## 3 Results
### Chromatic Analysis of Event 2  
For the analysis of chromaticity, two frames--one displaying pinkish/violet luminosity and another with emerald-green/blueish luminosity--are selected as reference frames. A pixel is selected at bright luminosity, most emphasizing these color spectra. Figure 11a represents a reference frame showing the luminosity with pinkish/violet light (at 9.950 s), as shown in Figure 7. The selected pixel coordinates (750, 860) have an RGB value of (112, 74, 97). Figure 11b illustrates a zoomed-in view of this selected pixel. Figure 11c illustrates the CIE 1931 chromaticity diagram. The CIE wavelength of the emitted light from the selected pixel on the image is 440 nm. Figure 11d displays a reference frame with emerald-green/blueish light (at 10.22 s), as shown in Figure 7. The selected pixel coordinates are (800, 880), with an RGB value of (40, 111, 155). Figure 11e illustrates a zoomed-in view of this selected pixel. Figure 11f illustrates the CIE 1931 chromaticity diagram. The CIE wavelength  
Figure 7: Video recorded images from Frame 11 (06:34:09.995 UTC) to Frame 53 (04:13:04.899 UTC) on 17 April. The images are captured by the camera, iPhone 13 ProMax, operated at a frame rate of 59.96 fps, resulting in a frame-to-frame interval of 16.67 ms. The camera’s location is the coordinates of 26.3419\({}^{\circ}\) N and 81.8013\({}^{\circ}\) W.  
of the emitted light from the selected pixel on the image is 490 nm. The pinkish/violet pixel, with a wavelength of 420 nm, is very short and close to UV light, influenced by nitrogen (N\({}_{2}\)) gas in the atmosphere [26]. On the other hand, the second frame with blueish/green luminous pixels has a wavelength of 490 nm, corresponding to part of the green spectrum produced by electrons colliding with oxygen atoms (O) [33], as indicated in the Introduction section. When the frame shows pinkish/violet luminosity, it indicates that electrons with high energy are colliding with atoms and molecules. These collisions cause the electrons in the atoms and molecules to move to higher energy levels, resulting in the emission of light with shorter wavelengths, which corresponds to the pinkish/violet color [34]. On the other hand, when the frame shows emerald-green/blueish luminosity, it suggests that the energy of the electrons involved in the collisions is lower compared to the energy levels associated with the pinkish/violet luminosity. The concentration of molecules is expected to remain consistent over the short timescale of a lightning discharge (tens of milliseconds). Changes in luminous color during a lightning discharge can be caused by momentary shifts in the discharge's behavior while interacting with atoms and molecules in cloud particles or water droplets. Additionally, abrupt changes in the concentration of these atoms and molecules, influenced by factors such as wind or humidity, can also affect the color of the emitted light. Figure 8: Lightning locations reported by the GLM data on 17 April, from 06:34:09.750 UTC to 06:34:10.750 UTC. The map displays a view of the coordinates of 26.05\({}^{\circ}\) N–26.35\({}^{\circ}\) N and 81.5\({}^{\circ}\) W–82.05\({}^{\circ}\) W. The colored dots represent the lightning flash locations, with a color scale ranging from red to violet within a 0.125 s time window. The total number of lightning detections in the time window is displayed in the box at the upper right corner of the figure. Yellow and blue lines represent transmission lines and river/canal lines, respectively. The grayscale indicates Clean-IR brightness temperature with longwave 10.3 μm, with units of Kelvin as in absolute temperature. Figure 9: Group energy of lightning discharges reported by GLM from 06:34:09.850 UTC to 06:34:10.600 UTC. The time along the \(x\)-axis shows seconds in the timeframe.