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/acp-2019-761
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-2019-761
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

Submitted as: research article 23 Sep 2019

Submitted as: research article | 23 Sep 2019

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Atmospheric Chemistry and Physics (ACP).

Deposition of brown carbon onto snow: changes of snow optical and radiative properties

Nicholas D. Beres1,2, Deep Sengupta1,2, Vera Samburova1, Andrey Y. Khlystov1, and Hans Moosmüller1 Nicholas D. Beres et al.
  • 1Division of Atmospheric Sciences, Desert Research Institute, Reno, NV, 89512, United States
  • 2University of Nevada-Reno, Reno, NV, 89512, United States

Abstract. Light-absorbing organic carbon aerosol – colloquially known as brown carbon (BrC) – is emitted from combustion processes and has a brownish or yellowish visual appearance, caused by enhanced light absorption at shorter visible and ultraviolet wavelengths (0.3 μm ≲ λ ≲ 0.5 μm). Recently, optical properties of atmospheric BrC aerosols have become the topic of intense research, but little is known about how BrC deposition onto snow surfaces affects the spectral snow albedo, which can alter the resulting radiative forcing and in-snow photochemistry. Wildland fires in close proximity to the cryosphere, such as peatland fires that emit large quantities of BrC, are becoming more common at high latitudes, potentially affecting nearby snow and ice surfaces.

In this study, we describe the artificial deposition of BrC aerosol with known optical, chemical, and physical properties onto the snow surface and we monitor its spectral radiative impact and compare it directly to modeled values. First, using small-scale combustion of Alaskan peat, BrC aerosols were artificially deposited onto the snow surface. UV-vis absorbance and total organic carbon (TOC) concentration of snow samples were measured for samples with and without artificial BrC deposition. These measurements were used to estimate the imaginary part of the refractive index of deposited BrC aerosol with a volume mixing rule. Single particle optical properties were calculated using Mie theory, and these values were used to show that the measured spectral snow albedo of snow with deposited BrC was in general agreement with modeled spectral snow albedo using calculated BrC optical properties.

The instantaneous radiative forcing by impurities present in the snow before the deposition experiments was found to increase the instantaneous radiative forcing at the surface of the natural snow at our site by 1.23 (+0.14/−0.11) W m−2 per ppm of BrC deposited. However, we estimate that deposition onto a clean snowpack without light-absorbing impurities would have resulted in a more than twice as large instantaneous radiative forcing of 2.68 (+0.27/−0.22) W m−2 per ppm of BrC deposited.

Nicholas D. Beres et al.
Interactive discussion
Status: open (until 21 Nov 2019)
Status: open (until 21 Nov 2019)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Nicholas D. Beres et al.
Nicholas D. Beres et al.
Viewed  
Total article views: 282 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
192 88 2 282 2 3
  • HTML: 192
  • PDF: 88
  • XML: 2
  • Total: 282
  • BibTeX: 2
  • EndNote: 3
Views and downloads (calculated since 23 Sep 2019)
Cumulative views and downloads (calculated since 23 Sep 2019)
Viewed (geographical distribution)  
Total article views: 246 (including HTML, PDF, and XML) Thereof 244 with geography defined and 2 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Cited  
Saved  
No saved metrics found.
Discussed  
No discussed metrics found.
Latest update: 20 Oct 2019
Publications Copernicus
Download
Short summary
Brown carbon (BrC) aerosol can be produced by the smoldering combustion of peat, a wildland fuel common at high latitude, often adjacent to the cryosphere. However, little is known about how BrC deposition onto snow changes snow optical and radiative properties. Here, we artificially deposited BrC onto natural snow surfaces, monitored changes of the spectral surface albedo, characterized optical properties of deposited aerosol, and compared to modeled values of albedo and radiative forcing.
Brown carbon (BrC) aerosol can be produced by the smoldering combustion of peat, a wildland fuel...
Citation