In the case of nuclear explosions, this is rather high in the atmosphere, normally in the ozone layer. According to an article in Scientific American , "All atomic bombs produce a bulge and a stem, but the really huge, mushroom clouds are produced by the very high-yield explosions of thermonuclear weapons hydrogen bombs. The fireball from an H-bomb rises so high that it hits the tropopause, the boundary between the troposphere and the stratosphere.
There is a strong temperature gradient at the tropopause, which prevents the two layers of the atmosphere from mixing much. The hot bubble of the fireball initially expands and rises. By the time the bubble has risen from sea level to the tropopause, it is no longer hot enough to break through the boundary. At that point, the fireball flattens out; it can no longer expand upward, so it expands to the side into an exaggerated mushroom cap.
We can all now visualize what a nuclear explosion looks like, but what is more difficult is to understand the scale of the explosion. Since it is unlikely that we have ever seen a nuclear explosion in-person, the scale can be difficult to grasp. In general, the mushroom clouds can rise up to tens of thousands of feet in minutes. For reference, most passenger planes cruise at around 33, feet, or 10, meters. Looking back at a historical explosion, let's take a look at what happened after the nuclear explosion in Hiroshima in Within the first 10 minutes, the mushroom cloud rose to more than 60, feet, or roughly 20, meters.
That doesn't give us the whole picture though. While it was more than 20, meters high in the first 10 minutes, within the first 30 seconds the cloud had risen over the cruising altitude of the Enola Gay, the plane that dropped the bomb. As the fireball cools and condensation occurs, the color changes to white, mainly due to the water droplets as in an ordinary cloud.
The cloud consists chiefly of very small particles of radioactive fission products and weapon residues, water droplets, and larger particles of dirt and debris carried up by the afterwinds.
The eventual height reached by the radioactive cloud depends upon the heat energy of the weapon and upon the atmospheric conditions. If the cloud reaches the tropopause, about miles above the Earth's surface, there is a tendency for it to spread out. An explosion of the magnitude and size of a nuclear detonation is not quickly forgotten, whether as a result of seeing documentaries and movies depicting an explosion or seeing images in pop culture.
The signature enormous mushroom clouds that these explosions produce are perhaps the most noticeable element of them. Most bombs produce clouds that are similar to but not identical to those seen after a nuclear explosion. In a nutshell, it's because the bomb releases massive amounts of energy all at once. This energy produces a highly hot gas bubble that interacts with the cooler surrounding air, causing it to become less dense.
When a nuclear weapon detonates, it emits a blast of x-rays that ionize and heat the surrounding air, forming a fireball.
The swiftly rising hot fireball creates a forceful updraft, eventually filled by the surrounding air and dust. This is what gives rise to the cloud. To comprehend why nuclear explosions produce mushroom clouds, it is necessary to first describe what these clouds are.
Atomic Archive said mushroom clouds are clouds of smoke and debris that move through the air following an explosion. These clouds arise not only after nuclear explosions but also after any event that generates a lot of heat in a short amount of time. An example would be the detonation of a conventional bomb or perhaps the eruption of a volcano. A big nuclear explosion creates a quick release of heat, which reacts with the surrounding air, making it less dense.
If you watch a movie of a nuclear detonation, you can see entrained material swirling outwards as a result. The fireball from an H-bomb rises so high that it hits the tropopause, the boundary between the troposphere and the stratosphere. There is a strong temperature gradient at the tropopause, which prevents the two layers of the atmosphere from mixing much.
The hot bubble of the fireball initially expands and rises. By the time the bubble has risen from sea level to the tropopause, it is no longer hot enough to break through the boundary. In other words, the bubble encounters material that has more energy than it does, so it is no longer buoyant. At that point, the fireball flattens out; it can no longer expand upward, so it expands to the side into an exaggerated mushroom cap. The same thing happens to big summer thundercloud when they rise up to the tropopause, producing a characteristic flattened-anvil shape.
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