- 1Leibniz Institute for Tropospheric Research, Leipzig, Germany
- 2University of Modena and Reggio Emilia, Modena, 41125, Italy
- 3Federal Office of Meteorology and Climatology, MeteoSwiss, Payerne, Switzerland, France
Particulate matter (PM) is a major climate-forcing agent and significantly impacts air quality. To grasp how environmental policies and climate change impact atmospheric aerosols, long-term measurements are vital, especially for organic aerosol (OA) and black carbon (BC). OA represents a large portion of aerosol mass, while BC has the strongest direct radiative forcing effect. State-of-the-art equipment like the Aerosol Chemical Speciation Monitor (ACSM) and the Multi-Angle Absorption Photometer (MAAP) help to identify OA and BC sources, respectively. Since 2012, an ACSM and a MAAP have operated at the ACTRIS-TROPOS research station in Melpitz, Germany, enabling a decade-long study of aerosol composition and OA sources for PM1 from September 2012 to August 2022.
To analyse these trends, a rolling Positive Matrix Factorization (PMF) approach was applied and implemented in SoFi Pro software (Datalystica Ltd., Villigen, Switzerland). The Melpitz station's strategic location allows for the study of particle composition changes typical of both Western and Eastern Europe (Spindler et al., 2010). This improves our understanding of emissions and the effects of air quality regulations on PM1 chemical species in these regions. The results reveal high PM1 mass concentrations were associated with eastern air masses across all meteorological seasons. However, the relative contributions of individual chemical components varied depending on the season and the origin of the air mass. Expanding on Atabakhsh et al. (2023) work, which analyzed a 12-month dataset, this study identified five OA factors: three associated with primary organic sources—hydrocarbon-like OA (HOA), biomass burning OA (BBOA), and coal combustion OA (CCOA)—and two oxygenated OA factors—more-oxidized OOA (MO-OOA) and less-oxidized OOA (LO-OOA). Trend analysis using a pre-whitening method (Collaud Coen et al., 2020) revealed a statistically significant annual decrease of -4.59% y-1 in total PM1 mass over the decade, driven by decreases in nitrate (-1.10% y-1) and equivalent BC (eBC) (-1.3% y-1) concentrations. However, HOA showed a minor decline (-0.25% y-1) under eastern air masses, BBOA increased by +0.94% y-1 during summer, and CCOA showed a modest increase (+0.27% y-1) in western air masses. The OOA factors showed declining trends in eastern air masses (-1.52% and -1.09% y-1), indicating improvements in the emissions of secondary aerosol precursors.
This study provides a comprehensive analysis of seasonal variability, source apportionment, and trends of PM1 components in Central Europe. It highlights differences in air masses from Eastern and Western Europe, providing insights into regional air quality regulations and sources of atmospheric aerosols.
References:
Atabakhsh, S., et al. (2023) Atmospheric Chem. Phys., 842.
Collaud Coen, et al. (2020) Atmos. Meas. Tech., 178.
Spindler, G., et al. (2010) Atmos. Environ., 44, 164-173
How to cite: Atabakhsh, S., Poulain, L., Bigi, A., Collaud Coen, M., Pöhlker, M., and Herrmann, H.: Decadal Trends in Atmospheric Aerosols: Insights into PM1 Composition, Seasonal Variability, and Source Apportionment in Central Europe, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11592, https://doi.org/10.5194/egusphere-egu25-11592, 2025.
