The pressure signals of figure 2 have been superimposed on each other (taking into account the difference in hydrostatic pressure) and are shown in part.
The pressure is also observed to return to the local hydrostatic value with less overshoot.
The flow remains hydrostatic and departs from geostrophic only in the first equation of motion.
Further, we assume that the waves are sufficiently long for the hydrostatic equation to be valid.
As the top of the cavity moves further away from the probes, the pressure returns to the local hydrostatic value.
The next step in analysing large-scale flow is to show that it is hydrostatic.
Thus, any departure from hydrostatic balance gives rise to flow, with effectively immediate adjustment of velocity profile across the narrow gap.
In a homogeneous fluid at rest, ver tical momentum conservation requires that the fluid be in hydrostatic balance.
