Section 5.4 Gravity Waves

Gravity Waves

Gravity acts as the restoring force on parcels displaced from hydrostatic equilibrium.

Pure gravity exists when the fluid is stably stratified.

Two types of gravity waves: external gravity waves: static stability is due to the

density discontinuity at the interface between two fluids

internal gravity waves: static stability arises from the stable stratification, buoyancy force acts as the restoring force

External Gravity Waves: Density Discontinuity

Air: Small Density

h’

h’

Water: Large Density

Transverse Waves:

Waves are oscillations (in field variables, such as velocity or pressure) that propagate in space.

Surface (External) Gravity Waves

Tsunami: Shallow Water Waves

Gravity Waves

Gravity acts as the restoring force on parcels displaced from hydrostatic equilibrium.

Pure gravity exists when the fluid is stably stratified.

Two types of gravity waves: external gravity waves: static stability is due to the

density discontinuity at the interface between two fluids

internal gravity waves: static stability arises from the stable stratification, buoyancy force acts as the restoring force

Internal Gravity Waves: Stable Stratification

Colder than the env.; Downward acc.

Warmer than the env.; Upward acc.

Vertical Velocity (w) Field During a Model Initial Adjustment Periods

Internal Gravity Waves Generated by Rapidly Rising Deep Convection

Mountain Waves and Clouds

Lenticular Cloud