The Hadley Cells (image) NASA/Goddard Space Flight Center Share Print E-Mail Caption The Hadley cells describe how air moves through the tropics on either side of the equator. They are two of six major air circulation cells on Earth. Credit Credits: NASA Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.