AURORA BOREALIS : STOCHASTIC CELLULAR AUTOMATA SIMULATIONS OF THE EXCITED-STATE DYNAMICS OF OXYGEN ATOMS

ABSTRACT: Emissions from the 1 S and D excited states of atomic oxygen play aprominent role in creating the dramatic light displays aurora borealis seen in the skies.over polar regions of the Northern Hemisphere. A probabilistic asynchronous cellularautomaton model described previously Seybold, Kier, and Cheng, J Phys Chem 1998,w102, 886]891 has been applied to the excited-state dynamics of atomic oxygenx . Themodel simulates the time-dependent variations in ground  3 P .and excited-statepopulations that occur under user-defined probabilistic transition rules for both pulseand steady-state conditions. Although each trial simulation is itself an independent‘‘experiment,’’ deterministic values for the excited-state emission lifetimes and quantumyields emerge as limiting cases for large numbers of cells or large numbers of trials.Stochastic variations in the lifetimes and emission yields can be estimated from repeatedtrials. Q 1999 John Wiley & Sons, Inc. Int J Quant Chem 75: 751]756, 1999