In order to alleviate the drought, some counties and cities in Honghe Prefecture have repeatedly used planes to spread dry ice (solid carbon dioxide) in the clouds to implement artificial precipitation enhancement. Dry ice (solid carbon dioxide) in the cloud will quickly absorb heat and sublimate into carbon dioxide, which will lower the surrounding temperature. Some water vapor will liquefy into water droplets, and some water vapor will condense into small ice crystals to form rainfall. In the process of falling, ice crystals will rub with air to generate heat and melt into water.

So the answer is: sublimation; Melting.