10.3 Convection

Convection is the transfer of thermal energy in fluids which involves the movement of hotter fluids from hot region to cold region.

The heat transfered through convection increases as the rate of fluid increases.




Convection currents occurs when the water is heated. Hot water will then expand due to heat and as it expands, it's density and volume decreases. Hence, the hotter water will rise.





At the same time, the cooler regions of the water will sink to take the place of the rising water, as it is much denser.






Thus, the movement in the water due to density difference will set up a convection current.








Sea breezes and land breezes are due to convection currents.

During the day, The land is heated up faster than the sea. Air above the land heats up and hot air rises up. Cool air above the sea will then blows in and take the place.

Yet at night, the land is cooled down faster than the sea. So, the hotter air above the sea will than rise up and thus, the cooler air above the land will rushed in and take the place.