Mechanism of formation of a heated ground layer by an intense air burst

A mathematical modeling study demonstrated the fundamental possibility of the formation of a heated layer (a meter-long layer of erosion vapor and air with temperatures of a few thousand degrees and a density 20–50 times lower than the normal air density) at the ground surface under the action of the long-distance traveling fireball radiation from an intense explosion at a moderate radiant flux density of about 1 GW/m$^2$ for a time of about 10 msec. The results of the numerical study agree with data from observations of the heated layer effect in nuclear-weapon tests.