Transient Luminous Events (TLEs) are short-lived electrical-breakdown phenomena that occur in the upper atmospheric layers over thunderstorm clouds. Also referred to as Upper-atmospheric lightings they result from positive discharge of electrical energy escaping upwards into higher atmospheric layers instead of grounding to the planet’s ground. (cloud-to-air discharge)
Jets
Jets last around 200-300 milliseconds. The bluish color is believed to be due to a set of blue and near-ultraviolet emission lines from neutral and ionized molecular nitrogen. Gigantic Jets are formed by electromagnetic leaders escaping out of an intracloud flash upwards to the ionosphere.