Velocity vectors and buoyancy perturbations in a vertically propagating
internal
gravity wave
Warm colors denote positive buoyancy perturbations, cold colors denote
negative
perturbations. Observe that:
- The perturbation velocity vector is always parallel to the lines of constant phase.
- Regions with downward motion are regions where the fluid is developing
positive
buoyancy and lead the regions of maximum buoyancy perturbation by one
quarter
of a wave period.
- Regions of maximum buoyancy perturbation are regions where the fluid is
undergoing an upward acceleration and lead the regions of maximum
vertical velocity by one quarter period.
- Although the net acceleration is upward in the region of maximum
buoyancy perturbation, the upward buoyancy forcing is partly compensated
by a downward perturbation pressure gradient force. (The perturbation
pressure field, which is not shown, is in phase
with the perturbation horizontal and vertical velocities.)
Zoom out to view the entire wave pattern
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This material is based upon work supported by the National Science Foundation under Grant No. ATM-0225441.
Last edited 17 Nov 06