1. cloudspotter

    cloudspotter Senior Member

    This jellyfish train has been photographed over Seattle. I guess it could be the remains of a contrail pendules since they are so regularly spaced. What does everyone else think?

    odd.
     
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  3. Mick West

    Mick West Administrator Staff Member

    They look like fallstreaks that you'd get in a fallstreak hole. Seems like a combination of the contrail breaking from crow instability, and then fallstreaks forming from a mostly invisible layer just beneath it.

    However it could also be a roll cloud of some kind that has just developed into this. See (d) in Figure 5.45 below

    http://books.google.com/books?id=5D...w of fallstreaks&pg=PA193#v=onepage&q&f=false
    upload_2013-8-7_7-47-1.
    upload_2013-8-7_7-47-30.
     
  4. Mick West

    Mick West Administrator Staff Member

    Last edited: Nov 20, 2013
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  5. solrey

    solrey Senior Member

    Cliff Mass from the UW in Seattle explains...



    http://cliffmass.blogspot.com/2013/08/stange-clouds-sighted-over-western.html (http://archive.today/Z1q4C)

    It looks like a N-W contrail or two may have been the trigger for a perpendicular line of clouds along an E-W line of atmospheric instability. I wonder if turbulence from wing tip vortices could have been a factor as well.
     
    Last edited by a moderator: May 21, 2014
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  6. Mick West

    Mick West Administrator Staff Member

    Last edited: Nov 20, 2013
  7. Pete Tar

    Pete Tar Moderator Staff Member

    Last edited by a moderator: Nov 20, 2013
  8. Cairenn

    Cairenn Senior Member

    http://www.truthcontrol.com/forum/chembombsthe-new-chemtrails

     
    Last edited by a moderator: Aug 8, 2013
  9. Met Watch

    Met Watch Moderator

    Last edited by a moderator: Nov 20, 2013
  10. cloudspotter

    cloudspotter Senior Member

    Last edited by a moderator: Nov 20, 2013
  11. Pete Tar

    Pete Tar Moderator Staff Member

    How *would* tonnes of magnetic dust act in the atmosphere?
     
  12. Met Watch

    Met Watch Moderator

    That's a fraction of it. Your mature thunderstorms can have up to 150 million tonnes of water. :eek:
     
  13. Pete Tar

    Pete Tar Moderator Staff Member

    Not sure if this is a *thing* or not...
    As the sun came up this morning it seemed to affect the clouds with virga that weren't there before, or at least couldn't be seen because of the angle. I suspect it was the light changing the temperature in the clouds.
    This was over ten minutes.
    IMAG0489. IMAG0493.
    IMAG0494. IMAG0496.
    IMAG0498. IMAG0502.
     
    Last edited by a moderator: May 21, 2014
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  14. Mick West

    Mick West Administrator Staff Member

    I think the virga are there in all the photos, it's just the lighting changes. The sun is basically becoming edge on to the cloud layer, and the more acute the angle the more detail is revealed. It's like shining a flashlight along a bumpy wall.
     
  15. Cairenn

    Cairenn Senior Member

    These are not as interesting as some pictures here, but I liked seeing the various layers of them. If I kept up with them, I was driving, some of them may have started out as contrails. The picture was taken on I20 about halfway between Midland and Dallas.
     

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  16. Critical Thinker

    Critical Thinker Senior Member

  17. Zane O'Neill

    Zane O'Neill Banned Banned

    Attached Files:

    Last edited by a moderator: May 20, 2014
  18. Pete Tar

    Pete Tar Moderator Staff Member

    [...]
    Atmospheric dynamics.
     
    Last edited by a moderator: May 20, 2014
  19. Zane O'Neill

    Zane O'Neill Banned Banned

    Please explain....?
     
    Last edited by a moderator: May 20, 2014
  20. Pete Tar

    Pete Tar Moderator Staff Member

    Geez I'll try but I am in no way an expert.
    Um, the sky is made of regions of moving gas, of different densities and pressures and temperatures. These interact and act on each other. Where these regions are made visible through frozen water vapour some of these interactions are observable. (clouds)
    Sometimes these interactions are chaotic and other times they have a relative symmetry.
    Know I'm just totally guessing here, but I would say the line of clouds represents a dense layer of air, and there is another layer with more energy pushing up through it, kind of 'washing away' around the clouds. It might not necessarily have been a contrail, it could have been a naturally formed long cloud, but it has been eroded by the air pushing on it.
    The landscape under it would likely have some influence as well.
    Ever seen water shift sand into patterns? Sort of like that, but not.

    Sorry I can't be more specific than that. You'll have to wait for someone who knows a bit more about it to tell you.
     
    Last edited: May 20, 2014
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  21. Zane O'Neill

    Zane O'Neill Banned Banned

    Ok Ill wait for the real CON..trail experts to finish coming up with an answer and scientific evidence on this one.
     
  22. Pete Tar

    Pete Tar Moderator Staff Member

    Similar to a kelvin helmholtz cloud.
    [​IMG]
    but yours looks lower and is probably in the midst of dissipating.
    It looks a bit mare's tail-ish too.
    [​IMG]
     
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  23. Pete Tar

    Pete Tar Moderator Staff Member

    Last edited: May 20, 2014
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  24. Zane O'Neill

    Zane O'Neill Banned Banned

    Looks to me more like Awacs on Awacs off Daniel son.
     
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  25. Trailspotter

    Trailspotter Senior Member

    Zane, while you are here at the site, please answer my question - when and where the photo in your avatar had been taken?
     
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  26. Hevach

    Hevach Senior Member

    You've been using that word for two threads now referring to the endpoints of a contrail. It does not mean what you seem to think it means.
     
