Nonclassical Mesoscale Fronts Caused by Solitary Waves 1. Hydraulic Jumps 2. Bores 3. Density Currents

1. Hydraulic Jumps The dynamic upfold of isentropic surfaces at the location of abrupt mass flux convergence accompanying a local near-surface surge in mass.

2. Bores A shallow, intense, near-surface wave forced by an upstream or downstream mass impulse and very effective at forward downward momentum fluxes and rearward upward momentum fluxes.

3. Density Currents A local, near-surface density gradient typically preceding relatively cold air or a surge of mass flowing out of deep convection, down a mountain, parallel to a mountain or over a relatively smooth surface.

Bore Genesis Supercriticality, Partial Blocking, Complete Blocking and Subcriticality all refer to the relative depth of the impulsive density current (Do) to the depth of the downstream inversion (Ho).

Bore Genesis Subcriticality: Ho >>> Do Supercriticality: Ho >> Do Partial Blocking: Ho > Do Complete Blocking: Ho < Do

Velocity Equations 1. 2. 3. 4.

Density Current Depth