Comment by ChuckMcM | Hacker News Reader

Comment by ChuckMcM | Hacker News Reader

Note to readers, land speed not equal to air speed. As the article discusses it doesn't break the sound barrier.

That said, the news here is that the jet stream is carrying more energy than it has in the past (air mass is moving faster, kinetic energy content is 1/2mv^2). I read a paper a long time ago which talked about the impact of thermal 'tubes' where denser cold air travelling at speed would "punch holes" in high pressure systems leading to more complex weather patterns. Sadly I cannot find it! The question I think about when reading this is the impact on the duration and temperature swings of the winter months in the north east of the continent. In particular, atmosphere so cold as to support hurricane formation over land. Most famously exploited in a fairly mundane movie "the day after tomorrow" but the modelling works if the temperatures meet certain conditions.

I don't know if winter "super storms" are possible due to other moderating influences but if they are, having the jet stream behave in a new way is a prerequisite (feeding very cold air into the system).

Do you know if the rides in higher energy jet streams are less comfortable, or is it undetectable by the passengers?

As far as I have been able to tell in flying across the continent is the change in flight time (arriving early or late after departing on time).

I was on a flight to London that caught one of these tailwinds last year. I recall a little buffeting mid–Atlantic, don't know if that was in the jet stream or not. Only problem really was that we arrived too early in London and had to circle for half an hour before landing and then wait for immigration & customs to open.

It would be as undetectable as the motion of the earth. It's the change in velocity (not the velocity itself) that causes you to feel something. Moving from one air current to another, with a large change in velocity, would be very noticeable.

They could be more turbulent. I presume they aren’t, though.

I’ve had a SFO -> London flight once where the pilot intentionally flew into a very strong jet stream current (saved us a lot of flight time, think it was close to an hour). Experienced a short burst of mildly rough turbulence entering and exiting, but otherwise smooth sailing.

Just curious... How do you know that? I wonder how some nervous passengers might react if they learned the pilot decided to enter a turbulence area on purpose.

The pilot got on the intercom and specifically stated he was doing it. He assured everyone there was zero risk outside the brief bumpiness and it would get us there much faster. He got loud cheers of support from the cabin, so I guess those nervous just kept to themselves.

I wonder if the pilot got any compensation for the fuel savings? I could see that being a dangerous incentive though, forcing pilots to opt for more risky conditions for the fuel savings bonus.

> Note to readers, land speed not equal to air speed. As the article discusses it doesn't break the sound barrier.

Yes, but the first sentence is not why it did not break the sound barrier. They state it is due to being in swiftly moving air. The speed otherwise, even at airspeed (which is a negligible difference to ground speed) is fast enough to break the sound barrier.

Reply on news.ycombinator.com