First Observations of Gigantic Jets From Geostationary Orbit

Abstract

Here we report the first observations of gigantic jets (GJs) by the Geostationary Lightning Mapper (GLM) on board the Geostationary Operational Environmental Satellite‐R series. Fourteen GJs produced by Tropical Storm Harvey on 19 August 2017 were observed by both GLM and a ground‐based low‐light‐level camera system. The majority of the GJs produced distinguishable signatures in the GLM data, which include long continuous emissions, large peak flash optical energies, and small lateral propagation distances in comparison with other flashes observed by GLM. For two GJs with the best ground‐based images, each have a single pixel that contains the largest optical energy throughout the duration of the GJ and also coincides with the azimuth of the GJ from the video images. The optical energy of the pixel increases as the GJ propagates upward, reaches its peak when the GJ connects to the ionosphere, and then fades away.

Gigantic jet discharges evolve stepwise through the middle atmosphere

“…Figure 6 shows the evolution of the brightest GLM pixel. Similar to Boggs et al 34 , we find that two adjacent pixels (about 14 × 7 km), the brightest one corresponding to the GJ azimuth, are consistently brighter than surrounding ones.…”

“…Their supplementary images 12 remarkably show how the lowest sections of two separate jet branches (frame 9) later fused into one bright stem (frame 12 and after). Similar persistent bright stems can be found between 18 and 26 km in the video images of close range recent jet events 16,18,24,34 resembling cloud-to-air lightning branches and their streamer coronas 35 . This stem flickers simultaneously with the cloud lightning flash, and often reappears brightest at the end of the event 11,12,16–18,36 .…”

Analysis of a Gigantic Jet in Southern China: Morphology, Meteorology, Storm Evolution, Lightning, and Narrow Bipolar Events

“…Journal of Geophysical Research: Atmospheres (Figure 4e). The GJ location was marked by cyan "×" in Figure 5a and was located in the area of the lowest cloud top brightness temperature with −64°C, which was consistent with the previous results (Boggs et al, 2019;Singh et al, 2017;Soula et al, 2011).…”

“…The GJ established a direct path of an electrical connection between the cloud top and the ionosphere (Cummer et al, 2009;Kuo et al, 2009), which has an important influence on the electron density and potential of the ionosphere, electromagnetic environment of the near space, and radio communication. Since the first GJ was observed on 14 September 2001 by Pasko et al (2002) in Puerto Rico, several GJs have been observed by ground-based (Cummer et al, 2009;He et al, 2019;Lu et al, 2011;Peng et al, 2018;Soula et al, 2011;Su et al, 2003;Van der Velde et al, 2007 and satellite-based experiments (Boggs et al, 2019;Chen et al, 2008;Kuo et al, 2009). Optical observations show that most of the observed GJs have "tree" or "carrot" shape (Liu et al, 2015;Pasko et al, 2002;Soula et al, 2011;Su et al, 2003) and there is a color transition zone between the two areas where the bottom (altitude 20-40 km) is blue and the top (altitude over 65 km) is red (Peng et al, 2018;Soula et al, 2011).…”

Changes to the Appearance of Optical Lightning Flashes Observed From Space According to Thunderstorm Organization and Structure

“…On the other hand, some lightning phenomena can generate optical emissions that persist over multiple frames. Examples include continuing currents (Bitzer, 2017), gigantic jets (Boggs et al, 2019), and K process waves in horizontally expansive lightning channels (Winn et al, 2011).…”