Relating ABI Products to GLM Sensor Characteristics and Performance

The recent deployment of the Geostationary Lightning Mapper (GLM) onboard GOES 16 and 17 provides a new perspective of total lightning production for the severe storms research and operational communities. In contrast to most ground-based networks which measure electromagnetic radiation from lightning flashes, the GLM detects the optical signal from lightning. These optical events collected by the GLM are clustered into groups and flashes which provide density, areal coverage, and optical energy characteristics in convective environments. While the GLM has met its performance targets, further understanding flash characteristics and the physical limitations of the GLM are required to increase the applicability of the data.

This study describes the effects of viewing angle and optical depth, using Level 2 and RGB products from the GOES 16 Advanced Baseline Imager (ABI), on flash characteristics from gridded GLM datasets. Distributions of GLM and ABI Level 2 variables under a variety of convective modes and viewing angles are used to define statistically significant relationships, with ABI RGB products employed to define convective and stratiform regions. GLM flash energy and flash area are examined to understand how decreasing flash size with increasing charge distribution complexity effects reduced flash counts in severe storms. Additionally, case studies are used to compare the GLM properties with both Multi-Radar/Multi-Sensor and ground-based lightning detection systems to test the operational applicability of these results.