WRF Model Simulations of Convective Weather for the Evaluation and Testing of NextGen Decision Making Tools

The evaluation of a NextGen decision support system, or tool, often involves testing the ability of a tool in hypothetical situation and comparing the performance over some baseline situation. A particular researcher may wish to impose a hazard to aviation at a particular location to then test their system. Such a capability is being developed for the evaluation of cockpit decision making support tools for self-separation around convective weather hazards. The Weather Research and Forecasting (WRF) modeling system is being used to develop this type of capability to support simulations at the NASA Langley Research Center Air Traffic Operations Laboratory (ATOL).

Two different methodologies are being applied to support the ATOL's simulation objectives. The first of these methods is the use the Advanced Research WRF (ARW)idealized simulations. Within the ARW distribution is the ability to run an idealized supercell from a set of base model configurations. The idealized simulations are conducted on a three dimensional Cartesian grid that can then be geo-referenced to an arbitrary location for the ATOL simulations. These 3-D simulations provide realistic weather features, in both space and time, which allow for the testing of self-separation decision support tools that flight crew will rely on in the future. Output from the model can be generated in sufficient detail for the environmental winds to be incorporated into a 4-D trajectory based simulation.

The second method being used is a non-standard application of the WRF real atmosphere forecast simulation capabilities. For these WRF model forecasts convective weather is forced at a particular location with the model domain through the modification of the surface temperature and land use characteristics. These simulations allow the researchers to conduct “What If” simulations in which convective weather is imposed at a particular location, such as along a dense flight corridor. These simulations provide for the ability to test procedures and software decision tools with and without the aviation hazard in the aircraft's path. Again the WRF model provides a 4-D data set that is environmentally consistent with the convective weather that is imposed in the simulation.

Examples of both types of simulations, idealized and real world forced convection, as well as the ATOL applications will be provided. Under development is the objective methodology for the throttling of the intensity of the convective features in the WRF simulations. Results of these efforts will be presented along with the base simulation methodologies.