LoudestWhoop - basically Emc77 is correct - it's cloud seeding. Cloud seeding is based on the concept that clouds are lacking in ice nuclei and therefore additions of silver iodide crystals that mimic the structure of ice should result in a more efficient precipitation producing cloud system.
We have a series of flares attached to the aircraft that contain the silver iodide. Once we release the silver iodide into an updraft of a cloud, supercooled liquid water is converted into ice particles, releasing latent heat, increasing buoyancy, and thereby invigorating cloud updrafts. Basically, this will cause the cloud to grow larger, process more water vapor, and yield more precipitation.
I have only been working on the project for around a month but so far I have really enjoyed it. I am still learning as I go, and by no means is this an exact science, but we are learning with each mission. I am only the pilot for the operation, but we are working with a comapny based in th panhandle region of Texas which has been in operation for some time. Let me know if you have any other questions.