NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
application of physical adsorption thermodynamics to heterogeneous chemistry on polar stratospheric cloudsLaboratory isotherms for the binding of several nonheterogeneously active atmospheric gases and for HCl to water ice are translated into adsorptive equilibrium constants and surface enthalpies. Extrapolation to polar conditions through the Clausius Clapeyron relation yields coverage estimates below the percent level for N2, Ar, CO2, and CO, suggesting that the crystal faces of type II stratospheric cloud particles may be regarded as clean with respect to these species. For HCl, and perhaps HF and HNO3, estimates rise to several percent, and the adsorbed layer may offer acid or proton sources alternate to the bulk solid for heterogeneous reactions with stratospheric nitrates. Measurements are lacking for many key atmospheric molecules on water ice, and almost entirely for nitric acid trihydrate as substrate. Adsorptive equilibria enter into gas to particle mass flux descriptions, and the binding energy determines rates for desorption of, and encounter between, potential surface reactants.
Document ID
19920036118
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Elliott, Scott
(Los Alamos National Laboratories NM, United States)
Turco, Richard P.
(California, University Los Angeles, United States)
Toon, Owen B.
(NASA Ames Research Center Moffett Field, CA, United States)
Hamill, Patrick
(San Jose State University CA, United States)
Date Acquired
August 15, 2013
Publication Date
October 1, 1991
Publication Information
Publication: Journal of Atmospheric Chemistry
Volume: 13
ISSN: 0167-7764
Subject Category
GEOPHYSICS
Funding Number(s)
CONTRACT_GRANT: NSF ATM-89-11836
Distribution Limits
Public
Copyright
Other