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: 5.414 IF 5.414
  • IF 5-year value: 5.958 IF 5-year
    5.958
  • CiteScore value: 9.7 CiteScore
    9.7
  • SNIP value: 1.517 SNIP 1.517
  • IPP value: 5.61 IPP 5.61
  • SJR value: 2.601 SJR 2.601
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 191 Scimago H
    index 191
  • h5-index value: 89 h5-index 89
Preprints
https://doi.org/10.5194/acp-2019-1183
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-2019-1183
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Submitted as: research article 27 Jan 2020

Submitted as: research article | 27 Jan 2020

Review status
A revised version of this preprint was accepted for the journal ACP and is expected to appear here in due course.

Modulation of radiative aerosols effects by atmospheric circulation over the Euro-Mediterranean region

Pierre Nabat1, Samuel Somot1, Christophe Cassou2, Marc Mallet1, Martine Michou1, Dominique Bouniol1, Bertrand Decharme1, Thomas Drugé1, Romain Roehrig1, and David Saint-Martin1 Pierre Nabat et al.
  • 1CNRM, Université de Toulouse, Météo-France, CNRS, Toulouse, France
  • 2CECI, Université de Toulouse, CNRS, CERFACS, Toulouse, France

Abstract. The present work aims at better understanding regional climate-aerosol interactions by studying the relationships between aerosols and synoptic atmospheric circulation over the Euro-Mediterranean region. Two 40-year simulations (1979–2018) have been carried out with the CNRM-ALADIN64 regional climate model, one using interactive aerosols and the other one without any aerosol. The simulation with aerosols has been evaluated in terms of different climate and aerosol parameters. This evaluation shows a good agreement between the model and observations, significant improvements compared to the previous model version, and consequently the relevance of using this model for the study of climate-aerosol interactions over this region. A first attempt to explain the climate variability of aerosols is based on the use of the North-Atlantic Oscillation (NAO) index, which explains a significant part of the interannual variability, notably in winter for the export of dust aerosols over the Atlantic Ocean and the Eastern Mediterranean, and in summer for the positive anomalies of anthropogenic aerosols over Western Europe. This index is however not sufficient to fully understand the variations of aerosols in this region, notably at daily scale. The use of weather regimes, namely persisting meteorological patterns, stable at synoptic scale for a few days, provide a relevant description of atmospheric circulation, which drives the emission, transport and deposition of aerosols. The four weather regimes usually defined in this area in winter and in summer bring significant information to answer this question. The blocking and NAO+ regimes are largely favourable to strong aerosol effects on shortwave surface radiation and surface temperature, either because of higher aerosol loads, or because of weaker cloud fraction, which reinforces the direct aerosol effect. Inversely the NAO- and Atlantic Ridge regimes are unfavourable to aerosol radiative effects, because of weaker aerosol concentrations and increased cloud cover. This study thus puts forward the strong dependence of aerosol loads on the synoptic circulation from interannual to daily scales, and as a consequence, the important modulation of the aerosol effects on shortwave surface radiation and surface temperature by atmospheric circulation. The role of cloud cover is essential in this modulation as shown by the use of weather regimes.

Pierre Nabat et al.

Interactive discussion

Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement

Interactive discussion

Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement

Pierre Nabat et al.

Pierre Nabat et al.

Viewed

Total article views: 342 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
192 144 6 342 5 5
  • HTML: 192
  • PDF: 144
  • XML: 6
  • Total: 342
  • BibTeX: 5
  • EndNote: 5
Views and downloads (calculated since 27 Jan 2020)
Cumulative views and downloads (calculated since 27 Jan 2020)

Viewed (geographical distribution)

Total article views: 202 (including HTML, PDF, and XML) Thereof 200 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: 04 Jul 2020
Publications Copernicus
Download
Short summary
The present work aims at better understanding regional climate-aerosol interactions over the Euro-Mediterranean region by studying the relationships between aerosols and atmospheric circulation. Based on 40-year regional climate simulations (1979–2018), our results show the role of the North-Atlantic Oscillation in driving the aerosol interannual variability, and that of weather regimes for the daily variability, with ensuing effects on surface shortwave radiation and surface temperature.
The present work aims at better understanding regional climate-aerosol interactions over the...
Citation