Application of φ-IASI to IASI: retrieval products evaluation and radiative transfer consistency

摘要

Retrieval products for temperature, water vapour and ozone have beenobtained from spectral radiances measured by the InfraredAtmospheric Sounding Interferometer flying onboard the firstEuropean Meteorological Operational satellite. These products havebeen used to check the consistency of the forward model and itsaccuracy and the expected retrieval performance. The study has beencarried out using a research-oriented forward-inverse methodology,called φ-IASI, that the authors have specifically developedfor the new sounding interferometer. The performance of theforward-inversion strategy has been assessed by comparing theretrieved profiles to profiles of temperature, water vapour andozone obtained by co-locating in space and time profiles fromradiosonde observations and from the European Centre forMedium-Range Weather Forecasts analysis. Spectral residuals havealso been computed and analyzed to assess the quality of the forwardmodel. Two versions of the high-resolution transmission molecularabsorption database have been used, which mostly differ for ozoneabsorption line parameters, line and continuum absorption of bothCO and HO molecules. Their performance has been assessed byinter-comparing the results, and a consistent improvement in thespectral residual has been found when using the most updatedrelease.