The issue of impact of increasing atmospheric carbon dioxide (CO2) on climate is a current research topic of substantial interest to scientists, policy makers and the public. Realistic simulations of the effects of such greenhouse gases can be achieved through judicious use of a fully coupled ocean- atmosphere general circulation model which can properly simulate critical horizontal and vertical heat transfers that must occur in the ocean-atmosphere system. The objectives of the proposed research are to simulate and understand the changes in the equilibrium climate of the earth that are brought on by an increase in the atmosphere's CO2 concentration, and to analyze the mechanisms which determine the time required for this new equilibrium climate to be established. Specific tasks include (1) numerical simulations using the Oregon State University's atmospheric general circulation model (GCM) coupled to a mixed layer ocean model to analyze the soil moisture budget (in order to understand the hypothesized CO2-induced dessication of the Northern Hemishphere continents in summer); (2) inclusion of the diurnal cycle in the numerical model; (3) further analyses of the results from a 20-year integration of the fully coupled ocean- atmosphere GCM; (4) investigation of the oceanic uptake of two passive tracers in the coupled GCM to determine the extent to which the observed penetration of passive tracers into and through the oceans can be used as an analog for the CO2-induced warming of the ocean. This work is important because it will increase our understanding of and our capability to predict climatic changes that must occur in response to the increasing levels of atmospheric CO2.
