Abstract
The ice-nucleating abilities of monodispersed airborne particles between 0.01 and 0.12 μm in diameter were determined at different temperatures for silver iodide, silver iodide/sodium chloride, 1,5-dihydroxynaphthalene and phloroglucinol, using the NCAR ice nucleus counter. The aerosol particles were studied as condensation and ice-forming nuclei concurrently to explain the mode of ice nucleation in clouds. Ice nucleation by contact only was operating in the cloud chamber of the NCAR counter for particles of silver iodide and 1,5-dihydroxynaphthalene. Particles of phloroglucinol and silver iodide/sodium chloride mixed particles formed ice by contact and/or by condensation freezing.