Relating hygroscopicity and composition of organic aerosol particulate matter

  • A hygroscopicity tandem differential mobility analyzer (HTDMA) was used to measure the water uptake (hygroscopicity) of secondary organic aerosol (SOA) formed during the chemical and photochemical oxidation of several organic precursors in a smog chamber. Electron ionization mass spectra of the non-refractory submicron aerosol were simultaneously determined with an aerosol mass spectrometer (AMS), and correlations between the two different signals were investigated. SOA hygroscopicity was found to strongly correlate with the relative abundance of the ion signal m/z 44 expressed as a fraction of total organic signal (f44). m/z 44 is due mostly to the ion fragment CO2+ for all types of SOA systems studied, and has been previously shown to strongly correlate with organic O/C for ambient and chamber OA. The analysis was also performed on ambient OA from two field experiments at the remote site Jungfraujoch, and the megacity Mexico City, where similar results were found. A simple empirical linear relation between the hygroscopicity of OA at subsaturated RH, as given by the hygroscopic growth factor (GF) or "ϰorg" parameter, and f44 was determined and is given by ϰorg = 2.2 × f44 − 0.13. This approximation can be further verified and refined as the database for AMS and HTDMA measurements is constantly being expanded around the world. The use of this approximation could introduce an important simplification in the parameterization of hygroscopicity of OA in atmospheric models, since f44 is correlated with the photochemical age of an air mass.

Download full text files

Export metadata

Additional Services

Share in Twitter Search Google Scholar
Author:Jonathan DuplissyORCiD, Peter F. DeCarlo, Josef Dommen, M. Rami Alfarra, Axel Metzger, Iakovos Barmpadimos, André Stephan Henry Prevot, Ernest Weingartner, Torsten Tritscher, Martin Gysel, Allison C. Aiken, Jose Luis Jimenez, Manjula R. Canagaratna, Douglas R. WorsnopORCiD, Donald R. Collins, Jason M. Tomlinson, Urs BaltenspergerORCiDGND
Parent Title (English):Atmospheric chemistry and physics
Publisher:European Geosciences Union
Place of publication:Katlenburg-Lindau
Document Type:Article
Date of Publication (online):2011/02/10
Date of first Publication:2011/02/10
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2012/10/15
Page Number:11
First Page:1155
Last Page:1165
© Author(s) 2011. This work is distributed under the Creative Commons Attribution 3.0 License.
Institutes:Geowissenschaften / Geographie / Geowissenschaften
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften
Licence (German):License LogoCreative Commons - Namensnennung 3.0