APPROXIMATE SEPARATION OF VOLCANIC AND 11-YEAR SIGNALS IN THE SBUV-SBUV 2 TOTAL OZONE RECORD OVER THE 1979-1995 PERIOD/

The combined Nimbus 7 SBUV, NOAA 11, and preliminary NOAA 9 SBUV/2 mon thly zonal mean total ozone data set, extending from January 1979 to D ecember 1995, is analyzed with a multiple regression statistical model that includes a term to describe the direct effect of volcanic aeroso ls on total ozone. Outside of polar regions, which are not included in this analysis, the volcanic regression coefficients in the northern h emisphere are negative (consistent with heterogeneous chemical losses of ozone on volcanic sulfate aerosols) and reach their maximum values between 40 degrees N-60 degrees N latitude. Although inclusion of the aerosol term in the statistical model introduces some additional uncer tainty to the derived solar response, statistically significant values of the solar coefficients are found in northern and southern subtropi cal regions throughout the year, with maximum amplitudes of similar to 2.5% at 30 degrees latitude in both hemispheres during winter. We con clude that the 11-year signal in the SBUV-SBUV/2 total ozone record is approximately separable from volcanic aerosol effects.