Hydrostatic equilibrium occurs when:
A)the force of gravity and the vertical pressure gradient both act to push air upward.
B)the force of gravity and the vertical pressure gradient both act to push air downward.
C)the force of gravity and the vertical pressure gradient have equal value and oppose each other.
D)large air masses are moving either up or down.

Question

Quizplus · Accepted Answer

Hydrostatic equilibrium is achieved when the vertical pressure gradient force is balanced by the gravitational force, resulting in a state of no net force. This means that the force of gravity is exactly counteracted by the pressure gradient force, resulting in a stable atmospheric state where there is no net motion of air mass either upwards or downwards. Therefore, choice C is the correct option. Choices A, B, and D are incorrect because they describe scenarios that are not in equilibrium.

Hydrostatic Equilibrium Occurs When