Intercomparison of stratospheric ozone profiles obtained by stratospheric aerosol and gas experiment II, halogen occulation experiment, and ozone sondes in 1994-1995
Stratospheric ozone mixing ratio profiles measured by satellite-borne Stratospheric Aerosol and Gas Experiment (SAGE 11 data version 5.93) and Halogen Occultation Experiment (HALOE data versions 17 and 18) are compared with each other and with balloon-borne ozonesonde profiles at Payerne, Lauder, and Macquarie Island stations during 1994-1995. The SAGE 11-HALOE ozone mixing ratio profiles are compared at 13-55 km altitudes, and the satellite-ozonesonde profiles are compared at 13-33 km altitudes. It is found that HALOE data version 18 ozone values are systematically larger than HALOE data version 17, particularly in the lower stratosphere. HALOE data version 18 ozone profiles are about 2 per cent, 5-8 per cent, and 10-20 per cent larger than the corresponding HALOE data version 17 at 40-55, 25-40, and 15-25 km altitudes, respectively. The new version of HALOE ozone agrees better with SAGE 11 and Payerne ozonesonde profiles than HALOE data version 17 does. In general, the agreements bet ween satellite-borne sensors and ozonesondes are all within their stated level of uncertainties. Intercomparison results between SAGE 11-Payerne ozonesonde and SAGE II-Lauder ozonesonde are compared with earlier comparative studies between SAGE II Payerne ozonesonde and SAGE II-Lauder ozonesonde by Veiga et al. (1995). Better agreement is achieved at Payerne station, but no improvement is discernible at Lauder ozonesonde station. At altitudes above 20 km the intercomparisons between SAGE II and HALOE data version 18 and between SAGE 11 and ozonesondes seem to indicate that aerosol has no statistically significant impact on SAGE 11 ozone retrieval during the period of 1994-1995.