Runaway breakdown in the Jovian atmospheres
Abstract
Electromagnetic pulses associated with electrical discharges have been observed to radiate from Jupiter and Saturn, and optical emissions have been correlated with these electrical discharges on Jupiter. This suggests that a phenomenon similar to terrestrial lightning may occur on at least these two of the Jovian planets. In this study, a Monte Carlo model is used to calculate the properties of runaway breakdown in an atmosphere similar to the four gas giant planets in our solar system, and the runaway avalanche lengths and average runaway electron kinetic energies are presented as a function of atmospheric electric field strengths. The runaway breakdown threshold field for the Jovian atmospheres is found to be at least 10 times smaller than the conventional breakdown field at similar gas densities and compositions, indicating that runaway breakdown processes may be much more efficient in the gas giants than on Earth. Because runaway breakdown is known to produce large bursts of x-rays and gamma-rays such as terrestrial gamma-ray flashes from thunderstorms in Earth's atmosphere, and may play a role in lightning initiation on Earth, these results suggest that runaway breakdown may also play an important role in thunderstorm and lightning processes on the Jovian planets.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AGUFMAE23A..07C
- Keywords:
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- 0343 Planetary atmospheres (5210;
- 5405;
- 5704);
- 0545 Modeling (4255);
- 3304 Atmospheric electricity;
- 3324 Lightning;
- 3359 Radiative processes