Study finds more evidence for link between wavy jet stream and extreme weather

February 18, 2015 by Kirk Moore
Climate change driving brutal winter?
Credit: National Weather Service

Prolonged cold snaps on the East Coast, California drought and frozen mornings in the South all have something in common – the atmospheric jet stream which transports weather systems that's taken to meandering all over North America.

Rutgers University climate scientist Jennifer Francis and colleagues link that wavy jet stream to a warming Arctic, where climate changes near the top of the world are happening faster than in Earth's middle latitudes.

A new study from Francis and University of Wisconsin-Madison scientist Stephen Vavrus, published in IOPscience, backs up that theory, with evidence linking regional and seasonal conditions in the Arctic to deeper north-south jet stream waves which will lead to more extreme weather across the country.

"The real story is how persistent the pattern has been. It's been this way nearly continually since December 2013…Warm in the west, cold in the east," Francis said. "We think with the warming Arctic these types of very wavy patterns, although probably not in the same locations, will happen more often in the future."

This research has been controversial since the Hurricane Sandy disaster, when the wavy jet stream steered the storm on its sharp left turn and smack into the Jersey Shore. Francis and other researchers say the jet stream's configuration was a key ingredient in the monster storm.

Very wavy jet-stream patterns have been occurring more often since the 1990s, Francis says, and are now affecting weather around the northern hemisphere. This mid-February cold snap, for example, that has left millions of people waking up to below-zero and single-digit temperatures, might not be as deep as some southward dips, called troughs, in the jet stream. But the overall pattern has been around for weeks, and is also responsible for Boston's record snowfall this winter and the worsening drought in western states.

In contrast, an opposite pattern in winter 2012 led to more than 3,000 high winter temperature records being broken in the eastern U.S., Francis notes.

"California is still dealing with this record-breaking drought, and Alaska is having one of its warmest winters on record," Francis said.

In Florida, orange growers have not had to deal with freezing temperatures for the past two years. But they are looking at their smallest harvest on record because of citrus disease and watching the southward cold outbreaks closely. "We've been fortunate that those have not reached into our citrus production areas," said Andrew Meadows, a spokesman for Florida Citrus Mutual, the industry's biggest trade group.

On the West Coast, the Pacific Ocean water temperatures off California are much warmer than normal, holding at uncanny 64- to 65-degree levels this winter, according to Mike Conroy of West Coast Fisheries Consultants, who works with commercial fishermen still catching bluefin tuna on the Cortes Bank 100 miles off San Diego.

Francis says these conditions make sense because water temperature trends in the eastern Pacific have reversed from the past decade and could be contributing to California's warmer and drier weather as the jet stream takes an unusually large swing to the north.

The phenomenon called Arctic amplification – defined as the enhanced sensitivity of the Arctic region to warming compared to lower latitudes – is changing large-scale upper level flows in the atmosphere, the paper suggests. Looking back at records dating to the late 1940s, it is evident that Arctic amplification of global warming is now continuing through all four seasons of the year, according to Francis and Vavrus.

One challenge addressed by the new study is measuring the extent and strength of those jet stream waves, Vavrus said.

While using a traditional measure of surface air temperature changes between Arctic regions and lower latitudes, Francis and Vavrus also present an alternative measure of the thickness of temperature layers higher in the atmosphere.

Even scientists who are skeptical of the findings say it's a good effort to resolve the problem of differentiating real changes in the jet stream's behavior from random noise. This is an issue inherent in climate research – teasing out real long-term climate change from mere year-to-year variability of weather.

Francis and Vavrus acknowledge criticism that their work is looking at relatively recent years since Arctic amplification emerged as a clear signal. Still, the researchers say there is no mistaking the trend since the 1990s: the Arctic probably hasn't been this warm since the last major inter-glacial period 125,000 years ago.

Back then, Francis said, the Earth was several degrees warmer than now and sea levels were several meters higher. "The recent changes we've seen are clearly linked to increasing greenhouse gases, and there's no sign of abatement in our use of fossil fuels. This does not bode well for impacts of extreme weather and the ecosystem as a whole," she said.

"The biggest challenge in our research," Francis said. "Is that rapid Arctic warming started very recently, so detecting a clear atmospheric response and linking it to a particular cause may take another decade. In the meantime, Mother Nature seems to be acting out."

Explore further: Record loss of Arctic ice may trigger extreme weather

More information: "Evidence for a wavier jet stream in response to rapid Arctic warming." Jennifer A Francis and Stephen J Vavrus 2015 Environ. Res. Lett. 10 014005. DOI: 10.1088/1748-9326/10/1/014005

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19 comments

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runrig
4.1 / 5 (10) Feb 18, 2015
This is not new Earth-shattering news.

