Sudden stratospheric warming linked to open water in polar ice pack

December 11, 2018 by Tyrone Burke, University of Toronto Mississauga
Sudden stratospheric warming linked to open water in polar ice pack
Sea ice concentration from space on February 25, 2018. Credit: Kent Moore

In the depths of the long night that cloaks the Arctic in frigid darkness for three months each winter, a surprising patch of open water appeared, just to the north of Greenland.

It was a polynya – an area of unfrozen water surrounded by the polar ice pack. Though not especially rare in some parts of the Arctic, the north Greenland polynya of February 2018 was most unexpected. 50,000 km² of open water in the Wandel Sea, an area the size of the state of Kentucky or the province of Nova Scotia.

The Wandel is part of a region known as the "last ice area". It abuts northern Greenland and Canada's Arctic Archipelago, and sea ice there is expected to persist longer than anywhere else. As recently as the 1980s, its ice cover was thicker than an elephant is tall. Today, it's about half that.

Was this unusual polynya another harbinger of climate change?

That was the initial hypothesis of a team led by Kent Moore and Axel Schweiger. Polynyas had not previously been observed in the region, and temperatures in north Greenland had been startlingly warm, as much as 30°C above average.

But as Moore, a University of Toronto-Mississauga Professor of Atmospheric Physics, dug deeper with his colleagues from the University of Washington's Polar Science Center, an alternative explanation emerged.

In their paper, What caused the remarkable February 2018 Greenland Polynya?, Moore, Schweiger, Jinlun Zhang and Mike Steele identify the polynya's cause to be strong surface winds catalyzed by a dramatic warming in Earth's upper atmosphere known as a Sudden Stratospheric Warming.

"During these events, temperatures in the stratosphere – about 30km above ground level—can warm by 10° or 15°C in just a few days," Moore says.

"This causes a change in that includes a reversal in the winds in the stratosphere. These high altitude winds blow against the west-to-east direction of the jet stream, descending toward the Earth's surface. In February 2018, this caused winds from Siberia to blow cold air into northern Europe, creating a weather system that became known as the 'Beast from the East'. It brought temperatures of minus 20°C to northern Europe, and the same weather pattern moved warmer air northwards up the east coast of Greenland."

Strong southerly winds forced mild air to Greenland and beyond, but it wasn't their warmth that caused the polynya.

"Most Arctic warmings last a day or two," says Moore. "This lasted a week, and these were the warmest temperatures and strongest winds observed in north Greenland since observations began in the 1960s. Winds were close to hurricane force (93+km/h) and temperatures were above freezing. Once we got that piece of the puzzle, we realized it could be rather than warmth that caused the polynya."

While the size of the polynya was unprecedented over the period we have good data, it appears not to be tied to the thinning of the ice pack that has occurred over the same period. Simulations with the University of Washington's Pan-Arctic Ocean Modeling and Assimilation System (PIOMAS) indicate that similar conditions would have created a polynya, even without the recent thinning of the ice north of Greenland.

Using PIOMAS, the team crunched 2018 weather conditions and ice concentration data to numerically simulate the polynya. Then, using historical data, they simulated 2018 weather conditions on the ice packs of the past.

Their findings: similar wind speeds would have caused the polynya to occur even in years with thicker ice, while weaker winds would not have resulted in the 2018 north Greenland polynya, despite thinner ice conditions.

"We used to ask the question hypothetically: what would have happened if the ice had been as thick as in 1979," says Schweiger.

"Now, we simulate it. The answer was that the thinning of the ice didn't matter much, but strong winds were responsible."

A long-time sea ice researcher, Schweiger was surprised. He thought thinning ice would be the decisive factor.

"But when we looked closer, it wasn't. Letting your intuition guide your hypothesis, then letting yourself be convinced otherwise… that's science."

Explore further: Scientists show polar 'polynya' supported marine life during last Ice Age

More information: G. W. K. Moore et al. What caused the remarkable February 2018 North Greenland Polynya?, Geophysical Research Letters (2018). DOI: 10.1029/2018GL080902

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Scroofinator
2 / 5 (4) Dec 11, 2018
Two weeks straight of active solar flares (and stratospheric UV forcing) preceding the event is a likely cause.

https://www.space.../archive
Da Schneib
2.6 / 5 (5) Dec 12, 2018
But it's still due to global climate change- just not directly. It's from this unusual blast of Siberian air that was driven by GCC.
SteveS
3.7 / 5 (6) Dec 12, 2018
Two weeks straight of active solar flares (and stratospheric UV forcing) preceding the event is a likely cause.

https://www.space.../archive


The site you linked shows solar activity at very low levels throughout February. This is from the report for Feb 14th, but all other days are similar

"Solar activity has been at very low levels for the past 24 hours."

