Arctic Sea Ice

When the Arctic was 8 °C warmer

You won't see it in any travel guides, probably because of its name, but Lake El'gygytgyn offers many wonders. Lately it's been in the news because of fascinating paleoclimatic data the lake has yielded to researchers drilling its bottom. They managed to extend the climatic chronology of northern latitudes by a couple of millions of years and showed, besides a lot of other interesting stuff, that the last time the atmosphere contained 400 ppm of carbon dioxide, the Arctic was around 8 °C warmer than it is now.

In this video one of the authors of the paper explains what was done exactly (hat-tip to commenter Boa05att):

Edit: There's been some confusion due to my not being precise enough. The video below is from a previous paper, a couple of months ago, by the same group. The second paper extends the paleoclimatic data even further. Still the video below explains what was done exactly to retrieve the data and has fancy images of Lake El'gygytgyn. See the end of this blog post for links to more info.

Blogger Alexander Ač sent me this short blog post to explain the implications:

Springer science summary

Steve Bloom writes:

It looks like Springer [a company that publishes many science journals, N.] is providing a useful service in issuing open-access summaries of the state of the science within each Earth Science specialty (many, but not all, will pertain to climate science).

The new polar science one is further organized by sub-specialty, each containing a brief discussion of the science and (most valuable IMO) links to a number of papers comprising the state of the science. It's short enough so that someone unfamiliar with the field can acquire an overview in short order. Apparently the plan is to update annually.

Here's the intro to their Polar science news in brief summary:

The addition of the ‘‘News in Brief’’ series to our Views and News section will highlight recent significant research in the last year—from high-impact papers to emerging research fronts—and will include papers with both classic and new hot topics. This series will offer a rotating view among the major Earth Science areas, as various experts will be invited to provide a brief look around the recent research conducted in their area. This selection of research papers is left up to each expert and due to the broadness of each field is not intended to be a comprehensive overview. Links to the published work are provided in each section.

David Carlson, former Director of the International Programme Office for the International Polar Year, has been invited to provide a glimpse into the latest findings in polar science. Carlson outlines selected research of global relevance hoping that readers will discover the fascinating connections among and across these topics, and the unintended prominence of three restless partners: ocean, wind and ice.

The summary's summary is also well worth reading:

Survey measuring consensus in climate research

I received this request from Skeptical Science's John Cook:

As one of the more highly trafficked climate blogs on the web, I’m seeking your assistance in conducting a crowd-sourced online survey of peer-reviewed climate research. I have compiled a database of around 12,000 papers listed in the 'Web Of Science' between 1991 to 2011 matching the topic 'global warming' or 'global climate change'. I am now inviting readers from a diverse range of climate blogs to peruse the abstracts of these climate papers with the purpose of estimating the level of consensus in the literature regarding the proposition that humans are causing global warming. If you’re interested in having your readers participate in this survey, please post the following link to the survey:

http://survey.gci.uq.edu.au/survey.php?c=QQ5LENROSHQM

The survey involves rating 10 randomly selected abstracts and is expected to take 15 minutes. Participants may sign up to receive the final results of the survey (de-individuated so no individual's data will be published). No other personal information is required (and email is optional). Participants may elect to discontinue the survey at any point and results are only recorded if the survey is completed. Participant ratings are confidential and all data will be de-individuated in the final results so no individual ratings will be published.

The analysis is being conducted by the University of Queensland in collaboration with contributing authors of the website Skeptical Science. The research project is headed by John Cook, research fellow in climate communication for the Global Change Institute at the University of Queensland.

As Cook explains on SkS:

A drastically greener Arctic to come

I try to donate money to organisations that plant trees from time to time, often combined with efforts to provide the poor in Africa and Asia with efficient wood stoves, but also try to make sure the trees are planted in more southerly latitudes, as green stuff in more northerly latitudes tend to increase warming.

From Science Daily (hat-tip to Steve Bloom), news about yet another positive feedback in the Arctic:

New Models Predict Drastically
Greener Arctic in Coming Decades

Mar. 31, 2013 — New research predicts that rising temperatures will lead to a massive "greening," or increase in plant cover, in the Arctic. In a paper published on March 31 in Nature Climate Change, scientists reveal new models projecting that wooded areas in the Arctic could increase by as much as 50 percent over the next few decades. The researchers also show that this dramatic greening will accelerate climate warming at a rate greater than previously expected.

