The polar low pressure belt is a band of low pressure that circles the earth near the poles. This belt of low pressure is caused by the cold temperatures of the polar regions, which create areas of warm air rising and cold air sinking in the atmosphere. This creates a pattern of low pressure that circles the Earth near the poles. This low pressure belt is associated with the polar jet stream, a fast-moving band of air that circles the Earth near the poles and helps to drive the weather patterns in the mid-latitudes.