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

Journal metrics

IF value: 5.414
IF5.414
IF 5-year value: 5.958
IF 5-year
5.958
CiteScore value: 9.7
CiteScore
9.7
SNIP value: 1.517
SNIP1.517
IPP value: 5.61
IPP5.61
SJR value: 2.601
SJR2.601
Scimago H <br class='widget-line-break'>index value: 191
Scimago H
index
191
h5-index value: 89
h5-index89
Download
Short summary
Human-induced aerosols concentrate around their emission sources, yet their climate effects span far and wide. Here, we use two climate models to robustly explore the mechanisms how Asian aerosols impact temperatures across the globe. A total removal of Asian aerosols increases the global temperatures by 0.26 ± 0.04 °C in the models, with most of the uncertainty arising from modelled cloud responses.
Altmetrics
Preprints
https://doi.org/10.5194/acp-2020-1029
https://doi.org/10.5194/acp-2020-1029

  10 Dec 2020

10 Dec 2020

Review status: this preprint is currently under review for the journal ACP.

How Asian aerosols impact regional surface temperatures across the globe

Joonas Merikanto1, Kalle Nordling1, Petri Räisänen1, Jouni Räisänen2, Declan O'Donnell1, Antti-Ilari Partanen1, and Hannele Korhonen1 Joonas Merikanto et al.
  • 1Finnish Meteorological Institute, Helsinki, Finland
  • 2INAR/Physics, University of Helsinki, Helsinki, Finland

Abstract. South and East Asian anthropogenic aerosols mostly reside in an air mass extending from the Indian Ocean to the North Pacific. Yet the surface temperature effects of Asian aerosols spread across the whole globe. Here, we remove Asian anthropogenic aerosols from two independent climate models (ECHAM6.1 and NorESM1) using the same representation of aerosols via MACv2-SP (a simple plume implementation of the 2nd version of the Max Planck Institute Aerosol Climatology). We then robustly decompose the global distribution of surface temperature responses into contributions from atmospheric energy flux changes. We find that the horizontal atmospheric energy transport strongly moderates the surface temperature response over the regions where Asian aerosols reside. Atmospheric energy transport and changes in clear-sky longwave radiation redistribute the temperature effects efficiently across the Northern hemisphere, and to a lesser extent also over the Southern hemisphere. The model-mean global surface temperature response to Asian anthropogenic aerosol removal is 0.26 ± 0.04 °C (0.22 ± 0.03 for ECHAM6.1 and 0.30 ± 0.03 °C for NorESM1) of warming. Model-to-model differences in global surface temperature response mainly arise from differences in longwave cloud (0.01 ± 0.01 for ECHAM6.1 and 0.05 ± 0.01 °C for NorESM1) and shortwave cloud (0.03 ± 0.03 for ECHAM6.1 and 0.07 ± 0.02 °C for NorESM1) responses. The differences in cloud responses between the models also dominate the differences in regional temperature responses. In both models, the Northern hemispheric surface warming amplifies towards the Arctic, where the total temperature response is highly seasonal and weakest during the Arctic summer. We estimate that under a strong Asian aerosol mitigation policy tied with strong climate mitigation (Shared Socioeconomic Pathway 1-1.9) the Asian aerosol reductions can add around 8 years' worth of current day global warming during the next few decades.

Joonas Merikanto et al.

 
Status: open (until 04 Feb 2021)
Status: open (until 04 Feb 2021)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Joonas Merikanto et al.

Joonas Merikanto et al.

Viewed

Total article views: 201 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
144 54 3 201 3 4
  • HTML: 144
  • PDF: 54
  • XML: 3
  • Total: 201
  • BibTeX: 3
  • EndNote: 4
Views and downloads (calculated since 10 Dec 2020)
Cumulative views and downloads (calculated since 10 Dec 2020)

Viewed (geographical distribution)

Total article views: 305 (including HTML, PDF, and XML) Thereof 297 with geography defined and 8 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 20 Jan 2021
Publications Copernicus
Download
Short summary
Human-induced aerosols concentrate around their emission sources, yet their climate effects span far and wide. Here, we use two climate models to robustly explore the mechanisms how Asian aerosols impact temperatures across the globe. A total removal of Asian aerosols increases the global temperatures by 0.26 ± 0.04 °C in the models, with most of the uncertainty arising from modelled cloud responses.
Citation
Altmetrics