Preprints
https://doi.org/10.5194/egusphere-2023-556
https://doi.org/10.5194/egusphere-2023-556
24 Apr 2023
 | 24 Apr 2023

Measurements and Calculations of Enhanced Side/Back Scattering of Visible Radiation by Black Carbon Aggregates

Carynelisa Haspel, Cuiqi Zhang, Martin Johann Wolf, Daniel James Cziczo, and Maor Sela

Abstract. Aerosol particles have both natural and anthropogenic origins and are ubiquitous in the atmosphere. One particularly important type is carbonaceous aerosol, including a specific subset, often termed ‘elemental carbon’ chemically or ‘black carbon’ (BC) radiatively. Carbonaceous aerosol particles have implications for atmospheric chemistry, human health, and climate both directly and via their ability to act as site of cloud droplet or ice crystal formation. Laboratory experiments and theory are needed to better understand these particles, specifically their radiative impact. We present here laboratory measurements of side/back scattering of visible radiation by analogues of atmospheric BC aggregates obtained using a depolarizing optical particle counter and accompanying theoretical calculations of scattering by compact and fractal theoretical BC aggregates. We show that with random-orientation, the theoretical calculations reproduce the qualitative behavior of the measurements but are unable to reproduce the highest values of the linear depolarization ratio; we are only able to obtain high values of the linear depolarization ratio using fixed orientation. Thus, we suggest that it is possible that models of scattering by BC aggregates that employ the random orientation assumption/option may underpredict the linear depolarization ratio of actual BC aggregates. Both our measurements and our theoretical calculations point to the possibility that bare (uncoated) BC aggregates, as opposed to the aged/coated BC or soot that was investigated in previous studies, can exhibit higher backscattering linear depolarization than previously assumed.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.

Journal article(s) based on this preprint

08 Sep 2023
Measurements and calculations of enhanced side- and back-scattering of visible radiation by black carbon aggregates
Carynelisa Haspel, Cuiqi Zhang, Martin J. Wolf, Daniel J. Cziczo, and Maor Sela
Atmos. Chem. Phys., 23, 10091–10115, https://doi.org/10.5194/acp-23-10091-2023,https://doi.org/10.5194/acp-23-10091-2023, 2023
Short summary
Carynelisa Haspel, Cuiqi Zhang, Martin Johann Wolf, Daniel James Cziczo, and Maor Sela

Interactive discussion

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2023-556', Anonymous Referee #1, 15 May 2023
  • RC2: 'Comment on egusphere-2023-556', Anonymous Referee #2, 07 Jun 2023
  • AC1: 'Comment on egusphere-2023-556 - responses to the referee comments', Carynelisa Haspel, 13 Jul 2023

Interactive discussion

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2023-556', Anonymous Referee #1, 15 May 2023
  • RC2: 'Comment on egusphere-2023-556', Anonymous Referee #2, 07 Jun 2023
  • AC1: 'Comment on egusphere-2023-556 - responses to the referee comments', Carynelisa Haspel, 13 Jul 2023

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload
AR by Carynelisa Haspel on behalf of the Authors (13 Jul 2023)  Author's response   Author's tracked changes   Manuscript 
ED: Publish subject to technical corrections (19 Jul 2023) by Stefania Gilardoni
AR by Carynelisa Haspel on behalf of the Authors (26 Jul 2023)  Author's response   Manuscript 

Journal article(s) based on this preprint

08 Sep 2023
Measurements and calculations of enhanced side- and back-scattering of visible radiation by black carbon aggregates
Carynelisa Haspel, Cuiqi Zhang, Martin J. Wolf, Daniel J. Cziczo, and Maor Sela
Atmos. Chem. Phys., 23, 10091–10115, https://doi.org/10.5194/acp-23-10091-2023,https://doi.org/10.5194/acp-23-10091-2023, 2023
Short summary
Carynelisa Haspel, Cuiqi Zhang, Martin Johann Wolf, Daniel James Cziczo, and Maor Sela
Carynelisa Haspel, Cuiqi Zhang, Martin Johann Wolf, Daniel James Cziczo, and Maor Sela

Viewed

Total article views: 261 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
197 52 12 261 4 5
  • HTML: 197
  • PDF: 52
  • XML: 12
  • Total: 261
  • BibTeX: 4
  • EndNote: 5
Views and downloads (calculated since 24 Apr 2023)
Cumulative views and downloads (calculated since 24 Apr 2023)

Viewed (geographical distribution)

Total article views: 271 (including HTML, PDF, and XML) Thereof 271 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 18 Sep 2024
Download

The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

Short summary
Small particles, commonly termed aerosols, can be found throughout the atmosphere and come from both natural and anthropogenic sources. One important type of aerosol is black carbon (BC). In this study, we conducted laboratory measurements of light scattering by particles meant to mimic atmospheric BC and compared them to calculations of scattering. We find that it is likely that calculations underpredict the scattering by BC particles of certain polarizations of light in certain directions.