Winters in Siberian permafrost regions have warmed since millenia

January 26, 2015, Helmholtz Association of German Research Centres
Aerial photo of the Lena delta, taken during a summer expedition in July 2012. Credit: Volkmar Kochan/rbb

For the first time, researchers at the Alfred Wegener Institute have successfully decoded climate data from old permafrost ground ice and reconstructed the development of winter temperatures in Russia's Lena River Delta. Their conclusions: over the past 7,000 years, winter temperatures in the Siberian permafrost regions have gradually risen. The study will be published today on Nature Geoscience's website.

You won't find any glaciers in Russia's Lena River Delta. Unlike in Antarctica or Greenland, in the Siberian tundra ice doesn't form above ground on hillsides or elevated plains. Rather, it forms directly underground as ice wedges.

"Ice wedges are a typical feature of permafrost regions. They are formed when the permanently frozen soil contracts in response to intensively cold , causing it to crack. When the snow melts in spring, the melt water fills these cracks. Since the ground temperature is roughly minus ten degrees Celsius, the water refreezes immediately. If this process repeats itself winter after winter, over the decades and centuries an ice body shaped like a giant wedge is formed," explains Dr Hanno Meyer, a permafrost researcher at the AWI Potsdam and first author of the study.

With a depth of up to 40 metres and a width of up to six metres, the ice wedges of the Siberian Arctic may not be as physically impressive as Antarctic glaciers. However the ice wedges, some of which are more than 100,000 years old, store climate information in much the same way, allowing scientists to investigate them using glacier research methods. "The melt water always comes from the snowfall of a single winter. Therefore, when it freezes in these frost cracks, information on the winter temperatures in that specific year is also preserved. We have now succeeded for the first time in using oxygen isotope analysis to access the temperature information stored in the ice and compile it into a climate curve for the past 7,000 years," states AWI researcher and co-author Dr Thomas Opel.

Exposed ice wedges at the coast of the Siberian island Muostakh. With this picture in mind, one can understand, why early researchers thought ice wedges could be nothing else than buried glaciers. Credit: Thomas Opel, Alfred-Wegener-Institut

The new information represents the first well dated winter-temperature data from the Siberian permafrost regions and indicates a clear trend: "Over the past 7,000 years, the winters in the Lena River Delta have steadily warmed - a trend we haven't seen in almost any other Arctic climate archive," says Hanno Meyer. As the permafrost expert explains, the likely reason is: "To date, primarily fossilised pollen, diatoms and tree rings from the Arctic have been used to reconstruct the climate of the past. But they mostly record temperature information from the summer, when the plants grow and bloom. Ice wedges are among the few archives that can exclusively record winter data."

Further, the new data will allow the researchers to fill an important gap: "Most climate models indicate a long-term cooling in the summer and long-term warming in the winter for the Arctic over the past 7,000 years. But until now, there has been no temperature data to support the second claim, essentially because the majority of climate archives record information from the summer. Now we can finally demonstrate that ice wedges contain similar winter-temperature information as predicted by climate models," says AWI modeller and co-author Dr Thomas Laepple.

At this point, the researchers can't exactly determine yet how many degrees the Arctic winters have warmed. As Thomas Opel explains, "The results of the oxygen isotope analysis can only tell us whether and how the isotopic composition has changed. If it rises, it indicates a warming. But the exact extent of warming is something we can't yet make a statement on."

Nevertheless, the researchers found clear indications for the causes of this warming.

According to Hanno Meyer: "The curve shows a clear partitioning. Up to the dawn of industrialisation around 1850, we can attribute the development to changes in the Earth's position relative to the sun. In other words, the duration and intensity of the solar radiation increased from winter to winter, causing temperatures to rise. But with industrialisation and the strong increase in the emissions of greenhouse gases like carbon dioxide, this was supplemented by the anthropogenic greenhouse effect. Starting at that point, our data curve shows a major increase that clearly differs from the gradual warming in the previous phase."

In a next step, the researchers will investigate whether the same indicators for a gradual rise in winter temperatures in the Arctic can also be found in other permafrost regions around the globe. As Thomas Opel elaborates: "We already have data from an area 500 kilometres east of the Lena River Delta that supports our findings. But we don't know how it looks for example in the Canadian Arctic. We suppose the development was similar there, but don't yet have evidence to back up that assumption."

The data for the new Lena River Delta temperature curve comes from 42 ice samples, which AWI researchers collected over the course of several expeditions from 13 ice wedges that the river had uncovered during flooding. "For the purposes of the study, we only included samples for which we could clearly determine the age. Fortunately, for ice wedges this is relatively simple as a large number of plant remains and other organic material enters the ground ice during snow melt- and we can use the radiocarbon method to precisely determine the age of this material," says Hanno Meyer.

