Atmospheric plumes created by meteoroids impacting the Earth

The problem of plume-forming meteoroid impacts into the Earth's atmosphere is investigated with the use of a simplified analytical model and detailed numerical simulations. The process of plume formation is found to depend st rongly on the meteoroid size due to development of Kelvin-Helmholtz instabi lities at the entry column boundary. As a result, the height of plume risin g proves to be considerably less than that obtained using simplified model or numerical simulations with low spatial resolution. It is shown that mete oroids several meters or less in size do not create ballistic plumes at all . The results of general consideration are applied to the Sumava bolide (on e of the brightest detected by the European Fireball Network). The debris c loud created by this impact rises to an altitude of about 190 km.