Today, we'll talk to a NASA scientist about cloud formation. Of course, there are water clouds, ice clouds, there are mix-phase clouds, there are hail, various things. But fundamentally, clouds occur in the Earth's atmosphere because there are particles in the Earth's atmosphere on which water vapor condenses to form water drops, freeze, form ice. If there were no particles in the Earth's atmosphere, there would be no clouds, there'd be no rain, and the planet would not be very habitable. In other words, clouds don't just appear out of thin air.
Clouds form as water vapor condenses around tiny particles.
So in the Earth's climate today, the dominant particles on which clouds form are sulfate particles. Some salt from the ocean, mostly sulfate, and in an updraft or a lifting air condition water vapor condenses on these particles and forms cloud drops. With thanks to the National Science Foundation, we're Block and Byrd for Earth and Sky.