There are many different types of atmospheric particulates that can act as CCN. The particles may be composed of dust or clay, soot or black carbon from grassland or forest fires, sea salt from ocean wave spray, soot from factory smokestacks or internal combustion engines, sulfate from volcanic activity, phytoplankton or the oxidation of sulfur dioxide and secondary organic matter formed by the oxidation of VOCs. The ability of these different types of particles to form cloud droplets varies according to their size and also their exact composition, as the hygroscopic properties of these different constituents are very different. Sulfate and sea salt, for instance, readily absorb water whereas soot, organic carbon and mineral particles do not. This is made even more complicated by the fact that many of the chemical species may be mixed within the particles (in particular the sulfate and organic carbon). Additionally, while some particles (such as soot and minerals) do not make very good CCN, they do act as very good ice nuclei in colder parts of the atmosphere.
The number and type of CCNs can affect the lifetimes and radiative properties of clouds as well as the amount and hence have an influence on climate change , but the details of this are still not well understood but are the subject of much research by many groups worldwide. One such experiment is CLOUD, a facility to explore the relationship between CCNs and Galatic cosmic rays.
A counter-hypothesis is advanced in The Revenge of Gaia, the book by James Lovelock. Warming oceans are likely to become stratified, with most ocean nutrients trapped in the cold bottom layers while most of the light needed for photosynthesis in the warm top layer. Under this scenario, deprived of nutrients, marine phytoplankton would decline, as would sulfate cloud condensation nuclei, and the high albedo associated with low clouds. As of 2007 this hypothesis remains speculative.
Publication No. WO/2010/071305 Published on June 24, Assigned to Korea Meteorological Administration for Seeding, Verification Method (South Korean Inventors)
Jun 25, 2010; GENEVA, June 26 -- Jae Won Jung, Myoung Joo Lee, Ki Ho Chang, Young Jin Jang, Jin Yim Jeong, Ha Young Yang, Kyung Yeub Nam, Yong...