Convection Currents

[KaneOris]

Do convection currents occur in all bodys of water and gas?
Or are they only at a certain temperature, under certain circumstances?

[Sirus]

I believe that on a very small level, they occur under all circumstances in all fluids. In theory, any variation in, for example, the exterior temperature around a Thermos bottle will cause the fluid inside to exhibit convection. More practically, however, convection occurs most notably when specific sources of heat/cooling exist, for example in a room with a heater. Remember how convection works and you should be able to figure out when it will occur.