Premium
Ozone depletion at mid‐latitudes: Coupling of volcanic aerosols and temperature variability to anthropogenic chlorine
Author(s) -
Solomon S.,
Portmann R. W.,
Garcia R. R.,
Randel W.,
Wu F.,
Nagatani R.,
Gleason J.,
Thomason L.,
Poole L. R.,
McCormick M. P.
Publication year - 1998
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/98gl01293
Subject(s) - ozone depletion , volcano , ozone , sulfate aerosol , stratosphere , atmospheric sciences , environmental science , latitude , chlorine , aerosol , ozone layer , sulfate , climatology , middle latitudes , geology , meteorology , chemistry , geography , geodesy , organic chemistry , seismology
Satellite observations of total ozone at 40–60°N are presented from a variety of instruments over the time period 1979–1997. These reveal record low values in 1992–3 (after Pinatubo) followed by partial but incomplete recovery. The largest post‐Pinatubo reductions and longer‐term trends occur in spring, providing a critical test for chemical theories of ozone depletion. The observations are shown to be consistent with current understanding of the chemistry of ozone depletion when changes in reactive chlorine and stratospheric aerosol abundances are considered along with estimates of wave‐driven fluctuations in stratospheric temperatures derived from global temperature analyses. Temperature fluctuations are shown to make significant contributions to model calculated northern mid‐latitude ozone depletion due to heterogeneous chlorine activation on liquid sulfate aerosols at temperatures near 200–210K (depending upon water vapor pressure), particularly after major volcanic eruptions. Future mid‐latitude ozone recovery will hence depend not only on chlorine recovery but also on temperature trends and/or variability, volcanic activity, and any trends in stratospheric sulfate aerosol.