Condensed water vapor that is so small that it can only be seen through a microscope. CCN are actually the center of the droplet. Many of these nuclei are tiny salt particles, sulfate or nitrate aerosol, or small particles present in smoke. See dimethyl sulfide. Most droplets measure from 1/2,500 to 1/250 inch (0.01 to 0.1 millimeter) in diameter. [Journal of Applied Meteorology. v 32, 666, 1993.] [Journal of Aerosol Science. v 23 supp. page S865, 1992.] Coarse Mode Particles - are particles that are larger than two ïm in diameter. They come form sea sprays, volcanoes, crushing or grinding of rocks, wind blown soil, and account for about 95% of the aerosol particles in ambient air.
Aerosol particles that provide a platform for the condensation of water vapor, resulting in clouds with higher droplet concentrations and increased albedo.
(Abbreviated CCN.) Hygroscopic aerosol particles that can serve as nuclei of atmospheric cloud droplets, that is, particles on which water condenses (activates) at supersaturations typical of atmospheric cloud formation (fraction of one to a few percent, depending on cloud type). Concentrations of CCN need to be given in terms of a supersaturation spectrum covering the range of interest or at a specified supersaturation value. Compare condensation nucleus.
Cloud condensation nuclei or CCNs (also known as cloud seeds) are small particles (typically 0.0002 mm, or 1/100 th the size of a cloud droplet http://apollo.lsc.vsc.edu/classes/met130/notes/chapter5/ccn.html) about which cloud droplets coalesce. Water requires a non-gaseous surface to make the transition from a vapour to a liquid. In the atmosphere, this surface presents itself as tiny solid or liquid particles called CCNs.