Analyzing Doppler On Wheels Dual-Polarization Radar Parameters During a Lake-effect Snowstorm

The Ontario Winter Lake-effect Systems (OWLeS) project took place during the winter of 2013-2014. Twenty-four Intensive Observation Periods (IOPs) were executed during the project, according to Kristovich et al. (2017). Doppler-On-Wheels (DOW) mobile radars and the University of Wyoming King Air Research Aircraft (UWKA) sampled lake-effect processes. The DOW’s measured dual-polarization variables such as Differential Reflectivity (ZDR), Correlation Coefficient (ρHV), and Specific Differential Phase (KDP). Meanwhile, the UWKA recorded 2D photographic images of hydrometeors using the Cloud Imaging Probe (CIP), among other meteorological observations. While previous studies, such as that in Liu and Chandresekar (2000), have related radar and aircraft observations to hydrometeor classification for summer storms, that for winter storms is largely unexplored.

This study used data from IOP 2b (11 Dec 2013), in which the UWKA transected a lake-effect snow band several times. ZDR values of around 0 dB were noted in the core of the snow band, with hydrometeors including dendritic clumps and some dendrites observed by the UWKA and at the surface in the core. The results from this study showed the DOW’s measurements are useful for hydrometeor identification, and possible precipitation rate estimation at the ground; this was one of the primary goals of OWLeS outlined in Kristovich et al. (2017). Further work will include investigating more case studies, particularly those with a mix of winter precipitation, such as graupel.