February 28, 2007
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A Guide to Information on Greenhouse Gases and Ozone Depletion
Published July 1988 through June 1999
FROM VOLUME 9, NUMBER 9, SEPTEMBER 1996
OZONE DEPLETION: AIRCRAFT EMISSIONS
Transport Between the Tropical and Mid-Latitude Lower Stratosphere," C.M.
Volk (CMDL, NOAA, 325 Broadway, Boulder CO 80303), J.W. Elkins et al., Science,
272(5269), 1763-1768, June 21, 1996.
Used airborne in situ observations of molecules with a wide range of
lifetimes in a tropical tracer model to show that mid-latitude air is entrained
into the tropical lower stratosphere within about 13.5 months. Because this
exchange is slower than models generally assume, ozone at mid-latitudes may be
more sensitive to elevated levels of industrial Cl than currently predicted.
Nevertheless, nearly half the air in the tropical ascent region at 21 km is of
mid-latitude origin, implying that a significant fraction of emissions from
supersonic aircraft could reach the middle stratosphere, contributing to reduced
Simulation of the Aviation Release Impact on the Ozone Layer," S.P.
Smyshlyaev (Russian State Hydrological Institute), V.A. Yudin,
Atmos. & Oceanic Phys., 31(1), 116-124, June 1995. English
The authors' 2-D zonal mean photochemical model was used to study the
effects of heterogeneous processes of denitrification on sulfur aerosol in the
stratosphere, and of the washing down of OH in the troposphere. Demonstrates
that uncontrolled flights of 500 supersonic aircraft at 20 km altitude would
lead to depletion of total ozone of 10-15% in the beginning of the next century,
a problem of no less importance than destruction by CFCs.
"The Role of
Aerosol Variations in Anthropogenic Ozone Depletion at Northern Midlatitudes,"
S. Solomon (Aeronomy Lab., NOAA, 325 Broadway, Boulder CO 80303), R.W. Portmann
et al., J. Geophys. Res., 101(D3), 6713-6727, Mar. 20, 1996.
Quantifies the role of volcanic stratospheric aerosols in ozone depletion by
using satellite measurements of aerosol extent as input to a two-dimensional
dynamical-chemical model. The model simulated the effects of heterogeneous ozone
chemistry at northern midlatitudes over the last 15 years, a time period that
included major volcanic eruptions. Results show that interannual and decadal
changes in aerosols likely played a substantial role, along with trends in
anthropogenic Cl and Br, in triggering the observed ozone losses. The timing and
magnitude of future ozone losses in the area of investigation are likely to be
strongly dependent on volcanic aerosol variations, as well as on future Cl and
Br loading. The results also underscore the potential importance of any future
source of particles, such as supersonic aircraft emissions.
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