Re: Cloud
Yes, Andy.
When the sun rises, it warms the earth's surface. Different areas warm at different rates, depending on the make-up of the surface. The surface then warms the air in contact with it, causing it to expand. As the air expands, it becomes less dense than the cooler air around it, and so rises.
As it rises, it expands more, because the atmospheric pressure decreases as you ascend. Because of the drop in pressure, the rising air cools adiabatically (i.e. without loss of heat). Its rate of cooling will probably be different from that of the surrounding air: if it is a lower rate it becomes relatively warmer than the surrounding air, and will continue to ascend at an increasing rate; if it cools at a higher rate it will soon reach the same temperature as the surrounding air, and stop ascending.
If the rising air has a high enough relative humidity, it will cool to its dew point. It is then saturated, and any further cooling will cause water vapour within it to condense into water droplets, and cloud is the result.
Referring to my first paragraph, small areas of surface heated cause small pockets of air to warm and rise, which is why you see small, puffy clouds on a summer's morning. Fair weather cumulus is one name for it.
When the surface, and the air in contact with it, cools in the evening the air is no longer heated, so is not caused to rise.