Use of synthetic RGB images in train

Abstract

This paper compares actual and synthetic (calculated) airmass RGB composites, before and after applying different corrections: (a) synthetic airmass RGB calculated with the satellite zenith angle corresponding to the pixel, versus others with fixed zenith angles (0º, 15º, 30º, 45º, 60º and 75º), to observe the blue shift close to the disk boundary due to a longer atmospheric path for the signal in oblique views, (b) Synthetic airmass RGB in areas of sinking tropopause with ozone intrusion for different values in the ozone concentration and humidity. The synthetic RGB for MSG are based on the use of the ECMWF model with RTTOV package and the METEOSAT Second Generation coefficients. Also synthetic MTG-IRS sounder RGBs have been generated. Based on the use of the RTTOV package with the IASI coefficients for one GRIB file of the ECMWF model, synthetic IASI RTTOV radiances are converted to synthetic MTG-IRS RTTOV brightness temperatures (BT). After one selection of the most adequate MTG-IRS brightness temperatures (BTs), two MTG-sounder synthetic RGBs are created. This is a proving ground experiment for the MTG sounder era.