On the relationship between precipitation and lightning as revealed by multiparameter radar observations

Since collisions between graupel (or hail) and ice crystals in the presence of supercooled cloud water is hypothesized to generate charge in thunderstorms, and since multiparameter radar techniques allow the identification of precipitation sized ice and provide a gross estimate of ice mass, multiparameter radar is an ideal remote sensing platform for the study of precipitation processes relevant to storm electrification and lightning. As a result, the scientific objectives of this research are (1) the development and validation of a propagation correction algorithm, (2) the refinement of techniques to infer bulk hydrometeor types and to estimate precipitation amounts at two radar wavelengths (S- and C-band), and (3) the application of these methods to convective types of which our knowledge of cloud electrification is rudimentary.;Using data from the 11 cm, CSU-CHILL multiparameter radar, the simultaneous evolution of precipitation structure and electrical characteristics of a severe hailstorm is investigated. The electrical characteristics of this storm are unique. The hailstorm exhibited an extremely high i&barbelow;ntrac&barbelow;loud-to-c&barbelow;loud-to-g&barbelow;round (IC/CG) ratio and predominantly positive CG lightning after it became severe. We investigate the reported relationship between large hail and positive CG lightning. Although a direct correlation is found between a rapid increase in IC/CG, the first positive CG lightning flashes, and the initial production of hail aloft, the temporal and spatial behavior of large hail and positive CG lightning were anti-correlated.;Using C-pol radar observations of the propagation corrected horizontal reflectivity and differential reflectivity, along with specific differential phase, three-dimensional rain and ice mass were estimated during the life cycle of an electrically active tropical convective complex over the Tiwi Islands during the Maritime Continent Thunderstorm Experiment (MCTEX). The precipitation structure as inferred from these raw and derived radar fields was then compared in time and space to the surface electric field, cloud-to-ground and total lightning flash rates, and ground strike locations. No significant electric fields or lightning were associated with the developing, warm rain stage, despite substantial rainfall. During the mature phase, lightning and the surface electric field were strongly correlated to the mixed phase ice mass and convective rainfall.