Global stratospheric ozone profiles from GOME in near-real time

Abstract

The Global Ozone Monitoring Experiment (GOME) on the European Space Agency's (ESA) platform European Remote Sensing Satellite (ERS)-2 provides ozone column densities derived from ultraviolet (UV) Earth-shine spectra in nadir. The UV part of the spectrum also contains information on the vertical ozone distribution. However, until now, ozone profiles were not derived on an operational basis. Numerical weather prediction could benefit from assimilation of stratospheric ozone profiles, if they are retrieved with sufficient coverage of the Earth and within 3–4 h after observation. This requires a fast retrieval algorithm and near-real time (NRT) availability of the spectra. In this Letter, the first operational retrieval of global stratospheric ozone profiles in NRT is described. NRT availability of the spectra is assured by including carefully selected parts of the raw data in the GOME instrument monitoring files, which are obtained directly from the ESA ground stations. An existing off-line profile retrieval algorithm has been adapted to produce reliable stratospheric profiles within strict time constraints. The consequences for the quality of the profiles have been discussed.