SIMULATN.TXT Atmosphere-Ocean Model Simulations 2000/05/17 Each Model simulation has two names: an internal run number and an external descriptive acronym. Each Model simulation was integrated for 150 years, from 1950 to 2099. C089 or Con1 ------------ A control simulation with constant 1950 atmospheric composition. Its initial state comes from a 40 year spin-up from Levitus 1994 initial conditions. C089 has significant climate drift in its surface air temperature amounting to 0.5øC in its first 60 years but less than 0.1øC for the last 90 years. C090 or GHG1 ------------ Uses observed greenhouse gases until 1990 and compounded 0.5% annual increases of CO2 after 1990. C090 has the same initial state and aersols as C089. C091 or SUL1 ------------ Uses the same greenhouse gases as C090 but also uses varying tropospheric sulfate aerosols that cool the planet when they increase. C091 has the same initial state as C089. The sulfate aerosols are from Mitchell et al. [1995] who provided two normalized sulfate loading patterns and global annual amounts for each pattern. The first pattern has the greatest aerosol concentration in central Europe and local maxima in the eastern United States and eastern China. The second pattern has a strong maximum in eastern China and weaker maxima in India, Turkey, southern Africa, and Mexico. Before 1991, the first pattern is used exclusively; after 2049, the second pattern is used exclusively; and from 1991 to 2049, a combination of the patterns is used. C092 or Con2 ------------ A control simulation with constant 1950 atmospheric composition. Its initial state comes from a 100 year spin-up from Levitus 1994 initial conditions. C093 or GHG2 ------------ Uses observed greenhouse gases until 1990 and compounded 0.5% annual increases of CO2 after 1990. It has the same initial state and aersols as C092. C093's gases include chlorofluorocarbons in addition to F11 and F12 whereas C090 and C091 did not. In 1990, the additional chloroflurocarbons have 60% of the radiative effect of F11 or 2% of the total greenhouse gas forcing since 1950. C094 or SUL2 ------------ Uses the same greenhouse gases as C093 and the same varying tropospheric sulfate aerosols as C091. C094 has the same initial state as C092. Cons is the ensemble of Con1 and Con2. GHGs is the ensemble of GHG1 and GHG2. SULs is the ensemble of SUL1 and SUL2.