Contrails?
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Hi Roger. Don’t know why it might not have been a contrail or multiple contrails at the start. Just this week we had a couple of days in which the sky was filled with persistent contrails in central Ohio. As my job entails a lot driving, I was able to observe a number of them evolve from obvious contrails into cirrus and what I believe is known as floccus. Over the day they crisscrossed and spread until it was difficult to tell that they had ever been contrails. It was fascinating. As they slowly covered the sky I thought of the people who get nervous about “chemtrails.”
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Hmm, good question, Roger. I tend to vote with Noctilucy. Thoughts:
1) These contrails may be unconnected to the ‘floccus’, though contrails can degrade into Cirrus
2) The perspective of the contrail(s) suggests a spreading out towards the top of the picture
3) If it is Cirrus floccus CH2 species it might be intortus variety (*)
4) Floccus can occur in Cirrocumulus and Altocumulus species (#)(*) Cloud Collector’s Handbook, Cirrus, p19
(#) Ditto, Cloud Classification table pp 104, 105 -
Being born in the very 1950’s there were no contrails that I recall. I realize air traffic is 100 fold compared to my younger years. I am but a novice to identify clouds but certainly not a novice watcher.
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I was born in 1944 and remember seeing contrails back in the fifties. For an example of a contrail from that era, check the opening scenes of 3:10 to Yuma (the 1957 version) when a persistent trail can clearly be seen. Then forget that anachronism and enjoy the rest of that great film.
The first contrail was seen as early as 1919 (see https://science-edu.larc.nasa.gov/contrail-edu/history.php) and were often seen in the dogfights over SE England during WWII. The forecasting tool used in the Met Office when I joined in 1962 was based on research made using the legendary Spitfire fighter and this method was still referenced in a 1993 print of the Met Office’s Forecasters’ Reference Book although it also included reference to a more modern technique.
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I guess it depends on your location and your interest at the time. I don’t remember contrails growing up in the 50s in Bucharest, Romania. Now I’m in New York, where I see A LOT of them. The air traffic has increased tremendously since the 50s everywhere and the aircraft changed.
I suppose people remember that after September 11, 2001, the air traffic was stopped completely over the US. That provided an opportunity to study the effect of contrails. Here is an article about that event, which raises some interesting, perhaps controversial, issues:
http://www.greenmedinfo.com/blog/artificial-weather-revealed-post-9-11-flight-groundings
From the esthetic standpoint, I have mixed feelings about contrails. Sometimes they are beautiful, other times they can be just “noise”.
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Thanks Graham for the link with information about the history and science of contrails and George for the link of the effects of the post 9/11 flight groundings.
Being from the 50’s one can say that the sky is changed since then, certainly in the neighborhood of air traffic. Just an example below made with the cloudspotter app.
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Hello Hygge, you make me curious about this survey concerning contrail. I have no idea what is was about or what purpose it had. I notice that this is the second time you come up with it. Like you I hope it will be answered, but “if not” it might be an idea to put forward the question directly via the info address of CAS? Does this help?
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Here are some contrails, that I think are just smoke. This is the photo of the day in the CloudStream. Notice the first first three airplanes don’t leave a trail.
Very nice shot, though.
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And, in the same vein, here are some red, white and blue ‘contrails’:
https://www.youtube.com/watch?v=gpLqymNI3A8
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