Preprints
https://doi.org/10.5194/acpd-13-23691-2013
https://doi.org/10.5194/acpd-13-23691-2013
10 Sep 2013
 | 10 Sep 2013
Status: this preprint was under review for the journal ACP but the revision was not accepted.

The sensitivity of global climate to the episodicity of fire aerosol emissions

S. K. Clark, D. S. Ward, and N. M. Mahowald

Abstract. One of the major ways in which forest and grass fires have an impact on global climate is through the release of aerosols. Most studies focusing on calculating the radiative forcing and other climate impacts of fire aerosols use monthly mean emissions derived from the Global Fire Emissions Database that captures only the seasonal cycle of fire aerosol emissions. Here we present the results of a sensitivity study that investigates the climate response to the episodicity of the fires, based on the standard approach which releases emissions every day, and contrasts that to the response when fires are represented as intense pulses of emissions that occur only over 1–2 days on a monthly, yearly, or five-yearly basis. Overall we find that in the modified cases with increased levels of episodicity, the all sky direct effect radiative forcing increases, the clear sky direct effect radiative forcing remains relatively constant, and the magnitude of the indirect effect radiative forcing decreases by about 1 W m−2 (from −1.6 to −0.6 W m−2). In the long term, we find that an increase in aerosol emission episodicity leads to an asymmetric change in indirect radiative forcing in the Northern Hemisphere compared to the Southern Hemisphere contributes to a slight shift in the annual average position of the intertropical convergence zone (ITCZ). This shift is found to have a mixed effect on the overall performance of the model at predicting precipitation rates in the tropics. Given these results we conclude that future studies that look to assess the present day global climate impacts of fire aerosols should consider the need to accurately represent fire episodicity.

S. K. Clark, D. S. Ward, and N. M. Mahowald
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
S. K. Clark, D. S. Ward, and N. M. Mahowald
S. K. Clark, D. S. Ward, and N. M. Mahowald

Viewed

Total article views: 1,812 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
1,238 442 132 1,812 92 86
  • HTML: 1,238
  • PDF: 442
  • XML: 132
  • Total: 1,812
  • BibTeX: 92
  • EndNote: 86
Views and downloads (calculated since 10 Sep 2013)
Cumulative views and downloads (calculated since 10 Sep 2013)

Saved

Latest update: 28 Mar 2024
Download
Altmetrics