Ice nucleation and droplet formation by bare and coated soot particles

摘要: [1] We have studied ice formation at temperatures relevant to homogeneous and heterogeneous nucleation, as well droplet activation hygroscopicity, of soot particles variable size composition. Coatings adipic, malic, oleic acid were applied in order span an atmospherically range solubility, both uncoated coated exposed ozone simulate atmospheric oxidation. The results are interpreted terms onset with a comparison mineral dust particle that acts efficient nucleus, hygroscopicity. At 253 K 243 K, we found no evidence nucleation occurring above the level detection for our experimental conditions. Above water saturation, only was observed. 233 observe occurrence all studied. also did not significantly alter behavior but aided uptake water. Hygroscopicity studies confirmed pure hydrophobic, activated droplets high supersaturations. A small amount either below limit instrument or concurrent and/or freezing cannot be precluded, able set limits its frequency. We conclude comparable those generated unlikely contribute global budget nuclei between K.