SAGE II/Umkehr ozone comparisons and aerosols effects: An empirical and theoretical study. Final report
The objectives of this research were to 1) To examine empirically the aerosol effect on Umkehr ozone profiles using SAGE II aerosol and ozone data, 2) To examine theoretically the aerosol effect on Umkehr ozone profiles, 3) Examine the differences between SAGE II ozone profiles and both old-and new-format Umkehr ozone profiles for ozone-trend information, 4) Reexamine SAGE l-Umkehr ozone differences with the most recent version of SAGE I data, and 5) Contribute to the SAGE II science team.
... g the first year, Drs. Newchurch/UAH and Cunnold/Georgia Tech were funded on this project. During the second and third years, Drs. Allen and Herman are also funded. During the first year (FY94) of this research, we constructed a substantial database of available SAGE and Umkehr ozone measurements (540 SAGE I coincidences over 24 stations, and 7448 SAGE II coincidences over 34 Umkehr stations from 1979 to 1995). Newchurch and Cunnold  reported some results of the aerosol effect on Umkehr ozone profiles. A preliminary look at coincidences from a reasonable sample of stations [Newchurch et al., 1995a and Newchurch, 19931 indicated substantial differences between the 1964 Umkehr algorithm results and the 1992 Umkehr algorithm results. Because the most important aspect of the Umkehr record is multi-decadal length for trend analysis [WMO, 1988; Reinsel et a/., 1989, Stolarski et a/., 19921, we must understand how these differences between new and old Umkehr reduction algorithms propagate into the ozone trends. From inspection of the differences in the SAGE-Umkehr comparisons, we predicted [Newchurch, 19941 ozone trend estimates from new Umkehrs would be dissimilar to those previously deduced from old Umkehrs. Analysis of trends from 12 northern hemisphere stations using the new Umkehr inversion vary from 0% to -1 3% per decade at 40 km and -4% to +6% per decade at 20 km [Reinsel et a/., lJDatalRpWDoe/finaI dm Monday, July 20,1998 11.45 AM _.e .