Microphysics of Frozen Particles

A deeper understanding of snow microphysics is crucial in developing observing systems, remote sensing methods, and snowfall data products because microphysical properties of snow profoundly influence both bulk snow properties and the relationship between these properties and measurements made by remote sensing instruments like radars and radiometers. For snow, these relationships are complex because of the extreme variability of snow particle shapes and size distributions. We analyze intensive ground- or aircraft-based snow observations to determine how particle properties (mass, fall speed, concentration) vary with environment and particle size, then translate these data into relationships which can be applied in remote sensing algorithms and in models ranging in scale from weather systems to global climate. This work is funded by the NSF and NASA. (Figure: (top) snowflake images from the Multi-angle Snowflake Camera; (bottom) measurements showing changes in snowflake sizes over time from the Precipitation Imaging Package)