SUMMARY OF A MINI WORKSHOP ON CUMULUS PARAMETERIZATION FOR MESOSCALE MODELS

Representing the effects of cumulus parameterization in numerical mode ls, known as cumulus parameterization, is of fundamental importance in atmospheric sciences. Despite a significant amount of effort devoted to improving the understanding of the parameterization problem, a gene ral theory of cumulus parameterization does not exist. The problem is particularly difficult for a mesoscale model with a grid size of 1-20 km because at such a resolution, a numerical model introduces an artif icial spectral gap by splitting an organized mesoscale convective syst em into resolvable and subgrid scales of motions. To provide a forum f or a focused discussion on the problem of cumulus parameterization for mesoscale models, the Mesoscale and Microscale Meteorology Division o f NCAR conducted a mini workshop on 11-12 September 1995 in Boulder, C olorado. Approximately 50 scientists participated in this workshop. Th e workshop was organized into six sessions: 1) overview of the cumulus parameterization problem, 2) cloud model perspectives, 3) model sensi tivity to convective parameterization, 4) mesoscale organization and m omentum transport, 5) mesoscale observations and verification of schem es, and 6) summary and general discussion. The scientific presentation s and the discussion are summarized from reports submitted by the sess ion chairs.