Letter to the Editor A space charge model for electrophonic bursters

The sounds accompanying electrophonic burster meteors are characteristically described as being akin to short duration “pops” and staccato–like “clicks”. As a phenomenon distinct from the enduring electrophonic sounds that occasionally accompany the passage and ablation of large meteoroids in the Earth’s lower atmosphere, the bursters have proved stubbornly difficult to explain. A straightforward calculation demonstrates that in contradistinction to the enduring electrophonic sounds, the electrophonic bursters are not generated as a consequence of interactions between the meteoroid ablation plasma and the Earth’s geomagnetic field. Here we present a novel and hitherto unrecorded model for the generation of short–duration pulses in an observer’s local electrostatic field. Our model is developed according to the generation of a strong electric field across a shock wave propagating in a plasma. In this sense, the electrophonic bursters are associated with the catastrophic disruption of large meteoroids in the Earth’s atmosphere. We develop an equation for the description of the electric field strength in terms of the electron temperature and the electron volume density. Also, by linking the electron line density to a meteor’s absolute visual magnitude, we obtain a lower limit to the visual magnitude of electrophonic burster meteors of Mv ≈ −6.6, in good agreement with the available observations.