No abstract

This study investigates the structural composition and major sources of water-soluble organic matter (WSOM) from PM collected, in parallel, during summer and winter, in two contrasting suburban sites at Iberian Peninsula Coast: Aveiro (Portugal) and Coruña (Spain). PM samples were also collected at Coruña for comparison. Ambient concentrations of PM, total nitrogen (TN), and WSOM were higher in Aveiro than in Coruña, with the highest levels found in winter at both locations. In Coruña, concentrations of PM, TN, and WSOM were higher than those from PM. Regardless of the season, stable isotopic δC and δN in PM suggested important contributions of anthropogenic fresh organic aerosols (OAs) at Aveiro. In Coruña, δC and δN of PM and PM suggests decreased anthropogenic input during summer. Although excitation-emission fluorescence profiles were similar for all WSOM samples, multi-dimensional nuclear magnetic resonance (NMR) spectroscopy confirmed differences in their structural composition, reflecting differences in aging processes and/or local sources between the two locations. In PM WSOM in Aveiro, the relative distribution of non-exchangeable proton functional groups was in the order: HC (40-43%) > HCC (31-39%) > HCO (12-15%) > Ar-H (5.0-13%). However, in PM and PM WSOM in Coruña, the relative contribution of HCO groups (24-30% and 23-29%, respectively) equals and/or surpasses that of HCC (25-26% and 25-29%, respectively), being also higher than those of Aveiro. In both locations, the highest aromatic contents were observed during winter due to biomass burning emissions. The structural composition of PM and PM WSOM in Coruña is dominated by oxygenated aliphatic compounds, reflecting the contribution of secondary OAs from biogenic, soil dust, and minor influence of anthropogenic emissions. In contrast, the composition of PM WSOM in Aveiro appears to be significantly impacted by fresh and secondary anthropogenic OAs. Marine and biomass burning OAs are important contributors, common to both sites.

No abstract

REDMAAS (Red Española de DMAs Ambientales), the Spanish network of environmental Differential Mobility Analyzers (DMAs), currently consists of six research groups involved in the measurement of atmospheric aerosol size distributions by means of DMAs. The aim of this network is to guarantee the good quality and comparability of the routine measurements carried out at each different location and in diverse environments across Spain. In order to reach this objective, one of its main activities is an annual intercomparison of mobility size spectrometers used within the network (five units Scanning Mobility Particle Sizers (SMPS) and one Ultrafine Particle Monitor (UFPM)). Here we report the main results obtained during the 2010-1012 campaigns, including a study on particle deposition in dryers used in ambient air sampling systems. In general, all instruments showed a good performance with deviations in an accepted tolerance. The intercomparisons have been proven to be a useful exercise to detect instrument problems, such as incorrect calibrations. DMA calibration checks were performed with polystyrene latex (PSL) reference particles. Deviations of less than 1% were observed during the first year, which increased to a value of 4.7% during the last campaign. Some differences among the responses of different Condensation Particle Counter (CPC) models were encountered, being mainly connected to the intrinsic characteristics of each counter. The comparison of the UFPM with the CPCs has given good results. The SMPS intercomparisons, especially for particles Downloaded by [University of Otago] at 00:40 27 July 2015 ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT3 above 20 nm, have been within +/-15% tolerances. Regarding the particle deposition in dryers used in sampling systems, particle penetration was lower than predicted by the recommended model. This result was probably due to the fact that not all the possible mechanisms were considered in the model.---

Highlights Spatio-temporal variability of ultrafine particles at 7 sites in Spain was assessed. Meteorology and ultrafine particles sources control the site-to-site variability. Differences in ultrafine particles between inland and coastal sites were documented. Ultrafine particle bursts influenced the total number concentration in clean areas. Shrinkages processes were noticed at several sites during the warm period.