Evolution of the Complex Refractive Index of Secondary Organic Aerosols during Atmospheric Aging

Quanfu He, Nir Bluvshtein, Lior Segev, Daphne Meidan, J. Michel Flores, Steven S. Brown, William Henry Brune, Yinon Rudich

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The wavelength-dependence of the complex refractive indices (RI) in the visible spectral range of secondary organic aerosols (SOA) are rarely studied, and the evolution of the RI with atmospheric aging is largely unknown. In this study, we applied a novel white light-broadband cavity enhanced spectroscopy to measure the changes in the RI (400-650 nm) of β-pinene and p-xylene SOA produced and aged in an oxidation flow reactor, simulating daytime aging under NOx-free conditions. It was found that these SOA are not absorbing in the visible range, and that the real part of the RI, n, shows a slight spectral dependence in the visible range. With increased OH exposure, n first increased and then decreased, possibly due to an increase in aerosol density and chemical mean polarizability for SOA produced at low OH exposures, and a decrease in chemical mean polarizability for SOA produced at high OH exposures, respectively. A simple radiative forcing calculation suggests that atmospheric aging can introduce more than 40% uncertainty due to the changes in the RI for aged SOA.

Original languageEnglish (US)
Pages (from-to)3456-3465
Number of pages10
JournalEnvironmental Science and Technology
Volume52
Issue number6
DOIs
StatePublished - Mar 20 2018

Fingerprint

Atmospheric aerosols
refractive index
Aerosols
Refractive index
Aging of materials
aerosol
radiative forcing
xylene
cavity
spectroscopy
Spectroscopy
wavelength
oxidation
Wavelength
Oxidation

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Environmental Chemistry

Cite this

He, Q., Bluvshtein, N., Segev, L., Meidan, D., Flores, J. M., Brown, S. S., ... Rudich, Y. (2018). Evolution of the Complex Refractive Index of Secondary Organic Aerosols during Atmospheric Aging. Environmental Science and Technology, 52(6), 3456-3465. https://doi.org/10.1021/acs.est.7b05742
He, Quanfu ; Bluvshtein, Nir ; Segev, Lior ; Meidan, Daphne ; Flores, J. Michel ; Brown, Steven S. ; Brune, William Henry ; Rudich, Yinon. / Evolution of the Complex Refractive Index of Secondary Organic Aerosols during Atmospheric Aging. In: Environmental Science and Technology. 2018 ; Vol. 52, No. 6. pp. 3456-3465.
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Evolution of the Complex Refractive Index of Secondary Organic Aerosols during Atmospheric Aging. / He, Quanfu; Bluvshtein, Nir; Segev, Lior; Meidan, Daphne; Flores, J. Michel; Brown, Steven S.; Brune, William Henry; Rudich, Yinon.

In: Environmental Science and Technology, Vol. 52, No. 6, 20.03.2018, p. 3456-3465.

Research output: Contribution to journalArticle

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AU - Brown, Steven S.

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