Technical Note: Validation of Odin/SMR limb observations of ozone, comparisons withOSIRIS, POAM III, ground-based and balloon-borne instruments

[摘要] The Odin satellite carries two instruments capable of determiningstratospheric ozone profiles by limb sounding: the Sub-MillimetreRadiometer (SMR) and the UV-visible spectrograph of the OSIRIS(Optical Spectrograph and InfraRed Imager System) instrument. A largenumber of ozone profiles measurements were performed during six yearsfrom November 2001 to present. This ozone dataset is here used to makequantitative comparisons with satellite measurements in order toassess the quality of the Odin/SMR ozone measurements. In a firststep, we compare Swedish SMR retrievals version 2.1, French SMR ozoneretrievals version 222 (both from the 501.8 GHz band), and theOSIRIS retrievals version 3.0, with the operational version 4.0 ozoneproduct from POAM III (Polar Ozone Atmospheric Measurement). In a secondstep, we refine the Odin/SMR validation by comparisons withground-based instruments and balloon-borne observations. We useobservations carried out within the framework of the Network forDetection of Atmospheric Composition Change (NDACC) and balloon flightmissions conducted by the Canadian Space Agency (CSA), the Laboratoirede Physique et de Chimie de l\'{}Environnement (LPCE, Orléans,France), and the Service d'Aéronomie (SA, Paris, France).Coincidence criteria were 5° in latitude×10° inlongitude, and 5 h in time in Odin/POAM III comparisons, 12 h inOdin/NDACC comparisons, and 72 h in Odin/balloons comparisons. Anagreement is found with the POAM III experiment (10–60 km) within−0.3±0.2 ppmv (bias±standard deviation) for SMR (v222,v2.1) and within −0.5±0.2 ppmv for OSIRIS (v3.0). Odin ozonemixing ratio products are systematically slightly lower than the POAMIII data and show an ozone maximum lower by 1–5 km in altitude. Thecomparisons with the NDACC data (10–34 km for ozonesonde, 10–50 kmfor lidar, 10–60 for microwave instruments) yield a good agreementwithin −0.15±0.3 ppmv for the SMR data and −0.3±0.3 ppmvfor the OSIRIS data. Finally the comparisons with instruments on largeballoons (10–31 km) show a good agreement, within−0.7±1 ppmv. The official SMR v2.1 dataset is consistent in allaltitude ranges with POAM III, NDACC and large balloon-borneinstruments measurements. In the SMR v2.1 data, no differentsystematic error has been found in the 0–35km range in comparisonwith the 35–60 km range. The same feature has been highlighted inboth hemispheres in SMR v2.1/POAM III intercomparisons, and nolatitudinal dependence has been revealed in SMR v2.1/NDACC intercomparisons.

[学科分类] 大气科学