Developing & Deploying Tools to Better Observe Lightning in the Washington D.C. Area & Beyond

The greater Washington D.C. area is a populous area with high lightning risk. Currently, both satellite- and ground-based lightning detection networks are used to observe and locate lightning occurrences and mitigate potential lightning risks. The Geostationary Lightning Mappers (GLMs) on NOAA's GOES-16 and -17 satellites continuously detect total lightning over the Americas and adjacent oceans (Rudlosky et al., 2019; Rudlosky and Virts, 2021). The ground-based networks such as the Earth Networks Total Lightning Network (ENTLN) locates lightning discharges (e.g., cloud-to-ground, CG strokes) with an accuracy of a few hundred meters (Mallick et al., 2015; Zhu et al., 2017). Additionally, a regional network Mid-Atlantic Lightning Mapping Array (MALMA) is run and maintained by the University of Maryland. It maps the 3D structure of lightning channels with a very high detection efficiency within a few tens of kilometers (Thomas et al., 2004; Krehbiel, 2008; Quick et al., 2020). The combined lightning networks have provided us a complementary understanding of the lightning activity in the greater D.C. area.

To better characterize the detection performance of these networks, two Raspberry Pi cameras were used to take lightning videos during the summer of 2021 as the ground-truth dataset. Initial findings show that the MALMA network was able to detect all of the CG flashes that were captured on Aug. 26, 2021. However, the GLM showed a reduced detection efficiency on that day, possibly due to abundant hydrometeors between the cloud top and the flash which increased light scattering, leading to fewer photons being received by GLM pixels. The successful camera settings and collections have led us to expand the camera network to widen our observation coverage this year. We now have installed five cameras in the D.C. area, one in Norman, OK and one in Flagstaff, AZ in collaboration with the University of Oklahoma and Earth Networks. So far, we have successfully collected dozens more days with clear high-speed lightning videos. This ongoing project will build a set of low-cost and innovative lightning measurement tools to augment existing lightning networks such as GLM and MALMA to better characterize lightning in the greater Washington D.C. area, along with potential NOAA field campaigns and other educational purposes.