S. Chandra et al., RECENT TRENDS IN OZONE IN THE UPPER-STRATOSPHERE - IMPLICATIONS FOR CHLORINE CHEMISTRY, Geophysical research letters, 22(7), 1995, pp. 843-846
We have studied the implications of recent trends in the annual mean a
nd the amplitude of the annual harmonic of ozone in the upper stratosp
here from the 15 years of the combined data from the Nimbus-7 SBUV and
the NOAA-11 SBUV/2 instruments. This was done in the context of the G
SFC 2D model predictions of these trends which are based on plausible
scenarios of anthropogenic Cly increase in the atmosphere. The compari
son of the observed and model-estimated annual mean ozone trends show
some similarity in their latitude and altitude characteristics. Both t
he model and data show a maximum ozone decrease of -6 to -10% per deca
de at high latitudes in the upper stratosphere. However, there are als
o significant differences between the observed and computed trends whi
ch may be related to both the model uncertainty and the uncertainty fo
r the long term instrument drift. The observations also suggest a decr
ease of 10-25% per decade in the annual amplitude of ozone at 2 mb bet
ween 40-degrees-60-degrees in both hemispheres, with a relatively larg
er interannual variability in the northern hemisphere. These values ar
e in general agreement with the model predictions and thus provide add
itional support in favor of the chlorine induced changes in ozone in t
he upper stratosphere.