"Such widespread redistribution of Arctic vegetation would have impacts that reverberate through the global ecosystem," said Richard Pearson, lead author on the paper and a research scientist at the American Museum of Natural History's Center for Biodiversity and Conservation.

(..)

In addition, the researchers investigated the multiple climate change feedbacks that greening would produce. They found that a phenomenon called the albedo effect, based on the reflectivity of Earth's surface, would have the greatest impact on the Arctic's climate. When the sun hits snow, most of the radiation is reflected back to space. But when it hits an area that's "dark," or covered in trees or shrubs, more sunlight is absorbed in the area and temperature increases. This has a positive feedback to climate warming: the more vegetation there is, the more warming will occur.

"By incorporating observed relationships between plants and albedo, we show that vegetation distribution shifts will result in an overall positive feedback to climate that is likely to cause greater warming than has previously been predicted," said co-author Scott Goetz, of the Woods Hole Research Center.

Read the whole article here. And while you're at it, make sure to read this interesting BBC article about a research paper that investigated one of the reasons Antarctic sea ice is growing.

Looking for winter weirdness 6

I wasn't expecting another instalment in this year's series of blog posts on Winter Weirdness, extreme weather events that could be linked to the decline in Arctic sea ice. It's not even winter anymore officially. But as spring has been revoked in large parts of Europe, and the atmospheric blocking that is causing it is being linked to Arctic sea ice as a potential cause, I figure it's a fitting end for the series.

One of the first articles alluding to the link, appeared on the Guardian's website on Monday: Scientists link frozen spring to dramatic Arctic sea ice loss. Stefan Rahmstorf, professor of Physics of the Oceans at Potsdam University, went further, writing a blog post showing the similarities between the current event and modeled projections in recent research that investigated the influence of Arctic sea ice loss on atmospheric patterns. Lepus Universalis Eli Rabett was so kind as to translate Rahmstorf's blog post to English:

Melting Ice and Cold Weather

The media are debating if the decrease in  Arctic ice  is related to this winter's cold weather in Germany. This post discusses the most recent current research about this including the most important figures from relevant studies.

First, what does the unusual temperature distribution observed this March actually look like? Here is a map showing the data (up to and including March 25, NCEP / NCAR data plotted with KNMI Climate Explorer):

Freezing cold in Siberia, reaching across northwestern Europe, unusually mild temperatures over the Labrador Sea and parts of Greenland and a cold band diagonally across North America, from Alaska to Florida. Averaged over the northern hemisphere the anomaly disappears - the average is close to the long-term average. Of course, the distribution of hot and cold is related to atmospheric circulation, and thus the air pressure distribution. The air pressure anomaly looks like this:

There was unusually high air pressure between Scandinavia and Greenland. Since circulation around a high is clockwise [anticyclone], this explains the influx of arctic cold air in Europe and the warm Labrador Sea. 

Arctic sea ice

Let us now discuss the Arctic sea ice.  The summer minimum in September set a new record low, but also at the recent winter maximum there was unusually little ice (ranking 6th lowest - the ten years with the lowest ice extent were all in the last decade). The ice cover in the Barents sea was particularly low this winter.  All in all until March the deficit was  about the size of Germany compared  to the long-term average.

Is there a connection with the winter weather?  Does the shrinking ice cover influence the atmospheric circulation, because the open ocean strongly heats the Arctic atmosphere from below?  (The water is much warmer than the overlying cold polar air.) Did the resulting evaporation of sea water moisten the air and thus lead to more snow? These questions have been investigated by several studies in recent years.

Read the rest over at Eli's, or in German at KlimaLounge.

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Update: Commenter R. Gates has a firm meteorological grasp of current events, which not only could be influenced by the state of the sea ice, but also have to do with the early breaking down of the Polar Vortex I alluded to in my latest blog post on the cracking event (Arctic freezing season ends with a loud crack). Here's his explanation in a comment below:

CryoSat-2 reveals major Arctic sea-ice loss

We knew that observations by the CryoSat-2 satellite were by and large confirming the modeled data from the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center, because of the recent publication in GRL of Laxon et al.'s CryoSat-2 estimates of Arctic sea ice thickness and volume,
but now it's official.

Here's the press release from the National Environment Research Council:

CryoSat-2 mission reveals major Arctic sea-ice loss

Arctic sea ice volume has declined by 36 per cent in the autumn and 9 per cent in the winter between 2003 and 2012, a UK-led team of scientists has discovered.

