I am planning on writing a science fiction book that uses a meteor strike on the earth as a big part of the story. How long do you think a cloud, or "nuclear winter" effect would last after such an event? Lets say a chunk of rock the size of New York City.

http://www.compsoc.man.ac.uk/~samp/nuclearage/scien.html

That has a few things to say and then this site

http://www.cooperativeindividualism.org/sagan_nuclear_winter.html

had this to say in one part...

The cold, the dark and the intense radioactivity, together lasting for months, represent a severe assault on our civilization and our species. Civil and sanitary services would be wiped out. Medical facilities, drugs, the most rudimentary means for relieving the vast human suffering, would be unavailable. Any but the most elaborate shelters would be useless, quite apart from the question of what good it might be to emerge a few months later. Synthetics burned in the destruction of the cities would produce a wide variety of toxic gases, including carbon monoxide, cyanides, dioxins and furans. After the dust and soot settled out, the solar ultraviolet flux would be much larger than its present value. Immunity to disease would decline. Epidemics and pandemics would be rampant, especially after the billion or so unburied bodies began to thaw. Moreover, the combined influence of these severe and simultaneous stresses on life are likely to produce even more adverse consequences -- biologists call them synergisms -- that we are not yet wise enough to foresee.

My own idea of it would be that it would probably kill 60% of the worlds population in one go, out of the rest maybe 20% would die quickly of radiation effects and the last 20% would probably make maybe 1 to 2 generations before the sheer effects wiped them out.

The whole Post Apocolyptic world scenario has always interested me so if its ok trav id love to read some extracts if your willing to share (once youve wrote them obviously, i realise you havent started).

Good luck!

Originally posted by Lokideviluk
The cold, the dark and the intense radioactivity,
Meteors generally aren't radioactive...

Yeh this i know, but wouldnt the meteor take out a few sites that had radioactive materials thus leaking it??

One way to consider this problem is to look at other events that have blown large amounts of dust and rock into the atmosphere. The explosion of Krakatoa is perhaps the most similair to what you are describing. The dust and ash was in the atmosphere in detectable levels for several years. It produced amazing sunsets for all that time.

actually in my story the composition of the asteroid itself interacts with the earths atmosphere and creates a toxic cloud the mutates all in its path

Originally posted by Travh20
actually in my story the composition of the asteroid itself interacts with the earths atmosphere and creates a toxic cloud the mutates all in its path

AGGGH! Don't tell me how it ends!:D

Originally posted by Travh20
actually in my story the composition of the asteroid itself interacts with the earths atmosphere and creates a toxic cloud the mutates all in its path
Eeeeewww, BAD sci-fi premise...

What about an Asteroid that flys through the atmosphere crashes into the earth and creates the tremors explosions and the like for 3 seconds and then stops in motion as if something had just stopped the total destruction of earths population by freeze framing the whole world at that point except for everyone who technically died at that exact moment.

They would find themselves in a planet suspended in stasis where some mysterious force had destined the world to not end like that.

The key here is that at various points they will stumble into random variotions on their current world (visions if you will) of, a world of moving talking people and sounds before the asteroid crashed.

As if these people are trapped within a reality halted in time as a mirrored reality continues as if the asteroid never crashed.

Their mission to find a way to break through and reach that reality so they can be with their familys, freinds etc.

These people have died in the new reality yet they have been giving a second chance in the halted reality to relive in the new one if they could just find a way to reach the other side.

Youd obviously for the purpose of character building choose 5 or 6 main characters so that the reader can truly embrace the emtion of those characters.

This is partly inspiried by that Steven King thing with the chompers in time and that aeroplane that sorta leaps out of time,

Just an idea i came up with as i was reading this post, does that sound corny?

Originally posted by BorgHunter
Eeeeewww, BAD sci-fi premise...

thats not really what the story is about, that is just a set up for the actual story which takes place some time after this happens, thats why I wanted to know how long the cloud would last, so I could give an accurate time frame from meteor impact through nuclear winter throuhg rebirth to the time of the story.

As long as you stop calling it "nuclear winter". There's nothing nuclear about the cloud that arises from a meteor impact.

Here, Trav, found this on Wikipedia:

The resulting blast would have been hundreds of millions of times more devastating than the most powerful nuclear weapon ever detonated, may have created a hurricane of unimaginable fury, and certainly would have thrown massive amounts of dust and vapor into the upper atmosphere and even into space. A global firestorm may have resulted as the incendiary fragments from the blast fell back to Earth. Analyses of fluid inclusions in ancient amber suggest that the oxygen content of the atmosphere was very high (30 - 35%) during late Cretaceous. This high O2 atmospheric content would have supported massive combustion. The level of atmospheric O2 plummeted in the early Tertiary. In addition the worldwide cloud would have choked off sunlight for years, resulting in a "long winter" that wiped out many existing species, as well as creating "acid rains" that would have inflicted further hardship on the environment.

thanks borg. I was only calling it nuclear winter becasue thats all I know the effect as. Long Winter sounds good too.