https://phys.org/news/2018-06-ammonia-earth-upper-atmosphere.html

The research is important because it answers on a molecular scale how ammonia is absorbed by liquid water droplets and later is pushed into air during convection, when air rises from Earth's surface, and freezes in the upper atmosphere.

"We found we can simulate and predict where ammonia should be, and our predictions align with satellite measurements," says Jun Wang, professor in chemical biochemical engineering in the UI's College of Engineering and whose team led the study. "The novelty of the research is to combine what we know at the molecular level and put that into a global-scale simulation model."