What must be present in order for clouds to form?
1 Answer
Water vapor, condensation nuclei and cooling temperatures.
Explanation:
Clouds are liquid water. For them to form you first need water vapor in the air, up to the point where you are almost at 100% relative humidity (basically the air is holding almost all the water vapor it can).
In order for liquid water to form from water vapor you need something for the water to condense on. In the atmosphere this occurs with dust particles, smoke particles and the like. These are called condensation nuclei.
Finally you need the air to cool. The reason for this is the amount of water vapor the air can hold is proportional to it's temperature. If you have air that is close to saturation or actually saturated, any drop in temperature is going to cause the water vapor to turn to liquid.
