The Satellite Radiance Assimilation Group (SRAG) is currently
researching precipitation-affected satellite microwave radiances.
Recently developed scattering modules for precipitation are being
incorporated into the radiative transfer model RTTOV to compare model
brightness temeratures (calculated from NWP model fields of cloud and
precipitation) with observed SSM/I and AMSU brightness temperatures,
and in this way, it is hoped that we can gain insight into how the Met
Office model may respond to assimilation of this kind of data.
Another aspect of the work is a comparison between the
precipitation-affected AMSU-B brightness temperatures generated by
RTTOVSCATT and those produced by ARTS (Atmospheric Radiative Transfer
System), a RT model developed at Bremen University. It is hoped that
such a comparison will lead to a greater understanding of precipitation
and ice cloud modelling at millimetre wavelengths.