Atmospherical nuclear detonation?

Question

What effects would there be for a nuclear detonation in the atmosphere?

Answer 1

Heat, shock wave, projectiles, radioactivity, and electro-magnetic (EM) pulse are the major manifestations of energy released in an atomic bomb. Heat/light is the first thing you see. Traveling at the speed of light, it will reach distances almost immediately. Shock waves travel at the speed of sound. They create the sound and extreme winds (hundreds of mph) that follow the heat/light.

If the A-bomb is close enough to the surface, debris, dirt, ejecta, and just plain junk will be sucked up into the mushroom cloud that forms. That will eventually come back to Earth, and much of it will be radioactive as well.

In addition, much of the stuff on the ground at epicenter, will be turned into radioactive molten dust; some of which could be carried around the world in the trade winds as it cooled. The heavier dust would settle much closer to the blast site and the area around the explosion would be irradiated by that radioactive fallout.

If the A-bomb explodes high enough above the soil, there will be little or no projectiles or molten dust thrown out beyond the site of the explosion. That results because at higher altitudes, the fire ball fails to reach the ground to suck up stuff. Radioactive fallout would be minimized.

The air near the blast would be ionized from neutron flux released by the explosion. How much and for how long the air would be ionized depend on the yield of the A-bomb. But the effect would not last more than a few hours to a day at most. The ionized air would interrupt radio and TV transmissions for some time. In addition to the ionization, the EM pulse could short out vulnerable, high-end electronics.

Answer 2

Nuclear weapons are designed to detonate at some specific distance above the Earth's surface. This is far more effective than detonation when it hits the ground (a large amount of energy is 'lost' to the ground in creating a crater and travels through the Earth).

Atmospheric detonation permits the shockwave to be reflected off the ground and effectively increases the 'blast radius'. Most of the damage done by a nuclear explosion is due to the blast.

Wikipedia has quite a bit on this...http://en.wikipedia.org/wiki/Nuclear_explosion