Final answer:
The process where warmer, less dense air rises over cooler, denser air is called convection, and it is described by Charles's law which indicates that gases expand when heated, creating a density difference that causes the warmer air to rise.
Step-by-step explanation:
The process where cool air acts as a barrier over which warmer, less dense air rises is commonly referred to as convection. This happens because of basic principles of thermodynamics, as eloquently explained by Charles's law.
Charles's law states that the volume of a gas expands when it is heated and, consequently, its density decreases leading to a rise through cooler, denser air. This principle can be seen in everyday life through phenomena such as hot air balloons and natural weather patterns.
An example of this is the heating of air by a gravity furnace, which expands and rises to form a convective loop that transfers energy to other parts of a room. Similarly, the evaporation and subsequent condensation of water in the atmosphere is a natural example of convection and phase change that combine to drive weather systems like thunderheads and hurricanes.
This process acts as a comprehensive heat transfer system, often resulting in the formation of powerful storms due to positive feedback mechanisms.