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Surfers think catching a gnarly wave is radical?
Thanks to some science we can ride air currents at almost the speed of sound with 200 ton
surfboards in the sky.
How’s that for radical?
Hey silver surfers, Julian here for DNews.
British airways flight 114 recently made a transatlantic crossing almost an hour quicker
than usual, and was clocking ground speeds of 745 miles per hour, or nearly 1,200 kph.
It’s been making news because that is a frankly ludicrous speed, considering the speed
of sound at that altitude is somewhere around 1100 kph.
But when you take into account the airspeed, that is the speed the airplane is traveling
through the air around it, instead of the groundspeed it didn’t actually break the
sound barrier, which is a good thing because the Boeing 777 really wasn’t designed for
that.
Fortunately for everyone stuck in coach, the aircraft was riding a particularly ferocious
jet stream that was at times over 320 kilometers per hour.
But why do we have jet streams?
First of all jet streams are not unique to earth.
We’ve observed them on Jupiter and Saturn.
Here on Earth jet streams form in the troposphere, the lowest atmospheric level, and there can
be many that swirl and flow and join and split.
Most of them head from west to east, so if you’ve flown from North America to Europe,
you’ve probably noticed your flight is shorter in that direction.
The one you and flight 114 cruised on is the northern hemisphere’s polar jet stream.
The polar jet streams are from 7 to 12 kilometer up, but each hemisphere also has weaker subtropical
jet streams that are 10 to 16 kilometers up.
Jet streams form at boundary layers between warm air and cold air.
The higher pressure cold air pushes into the low pressure area, and in the winter the pressure
differences are greater so you get stronger winds.
But the wind doesn’t just move in a straight line from pole to tropics because of the coriolis
effect.
Basically the planet spinning underneath the moving air deflects it east.
Higher in the troposphere there’s less friction so these winds can go unbroken for thousands
of miles and voila, jet steam.
Throw in modern air travel and if you’re lucky you can get where you want to go at
almost the speed of sound.
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If you don’t think I’ve gone basic enough to explain why there are jet streams, Trace
explains air itself here.
Also, you were probably one of those kids who kept asking why all the time, huh?
I like it, keep it up.
So planning a world trip, would you head westerly to ride the current, or east to west to feel
like a time traveler?
Tough call, but me, I like cruising into the sunset for hours.
Let us know in the comments and I’ll see you next time on DNews.