Amanda Murphy-March 15

Convective Meteorology (Mesoscale Dynamics) Seminar

Polarimetric Investigation of Precipitation within the Comma Head of the 2 February 2015 Nor’easter

Amanda Murphy

Friday, March 15^th

3:00pm/NWC 5600

A number of novel techniques to examine polarimetric radar data collected via PPI scans in a time-height format have been developed in recent years. Using primarily polarimetric radar data collected by WSR-88D radars, techniques such as quasi-vertical profiles (QVPs), range-defined quasi-vertical profiles (RD-QVPs), and column vertical profiles (CVPs) have been used to investigate the vertical structure of precipitating systems such as winter storms, mesoscale convective systems, and landfalling hurricanes. Each with their respective advantages, dual polarization signatures observed in these profiles lend a qualitative understanding of potential microphysical processes occurring, and microphysical retrievals performed on these data give quantitative estimates of the size, composition, and concentration of ice particles.

A Nor’easter that produced up to 2 feet of snow in New England on 2 February 2015 is examined using QVPs, RD-QVPs, and CVPs. The NCAR G-V aircraft flew above this storm, and W-band downward pointing radar data from the aircraft is compared to generated vertical profiles. Dual polarization signatures hint at various microphysical processes happening within the storm, including aggregation, increases in particle concentration, and complex melting layer evolution. Strengths of each technique and plans for further analyses will be discussed.