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  27. deirdre

    deirdre Moderator Staff Member

    whats an awac?
     
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  28. M Bornong

    M Bornong Senior Member

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  29. WeedWhacker

    WeedWhacker Senior Member

    As mentioned above, what is your understanding of the terms "Awacs" (as you spelled it)?

    Sounds as if you are pronouncing it as "a-wax"? And thinking of an old TV commercial for a floor product:
    "Wax On, Wax Off" was their slogan.

    EDIT: Oh, it was later an iconic 'Karate Kid' movie reference!!! Hilarious:


    But, THAT movie got it from a 1970s TV commercial!!! :)


    In any case, the actual acronym 'AWACS' (you can look it up) is indeed pronounced "a-wax", just for ease of communication usually, when discussing it.

    But, this is in no way pertinent to contrails.

    Your photo shows a situation where there was likely some strong mountain wave airflow activity.
    [​IMG]

    An airplane flying through that will experience turbulence, depending on various factors....AND its contrail can appear intermittent. Later, after the airplane has passed, the contrail fragments are undergoing more "stress" from the prevailing air currents.
     
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  30. Zane O'Neill

    Zane O'Neill Banned Banned

    It’s hardly likely the ambient temperature and humidity uniformly varied where the plane traveled.
     
  31. Mick West

    Mick West Administrator Staff Member

    I'm not sure what you are referring to here, but relative humidity varies as much as clouds vary. The visibility of a cloud is essentially a measure of the relative humidity in that parcel of air going above the threshold for condensation. Or as this 1894 book on clouds puts it:

    "[Clouds are] portions of the atmosphere which, from natural causes, have become temporarily visible"
    - Cloudland, W. Clement Ley, 1894

    So in all the hugely varied ways that the boundaries and repetitions of clouds can vary, so can the invisible areas of higher and lower relative humidity.
     
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  32. Trailspotter

    Trailspotter Senior Member

    I have missed the first discussion of this interesting phenomenon and now have done my own research into it. My conclusion is that the formation of a row of fallstreak clouds most likely has not been caused by a contrail or triggered by a passing plane after all, but it "was purely meteorological in origin".

    There are three 'new' lines of evidence for this.

    1. The line of clouds was formed at a relatively low altitude of about 20,000 ft.
    2. The line was perfectly aligned with the wind; it remained in essentially the same spatial position while clouds were moving along it from the west to the east.
    3. W-E commercial flights in this location are rare and none was recorded on flightradar24 at the time.

    I will elaborate on these tomorrow, it is past midnight here.
     
  33. Mick West

    Mick West Administrator Staff Member

    I will merge this with the other thread.
     
  34. Mick West

    Mick West Administrator Staff Member

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  35. Trailspotter

    Trailspotter Senior Member

  36. Mick West

    Mick West Administrator Staff Member

    Stuck it on Youtube: Skip to 1:15
     
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  37. Trailspotter

    Trailspotter Senior Member

    What? Where? When?
    To figure out what was the row of clouds in the picture attached by Zane (#16) I firstly tried to find where and when it was observed. Fortunately, there is a copy of this picture with EXIF data with the date and time and, in the title, the name of the city where it had been taken. It took me a while to find the camera location at a road junction near Redmond, WA (47°39'15.34"N 122° 8'13.43"W) that placed the cloud row somewhere over Seattle.

    At this point M Bornong (#27) posted the link to previous discussion, from which I found my 'what' was the same phenomenon that happened in a big city and left plenty of photographic evidence. Having searched flickr, I have found quite a few photos from different viewpoints with readily identifiable camera locations. I've used them to model the row of clouds on Google Earth:
    Redmond road junction. Space Needle Seattle.

    In all used photos, the row of clouds aligns well with the same line passing from West to East just north of the SeaTac Airport at the altitude of about 7 km (23 000 ft):
    Cloud train line.

    It was surprising because the photos were taken at different times. This means that the row of clouds did not move laterally. Contrails usually do, as they rarely are aligned so perfectly with the wind direction.

    At this point I have paid more attention to the Cliff Mass Weather Blog and found there is a NOAA weather satellite image at 7 PM with a line of clouds in essentially the same location and orientation as my model line. This gave a high confidence to the altitude value determined by this approach. There was one thing, however. Fitting the webcam images from the blog to Google Earth showed that my model aligns with the earlier trail, not with the second one that was thought to produce the row of clouds. Fortunately, in the blog comments there was a link to a time lapse movie from this webcam for that day, August 6, 2013. It showed the evolution of these trails for longer. After the bits and pieces of the second trail went out of the frame or disappeared, along the line of the first trail arrived familiar clouds of the same shapes and sizes as seen on the other photographs taken at about the same time:
    UW Atm Sci webcam.

    The movie also revealed that both trails were at the same altitude and moved parallel to each other with the same speed. This is supported by another photo that I found this morning:
    9456080096_9bc8dc792c_o.
    It is geotagged to a location near the SeaTac Airport right under the modelled line.

    The webcam recorded the evolution of these trails into the row of fallstreaks clouds at one end. Snapshots of its evolution in other parts can also be seen on photos, for example:
    9459924434_2a3a96cc91_o. 9688148717_d0175799e2_o.
    Note, that in two hours between the two snapshots, the cloud shapes changed but their line remained in the same place.


    The movie provides no support to the hypothesis of these trails being originated from contrails or triggered by passing planes. On the contrary, the progressions of the tips of these trails were not gradual, unlike occasional contrails in the same movie.

    Given its relatively low altitude and perfect alignment with the direction of wind, the formation of a row of fallstreak clouds the most likely "was purely meteorological in origin".
     
    Last edited: May 23, 2014
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