Laboratory simulations of PSC particle formation

• Published in: Geophysical research letters Vol. 20; no. 5; pp. 359 - 362
• Main Authors: Marti, James, Mauersberger, Konrad
• Format: Journal Article
• Language: English
• Published: Legacy CDMS Blackwell Publishing Ltd 05.03.1993; American Geophysical Union
• Subjects: Approximation; Atmospheric composition. Chemical and photochemical reactions; CLOUDS; Condensing; CRYOSPHERE; DISPERSIONS; EARTH ATMOSPHERE; Earth, ocean, space; ENVIRONMENTAL SCIENCES; EQUILIBRIUM; Exact sciences and technology; External geophysics; Geophysics; HYDRATES; HYDROGEN COMPOUNDS; INORGANIC ACIDS; Meteorology And Climatology; MIXTURES; NITRIC ACID; OXYGEN COMPOUNDS; PARTICLES; PHYSICAL PROPERTIES; Physics of the high neutral atmosphere; POLAR REGIONS; SIMULATION; SOLIDS; STRATOSPHERE; THERMODYNAMIC PROPERTIES 540120 > Environment, Atmospheric > Chemicals Monitoring & Transport > (1990-); VAPOR CONDENSATION; VAPOR PRESSURE; WATER; Stratosphere; Laboratory study; Experimental study; Polar stratospheric cloud; Nitric acid; Hydrated particle
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/93GL00083

The growth of type I polar stratospheric cloud (PSC) particles was investigated. Mixtures of water and nitric acid vapor were condensed at temperatures and pressures approximating those of the polar stratosphere. Mono-, di-, and trihydrates of nitric acid were observed in condensed solids. Results indicate that precursor vapor composition determines solid composition. As solids grew and aged a slow increase in HNO3 was observed and composition appeared to change towards that of the more thermodynamically stable nitric acid trihydrate (NAT). Results suggest that over ten hours may be required for PSC particles to reach NAT composition and equilibrium NAT vapor pressure. Recent observations may have been from young clouds whose condensed materials have not yet reached equilibrium.