Contrail-Mapping Could Reduce Harmful Effects By Half

Image: Britannica
Gemini Sparkle

Key Takeaways:

  • Aircraft contrails contribute significantly to aviation's climate impact, accounting for up to 35% by trapping greenhouse gases, with only "persistent" contrails being problematic.
  • AI-generated contrail forecast maps, developed by organizations including American Airlines and Google, predict conditions likely to form these harmful contrails using satellite and weather data.
  • Pilots can use these AI predictions to make minor altitude or course adjustments (e.g., 2,000 feet change) to avoid creating persistent contrails, a method successfully tested with the potential to reduce aviation's contrail-related greenhouse effect by half globally.
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The virtual explosion of applications for using artificial intelligence (AI) could soon include minimizing aircraft condensation trails, the cloud-like results of high-altitude moisture meeting the disruptive churning of jet engines and/or aircraft wake turbulence. “Contrails” (not to be confused with the controversial concept known as “chemtrails”) have been shown to contribute as much as 35% of aviation’s climate impact by creating clouds that trap greenhouse gases that otherwise would dissipate into space.

According to Britannica, “A contrail forms when water vapor produced by the combustion of fuel in airplane engines condenses upon soot particles or sulfur aerosols in the plane’s exhaust. When the ambient relative humidity is high, the resulting ice-crystal plume may last several hours.” And not all contrails are harmful. Jill Blickstein, VP of sustainability at American Airlines, told CBS, “A contrail could form and then just dissipate, but the contrails that persist can be very warming.”

Based on a study involving American, Google and the Bill Gates-created Breakthrough Energy organization, AI-generated contrail forecast maps could enable pilots to alter course and/or altitude and reduce the overall greenhouse effect of contrails by as much as half, worldwide. The maps are generated using satellite imagery, weather data and flight path information to identify which flights are most likely to generate the worst contrails.

More than 70 test flights in the first half of last year showed that predictions of contrail-vulnerable conditions could enable pilots to make slight adjustments in course or altitude. Blickstein said a change of as little as 2,000 feet up or down could do the trick. “What the test showed is that you could use the predictions to avoid creating a contrail,” she said.

It’s a technique that was well known to American F-86 Sabrejet pilots during the Korean War, but for a different reason. For a fighter pilot, altitude is the “high ground” when entering a combat zone—the higher the better. But generating contrails alerted enemy pilots from miles away. So while still in safe airspace, the Sabre pilots would climb until they started generating contrails, then reduce altitude until the telltale plumes dissipated.

Mark Phelps

Mark Phelps is a senior editor at AVweb. He is an instrument rated private pilot and former owner of a Grumman American AA1B and a V-tail Bonanza.
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