During daytime in coastal regions, land heats up faster than the sea. The air above the land expands, becomes less dense, and rises, allowing cooler air from the ocean to move inland to form a sea breeze. Which mode of heat transfer is primarily responsible for this bulk movement of fluid, and what physical property change drives it?
- Convection, driven by a decrease in air density due to thermal expansionAnswer
- BConduction, driven by energy transfer through stationary molecular collisions at the land-air boundary
- CRadiation, driven by direct absorption of solar electromagnetic waves by atmospheric air
- DConvection, driven by an increase in air density due to thermal expansion
Answer
Convection, driven by a decrease in air density due to thermal expansion
Convection is the mode of heat transfer in liquids and gases where heat is carried from one place to another by the actual bulk movement of the heated fluid. As air over the land absorbs heat, thermal expansion causes its volume to increase and its density to decrease. The lighter, warm air rises and is replaced by cooler, denser air from over the water, creating a sea breeze.
Step-by-Step Solution
Key Concept
Convection in fluids and buoyancy driven by thermal expansion