Sensitivity of a General Circulation Model to Changes in Infrared Cooling due to Chlorofluoromethanes with and without Prescribed Zonal Ocean Surface Temperature Change
A detailed analysis is presented of the sensitivity of the 12-layer tropospheric/stratosphoric NCAR global circulation model (GCM) on a zonal, global and regional basis to changes in global radiative balance due to an atmospheric burden of 10 ppb of chlorofluoromethanes (CFM's). Large changes in both the amplitude and phase of Northern Hemisphere winter planetary waves are an apparent consequence of the prescribed change. Also, large and statistically significant changes in the regional distribution of mean surface temperature and precipitation patterns result. However, many of the regional details of the model's response appear to be sensitive to the change in ocean surface temperature, which was imposed in the model run with CFM added. Hence, any more definitive indication of the climatic impact of CFM's must await the development of physically reasonable, interactive, coupled ocean-atmosphere models.