The uniform distribution of atmospheric pressure at various altitudes on a spherical Earth can be explained by the gravitational forces acting on the Earth's atmosphere. Here's a brief explanation of how this works:
Gravitational Field: The Earth's gravitational field extends throughout its atmosphere. Gravity pulls all objects towards the center of the Earth, including the air molecules in the atmosphere.
Vertical Pressure Gradient: Due to the gravitational force, air molecules closer to the Earth's surface experience a greater weight or force per unit area than those at higher altitudes. This results in a vertical pressure gradient, where atmospheric pressure decreases as you move upwards.
Hydrostatic Equilibrium: The vertical pressure gradient is balanced by the weight of the air column above it. This balance, known as hydrostatic equilibrium, ensures that the pressure at any given altitude is sufficient to support the weight of the air above it.
Barometric Pressure: Barometric pressure is the pressure exerted by the atmosphere at a given altitude. The weight of the air column above a particular point causes the atmospheric pressure to decrease with increasing altitude. This decrease in pressure follows a well-known relationship known as the barometric formula.
Uniform Pressure Distribution: Although the pressure decreases with increasing altitude, the decrease is relatively gradual due to the large mass and thickness of the Earth's atmosphere. As a result, the vertical pressure gradient is relatively small compared to the total pressure at any given altitude. This leads to a nearly uniform distribution of atmospheric pressure across various altitudes.
It's important to note that these principles apply regardless of the shape of the Earth. The spherical shape of the Earth provides a gravitational field that naturally leads to a uniform distribution of atmospheric pressure. Alternative atmospheric models specific to a flat Earth would require additional assumptions or mechanisms to explain the uniform pressure distribution, as they deviate from the natural consequence of gravitational forces acting on a spherical Earth.