Geostationary Lightning Mapper Flash Characteristics of Electrified Snowfall Events

Abstract

This study examines characteristics of lightning in snowfall events (i.e., thundersnow, TSSN) from the perspective of the Geostationary Lightning Mapper (GLM) and the National Environmental Satellite Data and Information Service (NESDIS) merged Snowfall Rate (mSFR) product. A thundersnow detection algorithm (TDA) was derived from the GLM and mSFR that resulted in a probability of detection (POD) of 66.7% when compared to the aviation routine weather report (METAR) reports of TSSN. However, using the TDA an additional 2175 lightning flashes within detected snowfall were identified that were not observed by the METAR reports, indicating that TSSN has been under reported in previous literature. TSSN flashes observed by GLM have mean flash areas, durations, and total optical energy outputs of 754 km2, 402 ms, and 1342 fJ, which are between the 50th and 99th percentile values for all flashes within the GLM field of view. A comparison with data from the National Lightning Detection Network (NLDN) indicated that the NLDN had at least one cloud or ground flash detection in 1709 of the 2214 flashes observed by GLM in snowfall. An average of 5.85 NLDN flashes was assigned to a single GLM flash when the NLDN flash data were constrained by the GLM flash duration and spatial footprint. Statistically significant (p < 0.01) differences in flash area and flash energy were found between flashes that were observed by the NLDN and those that were not. Additionally, when GLM was combined with the NLDN, at least 11.1% of flashes involved a tall human-made object like an antenna or wind turbine.

Remote Sensing of Electric Fields Observed Within Winter Precipitation During the 2020 Investigation of Microphysics and Precipitation for Atlantic Coast‐Threatening Snowstorms (IMPACTS) Field Campaign

“…Thus, there is potential utility of this lightning nowcasting technique to the winter weather environment. However, developing applications requires a deeper look into when the use of these signatures is needed, given that each depolarization streak observed in this study did not produce lightning but was associated with cloud electrification, and in an initial look at the Harkema et al (2019) data set, not all lightning flashes in winter storms were accompanied by depolarization streaks in Z DR .…”

Further Investigation Into Detection Efficiency and False Alarm Rate for the Geostationary Lightning Mappers Aboard GOES‐16 and GOES‐17

“…To document the incremental effects of increasing the time coincidence window, we started the time window of the DE and FAR analysis at the value used for the previous work of ± 1 s (2 s total) (Harkema et al, 2019;Bateman & Mach, 2020). We then repeated the DE and FAR analysis for the same dataset, increasing the time window for each run.…”

“…In that study, we used a time coincidence criteria of ± 1 s and a distance criteria of 50 km. Another previous study (Harkema et al, 2019) used this same time and distance criteria when comparing GLM data to NLDN.…”

A Technique for Automated Detection of Lightning in Images and Video From the International Space Station for Scientific Understanding and Validation

“…In this section we will demonstrate how the geolocated video imagery of lightning can be used to derive accurate flash statistics. Flash area and length have been shown to be important to separate convective and stratiform regions individual in storms (e.g., Bruning & MacGorman, 2013; Calhoun et al., 2013; T. J. Lang et al., 2015; Schultz et al., 2015) and providing seasonal and climatological characteristics for lightning occurrence (e.g., Fuchs et al., 2016; Harkema et al., 2019; López et al., 2017; Rudlosky et al., 2019; Yoshida et al., 2019). In total, 7,105 unique METEOR frames with lightning were assigned to 289 flashes observed by GLM during 05:43:48–05:46:03 UTC (when METEOR was observing lightning).…”

“…This is not surprising because LMA flash area computations are not affected by light scattering; thus, LMA flash sizes will be smaller than optically detected flashes. Comparing to GLM observations of flash area and length places most of the flash lengths observed from the METEOR‐derived technique between the 90th and 99th percentile in observed flash area and radii (Harkema et al., 2019; Rudlosky et al., 2019). However, as noted earlier, the median difference in flash area between METEOR and GLM was 266 km 2 , and the matched GLM flashes had a median flash length of 51 km.…”