Keywords: Hurricane-profile-blank.svg Tropical cyclones form when the energy released by the condensation of moisture in rising air causes a positive feedback loop over warm ocean waters http //earthobservatory nasa gov/Library/Hurricanes/Images/hurricane_section gif 2007-03-31 Robert Simmon NASA GSFC Nichalp PD-NASA Nichalp http //en wikipedia org/wiki/Image Hurricane-profile-en svg Legend See Hurricane-profile-en svg for labelling details inkscape Structure of tropical cyclones Positive feedback Feedback loops |