correction schemes have to be determined experimentally using reference methods (e.g. photoacoustic photometers or extinction minus scattering). Often used correction schemes are described in Bond et al. (1999) and Virkkula et al. (2005) for PSAP and in Weingaartner et al. (2003) for Aethalometer. In the frameworks of EUSAAR a workshop for testing existing and developing new correction schemes has been conducted in 2009 at the Leibniz Institute for Tropospheric Research in Leipzig.
- Caracterização de alguns aniões presentes nos aerossóis da atmosfera do Atlântico Norte.Publication . Rodrigues, A. F.; Fialho, Paulo; Pio, Casimiro; Lobo, AdelaideOs aerossóis têm géneses e composições muito diferenciadas. Estes têm origem nas emissões naturais (por exemplo o spray marinho e as emissões vulcânicas) ou antropogénicas (por exemplo os processos de combustão). A caracterização física e química dos aerossóis, é importante para compreender a relação entre: a sua origem; os mecanismos de transporte difusivo das massas de ar atmosférico; os processos de nucleação associados à formação de nuvens; e os mecanismos de transformação química. O Arquipélago dos Açores, situado numa zona remota (longe das emissões poluentes do continente Europeu e Americano e com emissões locais desprezáveis), é o local ideal para a caracterização física e química das massas de ar que o atravessam. A sua atmosfera “limpa” permite o estudo do transporte a longas distâncias de poluentes entre os continentes europeu e americano. Neste contexto a massa de aerossol (previamente amostrada em fracções fina - diâmetros inferiores a 0,95 μm - e grosseira - diâmetros entre 0,95 μm e 10 μm) foi analisada, por cromatografia líquida de troca iónica, para determinar o seu teor em aniões cloreto, nitrato e sulfato.
- Comparison of Elemental Carbon (EC) and Black Carbon (BC) measurements derived by Thermo-Optical and filter-based light transmission techniques at North Atlantic.Publication . Barata, Filipe; Fialho, Paulo; Pio, CasimiroTerceira Island (38.691º; 27.354º; 50 m altitude) in the Azores Archipelago, developed to provide a base for remote marine boundary layer measurements at a location near the PICO-NARE (Honrath & Fialho, 2002) (Figure 1). In order to determine a long term carbonaceous component of atmospheric aerosols in North Atlantic, measurements of aerosol BC and EC were begun in 2002. EC and BC define similar fraction of the carbonaceous component of atmospheric aerosols and are supposed to be comparable, but have a delicate different thermal, optical and chemical behaviour in most cases (Lavanchy et al., 1999).
- Complexo CLIMAAT-TERCEIRA-NARE para a monitorização da composição da atmosfera na camada limite do Atlântico NortePublication . Fialho, Paulo; Henriques, Diamantino; Carvalho, Fernanda; Barata, Filipe; Azevedo, Eduardo B.As a result of the partnership between the University of Azores, and the Association for the Study of the Insular Environment through the Environment Observatory and the Meteorological Institute, during the 2004 summer it took place the beginning of the installation of the CLIMAAT – TERCEIRA – NARE (INTERREG IIIB – Projecto CLIMAAT – MAC 2.3/A3) platform. In this stage, it was also installed in the José Agostinho observatory, near the city of Angra do Heroísmo, several equipments to monitoring the atmospheric and sun irradiation. Near the coast, at the moment, and beside the meteorological common parameters, pressure, temperature, relative humidity, precipitation, wind direction and intensity some measurements of the black carbon and iron oxide aerosol absorption coefficients were also done. The results of this project should contribute to the study of the evolution and composition of the North Atlantic atmosphere, and in that matter to the study of the Global Changes, namely as a land platform of reference to remote sensing satellite systems. This platform is part of the Azores Global Atmosphere Monitoring Complex (AGAMC).
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