Computation of global photochemistry with SMVGEAR II

摘要: Abstract A computer model was developed to simulate global gas-phase photochemistry. The solves chemical equations with SMVGEAR II, a sparse-matrix, vectorized Gear-type code. To obtain the original code modified allow computation of different sets reactions for urban, free-tropospheric, and stratospheric regions during same run. also grid cells in each region atmosphere be reordered according stiffness equations, time interval. Reordering speeds solutions by factor more than two compared not reordering. Two 30 day simulations chemistry coupled (with feedback) radiation field calculations over grid, were performed. In one simulation, results obtained 49,680 (15-layers general circulation grid), other, 96,048 (29-layer grid). both simulations, 200 “urban” (assumed below 900 mb) solved., 169 “free tropospheric” (225–900 solved, 115 “stratospheric” (above 225 solved. times required on single processor Cray 90 6.2 11.6 h, respectively, at an average speed approximately 362 megaflops.