a) We can expect the atmospheric pressure to decrease as we go from the beach up the mountain. There is less air up in the mountain, which means the pressure will decrease.

Would the atmospheric pressure increase or decrease on the top of a mountain?

Pressure with Height: pressure decreases with increasing altitude. The pressure at any level in the atmosphere may be interpreted as the total weight of the air above a unit area at any elevation. At higher elevations, there are fewer air molecules above a given surface than a similar surface at lower levels.

What happens to air pressure when you go up to the mountains?

As altitude rises, air pressure drops. ... As altitude increases, the amount of gas molecules in the air decreases—the air becomes less dense than air nearer to sea level. This is what meteorologists and mountaineers mean by "thin air." Thin air exerts less pressure than air at a lower altitude.