What is the process of convection?

convection, process by which heat is transferred by movement of a heated fluid such as air or water. Forced convection involves the transport of fluid by methods other than that resulting from variation of density with temperature. Movement of air by a fan or of water by a pump are examples of forced convection.

Where does convection heat transfer occur?

Convection currents transfer thermal energy through many fluids, not just hot water in a pot. For example, convection currents transfer thermal energy through molten rock below Earth’s surface, through water in the oceans, and through air in the atmosphere.

How is heat transferred by convection in the mantle?

The mantle is heated from below (the core), and in areas that are hotter it rises upwards (it is buoyant), whereas in areas that are cooler it sink down. This results in convection cells in the mantle, and produces horizontal motion of mantle material close to the Earth surface.

What causes convection in Earth’s mantle?

Convection Currents in the Mantle Heat in the mantle comes from the Earth’s molten outer core, decay of radioactive elements and, in the upper mantle, friction from descending tectonic plates. The temperature difference between the upper and lower boundaries of the mantle requires heat transfer to occur.

How is heat transfer by radiation different from conduction and convection?

In conduction, heat transfer takes place between objects by direct contact. In convection, the heat transfer takes within the fluid. In radiation, heat transfer occurs through electromagnetic waves without involving particles. The heat transfer takes place due to the difference in temperature.

What is Earth’s convection?

Convection currents are identified in Earth’s mantle. Heated mantle material is shown rising from deep inside the mantle, while cooler mantle material sinks, creating a convection current. It is thought that this type of current is responsible for the movements of the plates of Earth’s crust.

Where does convection occur?

Convection occurs when particles with a lot of heat energy in a liquid or gas move and take the place of particles with less heat energy. … The liquid or gas in hot areas is less dense than the liquid or gas in cold areas, so it rises into the cold areas. The denser cold liquid or gas falls into the warm areas.

What does convection require to transfer heat?

Yes, convection requires a medium to transfer heat. In convection, in order to transfer heat, molecules have to move by their own. As it does, it removes or displaces cold air in its path. Convection above a hot surface occurs because, when the molecules become hotter, they become less denser and then rises.

How does convection help to heat the atmosphere?

Convection heat is what is responsible for constantly moving the air in the lower atmosphere. Air over water cools and heats slower than air over land. This creates a pressure difference that will shift larger bodies of air.

How do convection currents help distribute heat?

Convection currents rely on the constant cyclical motion of air, water and other substances to distribute heat. As heated air rises, for example, it pulls cooler air into its place — where it can be heated, rise, and pull in more cool air.

What does it mean for heat to be transferred by convection?

Convection is heat transfer by mass motion of a fluid such as air or water when the heated fluid is caused to move away from the source of heat, carrying energy with it. Convection above a hot surface occurs because hot air expands, becomes less dense, and rises (see Ideal Gas Law).