In the 1940’s, commercial aviation was extremely rare. So when the number of planes over England increased during WW2, the hundreds of white contrails in the sky were very obvious.
“Toward the end of the war there could be up to a thousand aircraft in the air, bombers and fighters, flying in one direction to one target,” Dr. Annette Ryan with the Lancaster Environment Centre told The Weather Network. “I think the sound and sight of those must have been quite phenomenal for people who were unfamiliar with that many aircraft.”
Annette, along with Professor Rob MacKenzie at the University of Birmingham, used this as the basis for their study.
“We were trying to compare regions that were directly underneath these bomber streams,” said Annette, “with adjacent regions that would be completely clear of contrails. And we wanted to make a direct comparison of the temperature range and high cloud cover between these two regions to try and see how much of an impact contrails and aviation induced cloud cover would have on temperature range.”
With the increase in bomb raids, weather observations became very crucial in the Second World War. In fact during the war, the U.K. meteorology office was integrated into the Royal Air Force. So Annette and Rob literally had thousands of weather observations to sift through.
“The scientific results we got from our research,” Rob said, “saw a small decrease in the heating of the morning and early afternoon caused by the fact that there were aviation induced clouds in the sky.”
While Rob and Annette’s research had them looking scientifically at weather observations from the bombing raids, it was always on their minds that real people lost their lives.
“It was never far from our minds that real people were risking and losing their lives in the course of the war,” Rob added. “And the war was a terrible moment in human history.”