what is a convection current and where do we see them?

Answer 1

Air is heated by contact with the earth surfaces and by the absorption of energy from the sun. When air is warmer than the surrounding air, it has less density and rises like a hot air balloon.

If this air has adequate moisture and it rises high enough and cools to the dew point this air start condensing and forming billions of small cloud droplets. Each puffy cumulus cloud that you see on a sunny warm summer day is formed by a convective current.

And all thunderstorms start as a puffy cumulus cloud. Most cumulus do not develop into a thunderstorm but a few do.

Cumulus clouds and thunderstorms are the result of convective flows of air.

Answer 2

The ascent of air is known as convection.This is caused by either buoyancy or by an external aid.The process may therefore be either free or forced one.
If air is forced to ascend a mountain barrier or a warm airmass is undercut by cold air,forced convection occurs.On the other hand,air goes up in an unstable atmosphere due to buoyancy,it is free convection.
The formation of cumulus cloud is an indication of the existance of convection.The base of the cloud is situated at the condensation level only,whereas, the top of the cloud may extend upto the height,upto which the convection current reaches with its condensed products.If the atmosphere is fairly dry,the rising convection currents are known as Thermals,which are well-known to glider pilots and low-flying aircraft.The bumpiness (which is an impulsive uplift) experienced by aircrafts sometimes ,are due to the upward convection currents.

Answer 3

Heat rising is a convection current. The waves above a campfire are convection currents. You can also see them on hot days above an asphalt parking lot.