"The geomagnetic field has been at quiet levels for the past 24 hours"
antigoracle
2.6 / 5 (5) Dec 12, 2018
But it's still due to global climate change- just not directly. It's from this unusual blast of Siberian air that was driven by GCC.

Da Snob, the "meat" loving jackass brays again and pulls another "gem" out of his rectum, where his boyfriend is still trying to find his "sweet spot"
LMAO.
Scroofinator
3 / 5 (4) Dec 12, 2018
This is from the report for Feb 14th

Look how red his fingers are from picking those cherries. Careful that will leave a stain..

From Feb 4th to the 17th, the 13th was the only day without a flare, and if you notice the Kp index there was in general instability in the space weather around the earth. The day after the 14th we had a G1 class solar storm, so much for a quiet geomagnetic field.

If you recall it's not necessarily just the strength of the flare that can affect the different levels of the atmosphere, but also the succession of many, as well as the solar wind stream that is blowing towards earth. The Carrington event was as bad as it was not because of single x class flare, but because of the two large flares in rapid succession.
Scroofinator
3 / 5 (4) Dec 12, 2018
But it's still due to global climate change- just not directly. It's from this unusual blast of Siberian air that was driven by GCC

Back pedaling is not a good look. If you actually read the article you'd understand the Siberian air mass was an effect of stratospheric changes, not the other way around...
This [SSW] causes a change in air circulation that includes a reversal in the winds in the stratosphere

We aren't talking new science, NASA has known since the 70's:
From "Genesis of Sudden Stratospheric Warmings and the Quasi-biennial cycles"
The 24-month [stratospheric wind] cycle becomes a 26-month cycle, in the long-term means, because of the action of the 11-year sunspot cycle. In the years when sunspot occurrence is at its lowest, the radiant heating of the southern stratosphere is insufficient to inititate the usual strong hemispheric exchange of stratospheric winds
SteveS
5 / 5 (4) Dec 12, 2018
Look how red his fingers are from picking those cherries


4 Feb
Solar activity has been at low levels for the past 24 hours
The geomagnetic field has been at quiet levels for the past 24 hours
5 Feb
Ditto
The geomagnetic field has been at quiet to unsettled levels for the past 24 hours
6 Feb
Ditto
The geomagnetic field has been at quiet levels for the past 24 hours.
7 Feb
Ditto
Ditto
8 Feb
Ditto
Ditto
9 Feb
Ditto
The geomagnetic field has been at quiet to unsettled levels for the past 24 hours.
10 Feb
Ditto
Ditto
11 Feb
Ditto
The geomagnetic field has been at quiet levels for the past 24 hours.
12 Feb
Ditto
Ditto
13 Feb
Ditto
Ditto
14 Feb
Ditto
Ditto
15 Feb
Ditto
The geomagnetic field has been at quiet to active levels for the past 24 hours
16 Feb
Ditto
The geomagnetic field has been at quiet to unsettled levels for the past 24 hours.
17 Feb
Ditto
The geomagnetic field has been at quiet to active levels for the past 24 hours
Happy now?
Scroofinator
3 / 5 (4) Dec 12, 2018
Solar flares emit x-ray and UV, which primarily interacts with the ionosphere and stratosphere respectively (the latter of which being the atmospheric layer in discussion). A CME on the other hand, not always a result of a flare, does influence the magnetosphere because there's actually plasma hitting it, but that's not what we're talking about.

So yea I'm happy you wasted your time because don't understand the physics behind how the stratosphere is heated. Here's some light reading for you...
https://hesperia....dex.html
SteveS
4.2 / 5 (5) Dec 12, 2018
Wow!

Look at how active Feb 2013 was.

Strange there wasn't a stratospheric warming event.

