Evaluation of ozonesondes, HALOE, SAGE II and III, Odin- OSIRIS and -SMR, and ENVISAT-GOMOS, -SCIAMACHY and -MIPAS ozone profiles in the tropics from SAOZ long duration balloon measurements in 2003 and 2004

Abstract

The performances of satellite and sondes ozone measuring instruments available in the tropics between 10 and 26 km during the southern hemisphere summer in 2003 and 2004, have been investigated by comparison with series of profiles obtained by solar occultation in the visible Chappuis bands using a SAOZ UV-Vis spectrometer carried by long duration balloons. When compared to SAOZ, systematic positive or negative altitude shifts are observed in the satellite profiles, varying from <50 m for the GOMOS v6.0b stellar occultation instrument, followed by +100/200 m for solar occultation systems (SAGE II v6.2, HALOE v19 above 22 km), but as large as −900 m for the OSIRIS limb viewing system. The ozone relative biases are generally limited, between −4% and +4%, for measurements in the visible Chappuis bands (SAGE II and SAGE III moon v3, GOMOS above 22 km and OSIRIS), the near IR (HALOE above 22 km) and the ozonesondes, but increase to +5.5% (SCIAMACHY IUP v1.63) though still in the visible, and +7% in the mid-IR (MIPAS NL v4.61) and the submillimetric range (SMR v222). Regarding precision, evaluated statistically from the zonal variability of ozone concentration, the best measurements are found to be those of SAGE II (2%), followed by HALOE above 22 km (3–4%), then the ozonesondes, SAGE III moon, SCIAMACHY and OSIRIS (4–5%), GOMOS above 22 km (~6%), MIPAS (8.5%) and finally SMR (16%). Overall, all satellite ozone measurements appear to be of little utility in the tropical troposphere except those of SAGE II (and eventually SAGE III), though low biased by 50% and of limited (50%) precision.