Change search
ReferencesLink to record
Permanent link

Direct link
Importance of aerosol composition and mixing state for cloud droplet activation over the Arctic pack ice in summer
Stockholm University, Faculty of Science, Department of Meteorology .
Stockholm University, Faculty of Science, Department of Meteorology .
2015 (English)In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 15, no 5, 2545-2568 p.Article in journal (Refereed) Published
Abstract [en]

Concentrations of cloud condensation nuclei (CCN) were measured throughout an expedition by icebreaker around the central Arctic Ocean, including a 3 week ice drift operation at 87 degrees N, from 3 August to 9 September 2008. In agreement with previous observations in the area and season, median daily CCN concentrations at 0.2% water vapour supersaturation (SS) were typically in the range of 15 to 30 cm(-3), but concentrations varied by 2 to 3 orders of magnitude over the expedition and were occasionally below 1 cm(-3). The CCN concentrations were highest near the ice edge and fell by a factor of 3 in the first 48 h of transport from the open sea into the pack ice region. For longer transport times they increased again, indicating a local source over the pack ice, suggested to be polymer gels, via drops injected into the air by bubbles bursting on open leads. We inferred the properties of the unexplained non-water soluble aerosol fraction that was necessary for reproducing the observed concentrations of CCN. This was made possible by assuming Kohler theory and simulating the cloud nucleation process using a Lagrangian adiabatic air parcel model that solves the kinetic formulation for condensation of water on size resolved aerosol particles. We propose that the portion of the internally/externally mixed water insoluble particles was larger in the corresponding smaller aerosol size ranges. These particles were physically and chemically behaving as polymer gels: the interaction of the hydrophilic and hydrophobic entities on the structures of polymer gels during cloud droplet activation would at first only show a partial wetting character and only weak hygroscopic growth. Given time, a high CCN activation efficiency is achieved, which is promoted by the hydrophilicity or surface-active properties of the gels. Thus the result in this study argues that the behaviour of the high Arctic aerosol in CCN-counters operating at water vapour SSs > 0.4% (high relative humidities) may not be properly explained by conventional Kohler theory.

Place, publisher, year, edition, pages
2015. Vol. 15, no 5, 2545-2568 p.
National Category
Meteorology and Atmospheric Sciences
URN: urn:nbn:se:su:diva-116843DOI: 10.5194/acp-15-2545-2015ISI: 000350559700021OAI: diva2:809442


Available from: 2015-05-04 Created: 2015-04-29 Last updated: 2015-05-04Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Leck, Caroline
By organisation
Department of Meteorology
In the same journal
Atmospheric Chemistry And Physics
Meteorology and Atmospheric Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 145 hits
ReferencesLink to record
Permanent link

Direct link