Simulation of gigantic jets propagating from the top of thunderclouds to the ionosphere

Abstract

A randomly stepped leader propagation model is developed to study gigantic jets, a new type of lightning, connecting thunderclouds to the ionosphere. The thundercloud is considered as one electrode igniting gigantic jets and the ionosphere is assumed as the other. The propagation of stepped leader is considered as a field controlled random growth process. The electric field is produced due to the thundercloud charges and the selfconsistently propagating leader. A leader propagation probability is proposed to determine whether the leader grows at the next step and what the step direction of the leader is in case of growth. The results show that leader propagation spans ∼72 km from igniting position to the ionosphere. The simulation of leader propagation appears to be in agreement with the structure of observed gigantic jets.

Leader–streamers nature of blue jets

“…Analysis of such problems is related to the formation of selfconsistent field, and how it falls below the streamer sustainment limit. Note that the fractal models (Pasko and George, 2002;Tong et al, 2005) are time independent and do not deal with the velocity of streamers and Jets.…”

“…More rigorous analysis made by Petrov and Petrova (1999) Pasko and George (2002) came to conclusion that Jets are similar to the streamer zone of a leader (streamer corona). In fact, Pasko and George (2002) presented a detailed model of a Jet as a ''fractal tree'' (see also Tong et al (2005)). Using the earlier developed numerical algorithm (Niemeyer et al, 1989) the branching in the streamer corona was described as that originates from a point base.…”

On the mechanism of blue jet formation and propagation

“…Another important reason why a leader is required as a source of long Jet streamers is that the electric field in the region where streamers are formed cannot be weaker than E S at the given local air density ( E S ≈ 500( N / N 0 ) kV/m where N 0 corresponds to the air density at the sea level [ Bazelyan and Raizer , 1998]). However, it is difficult to generate such a strong field by thundercloud charges alone, and this is the reason why the fractal model [ Pasko and George , 2002] was forced to use unrealistically large thunderstorm charges of Q C = 120–130 C. The models by Tong et al [2005] and Sukhorukov et al [1996] require still higher charges. Unlike these models, if a leader participates in the generation of strong E S field, such huge cloud charges are not needed.…”

Blue jets and gigantic jets: transient luminous events between thunderstorm tops and the lower ionosphere

“…In contrast to [105], in [106] the GJ in its entire altitude extent is considered as a negative leader phenomenon. The physics of stepping of negative leaders and their streamer zones has not been modeled in [106]. The model assumed the ground pressure value of the field inside the leader channel to be equal to E l = 1 kV cm −1 .…”

“…The discharge propagation concept of the model presented in [106] is similar to the fractal models developed previously in [81,140]. In contrast to [105], in [106] the GJ in its entire altitude extent is considered as a negative leader phenomenon. The physics of stepping of negative leaders and their streamer zones has not been modeled in [106].…”