Space Science and Engineering Center (SSEC), University of Wisconsin-Madison
Enhancing our Understanding of Snowfall Modes with Ground-Based
Observations: From the Great Lakes to Scandinavia
Room 811 AOSS, February 8, 2017, 2:30 PM
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 and how they are
measured from spaceborne instruments.
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. These statistics improve
our understanding of deep versus shallow precipitation. Additionally, these
statistical techniques are applied to similar datasets from Global Precipitation
Measurement (GPM) field campaigns for further insight into cloud and precipitation
macro- and microphysical processes.
In addition to presenting data from existing ground-based campaigns, 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). The logistics of preparing and planning this
deployment is outlined and some initial findings are presented.