Intercomparison between GOME Ozone Profiles Retrieved by Neural Network Inversion Schemes and ILAS Products

The Global Ozone Monitoring Experiment (GOME) is a spectrometer boarded on the European Space Agency (ESA) Remote Sensing Satellite (ERS)-2, which measures, in a nadir-viewing geometry, the solar radiation that is scattered by the earth's atmosphere. Measurements are performed in the wavelength range of 240-790 nm, with a spectral resolution of 0.2-0.4 nm. Vertical ozone profiles can be retrieved from observations of the backscattered light using neural network inversion schemes, which are able to provide real-time estimations with an accuracy that is comparable with the accuracy obtained by means of traditional optimal estimation (OE) methods, which are high-computation demanding and generally offline. In this study, neural network-estimated profiles have been compared to the ozone profiles that are retrieved by the Improved Limb Atmospheric Spectrometer (ILAS) boarded on the Japanese Advanced Earth Observing Satellite (ADEOS). From November 1996 to June 1997 more than 3000 coincident profiles have been found in the northern and southern high-latitude regions of the globe. The relative difference between GOME and ILAS profiles over the entire dataset and over subsets corresponding to different measurement and seasonal conditions have been calculated, and the results have been critically discussed.