Chaos Metrics for Testing Lagrangian Particle Models

摘要

The Lorenz and Henon attractors and two atmospheric Lagrangian particle modelswere tested using self-affine fractal dimension, DA, Shannon information entropy, S, and the Lyapunov exponent, lambda, along with turbulent kinetic energy, vertical variance, and Brunt-Vaisala Frequency. Results show that (1) chaos metrics are a new set of tools to assess the micro behavior of Lagrangian particle models, (2) that periodicity in bifurcatory systems differs from wave behavior in fluids, since wave states are not limited to amplitude extrema. (3) Non-spectral particle models lead to unrealistic variations in 'the chaos metrics with changes in buoyant stability. (4) S and DA behave oppositely at times, implying that diffusion and dispersion are not equivalent, even in the absence of mean windflow.... atmospheric dispersion/diffusion, Lagrangian particle models chaos, Self-affine fractals, Turbulence, Atmospheric boundary layer, strange attractors, Monte Carlo models, Lyapunov.