As you may know, the InterComparision of Radiation Codes for
use in Climate Models (ICRCCM) Programme (e.g., Fouquart et al.
1991) is being revived. One of its main initiatives is to assess
the performance of 1D, broadband radiative transfer models when
they are provided with profiles of cloud properties obtained by
horizontally averaging cloud-resolving model (CRM) data. Domain-
averaged benchmark fluxes and heating rates will be obtained by
a Monte Carlo photon transport algorithm acting directly on the
CRM fields.

The main objectives of this branch of ICRCCM are: i) to
investigate the range of 1D estimates and their discrepancies
with the benchmarks; and ii) discern how well the 1D codes both
interpret the 'degenerate' cloud information, and simulate
radiative transfer. The first part of this study deals with
shortwave radiation, and the second part deals with longwave.

Attached below is a brief overview of the project. Could you
please either pass this letter to the appropriate person in your
group, or if you are willing to participate, please fill-in and
return the short form at the end of this e-mail, and send it to
e-mail address:

howard.barker2@ec.gc.ca

Moreover, we would be most grateful if you forward this message
to anyone you feel may be interested but did not receive this
letter (we tried to cast the net as far as possible). We feel
this project will yield very interesting results and more
importantly provide guidance for development of more advanced and
efficient 1D radiation codes.

Thanking you in advance,
 

Howard Barker, Graeme Stephens, Philip Partain, and Gerald Potter
 

PS. Currently, a web-site is under construction for this project.
It's address will be relayed soon to positive respondents.