Sponsor Message:
Civil Aviation Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
I Have Question About Contrails.  
User currently offlineAileron11 From United States of America, joined Oct 2005, 183 posts, RR: 0
Posted (7 years 7 months 2 weeks 2 days 23 hours ago) and read 2903 times:

I checked to see if this has been discussed before but did not find anything, so my question is, why does some airplanes have contrails that look like they skip, just today I saw three airplanes flying and instead of seeing long continues line I saw the contrail stop and then start again I looked as long as I could see the airplane and it kept happening. Just wondering if any else seen this or maybe even have an answer thanks.


Jersey Lou
10 replies: All unread, jump to last
 
User currently offlineSteeler83 From United States of America, joined Feb 2006, 9178 posts, RR: 18
Reply 1, posted (7 years 7 months 2 weeks 2 days 23 hours ago) and read 2878 times:

It has to do with atmospheric conditions aloft. There must be some little isolated pockets of very dry air aloft for this phenomenon to occur. With more humidity at F.L. 20-something-000 feet, the water vapor discharged from the jets will condense into clouds, or what we see as contrails. If the air is very dry aloft, the vapor cannot condense and crystalize. Therefore no contrail is seen.

Please somebody correct me if I am wrong! I read about contrails in "The National Audaban Society Field Guide to North American Weather. (I don't think Audaban is spelled right btw.) Anyway, that is my source. Did I misinterpret or misread something? Please tell me!!



Do not bring stranger girt into your room. The stranger girt is dangerous, it will hurt your life.
User currently offlineWe're Nuts From United States of America, joined Jun 2000, 5722 posts, RR: 20
Reply 2, posted (7 years 7 months 2 weeks 2 days 23 hours ago) and read 2864 times:

It's because they are spraying chemicals as part of a top secret government program.  shhh 


Dear moderators: No.
User currently offlineAileron11 From United States of America, joined Oct 2005, 183 posts, RR: 0
Reply 3, posted (7 years 7 months 2 weeks 2 days 23 hours ago) and read 2845 times:

Quoting Steeler83 (Reply 1):
It has to do with atmospheric conditions aloft. There must be some little isolated pockets of very dry air aloft for this phenomenon to occur. With more humidity at F.L. 20-something-000 feet, the water vapor discharged from the jets will condense into clouds, or what we see as contrails. If the air is very dry aloft, the vapor cannot condense and crystalize. Therefore no contrail is seen.

Please somebody correct me if I am wrong! I read about contrails in "The National Audaban Society Field Guide to North American Weather. (I don't think Audaban is spelled right btw.) Anyway, that is my source. Did I misinterpret or misread something? Please tell me!!

Thanks for the info.

Quoting We're Nuts (Reply 2):
It's because they are spraying chemicals as part of a top secret government program.

i had feeling something like that was happening.



Jersey Lou
User currently offlineSteeler83 From United States of America, joined Feb 2006, 9178 posts, RR: 18
Reply 4, posted (7 years 7 months 2 weeks 2 days 22 hours ago) and read 2833 times:

Quoting Aileron11 (Reply 3):
Thanks for the info.

Anytime. Although, I must say that I don't know how accurate that is. I did have a supreme interest in meteorology, but of course, that interest has shifted towards geography and planning.

Quoting Aileron11 (Reply 3):
Quoting We're Nuts (Reply 2):
It's because they are spraying chemicals as part of a top secret government program.

i had feeling something like that was happening.

Heheh, yeah this is true as well Big grin

I think that the increasing number of really bad drivers has something to do with this, and one royally bad driver practically ran my girlfriend and myself off the road just last night! If he could've gotten any closer to my girlfriend's trunk, he would've been in it...



Do not bring stranger girt into your room. The stranger girt is dangerous, it will hurt your life.
User currently offlineVref5 From , joined Dec 1969, posts, RR:
Reply 5, posted (7 years 7 months 2 weeks 2 days 22 hours ago) and read 2809 times:

Quoting We're Nuts (Reply 2):
It's because they are spraying chemicals as part of a top secret government program. shhh

Hahaha Big grin

Ahh, yes, the good ol' chemtrails.  Silly

Quoting Steeler83 (Reply 1):
It has to do with atmospheric conditions aloft. There must be some little isolated pockets of very dry air aloft for this phenomenon to occur. With more humidity at F.L. 20-something-000 feet, the water vapor discharged from the jets will condense into clouds, or what we see as contrails. If the air is very dry aloft, the vapor cannot condense and crystalize. Therefore no contrail is seen.

