Sunday, February 16

Sticky jet stream and persistent weather

Back in 2012 when we last had significant amounts of flooding and weather patterns seem to be stuck for weeks on end, Jennifer Francis a professor at Rutgers University studying Arctic climate put forward the idea that the warming Arctic was forcing the jet stream South and making it stick there.

The type of weather that resulted depended on how far south the jet was pushed. But more importantly the jet was sticking in a relatively fixed position for many weeks or months.

The evidence is growing that the jet is often shifting as a result of the warming Arctic. It's interesting to note that at the time of writing the sea ice extent appears to be heading for a record winter minimum this year (see graph in right hand column).

At the American Association for the Advancement of Science 2014 meeting Jennifer Francis again presented work that shows that as the Arctic gets warmer the temperature difference between the Arctic and the mid-latitudes is reducing, making the jet stream weaker and meander more.

The result... Extreme and persistent weather. The big climate experiment continues. Do you want to continue? You don't have to.

2012 Yale article by Jennifer Francis:
Linking Weird Weather to Rapid Warming of the Arctic

Wired:
Wavier jet stream means changing weather patterns

NPR:
Warming Arctic May Be Causing Jet Stream To Lose Its Way

2 comments:

mike newey said...

Could you explain that bit more. In the first paragraph you say the jet stream is stuck more because of Arctic Warming, but later on you say it is meandering more because of Arctic warming?

TheVille said...

The jet is wavy, the Arctic warming means the waviness increases, with greater peaks and troughs. But the movement of the waves eastwards slows down at the same time, so the weather patterns at a given location stick for longer.

I suggest reading Jennifer Francis's article from 2012 that I have linked to. It's quite well written.

Also see this article by the Union of Concerned Scientists:

http://blog.ucsusa.org/wacky-weather-a-warmer-arctic-and-a-slower-jet-stream-is-there-a-link-194