Answer:
The initial energy emission occurs by 80% or more in the form of gamma rays but these are quickly absorbed and dispersed mostly by air in little more than a microsecond, converting gamma radiation into thermal radiation (thermal pulse ) and kinetic energy (shock wave) which are actually the two dominant effects in the initial moments of the explosion. The rest of the energy is released in the form of delayed radiation (fallout or fallout) and is not always counted when measuring the performance of the explosion.
Explanation:
High altitude explosions produce greater damage and extreme radiation flux due to lower air density (photons encounter less opposition) and consequently a higher blast wave is generated.