Vapor Buoyancy Graphic (IMAGE) University of California - Davis Caption This graphic illustrates the vapor buoyancy effect, in which cold, humid air rises because it is lighter than dry air. Credit Da Yang/UC Davis Usage Restrictions Provide credit. License Licensed content 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.