What is it they say about correlation and causation?

https://www.space.../archive
Scroofinator
3 / 5 (4) Dec 12, 2018
Take a look at the graph and let me know your observations:
http://www.polarl...2600.png
SteveS
5 / 5 (4) Dec 12, 2018
Take a look at the graph and let me know your observations:
http://www.polarl...2600.png


From the legend it all looks pretty low intensity.

Link to the site so I can compare it to other years
SteveS
5 / 5 (3) Dec 12, 2018
Link to the site so I can compare it to other years


Don't worry I found it

http://www.polarl...5000.png
Scroofinator
3 / 5 (4) Dec 12, 2018
You do realize 2013 was about the peak of solar activity for the last cycle, which means a warmer stratosphere through thermosphere, and thus less of an effect from localized events (flares) when compared to a cooler system. What happens when you put boiling water in a microwave?

https://spaceweat...minimum/
humy
4.3 / 5 (6) Dec 12, 2018
Two weeks straight of active solar flares (and stratospheric UV forcing) preceding the event is a likely cause.

Err, no. Just like the current positions of Mars and Venus is NOT a likely cause. You would need to explain by what physical process, and in full accordance to all the known laws of physics, one naturally lead to the other. You cannot randomly and arbitrary pick two events that happen to coincide and say one causes the other while ignoring the complete absence of any known physical process by which one, at least could in theory, lead to the other. Day is always followed by night; so day causes night?
I have heard of the theory you are refering to but sadly it isn't in full accordance to all the known laws of physics.
SteveS
5 / 5 (4) Dec 12, 2018
warmer stratosphere through thermosphere,


Ouch!

http://images.rem...ies.html
Scroofinator
3 / 5 (4) Dec 12, 2018
You would need to explain by what physical process, and in full accordance to all the known laws of physics

In the stratosphere molecular oxygen absorbs UV, which is the most affected wavelength throughout the solar cycle. Lower UV means colder stratosphere. Cold stratosphere impacted by solar flare UV and heats up local patch of stratosphere.

Seriously just read the NASA paper I already cited:
"Genesis of Sudden Stratospheric Warmings and the Quasi-biennial cycles"
Scroofinator
3 / 5 (4) Dec 12, 2018
Ouch!

You posted a graph for the troposphere...

If you knew what you were looking for (by selecting the C-channels) the stratosphere is showing anywhere from a -.7 to -.2 K/decade decrease depending on altitude. Baby it's cold outside...

Oof!
SteveS
4.2 / 5 (5) Dec 12, 2018
You posted a graph for the troposphere...!


I posted a link to a tool that allows you to to see the data sets for all altitudes, unlike your link to a particular period. Red fingers?
SteveS
4.2 / 5 (5) Dec 12, 2018
the stratosphere is showing anywhere from a -.7 to -.2 K/decade decrease


and no correlation to solar activity.

I can't remember, what were the predictions for stratospheric temperatures in a AGW scenario? Was it cooling?
Scroofinator
3 / 5 (4) Dec 12, 2018
I posted a link to a tool that allows you to to see the data sets for all altitudes, unlike your link to a particular period. Red fingers?

Sure I cherry picked a whole year in question, and used a link that is easily usable/accessible...
SteveS
4.2 / 5 (5) Dec 12, 2018
Sure I cherry picked a whole year in question

Nuff said
Scroofinator
3 / 5 (4) Dec 12, 2018
and no correlation to solar activity

Uggh you're thick, I'll post the evidence again:
https://spaceweat...minimum/
humy
4.2 / 5 (5) Dec 12, 2018
You would need to explain by what physical process, and in full accordance to all the known laws of physics

In the stratosphere molecular oxygen absorbs UV, which is the most affected wavelength throughout the solar cycle. Lower UV means colder stratosphere. Cold stratosphere impacted by solar flare UV and heats up local patch of stratosphere.

The solar heating isn't enough to account for that amount of heating on the Earth's surface.
Read the assertion in this above article:

"Once we got that piece of the puzzle, we realized it could be wind rather than warmth that caused the polynya."

If there is a causal link, it is vary indirect and the recent global warming cannot be explained by it ( -I just said that latter part in case someone here is trying to make out the contrary and not implying you said this )

SteveS
5 / 5 (4) Dec 12, 2018
and no correlation to solar activity

Uggh you're thick, I'll post the evidence again:
https://spaceweat...minimum/


And no mention of the stratosphere
Scroofinator
2.3 / 5 (3) Dec 13, 2018
And no mention of the stratosphere

You're right, I was mistaken, I thought stratospheric temperature was included in the TCI measurements.

