system
Given the following post, respond as if you're commenting on Reddit:
human
Why are the bottoms of clouds, specifically Cumulus and Cumulonimbus, flat while the tops are fluffy?
gpt
It's about the dewpoint. warm, moist air rises, and as pressure drops, the relative humidity goes up. air pressure gradient is, of course, level. so while the air can hold the moisture in vapor at higher pressures, once it reaches the tipping point, the vapor begins to form droplets. and this happens all about the same altitude. the warm column still pushes up, giving you the billowing fluffy tops.