Airplanes Unexpectedly Modify Weather 223
reillymj writes "Commercial airliners have a strange ability to create rain and snow when they fly through certain clouds. Scientists have known for some time that planes can make outlandish 'hole-punch' and 'canal' features in clouds. A new study has found that these odd formations are in fact evidence that planes are seeding clouds and changing local weather patterns as they fly through. In one case, researchers noted that a plane triggered several inches of snowfall directly beneath its flight path."
Re:Cloud Seeding (Score:5, Informative)
That was suggested back in 1970 [ametsoc.org]--- that cloud seeding experiments need to consider the possibility that the plane's flight itself is doing the seeding.
Re:Cloud Seeding (Score:2, Informative)
Clouds are substantially different, and waaaaay more complicated than human physiology. We're not at the stage that we can measure the amount of water and particle sizes in clouds yet. The best we can do is fly a 3cm diameter probe through a cloud, and sample something like a millionth of it.
In fact, cloud dynamics are so ridiculously complicated that we don't even have good models for them yet. Supercomputer time sort-of gets us close to working models. The fact that nobody can reliably predict rain and snowfall amounts, nor weather more than a week out should give you some indication of the complexity of clouds.
Re:Chemtrails? (Score:3, Informative)
A good photo of what an aircraft does do to the air see;
http://www.skysoaring.com/albums/gliderhumor/Box_This_Wake.jpg [skysoaring.com]
Re:Cloud Seeding (Score:3, Informative)
If you were going to test a fishing lure, would you use a "control group" consisting of trout, bass, pike, baleen whales, and tiger sharks? Would you then apply the results to all "fish", despite the fact that some of those weren't fish at all? I would hope not.
This is the case with clouds.
If you'd like to know more, try Wallace and Hobbs [amazon.com]. It's one of the cornerstones of modern atmospheric science. I know you're all hip and can make fancy [citation needed] fake-wiki code, but there are some subjects you can't be an expert on just by casually reading a page on the internet. Neurosurgery and cloud microphysics are two of those things.
Cheers!
Re:Forcing (Score:4, Informative)
Yeah, pity you're actually reading the fucking results wrong. *sigh* To quote wikipedia [wikipedia.org]:
The daytime temperature didn't increase. The difference between night and day increased. And guess what? That matches expectations! Why? Because:
So when there are contrails, it stays warmer at night, due to radiative forcing effects. No contrails? It gets colder at night. End result? *Larger night-day temperature difference*.
But, hey, let's actually look at your study, shall we? Hey, here's a choice quote from the abstract:
Hey, look at that... that's what they fucking found. Science at work: scientists make prediction. Scientists have convenient experiment. Observations match predictions. The system works.
But, hey, don't let facts get in the way of your "skepticism".
Ugh. The new deniers use fancier arguments. (Score:4, Informative)
Your post is littered with falsehoods. I barely know where to start. Whether you realize it or not, you're concern trolling from ignorance.
We still do not have enough evidence to prove that burning fossil fuels will produce global warming.
Eh? What?`
First off, basic physics predicts that more CO2 and methane (and other greenhouse gasses) in the air will cause the atmosphere, and hence, the ground, to heat up. In a glass jar, CO2 behaves precisely as expected.
The Earth is more complex than a glass jar, it's true, but to argue against global CO2-based warming, you need a plausible physical explanation for where the heat caused by the CO2 went. Unless some obscuring agent prevents sunlight from hitting the CO2, the heat from was undoubtedly generated in the atmosphere nearly exactly as predicted by physics. So where does it go?
In addition to a magic (heretofore invisible) heat-sink, you need a plausible alternative explanation for the geologic record, dating back 100s of thousands of years, showing that, indeed, CO2 and warming are in a feedback-loop, punctuated by various global disasters.
Now before I continue, let me just get this out of the way: there is a difference between someone who believes global warming *can't* be true in the religious sense, and someone who recognizes that climate is a difficult subject for which we just don't have the answers now.
This is a ridiculous cop-out, and is a lousy argument for destroying civilization as we know it.
The fact is, we've had a pretty nice equilibrium here for thousands of years. Throwing off that balance could mean a lot of different possible things, but it definitely means chaos and turmoil.
We don't know everything, but we know some things. We know that the gulf-stream is very important to heating up North America. We know that North America would turn in to a block of ice if it were to shut down. We may not know how to keep it running, but that's not a good reason to toss a bunch of carbon in the air to see what happens.
The best plan is probably to try to maintain the equilibrium somehow. It's worked for a while. I like the coasts where they are, and I don't want to experiment with their shape, thank you very much. If I were in a rowboat with you, I also wouldn't want you to experiment by standing up and rocking it back and forth.
I'll deal with two more of your arguments.
Global temperatures have been on the decline for the last decade, much as they did during the turn of the century 100 years ago.
Incorrect. 1999-2009 were the hottest decade in human history. 2009 was about as hot as the previously hottest year on record, 2005, and possibly hotter, depending on what source you use. This can hardly be described as a decline, and is a typical misconception sponsored by various media outlets.
2010 is trading on Intrade at 67% to be the warmest year on record. You could make a pretty nice sum by betting against it, getting back two times your money at that price level.
Only if you cherry pick 1998-2007 from the data can you claim a "decline", which really isn't a decline, it's a squiggle that bounces back and forth, ending up just below the top.
You may not be a denier, but you sure play one on /.
We can probably agree that CO2 is a greenhouse gas; what we can't explain is why increased generation of CO2 hasn't resulted in a proportionate increase in the atmospheric CO2 levels.
Possibly because you made up that as a requirement. Your argument is irrelevant and spurious. Physics predicts a warming as CO2 rises. CO2 levels are rising dramatically, as we have observed. The temperature is rising dramatically, as we have observed, your weak protestations to the contrary notwithstanding.
Yes, the oceans absorb some. This isn't a question as you intimate, it has been measured. The question of whether increased CO2 in the atmosp
Re:Cloud Seeding (Score:2, Informative)
As a cloud physicist I suggest you need to spend some time with a cloud physics text book not high energy physics textbook before you spout nonsense. You ASSUME (that's the Ass infront of U) that cloud droplets and rain drops are like your particles. They are not. Try your experiments where the source, make up and character of your particles varies not only from experiment to experiment, but minute by minute during the same experiment. The source of the cloud condensation nuclei (CCN) varies as the source of the air parcels changes as the cloud moves. Early experiments showed that sea salt and kaolin clays were acting as CCN's and that the concentration varied both with time and space. The equivalent HEP would be randomly supplying proton, neutrons and electrons in your collisions AND you are not allowed to know which kind of particle or it's energy participated in the collision. Your comment about only caring about the equivalent radar reflectivity shows a basic lack of understanding of physics. The equivalent radar reflectivity (dBZ) is based on an ASSUMED (there's that Ass again) drop-size distribution. There are hundreds of rain-reflectivity relationships that don't work for anything but the cloud sampled.