Abstract
"Different thermodynamic and physical mechanisms in the atmosphere drive shallow versus deep snowfall events. There are therefore different characteristics observed by remotely sensed instruments that can be attributed to modes of snowfall. Though satellites can observe and recognize these patterns in snowfall, these measurements are limited – particularly in cases of shallow and light precipitation. By enhancing satellite measurements with ground-based instrumentation, whether with limited-term field campaigns or long-term strategic sites, we can further our understanding and assumptions about different snowfall modes.
Three years of data are presented from a ground-based instrument suite consisting of a MicroRain Radar (MRR; optimized for snow events) and a Precipitation Imaging Package (PIP). These instruments are located at the Marquette, Michigan National Weather Service Weather Forecast Office to: a) use coincident meteorological measurements and observations to enhance our understanding of the thermodynamic drivers and b) use these instruments as an example of applied research to operations to enhance forecasts of shallow snow events. Three winters of MRR and PIP measurements are partitioned into two-dimensional histograms of reflectivity and particle size distribution data, respectively.
Additionally, a newly deployed ground suite of instruments based in Norway is discussed. The Meteorological Institute of Norway has a snow measurement site in Haukeliseter in the orographically complex Telemark Region. A joint project between University of Wisconsin and University of Utah augmented this site with an MRR, a PIP, and a Multi-Angle Snowflake Camera (MASC). Preliminary results from this campaign are presented with a focus on the estimation of snowfall from the MRR reflectivity measurements. These remotely sensed estimates of snowfall are compared with snow gauge observations from the Haukeliseter site. Finally, we discuss how observations from the PIP and MASC will be used to refine and improve the MRR-based snowfall retrieval scheme dependent upon environmental conditions at Haukeliseter.
About the speakers:
Claire Pettersen is an Associate Instrumentation Innovator University of Wisconsin-Madison, Space Science and Engineering Center
Steve Cooper is Research Assistant Professor University of Utah, Atmospheric Sciences
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The seminar is open for all interested in the topic of the seminar.