Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 5.668 IF 5.668
  • IF 5-year value: 6.201 IF 5-year
    6.201
  • CiteScore value: 6.13 CiteScore
    6.13
  • SNIP value: 1.633 SNIP 1.633
  • IPP value: 5.91 IPP 5.91
  • SJR value: 2.938 SJR 2.938
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 174 Scimago H
    index 174
  • h5-index value: 87 h5-index 87
Discussion papers
https://doi.org/10.5194/acpd-13-7113-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/acpd-13-7113-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.

Submitted as: research article 18 Mar 2013

Submitted as: research article | 18 Mar 2013

Review status
This discussion paper is a preprint. It has been under review for the journal Atmospheric Chemistry and Physics (ACP). The revised manuscript was not accepted.

Evolution of multispectral aerosol optical properties in a biogenically-influenced urban environment during the CARES campaign

M. Gyawali1,10, W. P. Arnott1, R. A. Zaveri2, C. Song2, M. Pekour2, B. Flowers3, M. K. Dubey3, A. Setyan4, Q. Zhang4, J. W. Harworth5, J. G. Radney5,*, D. B. Atkinson5, S. China6, C. Mazzoleni6, K. Gorkowski7, R. Subramanian8, B. T. Jobson9, and H. Moosmüller10 M. Gyawali et al.
  • 1Physics Department, University of Nevada, Reno, Nevada System of Higher Education, 1664 N. Virginia Street, Reno, NV, USA
  • 2Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USA
  • 3Earth System Observations, Los Alamos National Laboratory, Los Alamos, NM, USA
  • 4Department of Environmental Toxicology, University of California, Davis, CA, USA
  • 5Portland State University, Portland, OR, USA
  • 6Atmospheric Science Program, Michigan Technological University, Houghton, MI, USA
  • 7Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
  • 8Droplet Measurements Technologies, Boulder, CO, USA
  • 9Washington State University, Pullman, WA, USA
  • 10Desert Research Institute, Nevada System of Higher Education, 2215 Raggio Parkway, Reno, NV, USA
  • *now at: Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899, USA

Abstract. Ground-based aerosol measurements made in June 2010 within Sacramento urban area (site T0) and at a 40-km downwind location (site T1) in the forested Sierra Nevada foothills area are used to investigate the evolution of multispectral optical properties as the urban aerosols aged and interacted with biogenic emissions. Along with black carbon and non-refractory aerosol mass and composition observations, spectral absorptio (βabs), scattering (βsca), and extinction (βext) coefficients for wavelengths ranging from 355 to 1064 nm were measured at both sites using photoacoustic (PA) instruments with integrating nephelometers and using cavity ring-down (CRD) instruments. The daytime average Ångström exponent of absorption (AEA) was ~1.6 for the wavelength pair 405 and 870 nm at T0, while it was ~1.8 for the wavelength pair 355 and 870 nm at T1, indicating a modest wavelength-dependent enhancement of absorption at both sites throughout the study. The measured and Mie theory calculations of multispectral βsca showed good correlation (R2=0.85–0.94). The average contribution of supermicron aerosol (mainly composed of sea salt particles advected in from the Pacific Ocean) to the total scattering coefficient ranged from less than 20% at 405 nm to greater than 80% at 1064 nm. From 22 to 28 June, secondary organic aerosol mass increased significantly at both sites due to increased biogenic emissions coupled with intense photochemical activity and air mass recirculation in the area. During this period, the short wavelength scattering coefficients at both sites gradually increased due to increase in the size of submicron aerosols. At the same time, BC mass-normalized absorption cross-section (MAC) values for ultraviolet wavelengths at T1 increased by ~60% compared to the relatively less aged urban emissions at the T0 site. In contrast, the average MAC values for 870 nm wavelength were identical at both sites. These results suggest formation of moderately brown secondary organic aerosols formed in biogenically-influenced urban air.

M. Gyawali et al.
Interactive discussion
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
Interactive discussion
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
M. Gyawali et al.
M. Gyawali et al.
Viewed  
Total article views: 2,249 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
1,112 999 138 2,249 108 113
  • HTML: 1,112
  • PDF: 999
  • XML: 138
  • Total: 2,249
  • BibTeX: 108
  • EndNote: 113
Views and downloads (calculated since 18 Mar 2013)
Cumulative views and downloads (calculated since 18 Mar 2013)
Cited  
Saved  
Discussed  
No discussed metrics found.
Latest update: 17 Sep 2019
Publications Copernicus
Download
Citation