Common examples of convection include the boiling of water where bubbles become visible at the top, drinking coffee where steam rises upwards, using a fan to cool off the body and heating a room during the cold season. Convection also plays an important role in various atmospheric phenomena.
Thermal energy refers to the overall arbitrary movement of molecules in a body. It forms a direct relationship with temperature that is driven by the amount of random motion in an object, which in turn corresponds to the number of molecules moving within a system. Thermal energy is also known as internal kinetic energy.
The transfer of thermal energy from one body to another is the result of temperature variations. Heat moves along areas of higher temperature to areas of lower temperature. The three mechanisms for heat transfer include conduction, convection and radiation. Conduction takes place between solid objects, convection occurs in fluids and radiation directly transfers thermal energy from space.
Convection occurs when heated liquid or gaseous particles move to cooler areas. When boiling water or drinking a hot beverage, the visible bubbles or steam is the result of warm water that moves up to the surface, which is cooler in comparison to the bottom of the kettle or cup. In meteorology, convective processes are the driving forces of cloud formation, which may lead to thunderstorms in low pressure areas.