Differences in microphysical structures between continental and oceanic thunderstorms: a GPM/DPR-based comparison

Abstract

Although the disparities in lightning activity between continental and oceanic thunderstorms have been widely investigated from thermodynamic, dynamic, and aerosol perspectives, their hydrometeor characteristics remain inadequately understood. This study compares microphysical properties of total thunderstorms and lightning-bearing cloud columns (lightning columns) over continental South China (SC) and oceanic South China Sea (SCS) using the observations from the Dual-frequency Precipitation Radar onboard the Global Precipitation Measurement satellite and lightning data from the Earth Networks Total Lightning Network and World Wide Lightning Location Network. Results show that SC thunderstorms feature higher echo tops of strong echoes (≥40 dBZ) than SCS thunderstorms, while SCS thunderstorms are spatially about three times as large as SC thunderstorms. SC thunderstorms have higher volume fractions of low-density ice particles across all sizes and of larger-sized dense ice and mixed-phase particles, whereas SCS thunderstorms exhibit higher fractions of small-to-medium-sized dense ice/mixed-phase particles and liquid water. Lightning columns in both regions contain more abundant and larger hydrometeors than overall thunderstorms, and the regional differences in hydrometeor properties between lightning columns are broadly consistent with those between the thunderstorms. Differences in volume-weighted mean diameter are most pronounced within the mixed-phase zone (0 to −20 °C).