In a low-pressure system, these vertical winds travel upwards and suck air away from the surface of the Earth like a giant vacuum cleaner, decreasing the air pressure above the ground or sea. Conversely, in a high-pressure system, air is being pushed down on the ground like a vacuum put in reverse. A low pressure system will pull in air from the surrounding area.
Air is pushed away from a high pressure system.
He is an atmospheric scientist at Goddard Space Flight Center who has been studying Atlantic climate anomalies for the past ten years. For most of the year, the high and the low are mild, and their influence on the Atlantic Basin climate is minimal. However, when winter hits, all of this begins to change. Both pressure systems grow much more intense and begin to fluctuate from week to week between two different states. In the other state, known as a negative NAO, the high-pressure system weakens and the low becomes shallow, creating a mild pressure difference between the two regions of the Atlantic.