Mixing silicate dust and sea salt.Mixing silicate silicate, chemical compound containing silicon, oxygen, and one or more metals, e.g., aluminum, barium, beryllium, calcium, iron, magnesium, manganese, potassium, sodium, or zirconium. Silicates may be considered chemically as salts of the various silicic acids. dust and sea salt Particles found in the air, even over ocean regions far from land, often contain a mixture of silicate dust and sea salt. The dust travels long distances from sources on land and the sea salt particles are generated in spray at the ocean surface. A recent analysis shows that the mixing of these substances probably occurs within clouds above the water. Reporting in the June 27 SCIENCE, Meinrat O. Andreae of Florida State University Florida State University, at Tallahassee; coeducational; chartered 1851, opened 1857. Present name was adopted in 1947. Special research facilities include those in nuclear science and oceanography. in Tallahassee and his collegues suggest that wet dust particles can act as nuclei around which water condenses to form drops. Other dry particles collide with existing drops of water. Because most cloud droplets evaporate rather than fall, anything already dissolved in the water will be deposited as a layer on a particle's surface. This process, along with the coalescence coalescence /co·a·les·cence/ (ko?ah-les´ens) the fusion or blending of parts. co·a·les·cence n. See concrescence. coalescence a fusion or blending of parts. of cloud droplets, happens repeatedly for both salt and dust to create airborne particles that are rich in both silicates and salt. A similar process, the researchers say, may also lead to the mixing of sulfate-bearing particles with sea salt. That also brings sulfate sulfate, chemical compound containing the sulfate (SO4) radical. Sulfates are salts or esters of sulfuric acid, H2SO4, formed by replacing one or both of the hydrogens with a metal (e.g., sodium) or a radical (e.g., ammonium or ethyl). into cloud droplets where various chemical reactions This is the 18th episode of television drama Men in Trees. It originally aired on June 25, 2007 on the TV2 network in New Zealand as a continuation of season 1. Recap Marin and Cash have a stew cook off, she admits his is better than hers. can take place. Studies of the process may lead to better estimates of how long particles associated with acid rain or radioactive fallout stay in the atmosphere. |
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