Part of the University of Illinois Weather World 2010 project this guide uses multimedia technology and the dynamic capabilities of the web to incorporate text colorful diagrams animations computer simulations audio and video to introduce topics and concepts in the atmospheric sciences The purpose of this module is to introduce air masses where they originate from and how they are modified It examines fronts with detailed explanations about cold fronts stationary fronts occluded fronts dry lines and warm fronts and introduces the different types of advection temperature moisture and vorticity