THE 27 DAY SOLAR UV RESPONSE OF STRATOSPHERIC OZONE - SOLAR-CYCLE 21 VS SOLAR-CYCLE 22

A correlative study of ozone and the solar UV flux on the time scale o f a solar rotation shows an anomalous response of ozone in the upper s tratosphere during solar cycle 22. The study. which is based on the an alysis of ozone and solar UV flux measured by the SBUV/2 spectrometer on NOAA 11 (January 1989 December 1990), shows a sharp transition from an in-phase relation between ozone and the solar UV flux below 2 mb t o an almost out-of-phase relation above 1 mb. Such a phase change is n ot predicted by photochemical models and was not observed during solar cycle 21. The ozone measurements from the Nimbus-7 SBUV spectrometer from 1979 to 1984 showed an almost in-phase relation between ozone and the solar UV flux at these heights (in agreement with model predictio ns). Similar studies of ozone and temperature relations between 30 and 1 mb did not show significant changes from the solar cycle 21 to 22. The temperature oscillations appear to be primarily of dynamical origi n, with no apparent correlation with solar UV flux.