Convective cloud top altitude and temperature estimates from geostationnary satellites

Estimating cloud top altitude and temperature is particularly useful for analyzing and tracking convective clouds. As part of Eumetsat's SAF Nowcasting program, Météo France develops algorithms for retrieving cloud properties from geostationary satellites. More specifically, the Cloud Top Temperature and Height (CTTH) product is produced by comparing observations from different infrared channels with the corresponding simulations performed by the RTTOV radiative transfer model (Menzel et al., 1983; Schmetz et al., 1993; Saunders et al., 2018).

The launch of the polar satellite EarthCARE in 2024 offers interesting opportunities for evaluating and improving these algorithms. In particular, it carries a radar (CPR - Cloud Profiling Radar) and an atmospheric lidar (ATLID - ATmospheric LIDar), enabling cloud profiles to be produced vertically from the satellite, providing a precise measurement of cloud top altitude.

In this presentation, different methods of cloud top restitution from geostationary satellites will be evaluated on convective clouds and potential improvements will be discussed.

 

References

Menzel W.P., Smith W.L., and Stewart T.R., 1983, Improved Cloud Motion Wind Vector and Altitude Assignment using VAS, Journal of Climate and Applied meteorology, 22, 377-384.

Saunders, R., Hocking, J., Turner, E., Rayer, P., Rundle, D., Brunel, P., Vidot, J., Roquet, P., Matricardi, M., Geer, A., Bormann, N., and Lupu, C., 2018, An update on the RTTOV fast radiative transfer model (currently at version 12), Geosci. Model Dev., 11, 2717–2737

Schmetz J., Holmlund K., Hoffman J. and B.Strauss, 1993, Operational cloud motion winds from Meteosat infrared images. J.Appl.Meteor, 32, 1207-1225.