The effects of improved parameterizations for orography, snowcover, surface fluxes and condensational processes on the climate of a low resolution GCM.

Specific refinements in parameterization include: 1) smoothing the original orography to greatly diminish undesirable topographic 'ripples' occurring near high mountain ranges; 2) adding snowcover on the Tibetan plateau and representing winter snowcover in middle latitudes more realistically; 3) decreasing the land ground wetness and adjusting the drag coefficient and parameters governing condensation-moist convective adjustment. Results of comparative 5-year integrations show that better parameterization in the low resolution model produces significant improvement in simulation without resorting to the use of higher horizontal or vertical resolution. -from Authors