Retrieving cloud properties based on MTG/IRS (Meteosat Third Generation/InfraRed Sounder)

The next generation Meteosat Third Generation sounding satellite (MTG-S) is expected to be launched at the end of 2024. MTG-S will carry a hyperspectral interferometer, namely InfraRed Sounder (IRS), to provide a four-dimensional look at the atmosphere from a geostationary orbit. IRS will measure the radiance emission from the earth at 1960 infrared spectral channels at two bands (2250 ~ 1600 cm^-1 and 1210 ~ 680 cm^-1), with a spectral resolution of around 0.60 cm^-1.

Satellite-based cloud information is essential for the subsequent retrievals of atmospheric and surface products or for data assimilation in numerical weather prediction (NWP) models. Our project aims at studying the feasibility of retrieving cloud properties from MTG/IRS simulated data, notably cloud mask, cloud classification, and cloud top pressure/temperature/height following NWC SAF threshold methodologies. In this poster, the radiative transfer modelling by RTTOV is carried out at various atmospheric and cloud conditions to study the IRS spectral behaviours, especially at window channels. We will also discuss our preliminary retrieval of a cloud mask by brightness temperature thresholds using the selected IRS channels.