Explore further: River ice reveals new twist on Arctic melt

More information: Long-term winter warming trend in the Siberian Arctic during the mid- to late Holocene, Nature Geoscience, Vol 8, DOI: 10.1038/ngeo2349

Related Stories

River ice reveals new twist on Arctic melt

April 2, 2014

A new study led by Lance Lesack, a Simon Fraser University geographer and Faculty of Environment professor, has discovered unexpected climate-driven changes in the mighty Mackenzie River's ice breakup. This discovery may ...

Large sea ice changes North of Swalbard

June 12, 2014

During the last decades warmer Atlantic water has caused a retreat of the ice edge north of Svalbard. In contrast to other areas of the Arctic Ocean, the largest ice loss north of Svalbard occurred during winter.

Methane is leaking from permafrost offshore Siberia

December 22, 2014

Yamal Peninsula in Siberia has recently become world famous. Spectacular sinkholes, appeared as out of nowhere in the permafrost of the area, sparking the speculations of significant release of greenhouse gas methane into ...

Arctic sea ice helps remove CO2 from the atmosphere

September 22, 2014

Climate change is a fact, and most of the warming is caused by human activity. The Arctic is now so warm that the extent of sea ice has decreased by about 30 pct. in summer and in winter, sea ice is getting thinner. New research ...

Greenland Ice: The warmer it gets the faster it melts

January 20, 2015

Melting of glacial ice will probably raise sea level around the globe, but how fast this melting will happen is uncertain. In the case of the Greenland Ice Sheet, the more temperatures increase, the faster the ice will melt, ...

Recommended for you

Coffee-based colloids for direct solar absorption

March 22, 2019

Solar energy is one of the most promising resources to help reduce fossil fuel consumption and mitigate greenhouse gas emissions to power a sustainable future. Devices presently in use to convert solar energy into thermal ...

EPA adviser is promoting harmful ideas, scientists say

March 22, 2019

The Trump administration's reliance on industry-funded environmental specialists is again coming under fire, this time by researchers who say that Louis Anthony "Tony" Cox Jr., who leads a key Environmental Protection Agency ...

14 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Caliban
4.6 / 5 (9) Jan 26, 2015
Ahem.

Where are all the dumb-as-dirt deniers comments on the complete falsity of these findings?

They didn't fail to emit a few cubic meters of bad air following this article, also published here today:

http://phys.org/n...tml#nRlv

Perhaps because this was a strongly positive result, that didn't leave any room for sowing doubt in the minds of the credulous?
Shootist
1.6 / 5 (7) Jan 26, 2015
Stop with the ad hominem, its small minded.

Winters in Siberian permafrost regions have warmed since millenia


The climate changes. For 3 billion or more years the climate changed. Don't see any reason it should stop now.
Maggnus
4.7 / 5 (12) Jan 26, 2015
And this also fits nicely with what was considered for the climate prior to the industrial age, fitting right along side what we would expect from the Milankovitch cycles and progression. The northern hemisphere should be warming slightly in winter and cooling slightly in summer as the Earths orbit and progression begin to match up with a new round of glaciation. Exactly as what they found.

This suggests we have a pretty good handle on what our climate has been doing, and should be doing. And it also confirms what climate science has been saying - the Earth's temperature is going up when it should be going down.

Great study.
Caliban
4.6 / 5 (11) Jan 27, 2015
Stop with the ad hominem, its small minded.


Tell you what shooty --you stop posting the same tired fallacies, and I'll have one less target for ridicule.

Deal?

The climate changes. For 3 billion or more years the climate changed. Don't see any reason it should stop now.


Case in point.

But I'll forgo the usual --just this once-- as a gesture of goodwill.

Maggnus
4.7 / 5 (12) Jan 27, 2015
Stop with the ad hominem, its small minded.
Is this really a direct quote from him? Lol that's rich. Did that come from Dyson? I mean, Dyson says we should be nice to each other, and Dyson is smarter than anyone else alive, so that must be right. Right?

The climate changes. For 3 billion or more years the climate changed. Don't see any reason it should stop now.


Case in point.

But I'll forgo the usual --just this once-- as a gesture of goodwill.


