Meteorological Imagery for the Geostationary Lightning Mapper

Abstract

The Geostationary Lightning Mapper (GLM) on the Geostationary Operational Environmental Satellite‐R series of weather satellites provides point geolocations of lightning flashes that are further comprised of a hierarchy of geolocated groups and events. This study describes an open‐source method for reconstruction of imagery from those point detections that retains the quantitative physical measurements made by GLM, restores the spatial footprint of the events, and connects that spatial footprint to the groups and flashes. Meteorological signals are demonstrated to be more apparent in the gridded imagery than in the point detections, leading to their adoption by the United States National Weather Service as the first GLM product available in their real‐time displays. Analysis of a mesoscale convective system over Argentina confirms that there is a class of propagating lightning observed by GLM (distinct from that in storm cores) that can be visualized and quantified using our imagery‐based approach.

Where Are the Most Extraordinary Lightning Megaflashes in the Americas?

“…Distributions of the top GLM megaflashes across the Americas are shown in Figure 1. Figure 1a plots the two-year megaflash count over the hemisphere as a Flash Extent Density (FED: Lojou and Cummins, 2005;Bruning et al, 2019). FED accounts for the spatial extent of lightning by incrementing the flash count by one for every unique pixel that is illuminated by each GLM flash.…”

Holes in Optical Lightning Flashes: Identifying Poorly Transmissive Clouds in Lightning Imager Data

“…We will use holes in LIS groups to generate a large sample of poorly transmissive clouds and assess their microphysical properties using the meteorological instrumentation on the Tropical Rainfall Measuring Mission (TRMM; Kummerow et al., 1998) satellite. We will then attempt to identify the general case of all groups with radiance anomalies in a single storm—not just those that contain holes—and compare the locations of radiance anomalies with excursions in the meteorological imagery (E. Bruning et al., 2019) generated from the LIS data. This comparison will show that these radiance anomalies pose a challenge for understanding and correctly interpreting LIS and GLM measurements.…”

Observations of lightning in relation to transitions in volcanic activity during the 3 June 2018 Fuego Eruption

“…The red triangle indicates the location of the Fuego volcano.

Figure 4 Flash extent density plots of GLM data from between 18:14 UTC and 18:33 UTC using GLMTools software 62 . The black triangle indicates the location of the Fuego Volcano.

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