Ozone profile retrieval from nadir TROPOMI measurements in the UV range

Abstract. The TOPAS (Tikhonov regularised Ozone Profile retrievAl with SCIATRAN) algorithm to retrieve vertical profiles of ozone from space-borne observations in nadir-viewing geometry has been developed at the Institute Environmental Physics (IUP) University Bremen and applied TROPOspheric Monitoring Instrument (TROPOMI) L1B spectral data version 2. Spectral between 270 329 nm are used for retrieval. A recalibration measured radiances is done using MLS/Aura. Studies synthetic spectra show that individual stratosphere can be retrieved an uncertainty about 10 %. In troposphere, retrieval errors larger depending on a priori profile used. resolution above 18 km 6–10 km, it degrades 15–25 below. troposphere strongly dependent solar zenith angle (SZA). TROPOMI were validated ozonesondes stratospheric lidars. Above comparison sondes shows excellent agreement within less than ±5 % all latitudes. standard deviation mean differences Below relative tropics northern latitudes still quite good, remaining ±20 At southern latitudes, up +40 occur 15 km. 50 7–18 25 below 7 validation ground-based lidar measurements also very good agreement. 18–45 results 1 d compared Microwave Limb Sounder (MLS) Aura satellite Mapping Profiler Suite (OMPS-LP). difference was found largely 20–50 except high