NASA says the video utilizes imagery derived from data collected by the Jovian Infrared Auroral Mapper (JIRAM) instrument aboard NASA’s Juno mission during its fourth pass over Jupiter. Infrared cameras are used to sense the temperature of the massive planet’s atmosphere and provide insight into how the powerful cyclones at the poles work.
In the animation, the yellow areas are warmer (or deeper into Jupiter’s atmosphere) and the dark areas are colder (or higher up in Jupiter’s atmosphere).
In this picture the highest “brightness temperature” is around 260K (about -13°C) and the lowest around 190K (about -83°C). The “brightness temperature” is a measurement of the radiance, at 5 µm, travelling upward from the top of the atmosphere towards Juno, expressed in units of temperature.