Aerosols
; Air
; Americium
; Chemical laboratories
; Combustion
; Heating
; Housing
; Marine pollution
; Pollution
; Size distribution
; Soot
; Telecommunication traffic
; Wood
; Black carbon
; Chemical characterization
; Deposited surface areas
; Electron microscopy analysis
; Mobile laboratories
; Physicochemical property
; Residential wood combustions
; Wood burning
; Air pollution
; fuel oil
; organic compound
; sodium chloride
; sulfate
; aerosol
; aerosol composition
; aerosol property
; biomass burning
; black carbon
; chemical analysis
; concentration (composition)
; laboratory method
; measurement method
; metropolitan area
; physical analysis
; physicochemical property
; size distribution
; traffic emission
; winter
; wood
; aerosol
; air pollution
; airflow
; Article
; Atlantic Ocean
; combustion
; concentration (parameters)
; exhaust gas
; Finland
; laboratory test
; particle size
; physical chemistry
; plume
; priority journal
; smoke
; suburban area
; surface area
; traffic and transport
; transmission electron microscopy
; urban area
; winter
; wood
; Carbon
; Combustion
; Distribution
; Laboratories
; Size
; Wood
; Finland
; Helsinki
; Varsinais-Suomi
Scopus学科分类:
Environmental Science: Water Science and Technology
; Earth and Planetary Sciences: Earth-Surface Processes
; Environmental Science: Environmental Chemistry
英文摘要:
A two-week measurement campaign by a mobile laboratory van was performed in urban environments in the Helsinki metropolitan area, Finland, in winter 2012, to obtain a comprehensive view on aerosol properties and sources. The abundances and physico-chemical properties of particles varied strongly in time and space, depending on the main sources of aerosols. Four major types of winter aerosol were recognized: 1) clean background aerosol with low particle number (Ntot) and lung deposited surface area (LDSA) concentrations due to marine air flows from the Atlantic Ocean; 2) long-range transported (LRT) pollution aerosol due to air flows from eastern Europe where the particles were characterized by the high contribution of oxygenated organic aerosol (OOA) and inorganic species, particularly sulphate, but low BC contribution, and their size distribution possessed an additional accumulation mode; 3) fresh smoke plumes from residential wood combustion in suburban small houses, these particles were characterized by high biomass burning organic aerosol (BBOA) and black carbon (BC) concentrations; and 4) fresh emissions from traffic while driving on busy streets in the city centre and on the highways during morning rush hours. This aerosol was characterized by high concentration of Ntot, LDSA, small particles in the nucleation mode, as well as high hydrocarbon-like organic aerosol (HOA) and BC concentrations. In general, secondary components (OOA, NO3, NH4, and SO4) dominated the PM1 chemical composition during the LRT episode accounting for 70–80% of the PM1 mass, whereas fresh primary emissions (BC, HOA and BBOA) dominated the local traffic and wood burning emissions. The major individual particle types observed with electron microscopy analysis (TEM/EDX) were mainly related to residential wood combustion (K/S/C-rich, soot, other C-rich particles), traffic (soot, Si/Al-rich, Fe-rich), heavy fuel oil combustion in heat plants or ships (S with V-Ni-Fe), LRT pollutants (S/C-rich secondary particles) and sea salt (Na/Cl-rich). Tar balls from wood combustion were also observed, especially (∼5%) during the LRT pollution episode. � 2017 Elsevier Ltd
Department of Technology, Metropolia University of Applied Sciences, P.O. Box 4021, Helsinki, Finland; Department of Physics, University of Helsinki, P. O. Box 64, Helsinki, Finland; Helsinki Region Environmental Services Authority HSY, P.O. Box 100, Helsinki, HSY, Finland; Department of Environmental Sciences, University of Helsinki, P.O. Box 65, Helsinki, Finland; Air Quality, Finnish Meteorological Institute, P.O. Box 503, Helsinki, Finland; Department of Physics, Tampere University of Technology, P.O. Box 692, Tampere, Finland
Recommended Citation:
Pirjola L,, Niemi J,V,et al. Physical and chemical characterization of urban winter-time aerosols by mobile measurements in Helsinki, Finland[J]. Atmospheric Environment,2017-01-01,158