You've got the rough idea, though there are actually two things that matters here:

1. Low temperature

AND

2. Vapor pressure

It's pretty cold up there every day, but not always the vapor pressure needed. That's why you don't always see contrails.

Basically, if you have sufficient vapor pressure, it will form a "cloud"... and if you don't, it won't. There, that's a bit of my aviation meteorological training put to some use. Big grin


User currently offlineGraphic From , joined Dec 1969, posts, RR:
Reply 6, posted (7 years 7 months 2 weeks 2 days 22 hours ago) and read 2791 times:

There needs to not only be enough water vapor (not as much as you'd think because jet engines themselves produce a large amount of water vaport), but there also needs to be sufficient nuclei for the vapor to condense on (microscopic dust, smoke particles). When the temperature is so cold that the air cannot hold the water vapor the engines produce, it will condense on the nuclei and a cloud will be visible.

User currently offlineSteeler83 From United States of America, joined Feb 2006, 9178 posts, RR: 18
Reply 7, posted (7 years 7 months 2 weeks 2 days 22 hours ago) and read 2777 times:

Quoting Vref5 (Reply 5):

Thank you very much  Smile

Naturally I should've known about cold temperature, OF COURSE!!! Vapor pressure I didn't even think of! THANKS!!!

Quoting Vref5 (Reply 5):
Basically, if you have sufficient vapor pressure, it will form a "cloud"... and if you don't, it won't. There, that's a bit of my aviation meteorological training put to some use.

And good training put to good use at that!  Smile



Do not bring stranger girt into your room. The stranger girt is dangerous, it will hurt your life.
User currently offlineBimmerkid19 From , joined Dec 1969, posts, RR:
Reply 8, posted (7 years 7 months 2 weeks 2 days 22 hours ago) and read 2727 times:

Quoting Vref5 (Reply 5):

...and trails of the bluejuice  Wink


User currently offlineSteeler83 From United States of America, joined Feb 2006, 9178 posts, RR: 18
Reply 9, posted (7 years 7 months 2 weeks 2 days 21 hours ago) and read 2679 times:

Quoting Bimmerkid19 (Reply 8):
and trails of the bluejuice

what about the WN kool-aid?  Wink



Do not bring stranger girt into your room. The stranger girt is dangerous, it will hurt your life.
User currently offlinePihero From France, joined Jan 2005, 4389 posts, RR: 76
Reply 10, posted (7 years 7 months 2 weeks 2 days 14 hours ago) and read 2563 times:
Support Airliners.net - become a First Class Member!

Quoting Steeler83 (Reply 1):
It has to do with atmospheric conditions aloft. There must be some little isolated pockets of very dry air aloft for this phenomenon to occur.



Quoting Vref5 (Reply 5):
Basically, if you have sufficient vapor pressure, it will form a "cloud"... and if you don't, it won't.

All true, but if you both go just a bit further, it is a sure sign of clear air turbulence be it due to a wave or some drastic convective movements of the air mass.

Regards



Contrail designer
Top Of Page
Forum Index

This topic is archived and can not be replied to any more.

Printer friendly format

Similar topics:More similar topics...
Quick Question About Contrails... posted Sat Feb 11 2006 02:24:18 by Iah744
I Have A Question About Overbookings posted Mon Aug 8 2005 05:33:15 by Tsaord
I Have A Question About This Picture- Who Can Help posted Thu Apr 7 2005 18:08:42 by LH450
I Have A Question About This Picture- Who Can Help posted Thu Apr 7 2005 18:06:39 by LH450
I Have A Question About Southwest posted Sun May 26 2002 06:01:07 by Chi-town
Help! I Have A Question About The LAX Gathering! posted Thu Feb 8 2001 03:04:29 by ILUV767
A Question About Contrails posted Sat Oct 14 2000 04:02:56 by TurboTristar
I Have A Question About The AA-NWA Merger. posted Fri Aug 25 2000 23:33:32 by AerLingus
Question About EMA posted Thu Dec 14 2006 05:11:38 by Pe@rson
Question About Antrak Air (Ghana) posted Wed Dec 6 2006 14:08:08 by ENU