Comparison of POAM III ozone measurements with correlative aircraft and balloon data during SOLVE

Abstract

The Polar Ozone and Aerosol Measurement (POAM) III instrument operated continuously during the Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE) mission, making approximately 1400 ozone profile measurements at high latitudes both inside and outside the Arctic polar vortex. The wealth of ozone measurements obtained from a variety of instruments and platforms during SOLVE provided a unique opportunity to compare correlative measurements with the POAM III data set. In this paper, we validate the POAM III version 3.0 ozone against measurements from seven different instruments that operated as part of the combined SOLVE/THESEO 2000 campaign. These include the airborne UV Differential Absorption Lidar (UV DIAL) and the Airborne Raman Ozone and Temperature Lidar (AROTEL) instruments on the DC‐8, the dual‐beam UV‐Absorption Ozone Photometer on the ER‐2, the MkIV Interferometer balloon instrument, the Laboratoire de Physique Molèculaire et Applications and Differential Optical Absorption Spectroscopy (LPMA/DOAS) balloon gondola, the JPL in situ ozone instrument on the Observations of the Middle Stratosphere (OMS) balloon platform, and the Système D'Analyze par Observations Zénithales (SAOZ) balloon sonde. The resulting comparisons show a remarkable degree of consistency despite the very different measurement techniques inherent in the data sets and thus provide a strong validation of the POAM III version 3.0 ozone. This is particularly true in the primary 14–30 km region, where there are significant overlaps with all seven instruments. At these altitudes, POAM III agrees with all the data sets to within 7–10% with no detectable bias. The observed differences are within the combined errors of POAM III and the correlative measurements. Above 30 km, only a handful of SOLVE correlative measurements exist and the comparisons are highly variable. Therefore, the results are inconclusive. Below 14 km, the SOLVE comparisons also show a large amount of scatter and it is difficult to evaluate their consistency, although the number of correlative measurements is large. The UV DIAL, DOAS, and JPL/OMS comparisons show differences of up to 15% but no consistent bias. The ER‐2, MkIV, and SAOZ comparisons, on the other hand, indicate a high POAM bias of 10–20% at the lower altitudes. In general, the SOLVE validation results presented here are consistent with the validation of the POAM III version 3.0 ozone using SAGE II and Halogen Occultation Experiment (HALOE) satellite data and in situ electrochemical cell (ECC) ozonesonde data.