Loading…

Aerosol hygroscopicity: Hygroscopic growth proxy based on visibility for low-cost PM monitoring

Visibility is a simple indicator of air quality, and its drastic decrease is often related to poor air quality resulting from an increase in aerosol (particulate matter PM) concentration. Visibility is also related to water vapor due to the hygroscopicity of aerosols. As a result, water vapor may co...

Full description

Saved in:
Bibliographic Details
Published in:Atmospheric research 2020-05, Vol.236, p.104815, Article 104815
Main Authors: Molnár, Agnes, Imre, Kornelia, Ferenczi, Zita, Kiss, Gyula, Gelencsér, Andras
Format: Article
Language:English
Subjects:
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Visibility is a simple indicator of air quality, and its drastic decrease is often related to poor air quality resulting from an increase in aerosol (particulate matter PM) concentration. Visibility is also related to water vapor due to the hygroscopicity of aerosols. As a result, water vapor may considerably influence PM measurements especially in the case of low-cost PM sensors which typically measure the ambient (wet) size of PM. Several possibilities are available to eliminate the effect of aerosol hygroscopicity on PM10 measurements, and we aimed to discuss and compare three of the methods: gravimetry (mass change of aerosol filters due to RH variation), application of the AIM model (based on aerosol chemical composition) and estimation derived from visibility data. In this work, we discuss how hygroscopic growth factors, obtained from different methods, are related, as well as the relevance of the hygroscopic growth rate derived from visibility observations in PM10 measurements. Moreover, since in PM monitoring – including the low-cost PM sensors – a quasi-real time, appropriate and simple method would be desirable for consideration of aerosol hygroscopicity, we aimed to construct a proxy for this purpose. We found that the visibility-derived mass growth rate could serve as a simple basis for these requirements. •The hygroscopic growth factors obtained from different methods are compared.•The growth rates depend on chemical composition and the relative humidity history.•The relevance of visibility-derived hygroscopic growth rate in PM10 is studied.•A proxy from visibility-derived mass growth rate is constructed.•The proxy is in good correlation with the measurements.
ISSN:0169-8095
1873-2895
DOI:10.1016/j.atmosres.2019.104815