Here's a separate link showing the solar cycle and stratospheric connection
https://www.astro...the-sun/

The team first confirmed a theory that the slight increase in solar energy during the peak production of sunspots is absorbed by stratospheric ozone. The energy warms the air in the stratosphere over the tropics, where sunlight is most intense, while also stimulating the production of additional ozone there that absorbs even more solar energy. Since the stratosphere warms unevenly, with the most pronounced warming occurring at lower latitudes, stratospheric winds are altered and, through a chain of interconnected processes, end up strengthening tropical precipitation


@ humy
Not trying to say it's warming the troposphere, but it does affect it. See above
SteveS
5 / 5 (4) Dec 14, 2018
Here's a separate link showing the solar cycle and stratospheric connection
https://www.astro...the-sun/

An interesting article about the effects of the 0.1% increase in solar energy over the 11 year cycle with most effects occurring at lower latitudes during peak activity.

At 80 degrees north the sun doesn't rise until the 20th of February.
Da Schneib
4 / 5 (4) Dec 14, 2018
and no correlation to solar activity

Uggh you're thick, I'll post the evidence again:
https://spaceweat...minimum/


And no mention of the stratosphere
@Steve, one of the most perspicacious posts on the thread. The stratosphere *cools* if the CO2 in the troposphere *increases.* This is because the heat gets kept in the troposphere. Which side of the sleeping bag gets hot? Simple easy obvious stuff.
Scroofinator
1 / 5 (1) Dec 14, 2018
This is because the heat gets kept in the troposphere

That's not how it works. CFCs deplete ozone and CO2 displaces it, less ozone means less heat. To ignore the main UV aspect is insane.
https://www.earth...97/2016/
"While the window-grey model allows for a fully analytical treatment of CO2-induced MA cooling, it is not well suited to constrain the relative effect strengths. Uncertainties are large because the window-grey model entails a number of gross simplifications, including in particular: the assumption of vertically well-mixed greenhouse gases (violated in particular by water vapour); the simplistic LW band structure; and the neglect of vertical heat transport by convection (and conduction at the surface)...the neglect of chemical processes; the implicit treatment of solar radiation; the neglect of clouds, aerosols, and scattering in general; and the assumption of local thermodynamic equilibrium that does not hold in the upper mesosphere and beyond."
Scroofinator
1 / 5 (1) Dec 14, 2018
At 80 degrees north the sun doesn't rise until the 20th of February.

Funny, right around the time of this SSW event
antigoracle
1 / 5 (1) Dec 14, 2018
HAWW..HAWW...HEEE...The stratosphere *cools* if the CO2 in the troposphere *increases.* This is because the heat gets kept in the troposphere. Which side of the sleeping bag gets hot? Simple easy obvious stuff.

Da Snob the "meat" loving jackass brays again and pulls another nugget out from his arse.
Uh huh, that sleeping bag must get hot when his boyfriend is trying to find his "sweet spot".

Hey jackass, if manmade CO2 is trapping heat, then tell us why in the hottest places; ie. deserts, the temperature plummets towards freezing, during the night?
SteveS
5 / 5 (2) Dec 14, 2018
At 80 degrees north the sun doesn't rise until the 20th of February.

Funny, right around the time of this SSW event


At 85 degrees north the sun doesn't rise until the 6th of March.

There you go, coincidence gone.

How does the sun influence the troposphere in the arctic and nowhere else when it's not even above the horizon?
Scroofinator
not rated yet Dec 14, 2018
The horizon of the stratosphere is 10km high there, that's how
SteveS
5 / 5 (1) Dec 14, 2018
The horizon of the stratosphere is 10km high there, that's how


So why was the stratospheric warming limited to the arctic?
SteveS
not rated yet Dec 14, 2018
The horizon of the stratosphere is 10km high there, that's how

FYI at 85 degrees north on the 25th of Feb at an altitude of 10km the sun rose for the first time in months at 8:48 UTC and set three hours later at 11:43 UTC. Well after the slight rise in x-ray flux you linked to earlier

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