Chapter 6 Air Pressure and Winds

as the force per unit area on a surface exerted by the weight of the air above.

Average sea-level pressure is stated at 1013.25 millibars

High-pressure systems that are associated with dry conditions

Low-pressure systems are associated with stormy weather.

Lines that connect places of equal air pressure.

Are elongated high-pressure areas that extend toward the poles and are associated with warm, dry air.

Are elongated areas of low pressure that extend equatorward, and they are usually associated with cool, wet weather

The amount of pressure occurring over a given distance

Does not generate wind; rather, it modifies the direction of airflow.  Proportional to wind speed.

Is generated when a balance is reached between the Coriolis force (CF) and the pressure gradient force (PGF).

When the Coriolis force is exactly equal in strength to the pressure gradient force but acting in the opposite direction.

Winds that blow at a constant speed parallel to curved isobars.

Has the same direction of rotation as Earth: counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

Opposite that of Earth's rotation.

The inward turning of the air.  (Low-pressure center)

When the wind consistently blows more often from one direction than from any other.

Is the result of horizontal differences in atmospheric pressure.