TRMM provides a closer look at hurricanes using a unique combination of passive and active microwave instruments designed to peer inside cloud systems and measure rainfall. TRMM allows scientists to study the combustion process in the hurricane engine and relate this process to intensification or weakening. Cloud Growth - The release of latent heat warms the surrounding air, making it lighter, which promotes more vigorous cloud development. It is suspected that rapid bursts of cloud growth, particularly in the eyewall region of hurricanes, may relate to the intensification phase of a storm. Towering eyewall clouds are potential precursors to intensification of hurricanes. Note: This is the standard definition version of the Hurricane Heat Engine - Cloud Growth animation MPEG. Animator: Susan Twardy (HTSI). Scientist: J. Marshall Shepherd (NASA/GSFC).