Last Updated:
February 28, 2007

GCRIO Program Overview

Library 
Our extensive collection of documents.

Privacy Policy

Archives of the
Global Climate Change Digest
A Guide to Information on Greenhouse Gases and Ozone Depletion
Published July 1988 through June 1999

FROM VOLUME 6, NUMBER 6, JUNE 1993

PROFESSIONAL PUBLICATIONS...
GENERAL INTEREST--SCIENCE: OZONE DEPLETION

Item #d93jun12

"Record Low Global Ozone in 1992," J.F. Gleason (NASA-Goddard, Greenbelt MD 20771), P.K. Bhartia et al., Science, 260(5107), 523-536, Apr. 23, 1993.

The 1992 global average total ozone, measured by the Total Ozone Mapping Spectrometer on the Nimbus-7 satellite, was 2-3% lower than any earlier year observed (1979-1991). Ozone was low in a wide range of latitudes, with the largest decreases in the bands 10·S to 20·S and 10·N to 60·N. Global ozone in 1992 was at least 1.5% lower than would be predicted by a statistical model that includes a linear trend and accounts for solar cycle variation and the quasi-biennial oscillation.

Item #d93jun13

Two related items from Nature, 362(6421), Apr. 15, 1993:

"Satellite Maps Ozone Destroyer," M. Chipperfield (Dept. Chem., Univ. Cambridge, Cambridge CB2 1EW, UK), 592-593. Gives a research perspective on the following article.

"Stratospheric ClO and Ozone from the Microwave Limb Sounder on the Upper Atmosphere Research Satellite," J.W. Waters (Jet Propulsion Lab., 4800 Oak Grove Dr., Pasadena CA 91109), L. Froidevaux et al., 597-602. Reports the first 18 months of measurements by this instrument of ClO (the main form of reactive chlorine responsible for ozone depletion) and ozone. Chlorine in the lower stratosphere was almost completely converted to chemically reactive forms in both the northern and southern polar winter vortices. Concludes that chlorine depletion of stratospheric ozone is of greater concern than previously thought.

Item #d93jun14

"Stratospheric Chlorine Injection by Volcanic Eruptions: HCl Scavenging and Implications for Ozone," A. Tabazadeh (Dept. Atmos. Sci., Univ. California, Los Angeles CA 90024), R.P. Turco, Science, 260(5010), 1082-1086, May 21, 1993.

Although the output of volatile chlorine during a major volcanic event can greatly exceed the annual anthropogenic emissions of chlorine, observations show that volcanoes do not significantly contribute to the atmospheric chlorine burden. This paper uses a plume dynamics and thermodynamics model to demonstrate that HCl is removed effectively in condensed supercooled water, providing for the first time a mechanism explaining the observations, and supporting the importance of the anthropogenic contribution to ozone depletion.

Item #d93jun15

"Increased Chlorine Dioxide over Antarctica Caused by Volcanic Aerosols from Mount Pinatubo," S. Solomon (NOAA, 325 Broadway, Boulder CO 80303), R.W. Sanders et al., Nature, 363(6426), 245-248, May 20, 1993.

Levels of ClO were found to be elevated in the autumn of 1991, when polar stratospheric clouds were extremely unlikely to have been present, compared to a previous year. Model runs suggest that this result is related to the presence of Pinatubo aerosols, which probably contributed to the unprecedented depth and areal extent of Antarctic ozone depletion in 1992.