Influence of the heterogeneous reaction HCL + HOCl on an ozone hole model with hydrocarbon additions

Journal Article · Sun Feb 20 04:00:00 EST 1994 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/93JD03089· OSTI ID:136154

Elliott, S ^[1]; Cicerone, R J ^[2]; Turco, R P ^[3]

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1. Los Alamos National Lab., NM (United States)
2. Univ. of California, Irvine, CA (United States)
3. Univ. of California, Los Angeles, CA (United States); and others

Injection of ethane or propane has been suggested as a means for reducing ozone loss within the Antarctic vortex because alkanes can convert active chlorine radicals into hydrochloric acid. In kinetic models of vortex chemistry including as heterogeneous processes only the hydrolysis and HCl reactions of ClONO{sub 2} and N{sub 2}O{sub 5}, parts per billion by volume levels of the light alkanes counteract ozone depletion by sequestering chlorine atoms. Introduction of the surface reaction of HCl with HOCl causes ethane to deepen baseline ozone holes and generally works to impede any mitigation by hydrocarbons. The increased depletion occurs because HCl + HOCl can be driven by HO{sub x} radicals released during organic oxidation. Following initial hydrogen abstraction by chlorine, alkane breakdown leads to a net hydrochloric acid activation as the remaining hydrogen atoms enter the photochemical system. Lowering the rate constant for reactions of organic peroxy radicals with ClO to 10{sup {minus}13} cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} does not alter results, and the major conclusions are insensitive to the timing of the ethane additions. Ignoring the organic peroxy radical plus ClO reactions entirely restores remediation capabilities by allowing HO{sub x} removal independent of HCl. Remediation also returns if early evaporation of polar stratospheric clouds leaves hydrogen atoms trapped in aldehyde intermediates, but real ozone losses are small in such cases. 95 refs., 4 figs., 7 tabs.

• OSTI ID: 136154
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: D2 Vol. 99; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ANTARCTIC REGIONS
ATMOSPHERIC CHEMISTRY
CHLORINE NITRATES
ECOLOGICAL CONCENTRATION
ETHANE
HETEROGENEOUS EFFECTS
HYDROCHLORIC ACID
OZONE
PROPANE
STRATOSPHERE