COMPARISON OF STOIC 1989 GROUND-BASED LIDAR, MICROWAVE SPECTROMETER, AND DOBSON SPECTROPHOTOMETER UMKEHR OZONE PROFILES WITH OZONE PROFILESFROM BALLOON-BORNE ELECTROCHEMICAL CONCENTRATION CELL OZONESONDES

Ground-based measurements of stratospheric ozone using a Jet Propulsio n Laboratory (JPL) lidar, a NASA Goddard Space Flight Center (GSFC) li dar, a Millitech Corporation/NASA Langley Research Center (Millitech/L aRC) microwave spectrometer, and a NOAA Dobson ozone spectrophotometer were compared with in situ measurements made quasi-simultaneously wit h balloon-borne electrochemical concentration cell (ECC) ozonesondes d uring 10 days of the Stratospheric Ozone Intercomparison Campaign (STO IC). The campaign was conducted at Table Mountain Observatory, Califor nia, during the summer of 1989. ECC ozonesondes were flown by NOAA Cli mate Monitoring and Diagnostics Laboratory (CMDL) personnel as well as by personnel from the NASA Wallops Island Flight Facility (WFF). With in the altitude range of 20-32 km, ozone measurement precisions were e stimated to be +/-0.6 to +/-1.2% for the JPL lidar, +/-0.7% for the GS FC lidar, +/-4% for the microwave spectrometer, and +/-3% for the NOAA ECC ozonesonde instruments. These precisions decreased in the 32 to 3 8.6-km altitude range to +/-1.3, +/-1.5, and +/-3% to +/-10% for the J PL lidar, GSFC lidar, and the ECC sondes, respectively, but remained a t +/-4% for the microwave instrument. Ozone measurement accuracies in the 20 to 32 km altitude range were estimated to be +/-1.2 to +/-2.4% for the JPL lidar, +/-1.4% for the GSFC lidar, +/-6% for the microwave radiometer, and +/-5% for the ECC ozonesondes. The accuracies decreas ed in the 32 to 38.6-km altitude range to +/-2.6, +/-3.0, +/-7, and 1 +/-4% to -4 +/- 10% for the JPL lidar, the GSFC lidar, the microwave s pectrometer, and the ECC ozonesondes, respectively. While accuracy est imates for the ECC sondes were obtained by combining random and estima ted bias errors, the accuracies for the lidar instruments were obtaine d by doubling the measurement precision figures, with the assumption t hat such doubling accounts for systematic errors. Within the altitude range of 20-36 km the mean ozone profiles produced by the JPL, GSFC, a nd the Millitech/LaRC groups did not differ from the mean ECC sonde oz one profile by more than about 2, 4, and 5%, respectively, Six morning Dobson instrument Umkehr observations yielded mean ozone amounts in l ayers 3 and 5-7 that agreed with comparison ECC ozonesonde data to wit hin +/-4%. In layer 4 the difference was 7.8%, (Less favorable compari son data were obtained for six afternoon Umkehr observations made in h ighly polluted near-surface air.) This good agreement in overall resul ts obtained lends credence to the reliability of the ozone measurement s made at Table Mountain Observatory during STOIC 1989.