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Titolo:
Use of atmospheric elemental size distributions in estimating aerosol sources in the Helsinki area
Autore:
Pakkanen, TA; Kerminen, VM; Korhonen, CH; Hillamo, RE; Aarnio, P; Koskentalo, T; Maenhaut, W;
Indirizzi:
Finnish Meteorol Inst, FIN-00810 Helsinki, Finland Finnish Meteorol Inst Helsinki Finland FIN-00810 00810 Helsinki, Finland Helsinki Metropolitan Area Council, FIN-00520 Helsinki, Finland Helsinki Metropolitan Area Council Helsinki Finland FIN-00520 i, Finland State Univ Ghent, Inst Nucl Sci, B-9000 Ghent, Belgium State Univ Ghent Ghent Belgium B-9000 st Nucl Sci, B-9000 Ghent, Belgium
Titolo Testata:
ATMOSPHERIC ENVIRONMENT
fascicolo: 32, volume: 35, anno: 2001,
pagine: 5537 - 5551
SICI:
1352-2310(200111)35:32<5537:UOAESD>2.0.ZU;2-0
Fonte:
ISI
Lingua:
ENG
Soggetto:
LOW-PRESSURE IMPACTOR; TRACE-ELEMENTS; CHEMICAL-COMPOSITION; DICARBOXYLIC-ACIDS; FINE PARTICLES; URBAN; MASS; AIR; IDENTIFICATION; APPORTIONMENT;
Keywords:
atmosphere; urban; rural; elements; size distribution; sources; local; long-range transport;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Physical, Chemical & Earth Sciences
Citazioni:
43
Recensione:
Indirizzi per estratti:
Indirizzo: Pakkanen, TA Finnish Meteorol Inst, Sahaajankatu 20 E, FIN-00810 Helsinki,Finland Finnish Meteorol Inst Sahaajankatu 20 E Helsinki Finland FIN-00810
Citazione:
T.A. Pakkanen et al., "Use of atmospheric elemental size distributions in estimating aerosol sources in the Helsinki area", ATMOS ENVIR, 35(32), 2001, pp. 5537-5551

Abstract

In June 1996-June 1997 Berner impactors were used in the Helsinki area to measure size distributions of atmospheric aerosols simultaneously at an urban and at a rural site. Ten sample pairs were collected in the size range of 0.03-15.7 mum of equivalent aerodynamic diameter (EAD). Average size distributions at the two sites were calculated for 29 elements, particulate mass, and sulphate. At both sites especially sulphate, As, B, Bi, Cd, Ni, Tl, and V were enriched in fine particles (EAD <2.3 mum). In order to estimate local fine-particle sources of the various chemical components, the similarities and dissimilarities in the accumulation-mode parameters were studied separately for both sites. It was observed that often in different samples,different components had similar accumulation modes. At both sites, particulate mass, As, and Ph had similar accumulation modes to sulphate which suggests that long-range transport (LRT) is important for these components. V. Ni. Mo, and Co formed mother group of similar accumulation modes at both sites suggesting that these elements largely originated from local and regional oil combustion. In addition, other groups of similar accumulation modeswere observed but these groups were different between the sites. The meteorological parameters indicated that seven sample pairs formed a subset of the data in which the local emissions of the Helsinki area were transported to the urban site but not to the rural site. For this subset the rural fine-particle concentrations were considered to represent an upper limit estimate for the LRT. These upper limit LRT estimations were further improved by utilising the quantitative relative size distributions (QRSD) method at therural site. The QRSD method supposes that in the fine-particle size range the LRT fractions of all chemical components have a similar shape in their size distributions. Fine-particle sulphate is typically long-range transported, and was therefore selected as the model component that represents the shape of LRT material. Sulphate size distribution was then scaled to give an estimation of the LRT contribution of each component at the rural site. These rural "sulphate scaled" LRT estimates were subtracted from the corresponding urban concentrations to give the local contributions (ng/m(3)) downwind of the Helsinki area. In particles with EAD below 2.3 mum. the highest absolute and relative downwind local contributions were observed for several common sea-salt and road-dust components. Also the combustion-related elements Ni and V showed fairly high downwind local contributions. Because of the limited number of samples, the local and LRT contributions were not estimated for different wind directions. (C) 2001 Elsevier Science Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/01/20 alle ore 19:05:02