title: Spatial and temporal variability of carbonaceous aerosols: Assessing the impact of biomass burning in the urban environment.
abstract: Biomass burning (BB) is a significant source of atmospheric particles in many parts of the world. Whereas many studies have demonstrated the importance of BB emissions in central and northern Europe, especially in rural areas, its impact in urban air quality of southern European countries has been sparsely investigated. In this study, highly time resolved multi-wavelength absorption coefficients together with levoglucosan (BB tracer) mass concentrations were combined to apportion carbonaceous aerosol sources. The Aethalometer model takes advantage of the different spectral behavior of BB and fossil fuel (FF) combustion aerosols. The model was found to be more sensitive to the assumed value of the aerosol Ångström exponent (AAE) for FF (AAEff) than to the AAE for BB (AAEbb). As result of various sensitivity tests the model was optimized with AAEff=1.1 and AAEbb=2. The Aethalometer model and levoglucosan tracer estimates were in good agreement. The Aethalometer model was further applied to data from three sites in Granada urban area to evaluate the spatial variation of CMffand CMbb(carbonaceous matter from FF or BB origin, respectively) concentrations within the city. The results showed that CMbbwas lower in the city centre while it has an unexpected profound impact on the CM levels measured in the suburbs (about 40%). Analysis of BB tracers with respect to wind speed suggested that BB was dominated by sources outside the city, to the west in a rural area. Distinguishing whether it corresponds to agricultural waste burning or with biomass burning for domestic heating was not possible. This study also shows that although traffic restrictions measures contribute to reduce carbonaceous concentrations, the extent of the reduction is very local. Other sources such as BB, which can contribute to CM as much as traffic emissions, should be targeted to reduce air pollution.
authors.affiliation: Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain; Institute of Environmental Assessment and Water Research (IDÆA), Department of Geosciences, CSIC, Barcelona, Spain. Electronic address: gloria.titos@idaea.csic.es.
authors.forename: G
authors.initials: G
authors.lastname: Titos
authors.affiliation: Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Del Águila
authors.affiliation: Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain; Department of Applied Physics, University of Granada, Granada 18071, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Cazorla
authors.affiliation: Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain.
authors.forename: H
authors.initials: H
authors.lastname: Lyamani
authors.affiliation: Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain; Department of Applied Physics, University of Granada, Granada 18071, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Casquero-Vera
authors.affiliation: ARPA Lombardia, Settore Monitoraggi Ambientali, Milano, 20124, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Colombi
authors.affiliation: ARPA Lombardia, Settore Monitoraggi Ambientali, Milano, 20124, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Cuccia
authors.affiliation: ARPA Lombardia, Settore Monitoraggi Ambientali, Milano, 20124, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Gianelle
authors.affiliation: Aerosol d.o.o., Research and Development Department, Ljubljana, Slovenia; Department of Condensed Matter, Jozef Stefan Institute, Ljubljana, Slovenia.
authors.forename: G
authors.initials: G
authors.lastname: Močnik
authors.affiliation: Institute of Environmental Assessment and Water Research (IDÆA), Department of Geosciences, CSIC, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Alastuey
authors.affiliation: Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain; Department of Applied Physics, University of Granada, Granada 18071, Spain.
authors.forename: F J
authors.initials: FJ
authors.lastname: Olmo
authors.affiliation: Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain; Department of Applied Physics, University of Granada, Granada 18071, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Alados-Arboledas
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000393:Air Pollutants / Q000032:analysis*; D018533:Biomass; D002244:Carbon / Q000032:analysis*; D002947:Cities; D004784:Environmental Monitoring; D005060:Europe; D017745:Incineration; D052638:Particulate Matter; D012621:Seasons; D062211:Spatio-Temporal Analysis
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter; D002244:Carbon
keywords: Aethalometer; Biomass burning; Carbonaceous matter; Fossil fuel; Ångström exponent