Measuring frozen precipitation remains challenging because individual snowflakes vary widely in size, shape, and physical properties. Our research develops novel techniques for direct measurement of individual hydrometeors, including their mass, size, density, morphology, and precipitation characteristics. These measurements provide new insights into snow microphysics and its response to changing atmospheric conditions.

The settling velocity of snowflakes and raindrops directly influences the spatial distribution and intensity of precipitation. Our research uses field-scale PIV/PTV measurements around individual hydrometeors to investigate how turbulence and mean wind affect particle trajectories and settling velocities. We seek to understand why snowflakes may fall faster or slower than their expected terminal velocity under different turbulent conditions.

Accurate identification of precipitation phase is increasingly important as changing atmospheric conditions alter the transition between snow, rain, and mixed-phase precipitation. Our research develops novel methods for direct phase discrimination, including optical interferometry to distinguish liquid and frozen hydrometeors and a thermal–gravimetric approach combining thermal imaging, a heated mesh, and load-cell measurements. These techniques aim to improve measurements of precipitation phase under changing environmental conditions.