NEW EVIDENCE FOR OZONE DEPLETION IN THE UPPER-STRATOSPHERE

Differential absorption lidar measurements at the Meteorological Obser vatory Hohenpeissenberg between 1987 and 1993 show a statistically sig nificant ozone decrease between 32 and 42 km, peaking at about -1.7% p er year at 39 km altitude. This depletion is higher than reported by S AGE II or SBUV, yet the Hohenpeissenberg data agree very well with the results from Umkehr measurements. The observed ozone trend is in the upper range of predictions from photochemical models (-0.5 to -1.5% pe r year), whereas SBUV and SAGE II results are close to the lower end o f the simulations. The agreement with photochemical models indicates t hat the depletion is most likely caused by catalytic ozone destruction through anthropogenic chlorine.