SIMULA4X3.TXT 4x3 Atmosphere-Ocean Model Simulations 2005/12/09 C480: 1850 to 2100, Control Simulation -------------------------------------- A control simulation with constant 1850 atmospheric composition. Its initial state comes from a 200 year spin-up from Levitus 1994 initial ocean conditions; the last 50 years has identical coding to that used in the simulation itself. C480 has very little drift in its surface air temperature, northern hemisphere sea ice cover, or Atlantic Ocean heat transport (unlike the older 5x4 Model). On the other hand, the southern ice cover decreases significantly over time, and there are probably long term drifts in the ocean. C483: 1850 to 2000, Twentieth Century Experiment ------------------------------------------------ Starting from the same initial state as C480, C483 uses yearly estimated and observed greenhouse gases and Boucher's (via PCMDI) estimated values and spatial distributions of sulfate burdens. With greenhouse gas changes only, a Model experiment would be 1.2 (C) warmer than C480 by the year 2000. With its increasing tropospheric sulfate aerosols, C483 is 0.8 (C) warmer than C480 by the year 2000. C483 = C485: 2000 to 2100, IPCC SRES A1B ---------------------------------------- Experiment C483 is continued as run C485 after the year 2000. Observed greenhouse gases are used up to year 2003, but gases specified by SRES A1B are used after 2003. Boucher's sulfate burdens that are designated by SRES A1B are used. C484: 2000 to 2100, IPCC SRES B1 -------------------------------- C484 and C485 have the same initial state and the same greenhouse gases up to and including the year 2003. Gases for later years and the sulfate burdens of Boucher are specified by SRES B1. C490: 1850 to 2100, Control Simulation -------------------------------------- Coding wise, C490 is virtually identical to C480, but C490's initial state is from C480 after 50 years (a spin-up of 250 years from Levitus ocean conditions). C490 in 1850 diverges from C480 of 1900 because the Sun's position (the time of vernal equinox) is slightly different. C493: 1850 to 2000, Twentieth Century Experiment ------------------------------------------------ Coding wise, C493 is virtually identical to C483, but C493's initial state is the same as C490. C493 = C495: 2000 to 2100, IPCC SRES A1B ---------------------------------------- C495 and C485 use identical greenhouse gases and sulfate burdens, but their initial states are different. C495 is a continuation of C493. C494: 2000 to 2100, IPCC SRES B1 -------------------------------- C494 and C484 use identical greenhouse gases and sulfate burdens, but their initial states are different. C494 has the same initial state as C495.