Pressure-gradient force

Pressure-gradient force is the force per unit mass exerted on a fluid by spatial differences in pressure. It accelerates air from higher toward lower pressure, with its direction and magnitude set by the pressure gradient.

Pressure gradient: A spatial change in pressure, described by the rate and direction of pressure change. The force is the acceleration caused by this pressure variation across the air.
Isobar: A line on a map connecting locations with equal atmospheric pressure. Isobar spacing indicates the horizontal pressure gradient and therefore the force’s strength.
Atmospheric pressure: The force per unit area exerted by the weight and motion of air. Spatial differences in this quantity generate the pressure-gradient force.
Gravity: The attraction between masses, which near Earth pulls objects toward its center. Gravity acts mainly downward, while horizontal pressure gradients drive much atmospheric flow.
Ideal gas law: An equation relating a gas’s pressure, volume, temperature, and amount of substance. Temperature and density differences help create the pressure variations that drive the force.
Cyclone: A rotating atmospheric circulation around a low-pressure center. The inward pressure-gradient force helps draw air toward a cyclone’s low-pressure center.
Air density: The mass of air contained in a unit volume. For a given pressure gradient, density affects the force per unit mass experienced by air.
Centrifugal force: An apparent outward force in a rotating reference frame. It can balance pressure-gradient and Coriolis forces in curved atmospheric flows.
Geostrophic wind: A wind in which the pressure-gradient force balances the Coriolis force. This balance explains why large-scale winds often flow along isobars instead of directly down the pressure gradient.
Anticyclone: A rotating atmospheric circulation around a high-pressure center. The outward pressure-gradient force contributes to air spreading away from an anticyclone’s high-pressure center.

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