English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Concentrations of cloud condensation nuclei (CCN) were measured throughoutan expedition by icebreaker around the central Arctic Ocean, including a3 week ice drift operation at 87° N, from 3 August  to 9 September 2008.In agreement with previous observations in the area and season, mediandaily CCN concentrations at 0.2% water vapour supersaturation (SS) weretypically in the range of 15 to 30 cm<sup>−3</sup>, but concentrations varied by2 to 3 orders of magnitude over the expedition and were occasionallybelow 1 cm<sup>−3</sup>. The CCN concentrations were highest near the ice edge andfell by a factor of 3 in the first 48 h of transport from the opensea into the pack ice region. For longer transport times they increasedagain, indicating a local source over the pack ice, suggested to be polymergels, via drops injected into the air by bubbles bursting on open leads. Weinferred the properties of the unexplained non-water soluble aerosolfraction that was necessary for reproducing the observed concentrations ofCCN. This was made possible by assuming Köhler theory and simulating thecloud nucleation process using a Lagrangian adiabatic air parcel model thatsolves the kinetic formulation for condensation of water on size resolvedaerosol particles. We propose that the portion of the internally/externallymixed water insoluble particles was larger in the corresponding smalleraerosol size ranges. These particles were physically and chemicallybehaving as polymer gels: the interaction of the hydrophilic and hydrophobicentities on the structures of polymer gels during cloud droplet activationwould at first only show a partial wetting character and only weakhygroscopic growth. Given time, a high CCN activation efficiency isachieved, which is promoted by the hydrophilicity or surface-activeproperties of the gels. Thus the result in this study argues that thebehaviour of the high Arctic aerosol in CCN-counters operating at water vapourSSs > 0.4% (high relative humidities) may not beproperly explained by conventional Köhler theory

Importance of aerosol composition and mixing state for cloud droplet activation over the Arctic pack ice in summer