What causes convection and what role does it play in the adiabatic process?

Question

What will be an ideal response?

Answer 1

Answer: Convection is movement in a fluid, caused when part of the fluid (whether gas or liquid) is heated. The heated portion expands and becomes less dense, rising up through the cooler portion. It causes the turbulence in water and in puffy white clouds overhead. In becoming less dense, meaning weighing less per unit of volume, warm air rises above cooler, denser air, just as a hot-air balloon rises through the cooler air surrounding it. Convection is caused by heating the atmosphere from below. Temperature changes resulting from vertical motions create clouds and precipitation

When air rises, it has less weight above it, and the lower pressure allows the air to expand. The expansion leads to a decrease in temperature. The decrease in temperature that results is called adiabatic cooling. When convection causes air to rise, the pressure in that air decreases with elevation and this causes the air to cool. Cooling, in turn, lowers the amount of water vapor it can hold.

Condensation occurs when the amount of water the air can hold reaches the actual vapor content, that is the relative humidity reaches 100%. Above the condensation level, rising air continues to cool, further reducing its ability to hold water vapor leading to more condensation. This releases latent heat, warming than air. The added heat isn't enough to prevent condensation, but it does make the air warmer that the air around it at the same elevation, and so promotes further rising air.