1. skephu

    How much do contrails reduce the energy from solar cells?

    A recent paper by Austrian scientists seeks to answer this question: Weihs P, Rennhofer M, Baumgartner DJ, Gadermaier J, Wagner JE, Gehring JE, Laube W. Potential impact of contrails on solar energy gain. Atmospheric Measurement Techniques. 2015 Mar 5;8(3):1089-96. It contains very interesting...
  2. M

    Difference between the impact of Stratospheric Sulfate Aerosols and Contrails?

    I m a bit confused as to why would Stratospheric sulfate aerosols cause the decrease of the global temperature (as it has happened in the past with big volcanic erruptions) ( )while contrails are supposed to increase...
  3. Ray Von Geezer

    George Monbiot in the Guardian on "Chemtrails" &

    Environmental activist George Monbiot has weighed in on "Chemtrails", claiming that the conspiracy theory is diverting from genuine environmental concerns about the aircraft industry. He holds up Look-Up/Ian Simpson as an example. The contrails conspiracy is not just garbage, it's letting...
  4. Mick West

    Unusual Trail on the Russian Su-24 shot down By Turkey

    Source: A Russian Su-24 was shot down by Turkey on Nov 24 2015. This has serious geopolitical implications which can be discussed elsewhere. The pilot of the plane ejected before the above photo was...
  5. Balance

    Met Office - Case Study Contrail-induced Cirrus Apologies if already covered elsewhere (I tried searching but no obvious hits). Although a lot of the science goes over my head, it gives step-by-step analysis including tools used, which I assume could be useful to...
  6. Mick West

    Asymmetric Partially Aerodynamic Turboprop Contrails at 25,000 and 27,000 feet

    This photo is interesting for a number of reasons. It's a propellor plane flying at 27,000 feet and leaving a contrail. One side of the contrail is significantly larger than the other. The photo was taken at about 18:20 UTC (11:20 PDT) on Friday Oct 23, 2015. It appears at first as if it is...
  7. SR1419

    Water Vapor loop

    Check out this water vapor loop- you can see the contrails being laid out in front of the southern edge of the trailing front- pretty cool. (or are they ship trails?) (I dont know how save the loop as moment in time so it might be updated by...
  8. Trailblazer

    Altitude and contrail persistence

    Looking out of my window around sunset this evening I noticed a succession of planes lining up from the west, all with short contrails except one which was leaving a lengthy persistent trail. I thought it would make quite a good illustration of how "adjacent" flights can be at very different...
  9. Mick West

    A Coronal Iridescent Contrail

    I took this photo at 3:36 PM, Aug 25, 2015. The plane had just flown past the sun when I noticed this small region of interesting colors in the trail it left. Here you can see the position of the colors relative to the sun. This was a couple of seconds earlier, and the plane is still visible...
  10. eon_flux

    How to prove chemtrails are just contrails?

    I used to believe in 'chemtrails'. I even had a website ( - now dormant. I left 'the movement' after finally finding sensibility - only after asking myself and other people in 'the movement' some pertinent questions. Of course, no-one could answer these questions, but what I found...
  11. TEEJ

    Spherian7 video - Silver Spring, Maryland, US, 25th May 2014 - Contrails - Different Colours

    Another video highlighting different colours in contrails. The video covers two dates during 2014. 24th May covered from 0:00 to 2:52. 25th May 2014 from 2:54 till end Video description Published on 4 Jul 2014 Sorry for gap in uploading, but Weather Control Command has their thing...
  12. TEEJ

    Belfast Observer Skywatch - FedEx MD-11F with different coloured contrails 29th July 2015.

    Sunset on 29th July 2015 - Belfast UK was 9:31PM Nothing unusual in seeing different coloured contrails. Unlikely to be different engine variants, but simply down to the lighting or the camera not accurately recording colours...
  13. skephu

    Interesting articles about contrail research

    Thanks to the chemtrail theory, I got interested in the science of contrails, and I sometimes browse the latest articles on Google Scholar. So I thought a thread in which we report on the latest findings or interesting new articles could be useful. I just found this one: Bernhardt, J. and...
  14. Trailspotter

    The skies from above and below

    This thread is for the collections of images of clouds, contrails, etc., which are taken synchronously by both satellite and ground-based cameras. For example, the following images of skies to the East of Cornwall are from June 25, 2015 at 14:20 BST (13:20 UTC): In the upper left corner is the...
  15. Leifer

    1951 airplane spotters guide, USAF

    Here is a recent eBay purchase of mine, showing contrails from a 1951 USAF book/pamphlet. It describes using "vapor trails" (contrails) as a means to help determine aircraft type. (I have two videos back-to-back, one with reading the text, one without reading text.)
  16. Chew

    Yosemite Contrail Grid 17 June 2015

    Taken from Glacier Point ( 37.73083, -119.57278 ) at 09:44:29 PDT (16:44:29 UTC) with an iPhone 4. Center of image is azimuth 080°.
  17. Mick West

    Persistent Cumuliform Contrails at 25,000 feet over California?

    Very interesting skies today, halos, circumhorizon arc, other arcs, ripples, various layers of cloud. This one caught my eye because it had a dramatic looking bend in it. Taken at 00:42 May 29 2015 (today is the 28th, but in UTC it was the 29th), near Bullard, CA. Looking north. The bend can...
  18. Mick West

    Two Short Parallel Trails from one Plane

    The above image is a recreation of what I say yesterday, as unfortunately the trails had faded before I had a chance to grab my camera. I did not see the plane, but was told it was from a simple plane traveling north. Had I not been told this, I would have assumed that it was from two fighter...
  19. J

    What might these three planes be?

    Good Afternoon, Stumbled across this site the other day, and am enamored with what you all are doing. I've searched for any threads with similar questions, but came up dry. My hope is that you can assist... I've attached a couple shots that I took with my cell phone from the following...
  20. Trailblazer

    Contrails versus humidity: a timelapse project

    This is something I've been meaning to do for a while: a daily record of the contrails (or lack of contrails) in the sky, in a known location, compared to a daily record of the atmospheric conditions in that location, specifically the relative humidity at typical aircraft cruising height. I'm...