Séminaire vendredi 20 octobre 11h00 / Seminar Friday Oct. 20, 11:00 AM Conférencier/Lecturer: Jason Cole (ARMP, Downsview) Sujet/Subject: Parameterizing the interaction between radiation and clouds in dynamical models Presentation: Anglais / English Lieu/Room: Grande salle du premier étage CMC iweb: http://iweb.cmc.ec.gc.ca/rpn/SEM web: http://collaboration.cmc.ec.gc.ca/science/rpn/SEM/index.php -------------------------------------------------- RESUME / ABSTRACT This seminar briefly discusses some issues related to parameterizing the interaction between clouds and radiation in large and small-scale dynamical models. To illustrate these issues, results from three sets of numerical experiments will be presented. Results from the Monte Carlo Independent Column Approximation (McICA) model intercomparison will be presented as an example of parameterizing radiative transfer in conventional global climate models (GCMs). A review of results from experiments with small-scale dynamical models will be presented to discuss the possible impact of using one-dimensional radiative transfer rather than three-dimensional radiative transfer in these models. Offline radiative transfer calculations suggest that differences in radiative fluxes between these two radiative transfer methods can be significant in highly resolved cloud models. Finally, results from numerical experiments performed using the Multiscale-Modelling Framework (MMF) will be presented. The MMF is a GCM that uses two-dimensional cloud system resolving models instead of conventional parameterizations. This allows us to examine potential impacts of excluding small-scale cloud-radiation interactions, as is done in conventional GCMs, on season-long simulations.