Origin, transport and processing of organic aerosols at different altitudes in coastal Mediterranean urban areas

作者：Clara Jaén, Mireia Udina, Roy M. Harrison, Joan O. Grimalt, Barend L. van Drooge · 发表于：Atmospheric chemistry and physics · 年份：2025 · DOI：10.5194/acp-25-18389-2025 · 被引用次数：1 · 研究领域：Atmospheric chemistry and aerosols、Air Quality and Health Impacts、Plant responses to elevated CO2

Abstract. Organic molecular markers in atmospheric PM10 were analysed by off-line GC-MS techniques in an urban background site (81 m above sea level (a.s.l.)) and in a nearby elevated sub-urban background site (415 ma.s.l.), in cold and warm periods in Barcelona; situated in the Western Mediterranean Basin. Previous studies reported similar PM concentrations and substantial organic matter contributions in both sites but did not analyze the organic molecular composition, which is expected to vary within the city's vertical airshed due to a weakening influence of local emission sources and enhanced influence of regional air masses. Multi-variant analysis of organic molecular marker concentrations, together with major air quality parameters (NO, NO2, O3, PM10), resolved six components that represented primary emissions sources and secondary organic aerosol formation processes: (1) diurnal traffic, (2) nocturnal traffic, (3) biomass burning, (4) biogenic with primary and secondary organic markers, (5) fresh secondary, and (6) regional secondary. Urban traffic emissions reached the elevated site during daytime through the sea-mountain breeze, while nocturnal traffic emissions accumulated in the nighttime urban atmosphere, when the two sites were often disconnected by temperature inversions. Biomass burning, dominant in the cold period, was the main contributor to toxic PAHs in these two background sites. Regional secondary organic aerosol contribution was more abundant in the elev...