Why are rockets and artillery shells sometimes used in cloud-seeding operations?

In cloud-seeding operations, rockets and artillery shells are used as delivery mechanisms to transport seeding agents—typically ice nuclei like silver iodide or lead iodide—directly into specific, targeted regions of a cloud.1

This method allows for precise placement of the seeding material. For instance, in experiments conducted by Soviet researchers, artillery projectiles containing 100 to 200 grams of ice nuclei were fired into clouds; at a predetermined position, the shell would explode to disperse the nuclei. Similarly, rockets have been employed to ignite and release pyrotechnic mixtures containing seeding agents at various points along their flight path. By delivering these substances directly into supercooled parts of a cloud, the operations aim to induce the formation of ice crystals, which can then grow and result in precipitation.12