GEOG 214 Lecture Notes - Lecture 2: King Mackerel, Cloud Condensation Nuclei, Cirrostratus Cloud
Document Summary
Clouds are composed of water droplets and ice crystals. Condensation and cloud formation requires microscopic particles known as cloud condensation nuclei. Salt, dust, soot, ash are sources of ccn o h a d f i y o sit r e niv. Condensation requires a surface on which to condense. Usually plenty in the air called condensation nuclei (ccn). The saturation vst curve we have discussed is for a plane surface of pure water. In the air the relation, and e, at the surface of water droplets is affected by their curvature and chemical composition. Curvature: all droplets are in equilibrium with the layer next to their surface. However, more vapour molecules surround a droplet than a plane surface, and more around a small than a large droplet. Solute effect: condensation often causes part or all of the nucleus particle to dissolve, forming a solution. This has the effect of reducing the equilibrium vapour pressure.