Another of the "it's always been happening" crowd. Again, I don't want to complain too much, given that this is an admission that there is global warming. Baby steps.
ubavontuba
1 / 5 (7) Jan 27, 2015
"The curve shows a clear partitioning. Up to the dawn of industrialisation around 1850, we can attribute the development to changes in the Earth's position relative to the sun. In other words, the duration and intensity of the solar radiation increased from winter to winter, causing temperatures to rise. But with industrialisation and the strong increase in the emissions of greenhouse gases like carbon dioxide, this was supplemented by the anthropogenic greenhouse effect.
Sure, so now AGW begins a sharp rise in 1850? Where did all the CO2 suddenly come from? Oh yeah, it must have been all the automobiles, airplanes, and electricity generation.

Narf!

BTW, this was a study on WINTER temperatures. So, just how much sunlight falls in the arctic circle during winter?

Poit!

Vietvet
4.4 / 5 (13) Jan 27, 2015
@Uba

There's a CO2 producing fuel called coal. Your education is incomplete so I'm providing you a link so you can get up to speed.

http://en.wikiped...iki/Coal
ubavontuba
1 / 5 (6) Jan 27, 2015
@Vietvet
There's a CO2 producing fuel called coal. Your education is incomplete so I'm providing you a link so you can get up to speed.

http://en.wikiped...iki/Coal
Sure, and back then how much of it was burned efficiently and not released as soot and incompletely burned ash? How much was the snow darkened and transformed by this soot and ash? Is this accounted for?

And more importantly, how much did atmospheric CO2 rise during this time?

And most importantly, if that teeny-weeny little bit of added CO2 caused such a steepening gradient then, how come a whole lot more CO2 isn't doing much more so, today?

Vietvet
4.4 / 5 (13) Jan 27, 2015
@ubavontuba

If you would sincerely like to have your questions answered read the link.

http://www.skepti...ief.html

Maggnus
4.7 / 5 (12) Jan 27, 2015
National Geographic has put out an issue examining the effects of rising sea level and rising temperatures in Florida. As I recall Shootist said he lives in the area, Key West as I recall - or close to the ocean at least.

This is for him. Treading Water, the future of Florida, http://ngm.nation...ker-text
RealityCheck
4 / 5 (9) Jan 27, 2015
Hi Uba. :) Can't stay long oday, so briefly...
...so now AGW begins a sharp rise in 1850? Where did all the CO2 suddenly come from?

Recall that the reason so much coal was being burned was that population explosion/expanding cities/agriculture/industry had denuded the forests by that time. So not only was massively more CO2 being emitted by coal/wood/dung fuels of that era globally, but many forest 'sinks' were being effectively decimated globally for fuel and by 'slash and burn' farming/agriculture practices as well. Add to that the 'albedo effect' of soot and grime which you mentioned, and a spike in CO2 was unavoidable. ok? Bye.
ubavontuba
1 / 5 (5) Feb 01, 2015
@ubavontuba

If you would sincerely like to have your questions answered read the link.

http://www.skepti...ief.html
How does this blog, by a cartoonist, supposedly answer my questions? Is this just a brush off for asking difficult, but pertinent, questions?

Captain Stumpy
4 / 5 (4) Feb 17, 2015
How does this blog, by a cartoonist, supposedly answer my questions?
@Ubavontrollingtard
are you having literacy problems? you could start by reading the referenced matierial, like this link: http://www.skepti...hp?r=384
which also includes links in it to read
then there is this reference: http://cdiac.ornl...2008.ems
&: http://cdiac.ornl...hed.yr75
&: http://cdiac.ornl...2005.txt
& http://cdiac.ornl...aper.pdf
and every link back to the site also includes studies linked within the articles
which are there so that you can verify/validate the information

i know that is hard for you, and that you would rather argue semantics, definitions, and pointless strawman arguments but i am surprised that you would ignore the STUDIES linked for the sake of your beliefs and politics
(satirical hyperbole)
Captain Stumpy
4 / 5 (4) Feb 17, 2015
@Uba cont'd
Is this just a brush off for asking difficult, but pertinent, questions?
i didn't bother to go through ALL of the links as well as supporting evidence

I figured you wouldn't anyway
because that would mean you would have to address the science directly, and that is not how you operate

it is NOT a brush off, though
it does seem to answer your questions, it just gives you a whole lot of details and science to wade through in order to get all the answers you want
and since you are not going to read it to see if you are answered
nor will you read the studies linked and verify the information is correct
then why should anyone else hold your hand and do it for you?
Especially since the whole reason for your comment is to distract from the science and build a strawman argument?
(what in 1850? i mean, it's not like there were big smoking factories or industry or anything like that way back then!)

(satire and hyperbole included above)
Bye

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.