Hygroscopic properties of smoke-generated organic aerosol particles emitted in the marine atmosphere

Autor(en)

Anna Wonaschütz, M. Coggon, A. Sorooshian, R. Modini, A. A. Frossard, L. Ahlm, J. Mülmenstädt, G. C. Roberts, L. M. Russell, S. Dey, F. J. Brechtel, J. H. Seinfeld

Abstrakt

During the Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE), a

plume of organic aerosol was produced by a smoke generator and emitted into

the marine atmosphere from aboard the R/V Point Sur. In this study,

the hygroscopic properties and the chemical composition of the plume were

studied at plume ages between 0 and 4 h in different meteorological

conditions. In sunny conditions, the plume particles had very low

hygroscopic growth factors (GFs): between 1.05 and 1.09 for 30 nm and between 1.02 and 1.1

for 150 nm dry size at a relative humidity (RH) of 92%, contrasted by

an average marine background GF of 1.6. New particles were produced in large

quantities (several 10 000 cm⁻³), which lead to substantially increased

cloud condensation nuclei (CCN) concentrations at supersaturations between

0.07 and 0.88%. Ratios of oxygen to carbon (O : C) and water-soluble organic

mass (WSOM) increased with plume age: from < 0.001 to 0.2, and from

2.42 to 4.96 μg m⁻³, respectively, while organic mass fractions

decreased slightly (~ 0.97 to ~ 0.94).

High-resolution aerosol mass spectrometer (AMS) spectra show that the

organic fragment m/z 43 was dominated by C₂H₃O⁺ in the small,

new particle mode and by C₃H₇⁺ in the large particle mode. In

the marine background aerosol, GFs for 150 nm particles at 40% RH were

found to be enhanced at higher organic mass fractions: an average GF of 1.06

was observed for aerosols with an organic mass fraction of 0.53, and a GF of

1.04 for an organic mass fraction of 0.35.

Organisation(en)

Aerosolphysik und Umweltphysik

Externe Organisation(en)

California Institute of Technology (Caltech), University of Arizona, University of California, San Diego, Centre National De La Recherche Scientifique (CNRS), Brechtel Manufacturing Inc.

Journal

Atmospheric Chemistry and Physics

Band

13

Seiten

9819-9835

Anzahl der Seiten

17

ISSN

1680-7316

DOI

https://doi.org/10.5194/acp-13-9819-2013

Publikationsdatum

2013

Peer-reviewed

Ja

ÖFOS 2012

1030 Physik, Astronomie, 105204 Klimatologie, 105206 Meteorologie, 105904 Umweltforschung

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/cab0fbe5-bf05-487f-878e-2649bbb7d6ac