FAA Aircraft Dispatcher Practice Exam

What direction do circulations associated with low pressure systems rotate?

1. Clockwise

2. Counter-clockwise

3. Horizontally

4. Vertically

The correct answer is: Counter-clockwise

Low pressure systems are characterized by air converging towards the center of the system. In the Northern Hemisphere, this convergence causes the air to rise and spin in a counter-clockwise direction due to the Coriolis effect, which is a result of the Earth's rotation. The Coriolis effect causes moving air to deflect to the right in the Northern Hemisphere, leading to the counter-clockwise rotation characteristic of low pressure systems. In contrast, high pressure systems exhibit a clockwise rotation in the Northern Hemisphere as air descends and spreads outward. Understanding these patterns is crucial for aviators, as they can influence weather conditions and flight operations.