Title
Long-term observations of the background aerosol at Cabauw, The Netherlands
Author
Mamali, D.
Mikkilä, J.
Henzing, B.
Spoor, R.
Ehn, M.
Petäjä, T.
Russchenberg, H.
Biskos, G.
Publication year
2018
Abstract
Long-term measurements of PM2.5 mass concentrations and aerosol particle size distributions from 2008 to 2015, as well as hygroscopicity measurements conducted over one year (2008–2009) at Cabauw, The Netherlands, are compiled here in order to provide a comprehensive dataset for understanding the trends and annual variabilities of the atmospheric aerosol in the region. PM2.5 concentrations have a mean value of 14.4 μg m-3 with standard deviation 2.1 μg m-3, and exhibit an overall decreasing trend of −0.74 μg m-3 year-1. The highest values are observed in winter and spring and are associated with a shallower boundary layer and lower precipitation, respectively, compared to the rest of the seasons. Number concentrations of particles smaller than 500 nm have a mean of 9.2 × 103particles cm-3 and standard deviation 4.9 × 103particles cm-3, exhibiting an increasing trend between 2008 and 2011 and a decreasing trend from 2013 to 2015. The particle number concentrations exhibit highest values in spring and summer (despite the increased precipitation) due to the high occurrence of nucleation-mode particles, which most likely are formed elsewhere and are transported to the observation station. Particle hygroscopicity measurements show that, independently of the air mass origin, the particles are mostly externally mixed with the more hydrophobic mode having a mean hygroscopic parameter κ of 0.1 while for the more hydrophilic mode κ is 0.35. The hygroscopicity of the smaller particles investigated in this work (i.e., particles having diameters of 35 nm) appears to increase during the course of the nucleation events, reflecting a change in the chemical composition of the particles. © 2017 Elsevier B.V.
Subject
2015 Urban Mobility & Environment
CAS - Climate, Air and Sustainability
ELSS - Earth, Life and Social Sciences
Environment & Sustainability
Environment
Urbanisation
Air pollution
Atmospheric particles
HTDMA
PM2.5
SMPS
To reference this document use:
http://resolver.tudelft.nl/uuid:38780b2c-c845-44e9-bc1d-d5a6e6209f3d
DOI
https://doi.org/10.1016/j.scitotenv.2017.12.136
TNO identifier
784882
ISSN
0048-9697
Source
Science of the Total Environment, 625, 752-761
Document type
article