7. Cyclones occur in areas of very low pressure when air that is heated by the sun rises rapidly and becomes saturated with moisture which then condenses into high thunderclouds. As the hot air rises, cooler air rushes in to fill the area left vacant by the hot air. The Coriolis effect of the Earth spinning on its axis causes the air to spiral upwards with considerable force. This in turn causes the winds to rotate faster, causing the tropical low to deepen in intensity into a tropical depression, and eventually a cyclone.
