What is the purpose of convection currents?

Thermal Equilibrium: To achieve thermal equilibrium, thermal energy must flow from one point in space to another. Temperature can be thought of as the concentration of thermal energy. If the concentration of thermal energy is not uniform, energy flows from regions where it is more concentrated (higher temperature region) to regions where it is less concentrated (low temperature region) unit its concentration is uniform throughout the system.

Heat is the flow of thermal energy, and there are three modes in which it can be transferred: [1] Conduction: This is the predominant mode of heat transfer in solids; although the medium particles move (vibrate), there is no net flow of medium particles in this mode.

[2] Convection: There is a bulk flow of medium particles in this mode, and if the medium happens to be a fluid (i.e., things that can flow), then the medium particles themselves can carry thermal energy and deliver it across.

[3] Radiation: Thermal radiation is the process by which thermal energy is transferred in the form of electromagnetic waves to bring two points in thermal equilibrium when there is no medium between them.

In order to help distribute heat more evenly in a system, such as the atmosphere, oceans, or inside a heated room, convection currents are designed to transfer heat from one place to another, usually through the movement of fluids like air or water.