Wind & Global Systems Vocab

Newton’s 1st Law

An object at rest remains at rest, and an object in motion remains in motion unless an outside force acts upon it

Newton’s 2nd Law

The net force acting upon an object is a product of its mass multiplied by its acceleration (F = ma)

Pressure Gradient Force (PGF)

The change of pressure in a particular area. There is a force created as a result of the change in pressure from one location to another. It is a vector with magnitude and direction that is directed from HIGH to LOW pressure. Initiates all horizontal wind movement

Sea Breeze Warming

A local thermal wind system that blows from a cool body of water onto a warmer landmass during the day.

Coriolis Force (COF)

The force exerted on our planets atmosphere and ocean surface currents due to the Earth spinning on its axis

• Zero at the equator

• Highest at the poles

• PGF is equal and opposite to COF, causing the clockwise and counterclockwise direction of the wind

Isobars

Used on weather maps to connect areas of equal pressure

• Wind is always parallel to isobars (they do not cross isobars)

• Wind speed is proportional to the pressure gradient

Centrifugal Force

an apparent or fictitious outward force that seems to push an object away from the center when it is viewed from a rotating frame of reference. Pushes the air outwards when turning

Friction

the force of drag that slows wind down at the surface. The force acts in the direction opposite of the wind. It is greatest at the surface and decreases as you increase altitude