Microphysical and dynamical investigation of storms with distinct electrical characteristics

Previous research has provided evidence that storms in the High Plains region of the United States are often anomalously electrified, meaning that they possess strong mid-level positive charge rather than the more common upper-level positive charge. These anomalous storms are hypothesized to be microphysically distinct from normal polarity storms, namely, large supercooled liquid water contents leading to wet growth of ice particles (i.e., hail). To understand how microphysical and dynamical processes may produce anomalously electrified storms, detailed analysis of polarimetric radar and dual-Doppler derived vertical motion are carried out for a number of storms in several regions of the United States. Data from all regions of the Deep Clouds and Convective Chemistry (DC3) campaign during the summer of 2012 are used along with X/S dual frequency radar data from the CHILL Microphysical Investigation of Electrification (CHILL-MIE) in northeast Colorado (summer of 2013). Simultaneous dual-frequency observations provide additional microphysical information including higher resolution data along with differential attenuation and Mie scattering effects. For this study, ZDR columns indicative of liquid water lofted into the mixed-phase region and their impacts on storm electrification will be investigated for select cases. Additionally, recent studies suggest that microphysical processes can be inferred from polarimetric variable changes along a parcel trajectory. This study explores the feasibility of this technique and the implications for production and maintenance of positive charge regions in thunderstorms.