Rights statement: This is the author’s version of a work that was accepted for publication in Atmospheric Environment. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Atmospheric Environment, 195, 2018 DOI: 10.1016/j.atmosenv.2018.09.049
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - The influence of impactor size cut-off shift caused by hygroscopic growth on particulate matter loading and composition measurements
AU - Chen, Ying
AU - Wild, Oliver
AU - Wang, Yu
AU - Ran, Liang
AU - Teich, Monique
AU - Größ, Johannes
AU - Wang, Lina
AU - Spindler, Gerald
AU - Herrmann, Hartmut
AU - Pinxteren, Dominik van
AU - McFiggans, Gordon
AU - Wiedensohler, Alfred
N1 - This is the author’s version of a work that was accepted for publication in Atmospheric Environment. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Atmospheric Environment, 195, 2018 DOI: 10.1016/j.atmosenv.2018.09.049
PY - 2018/12
Y1 - 2018/12
N2 - The mass loading and composition of atmospheric particles are important in determining their climate and health effects, and are typically measured by filter sampling. However, particle sampling under ambient conditions can lead to a shift in the size cut-off threshold induced by hygroscopic growth, and the influence of this on measurement of particle loading and composition has not been adequately quantified. Here, we propose a method to assess this influence based on κ-Köhler theory. A global perspective is presented based on previously reported annual climatological values of hygroscopic properties, meteorological parameters and particle volume size distributions. Measurements at background sites in Europe may be more greatly influenced by the cut-off shift than those from other continents, with a median influence of 10–20% on the total mass of sampled particles. However, the influence is generally much smaller (<7%) at urban sites, and is negligible for dust and particles in the Arctic. Sea-salt particles experience the largest influence (median value ∼50%), resulting from their large size, high hygroscopicity and the high relative humidity (RH) in marine air-masses. We estimate a difference of ∼30% in this influence of sea-salt particle sampling between relatively dry (RH = 60%) and humid (RH = 90%) conditions. Given the variation in the cut-off shift in different locations and at different times, a consistent consideration of this influence using the approach we introduce here is critical for observational studies of the long-term and spatial distribution of particle loading and composition, and crucial for robust validation of aerosol modules in modelling studies.
AB - The mass loading and composition of atmospheric particles are important in determining their climate and health effects, and are typically measured by filter sampling. However, particle sampling under ambient conditions can lead to a shift in the size cut-off threshold induced by hygroscopic growth, and the influence of this on measurement of particle loading and composition has not been adequately quantified. Here, we propose a method to assess this influence based on κ-Köhler theory. A global perspective is presented based on previously reported annual climatological values of hygroscopic properties, meteorological parameters and particle volume size distributions. Measurements at background sites in Europe may be more greatly influenced by the cut-off shift than those from other continents, with a median influence of 10–20% on the total mass of sampled particles. However, the influence is generally much smaller (<7%) at urban sites, and is negligible for dust and particles in the Arctic. Sea-salt particles experience the largest influence (median value ∼50%), resulting from their large size, high hygroscopicity and the high relative humidity (RH) in marine air-masses. We estimate a difference of ∼30% in this influence of sea-salt particle sampling between relatively dry (RH = 60%) and humid (RH = 90%) conditions. Given the variation in the cut-off shift in different locations and at different times, a consistent consideration of this influence using the approach we introduce here is critical for observational studies of the long-term and spatial distribution of particle loading and composition, and crucial for robust validation of aerosol modules in modelling studies.
KW - Aerosol measurement
KW - Chemical composition
KW - Filter sampling
KW - Growth factor
U2 - 10.1016/j.atmosenv.2018.09.049
DO - 10.1016/j.atmosenv.2018.09.049
M3 - Journal article
VL - 195
SP - 141
EP - 148
JO - Atmospheric Environment
JF - Atmospheric Environment
SN - 1352-2310
ER -