Characteristics of Tropical and Midlatitude Convectively-Induced Turbulence from High Resolution Simulations

Convectively-induced turbulence (CIT) continues to be a forecast challenge as it occurs on scales that cannot be resolved by current operational models. While numerous scientific studies have aided the development of thunderstorm avoidance policies for aviation operations, the efficiency and application of these policies in various regions are limited. Another hazard that is not addressed in current avoidance policies is the turbulence potential associated with developing convection. Out-of-cloud turbulence caused by developing convection is a significant hazard to aviation because developing convection occurs on a small temporal scale, is difficult to accurately predict the initiation location and timing, and is hard to detect in data sparse regions especially if the pilot is using inadequate on-board radar tilt management. In this study, from the subset of numerous cases, one tropical and one midlatitude aviation incident that resulted in passenger or crew injuries due to convectively-induced turbulence are simulated at high temporal and spatial resolution using the Weather Research and Forecasting model. High resolution simulations of CIT have been limited to midlatitude regions, whereas this study will allow for a more thorough investigation of CIT characteristics (in-cloud and out-of-cloud) including gravity wave properties in various environmental conditions during the development stage of convective growth. The spatial and temporal coverage of out-of-cloud turbulence in terms of intensity are characterized for the development stage of convection using eddy dissipation rate diagnostics. Convective properties such as echo top height, vertical velocity, and radar reflectivity are compared among the simulations and related to turbulence potential. The results of this study provide new details on CIT properties that can be used to adapt the thunderstorm guidelines for regional and convective-type dependencies.