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-2016-103
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/acp-2016-103
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

Submitted as: research article 31 May 2016

Submitted as: research article | 31 May 2016

Review status
This preprint has been withdrawn by the authors.

Experimental study of the aerosol impact on fog microphysics

M. Mazoyer1, F. Burnet1, G. C. Roberts1, M. Haeffelin2, J.-C Dupont2, and T. Elias3 M. Mazoyer et al.
  • 1Meteo-France/CNRS-CNRM/GAME, Toulouse, France
  • 2Institut Pierre Simon Laplace/UVSQ, Palaiseau, France
  • 3HYGEOS, Lille, France

Abstract. Comprehensive field campaigns dedicated to fog life cycle observation were conducted during the winters of 2010–2013 at the SIRTA observatory in the suburb of Paris. In order to document their properties, in situ microphysical measurements collected during 23 fog events are examined here. They reveal large variability in number, concentration and size of both aerosol background before the fog onset and fog droplets according to the different cases. The objective of this paper is to evaluate the impact of aerosol particles on the fog microphysics.

To derive an accurate estimation of the actual activated fog droplet number concentration N act, we determine the hygroscopicity parameter κ, the dry and the wet critical diameter and the critical supersaturation for each case by using an iterative procedure based on the κ-Köhler theory that combines cloud condensation nuclei (CCN), dry particle and droplet size distribution measurements. Resulting values of κ = 0.17 ± 0.05 were found typical of continental aerosols. Our study reveals low values of the derived critical supersaturation with a median of 0.043 % and large values for both wet and dry activation diameters. Consequently, the corresponding N act values are low with median concentrations of 53.5 cm−3 and 111 cm−3 within the percentile 75th.

No detectable trend between the concentration of aerosol particles with diameter > 200 nm and N act was observed. In contrast the CCN data at 0.1 % supersaturation exhibits a strong correlation with these aerosol concentrations. We therefore conclude that the actual supersaturations reached during these fog episodes are too low and no simultaneous increase of aerosols > 200 nm and droplet concentrations can be observed. Moreover our analysis suggests that a high aerosol loading limits the supersaturation values. It is also found that the activated fraction mainly depends on the aerosol size while the hygroscopicity appears to be of a secondary importance.

Although radiative fogs are usually associated with higher aerosol loading rather than to stratus lowering events, our analysis reveals that the activated particle concentrations at the beginning of the event are similar for both types of fog. However the evolution of the droplet concentration during the fog life cycle shows significant differences between both types of fog.

This preprint has been withdrawn.

M. Mazoyer 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

M. Mazoyer et al.

M. Mazoyer et al.

Viewed

Total article views: 886 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
537 291 58 886 43 57
  • HTML: 537
  • PDF: 291
  • XML: 58
  • Total: 886
  • BibTeX: 43
  • EndNote: 57
Views and downloads (calculated since 31 May 2016)
Cumulative views and downloads (calculated since 31 May 2016)

Cited

Saved

No saved metrics found.

Discussed

No discussed metrics found.
Latest update: 04 Jul 2020
Publications Copernicus
Download
Withdrawal notice

This preprint has been withdrawn.

Short summary
Comprehensive field campaigns dedicated to fog life cycle observation were conducted during the winters of 2010–2013 at the SIRTA observatory in the suburb of Paris. The objective of this paper is to evaluate the impact of aerosol particles on the fog microphysics through an original method. We conclude that the actual supersaturations reached during these fog episodes are too low and no simultaneous increase of aerosols (D > 200 nm) and droplet concentrations can be observed.
Comprehensive field campaigns dedicated to fog life cycle observation were conducted during the...
Citation