This page shows a sampling of snow crystals grown in the Snow Crystal Lab at Caltech during 1999. The images were taken as part of our ongoing investigation into the morphology and dynamics of ice crystal formation. This year our efforts focused on growing crystals in free-fall, which has some advantages for making quantitative measurements. The basic idea is to nucleate tiny crystals in a large chamber, which then grow as they slowly fall.
Some crystals land on a window at the bottom of the chamber, where they can be measured.
These crystals were all grown under quite similar conditions, although some grew for a longer period of time before falling onto the observation window. The longest growth time was about two minutes. Even the small variations in temperature and supersaturation within the growth chamber resulted in the great variety of forms seen. This demonstrates that the final snow crystal shape is very sensitive to growth parameters, especially at -15 C when the supersaturation is high. This is a very basic snow crystal shape.