The effect of meteoroid impacts on the ozone and nitric oxide budget in the upper Earth's atmosphere

All optically detectable meteors, as well as some strong radio-detectable meteors, generate shockwaves during the lower transitional flow regimes in the mesosphere-lower thermosphere (MLT) region of the Earth's atmosphere, at altitudes between 75 km and 100 km. Meteor generated shock waves can modify the surrounding atmosphere and produce a range of physico-chemical effects, including removal of ozone (O₃) and production of nitric oxide (NO) (Silber et al. 2017; 2018a). It was previously shown that centimeter-sized meteoroids are capable of producing NO in the MLT region (Menees & Park 1976; Park & Menees 1978); however, as per most recent estimates, the total annual contribution is only about 1000 tons (Silber et al. 2018b). We expand on this recent work to explore the effect of large meteoroids (the Chelyabinsk class) on the surrounding atmosphere during their descent, and evaluate whether there is a detectable (albeit temporary) contribution to the O₃ and NO budget. We also contrast the NO production efficiency of large bolides and cm-sized meteoroids.

References:

Silber E. A. et al. (2018a) Adv. Sp. Res., 62(3), 489-532.

Menees G.P. & Park C. (1976) Atm. Env. 10, 535-545.

Park C. & Menees G.P. (1978) JGR: Oceans. 83, 4029-4035.

Silber E.A. et al. (2018b) Atmosphere, 9(202), 1-21.