12 documents found, page 1 of 2
Contribution of coal combustion to black carbon: coupling tracers with the aeth...
Blanco-Alegre, C.; Fialho, P.; Calvo, A. I.; Castro, A.; Coz, E.; Oduber, F.; Prévôt, A. S. H.; Močnik, G.; Alves, C.; Giardi, F.; Pazzi, G.; Fraile, R.Black carbon (BC) aerosol characteristics have been analysed from January 2016 to March 2017 in an urban background area (León, Spain), located in a coal-mining region, where this fuel is commonly used. The monthly and seasonal variations of BC and source contributions were examined. The mean equivalent BC concentration (eBC) during cold and warm months were 1.0±0.5 and 0.6±0.2 μg m-3, respectively. eBC can be ...
One-year study of airborne sugar compounds: cross-interpretation with other che...
Oduber, F.; Calvo, A.I.; Castro, A.; Alves, C.; Blanco-Alegre, C.; Fernández-González, D.; Barata, J.; Calzolai, G.; Nava, S.; Lucarelli, F.; Nunes, T.The daily evolution of seventeen sugar compounds (seven saccharides, seven alcohol-saccharides and three anhydrosaccharides) in atmospheric aerosol samples collected between 9 March 2016 and 14 March 2017 was studied in León (Spain). The main links between the concentration of sugar compounds and various chemical species, pollen, fungal spores and meteorological conditions were investigated. The results showed ...
Aethalometer measurements in a road tunnel: a step forward in the characterizat...
Blanco-Alegre, C.; Calvo, A. I.; Alves, C.; Fialho, P.; Nunes, T.; Gomes, J.; Castro, A.; Oduber, F.; Coz, E.; Fraile, R.A sampling campaign was conducted in the Liberdade Avenue tunnel (Braga, Portugal) during a week (with 56,000 vehicles) to monitor black carbon (eBC-equivalent black carbon) by means of an Aethalometer AE-31, and gaseous pollutants (CO2, CO, NOx). Inside the tunnel, the mean eBC mass concentration was 21 ± 10 μg m-3, reaching a maximum hourly value of 49.0 μg m-3. An hourly and weekday-weekend study was carried...
Unusual winter Saharan dust intrusions at Northwest Spain: air quality, radiati...
Oduber, F.; Calvo, A. I.; Blanco-Alegre, C.; Castro, A.; Nunes, T.; Alves, C.; Sorribas, M.; Fernández-González, D.; Vega-Maray, A. M.Saharan air masses can transport high amounts of mineral dust particles and biological material to the Iberian Peninsula. During winter, this kind of events is not very frequent and usually does not reach the northwest of the Peninsula. However, between 21 and 22 February 2016 and between 22 and 23 February 2017, two exceptional events were registered in León (Spain), which severely affected air quality. An int...
Residential wood combustion in two domestic devices: relationship of different ...
Calvo, A. I.; Martins, V.; Nunes, T.; Duarte, M.; Hillamo, R.; Teinilä, K.; Pont, V.; Castro, A.; Fraile, R.; Tarelho, L.; Alves, C.Logs of three common Southern and mid-European woods (Quercus pyrenaica, Populus nigra and Fagus sylvatica) were burned in two different combustion appliances, a fireplace and a stove. The flue gas composition was monitored continuously in the exhaust ducts of both burning appliances for total hydrocarbons (THC) and carbon oxides (CO2 and CO). Particulate matter with aerodynamic diameter below 2.5 mm (PM2.5) wa...
Research on aerosol sources and chemical composition: past, current and emergin...
Calvo, A. I.; Alves, C.; Castro, A.; Pont, V.; Vicente, A. M.; Fraile, R.In spite of considerable progresses in recent years, a quantitative and predictive understanding of atmospheric aerosol sources, chemical composition, transformation processes and environmental effects is still rather limited, and therefore represents a major research challenge in atmospheric science. This review begins with a historical perspective on the scientific questions regarding atmospheric aerosols ove...
Particulate emissions from the co-combustion of forest biomass and sewage sludg...
Calvo, A. I.; Tarelho, L. A. C.; Teixeira, E. R.; Alves, C.; Nunes, T.; Duarte, M.; Coz, E.; Custodio, D.; Castro, A.; Artiñano, B.; Fraile, R.In the present study, particulate emissions from the co-combustion of forest biomass residues with sewage sludge in a pilot-scale bubbling fluidised bed combustor were characterised. The combustion flue gas was exhausted to the atmosphere after passing through a cyclone separator. Physical-chemical characteristics of the particles were studied: i) morphology and aerosol size, surface and volume distributions be...
Error in the sampling area of an optical disdrometer: consequences in computing...
Fraile, R.; Castro, A.; Fernández-Raga, M.; Palencia, C.; Calvo, A. I.The aim of this study is to improve the estimation of the characteristic uncertainties of optic disdrometers in an attempt to calculate the efficient sampling area according to the size of the drop and to study how this influences the computation of other parameters, taking into account that the real sampling area is always smaller than the nominal area. For large raindrops (a little over 6 mm), the effective s...
Air masses and weather types: a useful tool for characterizing precipitation ch...
Calvo, A. I.; Pont, V.; Olmo, F. J.; Castro, A.; Alados-Arboledas, L.; Vicente, A. M.; Fernández-Raga, M.; Fraile, R.This study is an analysis of 344 days with rainfall recorded during five years in a remote regional background EMEP (Cooperative Programme for the Monitoring and Evaluation of the Long Range Transmission of Air Pollutants in Europe) station in Spain. The chemical composition of the rainwater associated with air masses (nine categories) and weather types (26 categories) was characterized. The chemical compositio...
The influence of wildfires on aerosol size distributions in rural areas
Alonso-Blanco, E.; Calvo, A. I.; Fraile, R.; Castro, A.The number of particles and their size distributions were measured in a rural area, during the summer, using a PCASP-X. The aim was to study the influence of wildfires on particle size distributions. The comparative studies carried out reveal an average increase of around ten times in the number of particles in the fine mode, especially in sizes between 0.10 and 0.14 μm, where the increase is of nearly 20 times...