Researchers used new data from the European Space Agency's CryoSat-2 satellite spanning 2010 to 2012, and data from NASA's ICESat satellite from 2003 to 2008 to estimate the volume of sea ice in the Arctic.

They found that from 2003 to 2008, autumn volumes of ice averaged 11,900 km3. But from 2010 to 2012, the average volume had dropped to 7,600 km3 - a decline of 4,300 km3. The average ice volume in the winter from 2003 to 2008 was 16,300 km3, dropping to 14,800 km3 between 2010 and 2012 - a difference of 1,500 km3.

"The data reveals that thick sea ice has disappeared from a region to the north of Greenland, the Canadian Archipelago, and to the northeast of Svalbard," says Dr Katharine Giles, a NERC-funded research fellow at the Centre for Polar Observation & Modelling (CPOM) at UCL (University College London), who co-authored the report, published online in Geophysical Research Letters.

The findings confirm the continuing decline in Arctic sea-ice volume simulated by the Pan-Arctic Ice-Ocean Modelling & Assimilation System (PIOMAS), which estimates the volume of Arctic sea ice and had been checked using earlier submarine, mooring, and satellite observations until 2008.

Other satellites have already shown drops in the area covered by Arctic sea ice as the climate has warmed. Indeed, sea-ice extent reached a record minimum in September 2012. But CryoSat-2, launched in April 2010, differs in that it lets scientists estimate the volume of sea ice - a much more accurate indicator of the changes taking place in the Arctic.

"While two years of CryoSat-2 data aren't indicative of a long-term change, the lower ice thickness and volume in February and March 2012, compared with same period in 2011, may have contributed to the record minimum ice extent during the 2012 autumn," says Professor Christian Haas of York University, Canada Research Chair for Arctic Sea Ice Geophysics, co-author of the study and coordinator of the international CryoSat sea ice validation activities.

Read the rest of the press release here. The European Space Agency also has one which includes a video that visualizes the CryoSat-2 results:

Well, I'll be damned, it looks like someone notified the BBC before me! Jonathan Amos writes:

2012 record not due to GAC-2012

A new research paper by scientists of the Polar Science Center of the Applied Physics Laboratory of the University of Washington, has been published this week in the online version of Geophysical Research Letters. It's called The impact of an intense summer cyclone on 2012 Arctic sea ice retreat and discusses the role the Great Arctic Cyclone of 2012 - or GAC-2012 - played in the incredible, unequivocal and unspinnable record streak
we witnessed towards the end of the melting season.

From the UW press release:

Cyclone did not cause 2012 record low for Arctic sea ice

It came out of Siberia, swirling winds over an area that covered almost the entire Arctic basin in the normally calm late summer. It came to be known as “The Great Arctic Cyclone of August 2012,” and for some observers it suggested that the historic sea ice minimum may have been caused by a freak summer storm, rather than warming temperatures.

But new results from the University of Washington show that the August cyclone was not responsible for last year’s record low for Arctic sea ice. The study was published online this week in Geophysical Research Letters.

“The effect is huge in the immediate aftermath of the cyclone, but after about two weeks the effect gets smaller,” said lead author Jinlun Zhang, an oceanographer in the UW’s Applied Physics Laboratory. “By September, most of the ice that melted would have melted with or without the cyclone.”

Recent research [covered on the ASI Blog here, N.] showed that the Arctic cyclone was the most powerful ever seen during the month of August, and the 13^th most powerful of all Arctic storms in more than three decades of satellite records.

“The storm was enormous,” said co-author Axel Schweiger, a polar scientist in the Applied Physics Laboratory. “The impact on the ice was immediately obvious, but the question was whether the ice that went away during the storm would have melted anyway because it was thin to begin with.”

The UW team performed the climate scientist’s equivalent of a forensic exam: They ran a computer simulation of last summer’s weather and compared it against a second scenario that was identical except that there was no cyclone.

Results showed the storm caused the sea ice to pass the previous record 10 days earlier in August than it would have otherwise, but only reduced the final September ice extent by 150,000 square kilometers (almost 60,000 square miles), less than a 5 percent difference. By comparison, the actual minimum ice extent was 18 percent less than the previous record set in 2007.

The storm apparently caused 150K km2 of extra melted ice and so the record(s) would have been broken anyway, as the difference with the 2007 minimum was much larger. The main reason the storm had such an effect, was that the ice was exceptionally thin. Just 10 years ago a storm, even of this size, wouldn't have had such an impact.

