Comment on egusphere-2026-794

<strong class="journal-contentHeaderColor">Abstract.</strong> Precipitation enhancement may augment water resources, yet questions still remain as to the effectiveness of current cloud seeding strategies. One such strategy, hygroscopic seeding, is designed to accelerate collision-coalescence and eventually precipitation by creating a large droplet tail in the size distribution. In the traditional approach, particles are released at cloud base, typically through burning a flare. The effect of directly injecting a hygroscopic powder into a preexisting cloud has not been experimentally tested in controlled conditions. We performed experiments in the Michigan Tech Pi Chamber to determine how a steady-state liquid water cloud responds to injection of hygroscopic powders. Three materials were tested: jet-milled NaCl, a newly developed NaCl-TiO₂ core-shell material, and Arizona test dust as a non-hygroscopic control. Injection of the powders produced a local increase in liquid water content and stimulated formation of droplets up to 60 microns in diameter&mdash;significantly larger than the background cloud droplet population. Analysis of relevant timescales indicates that NaCl particles with dry diameters between 4 and 25 <em>&mu;</em>m would be suitable for this application. These results demonstrate that in-cloud hygroscopic seeding can successfully generate large droplets that could accelerate warm rain processes, which supports reconsideration of in-cloud injection as a viable precipitation enhancement strategy alongside traditional cloud-base release, particularly for warm clouds in arid and semi-arid environments.