Validation of the Suomi NPP Ozone Mapping and Profiler Suite total column ozone using Brewer and Dobson spectrophotometers

Abstract. This study mainly focuses on the validation of total column (TC) ozone data derived from the Ozone Mapping and Profiler Suite (OMPS) on board the NASA's Suomi National Polar-orbiting Partnership satellite (NPP). OMPS is an advanced suite of three hyperspectral instruments that maps global ozone on a daily basis and extends the more than 30 yr total ozone and ozone profile records. The algorithm used to derive OMPS TC ozone is adapted from the heritage of Total Ozone Mapping Spectrometer (TOMS) Version 7 algorithm but with a number of enhancements. Validation is primarily performed through comparisons with an ensemble of 74 global distributed Brewer and Dobson spectrophotometers measurements. Linear regression performs fair agreement between OMPS TC ozone and ground-based TC ozone measurements with root mean square error (RMSE) around of 3% (10 DU). Comparison shows that OMPS TC ozone estimates 0.21% higher than Brewer measurements average, with station-to-station standard deviation of 3.14%. As comparing with Dobson measurements, OMPS TC ozone averages 0.86% higher than the station average with standard deviation of 3.05%. The relative differences between OMPS and ground TC ozone were analysed varying with latitude and time as well as viewing geometry respectively. Comparisons show relative differences within 2% over most of latitude and viewing conditions. Only comparing with Brewer measurements did it show an OMPS TC ozone dependent error, large negative bias was observed as OMPS TC ozone below 220 DU and positive bias shown above 460 DU.