The primary method of heat transfer in fluids is convection. This process occurs when warmer, less dense portions of a fluid rise while cooler, denser portions sink, creating a circulation pattern. Convection can be observed in various systems, including atmospheric weather, ocean currents, and heating of liquids. The movement facilitates the transfer of heat, distributing thermal energy throughout the fluid and influencing various natural processes, including climate patterns and the behavior of fluids in engineering systems.