What are convection currents and what do they do?
A convection current is basically a flow of a fluid or air because of heating and cooling of the fluid or air. Hot air rises. Cold air falls. If there is local heating of the air at some point, a convection current will be set up. An on shore breeze is one example. Here, the air that is heated by the land rises and moves out over the ocean where it is cooled and falls. the cool air moves inland as a breeze to complete the cycle.
Thanks to convection currents, warm air holdin moisture rises. While it cools the water vapor condenses to water droplets and we see the clouds. (Notice how often the clouds have flat bottoms? That's the level where the air became cool enough for the water vapor to condense.) Convection explains why upstairs is often warmer than downstairs: The warmest air will rise to the top. Even though convection addresses only vertical movement of a fluid, there are other results - and, in nature, they are often demonstrated by wind: If a large mass of warm air rises the surrounding air must rush in to replace the space it vacated.