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Falcon
Joined: 04 Aug 2000
Posts: 87
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 Sun Aug 06, 2000 1:25 pm
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Each one of the above images shows nothing more than an aircraft contrail with some high level cirrus cloud.
The picture titled "Gotcha" shows a contrail with a couple of gaps. Such gaps are not uncommon in and generally occur due to power changes as the aircraft climbs or descends or a change in that part of the atmosphere.
As for the one where two trails are seen to cross, well done you've photographed an airway intersection.
I really don't see where you get this "chemtrail" theory from. |
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Thermit
Joined: 08 Jul 2000
Posts: 3136
Location: Texas |
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Tue Aug 08, 2000 6:20 pm
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Explainations?
Atmospheric Changes
Contrails can fade in and out as aircraft enter or leave a body of air that supports their formation. These types of changes typically occur over large areas, the break in the trail is too small and too sharp to be the result an atmospheric change.
Power Changes
If this is a result of change in engine power, then the engine would apparently have been off (no contrail for some distance, I guess that jet was just gliding along for a while with no power), then turned on for a moment, back off, back on for another moment, and then back off again to continue the glide. Doesn't add up to me. Maybe someone could explain.
Chemtrails
Now if airplanes where spraying some substance via a pump driven system, they might turn the sprayer on a couple of quick times, producing two short strips with very defined edges as shown in the picture.
As can be seen in another previously posted picture:
http://www.chemtrailcentral.com/cgi-bin/db-search.cgi?temp late=img-detail&dbname=img&key2=333&action=searchdbdisplay
the start and stop trails are just part of the modus operandi of the sprayplanes.
Interestingly the photographer had been watching the skies for two weeks since the last sprayfest before he observed any trail formation of any kind.
Here is the atmospheric sounding for the day in question for Pittsburg (closest station to Canton, OH):
http://www-das.uwyo.edu/cgi-bin/sounding?OUTPUT= TEXT&TYPE=SKEWT&HOUR=12&DAY=4&MONTH=8&YEAR=2000&STATION=RIW&usa.x=514&usa.y=89
Notice that based on figures of less than -30C and more than 70% humidity, that they never really quite get to the necessary conditions for persistant contrail formation. The closest seems to be around 45,000 ft. roughly.
If science says that no persistant contrail formation is possible, what was it?
[Edited 1 times, lastly by Thermit on 06-17-2002] |
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orange_fuzzy
Joined: 08 Aug 2000
Posts: 1
Location: Baltimore, MD USA |
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Wed Aug 09, 2000 3:07 am
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Falcon, go back to sleep. |
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theseeker
Joined: 25 Jul 2000
Posts: 3403
Location: Damnit...I'm a doctor jim |
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Wed Aug 09, 2000 8:35 am
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Science has given the definition of contrail persistence,the 45,000 number is off....
maybe it is you that should 'wake-up' and smell the science....orange_fuzzy>>>>
out |
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Thermit
Joined: 08 Jul 2000
Posts: 3136
Location: Texas |
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Wed Aug 09, 2000 3:05 pm
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Seeker,
You are right, the 45,000ft number is off. I looked again and realized it never even got close. Notice that as the altitude of the soundings increase the relative humidity falls below 70% somewhere between 2380 and 3109 meters, but the temperature doesn't fall below -30C until somewhere above 8731 meters. Not even close.
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theseeker
Joined: 25 Jul 2000
Posts: 3403
Location: Damnit...I'm a doctor jim |
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Thu Aug 10, 2000 9:37 am
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you must remember altitude is key...
soundings are only good 50 miles around the site... some say less.....
good pic's |
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Thermit
Joined: 08 Jul 2000
Posts: 3136
Location: Texas |
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Thu Aug 10, 2000 5:18 pm
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Seeker,
Pittsburg seems to be about 75 miles from Canton, so yeah, the validity of the sounding will be less reflective of the actual values for Canton. I checked the chart for Detroit (since Canton is somewhat between Pittsburg and Detroit) for the same day, and it shows that there is possibly a chance of persistant contrail formation within a narrow altitude range:
http://www-das.uwyo.edu/cgi-bin/sounding?OUTPUT= TEXT&TYPE=SKEWT&HOUR=12&DAY=4&MONTH=8&YEAR=2000&STATION=RIW&usa.x=499&usa.y=81
LEV PRES HGHT TMP DWP RH DD WETB DIR SPD THETA THE-V THE-W THE-E W
-------------------------------------------------------------------------------
22 445 6646 -19.9 -22.5 80 2.6 -20.5 272 20 319.2 319.5 290.0 324.1 1.41
23 435 6815 -20.5 -25.2 66 4.7 -21.6 272 20 320.6 320.8 290.1 324.5 1.13
24 423 7021 -21.5 -23.5 84 2.0 -22.0 276 19 321.9 322.1 290.7 326.5 1.36
25 400 7430 -24.3 -26.8 80 2.5 -24.8 285 18 323.4 323.6 290.9 327.1 1.07
26 331 8781 -34.1 -38.3 66 4.2 -34.6 300 15 328.0 328.0 291.6 329.5 0.42
27 300 9460 -40.1 -43.7 68 3.6 -40.4 290 16 328.8 328.9 291.7 329.9 0.27
Somewhere between Level 25 and 26. If you averaged the data of the two soundings, there would probably be not be any altitudes that met the required figures.
Seeker, what were you specifically refering to when you said altitude is key?
I tried to find a reference which described the radius for which the soundings are valid and didn't find anything. Do you have any references which discuss this?
Thanks.
[Edited 1 times, lastly by Thermit on 08-14-2000] |
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theseeker
Joined: 25 Jul 2000
Posts: 3403
Location: Damnit...I'm a doctor jim |
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Sat Aug 12, 2000 2:33 am
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this will help you with the temperature @ altitude thing,RH and tafs as well
http://adds.awc-kc.noaa.gov/projects/adds/flight_path/index.html
enjoy
Forgot...DO NOT scroll while data is loading !
[This message has been edited by theseeker (edited 08-11-2000).] |
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Thermit
Joined: 08 Jul 2000
Posts: 3136
Location: Texas |
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Sat Aug 12, 2000 4:32 pm
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Thanks Seeker.
Will have to study this app for a while... |
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Thermit
Joined: 08 Jul 2000
Posts: 3136
Location: Texas |
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Mon Aug 14, 2000 3:37 pm
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I posted the link and a screen dump of this excellent application in the Sky Soundings thread. |
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Lulu
Joined: 22 Dec 2000
Posts: 2501
Location: right here |
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Tue Jun 18, 2002 4:25 am
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Bumped for the good info, links and picture! |
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Anne
Joined: 04 Feb 2001
Posts: 123
Location: Napa, CA USA |
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Tue Jun 18, 2002 4:34 am
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Just saw "Bourne Identity" movie and right at the beginning there were chemsprays and Xs in the sky in Paris. |
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