Researchers at MIT Environmental Solutions Initiative, with the support of NASA, have successfully demonstrated contrail mapping can be done at a large continental scale. 1 By comparing contrail coverage over the U.S. before and during the pandemic, the team has shown a relationship between contrail coverage and major flight routes and the feasibility of forecasting alternative flight routes to avoid contrail formation.
Research Method
Research began with approximately 100 continuous, high-resolution images from NASA’s GOES-16 geostationary satellite. A team used remote sensing data to label whether each image’s pixel contained a contrail.
Next, the team used this labeled dataset to train a computer-vision algorithm to continue the work of precisely labeling contrails, but now at a much larger scale. The model processed approximately 100,000 satellite images taken at 15-minute intervals from January 1, 2018 to December 31, 2020 over the continental United States and parts of Canada and Mexico.
The model autonomously labeled each pixel as a contrail or not a contrail and produced daily maps showing contrails mirroring major flight paths taken by most U.S. airlines.
Results
On average, contrails in the U.S. covered approximately 43,000 square miles in 2018 and 2019, about the combined area of Massachusetts and Connecticut. In March 2020, contrail coverage sharply dropped by 20% as major airlines cancelled flights in response to the pandemic. As air travel slowly resumed throughout the year, contrail coverage proportionately increased.
The data also showed contrails follow daily and seasonal patterns. Contrail coverage per distance flown generally peaks in the morning and decreases in the afternoon.
What’s next for the team?
Researchers are applying this technology to predict where contrails are likely to form in the atmosphere. The team is collaborating with major airlines to forecast regions likely to produce contrails and to reroute aircraft to avoid these regions and contrail formation.
Steve Barrett, professor and associate head of MIT’s Department of Aeronautics and Astronautics, is hopeful the application of this technology could significantly reduce the aviation industry’s contribution to global warming.
“This kind of technology can help divert planes to prevent contrails, in real time…There’s an unusual opportunity to halve aviation’s climate impact by eliminating most of the contrails produced today.” 2
Unlike other solutions to aviation’s climate impacts which would take several years, contrail avoidance can be accomplished in only a few years by using existing aircraft and technology and only making slight changes to flight routes.
[1] Contrail coverage over the United States before and during the COVID-19 pandemic – IOPscience
[2] New maps show airplane contrails over the U.S. dropped steeply in 2020 | ScienceDaily