08-17-2018, 07:58 AM
(08-15-2018, 10:13 AM)timetraveler Wrote: Taken 4 days ago in Yorkshire, UK, the sky was absolutely full of them...
Yes , you realise how much commercial air traffic there is up there under those conditions . Just spent some time in Yorkshire . It's very busy with air traffic . A lot of planes at lower levels approaching and departing l the airports in the North of England , and several high altitude routes used daily intersecting above too , but unless you are looking for them you don't tend to notice them on days when there are no contrails at all . Did you look up any atmospheric data for the altitude those planes were cruising at on that day ?