Jerry Griffin

By Sergey Kustov - http://www.airliners.net/photo/Qantas/Boeing-747-438/1729381/L/ (higher resolution image provided by email by the author), CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=16496086 ▪ What are contrails? ▪ Why do we care about them? ▪ How do we measure their environmental impact? ▪ What solutions exist for managing that impact? ▪ How is Delta working on those solutions? What are contrails? Contrails, short for condensation trails, are line-shaped clouds produced by aircraft engine exhaust or changes in air pressure. Illustration of mechanisms and timeline behind contrail formation This is not what always happens during flight. This is an illustration of contrail formation. Why do we care about them? There are 3 different types of contrails, and they have been researched for different reasons. Types of contrails: Short-Lived Persistent Non- Spreading Persistent Spreading Why do we care about them? There are 3 different types of contrails, and they have been researched for different reasons. Types of contrails: Short-Lived Persistent Non- Spreading Persistent Spreading Early interest in contrails was from militaries. Contrails revealed the locations of aircraft, which was a surprise in the early 20 th century. Why do we care about them? There are 3 different types of contrails, and they have been researched for different reasons. Types of contrails: Short-Lived Persistent Non- Spreading Persistent Spreading Today, research is focused on their environmental impact. In particular, persistent spreading contrails are widely considered a large portion of aviation’s contribution to warming Why do we care about them? Persistent contrails have a radiative forcing effect that can be…
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