Overview

  1. Build a 3-D model (mesh) of the air
  2. prescribe an initial wind field
  3. compute final mass/momentum conserving wind field.
  • Requires a good estimate of the initial wind field
  • Adjusts for terrain (conservation of mass/momentum)
  • Parameterizations for some other effects (e.g., diurnal slope flows)
fiyah!

To see a live WindNinja Simulation Online click here

Assumptions

  • No moisture/latent heat effects, steady-state, no conservation of energy
  • Conservation of momentum is optional
  • Some thermal energy parameterizations
  • diurnal slope flows, non-neutral atmospheric stability

Advantages

  • Fast
  • low computational requirements
  • simple to run
  • high spatial resolution

Limitations

  • No conservation of energy or large-scale/complex flow effects (e.g., land-sea breezes, thunderstorms)

More Information

Terrain Resolution

WindNinja approximates complex terrain with a finite number of points

WindNinja Solvers

WindNinja has two solvers, Conservation of Mass and Conservation of Mass/Momentum

Thermal Paramaterizations

Diurnal Winds and Non-neutral stability

Who Uses WindNinja?

SFE Webinar: WindNinja - Modeling Winds in Complex Terrain for
Wildland Fire Applications

A webinar on how WindNinja works, hosted on Youtube.