Organization Development in Precipitating Shallow Cumulus Convection: Evolution of Turbulence Characteristics

Abstract Horizontal organization or mesoscale variability is an important mechanism in the interaction of boundary layer with large-scale conditions. The development a precipitating cumulus trade wind studied using large-eddy simulations extensive horizontal domains, up to 160 × km 2 and fine grid resolution (40 m). cloud fields vary between different computational domain sizes. Mean profiles vertical velocity statistics do not significantly, both respect size when develops. Turbulent kinetic energy (TKE) rapidly increases increase TKE attributed component, whereas variance does change significantly. large domains blend local convective circulations motions leading dependence on LES size. Energy-containing length scales are defined based premultiplied spectra. When develops, spectra develop multiple peaks corresponding characteristic layer. All flow variables have small scale 1–2 km, which corresponds motions, e.g., updrafts clouds. Organization creates additional larger scales. growth rate linear it about 3–4 h −1 , agrees well cold pool radii. A single containing observed for entire run (even after organized convection develops) that fairly constant height.