Noctilucent Clouds Likely Caused By Shuttle Launches 132
icebike writes "In our recent discussion of the phenomenon of noctilucent clouds, there was some suggestions that these might be the product of global warming due to moisture being lofted high into the atmosphere. It now appears that these clouds are simply the product of Shuttle launches. In a story about the Tunguska blast, Science News says: 'Each launch of a space shuttle, which burns a combination of liquid hydrogen and liquid oxygen as fuel, pumps about 300 metric tons of water vapor into the atmosphere at altitudes between 100 and 115 kilometers. Soon after the January 16, 2003, launch of the shuttle Columbia, a liftoff that took place just after the height of summer in the Southern Hemisphere, noctilucent clouds appeared over Antarctica. Similarly, a widespread display of the night-shining clouds showed up over Alaska two days after the shuttle Endeavour blasted off on August 8, 2007. Previous studies show that in both instances those clouds included material from the shuttle plumes.' So, man-made after all?"
Why now? (Score:5, Interesting)
Disregarding the 1887 thing, which is amply discussed above, what amazes me is this:
If these luminous clouds are caused by shuttle launches, why has it taken, 32 years and 128 launches for someone to discover this relation?
Or, has something else happened to the atmosphere not-so-long ago which, together with the launches, have been causing these clouds only recently?
Facts FUD (Score:3, Interesting)
Carbon credits for shuttle launches? (Score:3, Interesting)
So, can shuttle launches get "carbon credits"? (I know that they aren't actually reducing carbon emissions but if these clouds reduce global warming perhaps they'd be eligible). Is the amount so negligible that it wouldn't come close to offsetting the (horrendously) expensive launches?
Do other spacecraft (Arianne, Delta, Soyuz) also create these clouds?
Re:Um, first observed in 1887 - well before shuttl (Score:3, Interesting)
Had you RTFA you would have seen this:
Scientists at the time suggested that the night-shining clouds over London were made of meteoritic dust. But those aerosols are typically too small to reflect sunlight efficiently, Kelley argues, suggesting the clouds above Europe were made of ice crystals. This assumption, along with the new analysis of shuttle plume movement, strongly suggests that the object that blazed into the atmosphere and disintegrated above Siberia was a moisture-rich comet rather than a relatively dry asteroid.
Re:Um, first observed in 1887 - well before shuttl (Score:5, Interesting)
And what happened around that time?
http://en.wikipedia.org/wiki/Krakatoa [wikipedia.org]
You totally miss the point of the story. Its not the fuel mixture. Its the fact that large amounts of water vapor find their way to the upper atmosphere. Some by natural causes. Some by shuttle launches.
few airplanes after 9-11 changed atmosphere (Score:4, Interesting)
Re:Noctilucent clouds have been observed in Europe (Score:3, Interesting)
Since this UV/EUV/X-ray flux is a significant fraction of the solar output and varies strongly with coronal conditions, it is the most important driver of global warming/cooling.
And that's why you see a strong correlation between solar output and global mean temperature!
Except, of course, there is no such correlation. After all, as you say, "the data does not lie". Whoops!