However, I don't like the linking of winter-time meridional extension of the PJS to AGW. Summer yes, but it's more likely to be a push from the other, warm side of the jet, northwards in the W Pacific that's the culprit (Alaska and E Siberia have had recent warm winters). Also NH wintertime meteorology is complicated, the polar vortex is very sensitive to the likes of the strength of the Siberian high and also stratospheric influences, that are in turn caused by up-welling waves from the Trop and also down-welling waves when solar is low (much lower UV to act on O3).
The major topological feature as regards the positioning of the PJS is the Rockies. This (mostly) has the effect of creating the downstream extension (long-wave or Rossby trough) over the E half of N America. Same way that water flowing around a wall extending into a stream will curl in behind the back as it tries to flow past.

https://www.youtu...Jg4Ebzo/
paulraup
1.8 / 5 (10) Feb 18, 2015
More proof that Mother Nature simply will NOT be controlled, not weather, not climate, not evolution, not human nature, and ANY scientist that is arrogant enough to say we CAN needs further education.
Politicians who finance studies influence them.................very UNscientifically, by the way.
Captain Stumpy
4.5 / 5 (8) Feb 18, 2015
This is not new Earth-shattering news.
@runrig
i think it is just piggybacking more evidence on the original study (published a few years ago, found here: http://marine.rut..._pub.pdf )
New metrics and evidence are presented that support a linkage between rapid Arctic warming, relative to Northern hemisphere mid-latitudes, and more frequent high-amplitude (wavy) jet-stream configurations that favor persistent weather patterns.
http://iopscience...4005.pdf

This seems to be more work extending the data collected earlier and expounding on it

KDK
1.7 / 5 (11) Feb 18, 2015
This is what happens with global COOLING folks, as the latitudinal temp and pressure differences increase to create more-vigorous storms of greater variability--per Solar Cycle 24 and likely the Milankovitch ice-age cycle as well! ! !
Captain Stumpy
4.1 / 5 (9) Feb 18, 2015
This is what happens with global COOLING folks,
@KDK
so... you did NOT read the studies i linked at all, then

is that what you're saying?

keith_hinkel_9
1 / 5 (9) Feb 18, 2015
Totally all wet. This is being caused by HAARP! Look up HAARP for proof. Nome, AK right now at 7:38 pm EST=30 deg F. This is all due to Feds and HAARP!
fire3000
4.4 / 5 (7) Feb 18, 2015
They predicted more extreme weather and that is what has been occurring.
earl_decker_33
1.6 / 5 (7) Feb 18, 2015
BS science. Do they get paid by the number of letters or the number of times global warming is referred to. Seems like new research articles are really old ones renewed.
mooster75
3.7 / 5 (9) Feb 19, 2015
Totally all wet. This is being caused by HAARP! Look up HAARP for proof. Nome, AK right now at 7:38 pm EST=30 deg F. This is all due to Feds and HAARP!

You know, if you're going to go all nutjob on us, you could at least put some work into it the way the other nutjobs here do. You know, make it sound all 'sciency' and stuff. All you're doing is barking like a chihuahua.
BrassOrchid
1 / 5 (1) Feb 19, 2015
Isn't this a bit like finding out that the course of a train (the Jetstream) is linked to the position of the tracks (underlying pressure systems) on which it runs?
Returners
1 / 5 (8) Feb 19, 2015
How 'bout that Global Warming?

8 feet of snow. Cars frozen solid to the road. "Snow Farms" with snow piled 50 feet high from bulldozers and tractor trucks trying to clear roads.

Millions of dollars in damage from irrational, habitual beings crashing cars on the road trying to drive to work for a single day's wages. (need some sort of new concept of what to do in these situations, btw).

Major derailment and explosion """""""" (same reason). Millions? A billion dollars damage? It was carrying millions of gallons of oil.

If they just used their brains, instead of being insane, this wouldn't happen.

Rooves collaps.

Rivers freeze over. Great rivers.

"Snow fatigue"

Coldest winter since 1870's.

God bless America, where Hot = Cold and Dry = Wet and Windy = Calm and apparently Good = Evil and Dumbass = Brainiac.

Returners
1 / 5 (7) Feb 19, 2015
Comic Idea:

First panel shows classroom with students at their desks.
Black Board has "Climatology" written on it.

They are watching the morning news (they used to do this when I was in school) and it's describing all the shit storm I just said above...

Second Panel:
Instructor says, "Notice students, this is exactly what we'd expect from Global Warming."
*Student's eyes are bulging with dark circles around them and steam coming off their heads...
Returners
1 / 5 (8) Feb 19, 2015
"Watch the trend, not the peaks and valleys."

