Complex Hydrometeor Aerial Locomotion and Image Capture Experiment

First deployment on November 19 of the tower and instrumentation for the Complex Hydrometeor Aerial Locomotion and Image Capture Experiment (CHALICE). This project is supported by the National Science Foundation to study how the snowflakes fall as a function of their mass, density, size, and type in turbulent winds. 

Understanding how fast precipitation particles fall has been determined to be one of the key sensitivities in weather and climate because it determines how long clouds and storms last, and whether snow falls more here than there. There are a few measurements of how fast complex snowfall shapes fall in still air, but next to none of how they fall in turbulent air. Professors Eric Pardyjak and Tim Garrett at the University of Utah have led development of new instruments for studying this problem. Postdoc Dhiraj Singh has created the first ever device to measure the mass and density of individual snowflakes even in intense snowfall. Given snowflakes can have a mass of just a fraction of a milligram, this is an incredible advance that offers the potential to transform the field of snow science. 

We had struggles finding an appropriate field site, but settled on a spot with power and internet just above the University of Utah campus. Basic meteorological instrumentation has been set up on the tower for measuring e.g. turbulence, temperatures and winds. Precipitation microphysics instrumentation is pending. Here's looking towards a great season of data collection!

Open Ph.D. position

A position is open in the Department of Atmospheric Sciences at the University of Utah to become a part of CHALICE. A successful applicant will study the observational and theoretical aspects of the response of falling precipitation particles to turbulent air. How fast snow falls has been identified as one of the key sensitivities in weather and climate predictions, but no models yet account for how snow swirls. A graduate student will collect field data and use numerical simulations to help solve this critical problem. Contact tim.garrett@utah.edu for more information.