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 1, JANUARY 1996
OZONE DEPLETION: OZONE CHEMISTRY AND DYNAMICS
"Total Ozone Trends from Quality-Controlled, Ground-Based Data
(1964-1994)," R.D. Bojkov (Atmos. Environ. Serv., 4905 Dufferin St.,
Downsview ON M3H 5T4, Can.), L. Bishop, V.E. Fioletov, J. Geophys. Res.,
100(D12), 25,867-25,876, Dec. 20, 1995.
Presents seasonal and year-round trend analyses for 46 Dobson stations, for
four regions of the former USSR and for the two polar regions. Most of the data
and calibrations used were the basis for the 1994 WMO/UNEP Ozone Assessment, but
results provide a further estimate of ozone trends in the northern middle
latitudes by adding another season of extremely ozone in the winter and spring
of 1994-1995. Middle latitude trends show continuous year-round decline since
1979 of -4.3% and -4.1% per decade in the Northern and Southern Hemispheres,
respectively. The winter-spring trend was -7.5% for the Arctic, and -22% in
spring over Antarctica.
"Observational Studies of the Role of Polar Regions in Mid-Latitude
Ozone Loss," R.L. Jones (Ctr. Atmos. Sci., Dept. Chem., Univ. Cambridge,
U.K.), A.R. MacKenzie, Geophys. Res. Lett., 22(24), 3485-3488,
Dec. 15, 1995.
The loss of ozone in the middle latitudes has prompted debate over whether
and how perturbations to the chemical composition within the polar vortex may
contribute to ozone reduction at lower latitudes. In this paper, in-situ
observations of nitrogen compounds from both hemispheres are used to show that
the transport of air from the polar vortex appears small, at least above the 400
K potential temperature surface.
"The Response of Stratospheric Ozone to Volcanic Eruptions:
Sensitivity to Atmospheric Chlorine Loading," X.X. Tie (NCAR, POB 3000,
Boulder CO 80307), G. Brasseur, ibid., 22(22), 3035-3038, Nov.
Model calculations described here suggest that the ozone decreases observed
a few years after the eruptions of Mt. Pinatubo and El Chichon may have been
unique in the Earth's history, and are directly linked to the presence of
industrially manufactured chlorofluorocarbons. For chlorine loadings prior to
1980, the model shows that ozone column abundance would have increased
after a large eruption, but after 1980, as chlorine levels became higher, the
ozone response was negative. The response of ozone is expected to become
positive again in the future as chlorine loadings diminish in response to
"Southern Hemisphere Mid-Latitude Ground-Based Measurements of
ClONO2: Method of Analysis, Seasonal Cycle and Long-Term Trend," A.R.
Reisinger (Natl. Inst. Water Res., Lauder, P.B. 50061, Central Otago, N.
Zealand), N.B. Jones et al., J. Geophys. Res., 100(D11),
23,183-23,193, Nov. 20, 1995.
Reports the first long-term analysis of the total column of chlorine nitrate
(ClONO2) from ground-based infrared solar absorption measurements recorded at
Lauder, New Zealand. Data show the first recorded seasonal variation of CLONO2,
with a maximum in early September. An increase of 1.3% per year over the
four-year period is consistent with determinations of the recent growth rate of
"Variations of the Total Ozone Trend over the Northern Hemisphere
Mid-latitudes in Winter-Spring Seasons 1963-1964 through 1992-1993," J.S.
Krzyscin (Inst. Geophys., Polish Acad. Sci., ul. Ks. Janusza 64, 01-452, Warsaw,
Poland), ibid., 100(D10), 20,927-20,935, Oct. 20, 1995.
Applies a multiple regression model to midlatitude total ozone observations
to isolate the anthropogenic trend component from natural fluctuations in the
polar low-pressure pattern. The analysis estimates the anthropogenic trend
component to be 3.5% per decade since winter-spring of 1969-1970, and supports
the hypothesis that the increased ozone loss over the northern midlatitudes
during the 1980s and 1990s may have been partially caused by natural long-term
oscillations in atmospheric dynamics.
"Further Ozone Decline During the Northern Hemisphere Winter-Spring
of 1994-1995 and the New Record Low Ozone over Siberia," R.D. Bojkov
(Atmos. Environ. Serv., 4905 Dufferin St., Downsview ON M3H 5T4, Can.), V.E.
Fioletov et al., Geophys. Res. Lett., 22(20), 2729-2732, Oct.
Ground-based total ozone observations show that from mid-January to early
April 1995, very low ozone values were again observed in northern middle and
high latitudes, with deficiencies of 10-20% being typical, and exceeding 35-40%
in one region and time period.
"Recovery of Ozone in the Lower Stratosphere at the South Pole
During the Spring of 1994," D.J. Hofmann (CMDL, NOAA, 325 Broadway, Boulder
CO 80303), S.J. Oltmans et al., Geophys. Res. Lett., 22(18),
2493-2496, Sep. 15, 1995.
During 1994, springtime Antarctic ozone measured at the South Pole did not
reach the record lows recorded during 1993. The recovery is probably the result
of diminishing stratospheric aerosol from the Pinatubo eruption. However, the
rate of decline in the 15-20 km region was as fast as or faster than in 1992 and
1993, indicating continuing saturation of the ozone destroying chemistry, which
is to be expected as stratospheric chlorine amounts continue to rise.
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