"It's an out-lier. The trend is still warming."

"Learn science: It obviously gets colder when the temperature rises."

"Man-made CO2 is causing the Earth to warm."

Really? So all those people burning heating oil are making this snow storm stronger because it releases CO2?

Interesting.

CO2 is almost is potent as Dark Matter.

It causes warming.
cooling
cloudy days
clear days
floods
droughts
pestilence
plague
famine
plenty
arguments
contentment
confusion
assurance
wisdom
foolishness
enlightenment
stupidity
melting
glaciation
freezing
thawing

Wow man, CO2 causes almost everything.

Here I thought there were other elements, other compounds and forces in the universe, but it appears man-made CO2 is the root causes of everything that happens on the face of the Earth.

Does man made CO2 causes the "Asexual Western Woman" phenomenon too?
runrig
5 / 5 (6) Feb 19, 2015
Isn't this a bit like finding out that the course of a train (the Jetstream) is linked to the position of the tracks (underlying pressure systems) on which it runs?

No.
Because pressure systems (highs, lows) are formed within the jet quite often. A jet is the deltaT of greatest horizontal gradient in the Troposphere. They divide air masses. The more the contrast of cold/warm next to each other then the Stronger the jet. Just like riding a bike the faster it goes the more stable it is.
winthrom
5 / 5 (4) Feb 19, 2015
@runrig:
I think you have the right of it. I will say that the article posits the rising of the Arctic trop as proportionately greater than the temperate trop in winter, pushing the JS further south, which seems logical. BUT: it also says the pacific currents are warmer in winter, so I would expect the temperate trop to be higher then too. Perhaps Arctic amplification is considerably more powerful than the temperate warming.
runrig
5 / 5 (5) Feb 19, 2015
Really? So all those people burning heating oil are making this snow storm stronger because it releases CO2?

Do excuse me if I attribute to your recent throwing out your dummy, to "small town USAism".
You are aware that you talk of weather?
You are aware the even the whole of the US is only 2% of the globe?
You are aware that you do science a great service in showing up the calibre of the intellect behind denialism.
Go figure... If you can.
winthrom
5 / 5 (5) Feb 19, 2015
@Returners:
CO2 traps heat in the lower atmosphere by reflecting it downward. The CO2 accumulates throughout the atmosphere and is being boosted by "...all those people burning heating oil..." plus coal fired power plants, plus cars/buses/trains/planes, plus ... plus ...! The heat is from darker objects on the ground (E.g., a black car in summer) turning sunlight into heat (very hot to the touch compared to a white car). The accumulating heat in the atmosphere is melting the Arctic ice that used to be there almost all year long reflecting sunlight back into space, now letting the Arctic ocean change from ice/snow white to water dark blue/green. The slight change in water temperature (less ice) up there melts more ice/snow, etc., etc. Arctic amplification. The Arctic is now a summer shipping lane, free of ice for the first time in thousands of years! Even while warmer, the Arctic is still cold enough to make snow further south when moist gulf stream air bumps cold air, east coast NYC.
phonesll1
1 / 5 (4) Feb 19, 2015
CO2 is such a miniscule part of the atmosphere versus water vapor which can trap much more heat. The scare mongers can't blame water vapor on man so they use CO2 but can't point to any science that proves CO2 is causing any kind of climate change. I find it interesting that they never discuss history. Look at the weater patterns in the 1960's. You'll see a lot of very cold and snowy weather along with some warm weather in the winter as well. If you look at geologic history we know there have been many times in the earth's history that the atmospheric CO2 content has been lower than it is today yet the temperatures have been much higher. The Permian era is a perfect example. But leave it to the those who worship at the alter of climate change to not want to discuss history. What do these people think will happen if the reverse of global warming occurs. Do they really think man is ready and can survive? It really doesn't matter to them since it is all about money anyway.
Captain Stumpy
5 / 5 (4) Feb 19, 2015
CO2 causes almost everything
@wade daniel smith AKA returners the genius who cant get a job and likes to rant and put FB posts on phys.org
http://phys.org/n...les.html
ok, lets take it really slow for you, since you seem to have lied about your intelligence (or your literacy skills are not as high as you think)
you would also think you could comprehend the difference between weather and climate, but i guess that wasn't covered in your job skills IQ test

the studies were based upon observation and measurement, then they made a prediction!
see this study: http://marine.rut..._pub.pdf

we see that today. now they are adding info to the study:
http://iopscience...4005.pdf
Now read this: http://www.scienc...abstract

water vapor
@phonesll1
please read the last study linked -explains the cycle/feedback

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