Preprints
https://doi.org/10.5194/acp-2022-648
https://doi.org/10.5194/acp-2022-648
19 Sep 2022
 | 19 Sep 2022
Status: this preprint was under review for the journal ACP but the revision was not accepted.

Predicted and Observed Changes in Summertime Biogenic and Total Organic Aerosol in the Southeast United States from 2001 to 2010

Brian T. Dinkelacker, Pablo Garcia Rivera, Ksakousti Skyllakou, Peter J. Adams, and Spyros N. Pandis

Abstract. Biogenic secondary organic aerosol (bSOA) is a major component of atmospheric particulate matter (PM2.5) in the southeast United States especially during the summer, when emissions of biogenic volatile organic compound (VOCs) are high and emissions from anthropogenic sources enhance the formation of secondary particulate matter. We evaluate the performance of PM2.5 organic aerosol predictions by a chemical transport model (PMCAMx) in response to significant changes in anthropogenic emissions during the summers of 2001 and 2010. Average predicted bSOA concentrations in the southeast US did not change appreciably from the summer of 2001 to the summer of 2010, while the anthropogenic SOA decreased by 45 %. As a result, the biogenic fraction of total OA increased from 0.46 in 2001 to 0.63 in 2010. Partitioning effects due to reduced anthropogenic OA from 2001 resulted in 0.4 µg m-3 less biogenic OA on average in the southeast US in the summer of 2010. This was offset by biogenic SOA increases due to higher biogenic vapor emissions in the warmer 2010 summer. Little noticeable difference was observed in OA prediction performance in the southeast US between the two summer simulation periods. The fractional error of OA predictions remained practically the same (0.41 and 0.44 at CSN sites and 0.40 to 0.41 at IMPROVE sites in the summers of 2001 and 2010 respectively). The fractional bias of OA predictions increased from 0.10 to 0.22 at CSN sites and decreased from 0 to -0.09 at IMPROVE sites between the two periods. Removing the NOx-dependence of SOA formation yields resulted in higher fractional error and fractional bias at both CSN and IMPROVE sites in both summer periods, demonstrating the efficacy of the current formulation of SOA yields. Our analysis suggests that the changes in biogenic OA in this forested relatively polluted region appear to be dominated by the partitioning effects and the NOx effects on SOA yields.

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.
Brian T. Dinkelacker, Pablo Garcia Rivera, Ksakousti Skyllakou, Peter J. Adams, and Spyros N. Pandis

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on acp-2022-648', Anonymous Referee #1, 24 Oct 2022
    • AC1: 'Response to Referee #1', Spyros Pandis, 12 Dec 2022
  • RC2: 'Comment on acp-2022-648', Anonymous Referee #2, 25 Oct 2022
    • AC2: 'Response to Referee #2', Spyros Pandis, 12 Dec 2022

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on acp-2022-648', Anonymous Referee #1, 24 Oct 2022
    • AC1: 'Response to Referee #1', Spyros Pandis, 12 Dec 2022
  • RC2: 'Comment on acp-2022-648', Anonymous Referee #2, 25 Oct 2022
    • AC2: 'Response to Referee #2', Spyros Pandis, 12 Dec 2022
Brian T. Dinkelacker, Pablo Garcia Rivera, Ksakousti Skyllakou, Peter J. Adams, and Spyros N. Pandis
Brian T. Dinkelacker, Pablo Garcia Rivera, Ksakousti Skyllakou, Peter J. Adams, and Spyros N. Pandis

Viewed

Total article views: 938 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
721 179 38 938 66 27 51
  • HTML: 721
  • PDF: 179
  • XML: 38
  • Total: 938
  • Supplement: 66
  • BibTeX: 27
  • EndNote: 51
Views and downloads (calculated since 19 Sep 2022)
Cumulative views and downloads (calculated since 19 Sep 2022)

Viewed (geographical distribution)

Total article views: 939 (including HTML, PDF, and XML) Thereof 939 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 11 Jul 2024
Download
Short summary
A number of factors have influenced the biogenic secondary organic aerosol (SOA) levels in the southeastern US from 2001 to 2010. The increases in temperature have led to an increase of the emissions of biogenic volatile organic compounds by trees and a corresponding increase of the SOA. However, this increase has been balanced by the reductions in the anthropogenic emissions of organic gases and particulate matter as well as of the oxides of nitrogen keeping the biogenic SOA roughly constant.
Altmetrics