You may have noticed in the news some recent stories about incredibly fast crossings of the Atlantic Ocean by passenger planes, such as this story from Business Insider. In addition to the speed of the airplane itself, the air that it was traveling in was moving at close to 200 miles per hour, one of the strongest jet streams ever observed. The combined speed of the airplane plus the speed of the air it was flying in resulted in a total speed of over 800 mph. According to a recent article in the University of Chicago News, research done at the National Centers for Atmospheric Research suggest that these jet streams will become stronger over time, making these rapid flights from the United States to Europe even faster (since the jet stream blows from west to east, flights in the other direction will take longer since they will be flying against the wind).
This result is surprising because scientists previously thought that as the Arctic warmed faster than the middle latitudes, the weaker temperature gradient from equator to pole would reduce in a slower jet stream. But the new research shows that the gradient in water vapor content, which also affects the air’s density, will have a bigger effect, resulting in a stronger jet stream in the future.