Read for instance this Skeptical Science article from October, with the figure below showing September Arctic sea ice extent data from NSIDC (blue) and years with Arctic summer storms similar to the 2012 storm depicted in red.

Remember that we started noticing that the ice seemed to be exceptionally thin weeks before the storm hit. It was the only way to explain the steadily rapid drop in extent and area levels, even though the weather wasn't conducive to that rate of melt.

Here's a quote from yours truly on July 28th, ten days before the Great Arctic Storm started to be great:

Dark Snow Project

I've waited with this blog post to kick off a second round of donations for this worthy project, aimed at measuring the impact of changing wildfire and industrial soot levels on snow and ice reflectivity.

Because of a lack of government funding Dr. Jason Box from the Byrd Polar Research Center (here's his blog) is now trying to raise through crowdfunding the money that is needed to fly to the top of the Greenland ice sheet and take samples. This data is very useful, as the reflectivity of the Greenland ice sheet has been decreasing steadily for a while now. The effects of this decrease have been documented here and elsewhere around the web last summer, when practically all of the surface of the ice sheet was melting at some point, a rare occurance.

Lower reflectivity of course means more melting, so reducing soot emissions might be a great help in slowing down the current melting trend of the Greenland ice sheet (and perhaps some of the Arctic sea ice melt as well), but for that we need to know how big a role soot is playing in all of this.

This video from Peter Sinclair's blog explains it all
(please watch if you haven't already):

You can donate at the Dark Snow Project website.

Another project that Dr. Box is involved in, is called Extreme Ice Survey, and that's the organisation that delivered the footage that was used for the popular Chasing Ice documentary:

The real AR5 bombshell

The whole fake skeptic propaganda effort disguised as 'leak' is boring me to death, but of course it's interesting to have a sneak peek preview of the IPCC Fifth Assessment Report (AR5) and see what they will have to say about Arctic sea ice. Geoff Beacon from the Brussels Blog already had a go at it, and found some frown inducing remarks. But for the sake of chronology I'm starting with first things first. 

From the Summary for Policymakers:

The average decadal extent of Arctic sea ice has decreased in every season since satellite observations commenced in 1979. The overall decrease in sea ice extent over the period 1979–2011 has been 3.9 [3.7 to 4.1] % per decade with larger changes occurring in summer and autumn (see Figure SPM.1). There is robust evidence of a decline in ice thickness, and in ice volume. The overall mean winter thickness has about halved between 1980 and 2009 {4.2.2}.

This, of course, is correct, and should give any sensible person pause. Given the magnitude of the event, the rate at which it is progressing (see long-term graphs), and the uncertainties with regards to possible consequences (in other words: we don't know what the worst case scenario could be), it's clear that just this short paragraph in the SMP (Summary for Policymakers) is enough to warrant some serious policymaking, which, I'm sorry to say, is not in favour of business-as-usual. Well done, IPCC!

But then, further on in the SMP, we get this:

There is very high confidence that climate models realistically simulate the annual cycle of Arctic sea ice extent, and there is high confidence that they realistically simulate the trend in Arctic sea ice extent over the past decades. {9.4.3}.

Very high confidence? I don't know about that, but before going to Chapter 9 let's first have a closer look at Chapter 4: Observations: Cryosphere, section 4.2.2.1:

2012 Greenland records

Thanks go out to commenter Lanevn for bringing this to our attention.

Some of the data concerning last summer's impact on the Greenland ice sheet has been released in a first paper by M. Tedesco, X. Fettweis, T Mote, J. Wahr, P. Alexander, J. Box, and B. Wouters: Evidence and analysis of 2012 Greenland records from spaceborne observations, a regional climate model and reanalysis (PDF).

As it says on the Greenland Melting blog: 

Overall, in 2012 ALL of the considered parameters (albedo, bare ice, surface mass balance, melting, total mass change, etc.) set a new record!

Records all around, not just for the Arctic sea ice. These two graphs say it all:

Daily time series of the cumulative SMB (Gtyr−1) using 1st of January as a reference for 2012 (dark blue), 2011 (light red) and 2010 (green) and for the 1958–2011 mean (50% grey).

And this adapted version of a figure in the paper by Al Rodger (here's his website full of climate graphs):

Al writes: "I scaled the data off the graph & produced a graph of rate of mass loss which shows the year October 2011-September 2012 has smashed through the 500 Gt/year barrier with a value of 570 Gt/year."

Here's the paper's abstract: