| 1. |
- Putaud, J. -P, et al.
(författare)
-
A European aerosol phenomenology-3 : Physical and chemical characteristics of particulate matter from 60 rural, urban, and kerbside sites across Europe
- 2010
-
Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 44:10, s. 1308-1320
-
Tidskriftsartikel (refereegranskat)abstract
- This paper synthesizes data on aerosol (particulate matter, PM) physical and chemical characteristics, which were obtained over the past decade in aerosol research and monitoring activities at more than 60 natural background, rural, near-city, urban, and kerbside sites across Europe. The data include simultaneously measured PM10 and/or PM2.5 mass on the one hand, and aerosol particle number concentrations or PM chemistry on the other hand. The aerosol data presented in our previous works (Van Dingenen et al., 2004; Putaud et al., 2004) were updated and merged to those collected in the framework of the EU supported European Cooperation in the field of Scientific and Technical action COST633 (Particulate matter: Properties related to health effects). A number of conclusions from our previous studies were confirmed. There is no single ratio between PM2.5 and PM10 mass concentrations valid for all sites, although fairly constant ratios ranging from 0.5 to 0.9 are observed at most individual sites. There is no general correlation between PM mass and particle number concentrations, although particle number concentrations increase with PM2.5 levels at most sites. The main constituents of both PM10 and PM2.5 are generally organic matter, sulfate and nitrate. Mineral dust can also be a major constituent of PM10 at kerbside sites and in Southern Europe. There is a clear decreasing gradient in SO42- and NO3- contribution to PM10 when moving from rural to urban to kerbside sites. In contrast, the total carbon/PM10 ratio increases from rural to kerbside sites. Some new conclusions were also drawn from this work: the ratio between ultrafine particle and total particle number concentration decreases with PM2.5 concentration at all sites but one, and significant gradients in PM chemistry are observed when moving from Northwestern, to Southern to Central Europe. Compiling an even larger number of data sets would have further increased the significance of our conclusions, but collecting all the aerosol data sets obtained also through research projects remains a tedious task.
|
|
| 2. |
- Yttri, K. E., et al.
(författare)
-
Source apportionment of the carbonaceous aerosol in Norway - quantitative estimates based on 14C, thermal-optical and organic tracer analysis
- 2011
-
Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 11:17, s. 9375-9394
-
Tidskriftsartikel (refereegranskat)abstract
- In the present study, source apportionment of the ambient summer and winter time particulate carbonaceous matter (PCM) in aerosol particles (PM(1) and PM(10)) has been conducted for the Norwegian urban and rural background environment. Statistical treatment of data from thermal-optical, (14)C and organic tracer analysis using Latin Hypercube Sampling has allowed for quantitative estimates of seven different sources contributing to the ambient carbonaceous aerosol. These are: elemental carbon from combustion of biomass (EC(bb)) and fossil fuel (EC(ff)), primary and secondary organic carbon arising from combustion of biomass (OC(bb)) and fossil fuel (OC(ff)), primary biological aerosol particles (OC(PBAP), which includes plant debris, OC(pbc), and fungal spores, OC(pbs)), and secondary organic aerosol from biogenic precursors (OC(BSOA)). Our results show that emissions from natural sources were particularly abundant in summer, and with a more pronounced influence at the rural compared to the urban background site. 80% of total carbon (TC(p), corrected for the positive artefact) in PM(10) and ca. 70% of TC(p) in PM(1) could be attributed to natural sources at the rural background site in summer. Natural sources account for about 50% of TC(p) in PM(10) at the urban background site as well. The natural source contribution was always dominated by OC(BSOA), regardless of season, site and size fraction. During winter anthropogenic sources totally dominated the carbonaceous aerosol (80-90 %). Combustion of biomass contributed slightly more than fossil-fuel sources in winter, whereas emissions from fossil-fuel sources were more abundant in summer. Mass closure calculations show that PCM made significant contributions to the mass concentration of the ambient PM regardless of size fraction, season, and site. A larger fraction of PM(1) (ca. 40-60 %) was accounted for by carbonaceous matter compared to PM(10) (ca. 40-50 %), but only by a small margin. In general, there were no pronounced differences in the relative contribution of carbonaceous matter to PM with respect to season or between the two sites.
|
|
