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Key drivers of cloud response to surface-active organics

Research output: Contribution to journalArticleScientificpeer-review

Details

Original languageEnglish
Article number5214
Number of pages12
JournalNature Communications
Volume10
Issue number1
DOIs
Publication statusPublished - 1 Dec 2019
Externally publishedYes
Publication typeA1 Journal article-refereed

Abstract

Aerosol-cloud interactions constitute the largest source of uncertainty in global radiative forcing estimates, hampering our understanding of climate evolution. Recent empirical evidence suggests surface tension depression by organic aerosol to significantly influence the formation of cloud droplets, and hence cloud optical properties. In climate models, however, surface tension of water is generally assumed when predicting cloud droplet concentrations. Here we show that the sensitivity of cloud microphysics, optical properties and shortwave radiative effects to the surface phase are dictated by an interplay between the aerosol particle size distribution, composition, water availability and atmospheric dynamics. We demonstrate that accounting for the surface phase becomes essential in clean environments in which ultrafine particle sources are present. Through detailed sensitivity analysis, quantitative constraints on the key drivers – aerosol particle number concentrations, organic fraction and fixed updraft velocity – are derived for instances of significant cloud microphysical susceptibilities to the surface phase.

Publication forum classification

Field of science, Statistics Finland