Arctic Sea Ice

Decreasing Arctic albedo boosts global warming

A new paper in PNAS, called Observational determination of albedo caused by vanishing sea ice, reminds me of scientific work Peter Wadhams published a year and a half ago wherein he showed Arctic ice melt is 'like adding 20 years of CO2 emissions'. He based this assertion on calculations, as can be read in this BBC article from around that time.

This new paper by Pistone et al., however, is based on observations (as it says in the title) and similarly concludes that the "decrease in albedo is equivalent to roughly 25 percent of the average global warming currently occurring due to increased carbon dioxide levels"

I've taken this last quote from a livescience article. Here's more:

Warming from Arctic Sea Ice Melting
More Dramatic than Thought

Credit: Stefan Hendricks, Alfred Wegener Institute

Since as early as the 1960s, scientists have hypothesized that melting sea ice amplifies global warming by decreasing Arctic albedo. Researchers have since devised climate models to demonstrate this phenomenon but, until now, nobody had relied entirely on satellite data to confirm this effect through time. [See Stunning Photos of Earth's Vanishing Ice]

Now, scientists based at the University of California, San Diego have analyzed Arctic satellite data from 1979 to 2011, and have found that average Arctic albedo levels have decreased from 52 percent to 48 percent since 1979 — twice as much as previous studies based on models have suggested, the team reports today (Feb. 17) in the journal Proceedings of the National Academy of Sciences.

The amount of heat generated by this decrease in albedo is equivalent to roughly 25 percent of the average global warming currently occurring due to increased carbon dioxide levels, the team reports.

"Although more work is needed, a possible implication of this is that the amplifying feedback of Arctic sea ice retreat on global warming is larger than has been previously expected," study co-author Ian Eisenman told Live Science.

Previous models of Arctic albedo have suggested the reflectiveness of white cloud cover could potentially mitigate a portion of albedo loss due to melting ice; but these new observations show that cloud cover has had a negligible effect on overall Arctic reflectivity, the team says.

While Arctic sea ice will not likely return to 1979 values in the near future, the ice does change from year to year and might still experience some comeback this century, though the extent to which this might happen remains unclear, Eisenman said.

Read the rest here.

Here's another quote from the September 2012 BBC article mentioned above:

Looking for winter weirdness 2014

There has been some stuff in the past 2 months that could be linked to erratic jet stream behaviour - which in turn could be influenced by Arctic sea ice loss - like a series of storms battering Europe's Northwest, such as the St. Jude storm at the end of October, followed in December by Xaver, Dirk and Erich. Or a huge part of Siberia being so anomalously not-cold that it helped November being the warmest on record globally.

Now we have this:

This funny image (though what it depicts isn't funny for people who live in the US) from Greg Laden's blog shows how a portion of the polar vortex has broken off and moved over to the US, bringing ultra-low temperatures and snow to the Midwest and Northeast. Just two weeks ago there was a winter heat wave on the US East Coast, now it's extremely cold, and who knows what' swings will follow in weeks to come.

Like Andrew Freedman wrote over at Climate Central a couple of days ago:

The cause of the Arctic outbreak can be traced to northeastern Canada and Greenland, where an area of high pressure and relatively mild temperatures is set to block the eastward progression of weather systems, like an offensive lineman protecting the quarterback from the other team.

Here's an animation of that high pressure area (that incidentally also causes something of a cracking event in the Beaufort Sea, but more on that later):

Arctic warming -> extreme weather debate

Andrew Freedman outdid himself on Climate Central with an excellent overview of the scientific debate on the link between Arctic sea ice loss and a wavy jet stream causing weird and extreme weather. Coincidentally (?) there's an "extreme kink" in it right now that just caused the warmest December temperature ever measured at any site on the Alaskan Arctic Ocean shoreline region.

Freedman wrote the piece following the publication in Nature of a new paper - with Jennifer Francis as co-author - that claims that rapid Arctic warming has an influence on extreme summer weather events. The last couple of years a lot of pioneering research is being done in this area, which in my view is one of the most exciting and important scientific corners currently around. Which explains why more and more experts are keeping an eye on developments.

Study Adds to Arctic Warming, Extreme Weather Debate

A new study for the first time found links between the rapid loss of snow and sea ice cover in the Arctic and a recent spate of exceptional extreme heat events in North America, Europe, and Asia. The study adds to the evidence showing that the free-fall in summer sea ice extent and even sharper decline in spring snow cover in the Northern Hemisphere is reverberating throughout the atmosphere, making extreme events more likely to occur.

A giant panda was playing with ice cubes in Chengdu, China to cool off from the summer heat in August 2011. Credit: Zhongjun Liu

The study, published Sunday in the journal Nature Climate Change, is the first to find correlations between rapid Arctic warming and extreme summer weather events, since previous research had focused on the links between Arctic warming and fall and winter weather patterns.

While the study adds to the body of evidence pointing to the outsized role the Arctic is playing in shaping weather patterns, it won't end the debate within the scientific community over whether and how what is happening in the Far North could be having such far-reaching impacts.

There is virtually no controversy among climate scientists and meteorologists that massive changes have occurred in the Arctic environment during the past three decades, and that those changes are largely due to manmade greenhouse gas emissions.

Since the 1980s, Arctic sea ice extent has dropped at a rate of about 8 percent per decade during September, which is when the sea ice cover reaches its annual minimum. A record minimum was set in 2012. For a size comparison, consider that the area of summer sea ice lost since the 1980s would cover about 40 percent of the continental U.S., the study said.

Spring snow cover extent loss during June has dropped even more precipitously than sea ice cover, the study found, at a rate of about 18 percent per decade since 1979.

Arctic sea ice and jet stream changes

It's the most interesting and actual of all potential risks tied to Arctic sea ice loss and could turn out to be one of the surest signs of changing weather patterns. Which explains the growth in interest and research.

One of the latest scientific papers on this subject, Influence of Arctic sea ice on European summer precipitation, has been written by Dr. James Screen of the University of Exeter and published in Environmental Research Letters (via the Econnexus Blog).

The publication of the paper has been accompanied by a video, which has been put on YouTube by Peter Sinclair from the ClimateCrocks Blog, which makes it easier to embed (thank you, Peter):

 

New map on the block

Further down is a short update on the effects the SAC-2013 (Small Arctic Cyclone of 2013) has had so far, but first I want to draw some attention to a great new product that has recently come online, a sea ice concentration map with the highest resolution so far. When I started this blog the NSIDC used a 25 km grid, meaning that every pixel on their SIC map represented an area of 25 x 25 km, or 625 square kilometres, on the ground. IJIS had a 12.5 km grid and the University of Bremen even had and still has a 6.25 km grid.

Last year the GCOM-W1 (Shizuku) satellite was launched, with the AMSR2 microwave sensor aboard, and soon after that the Japanese space agency JAXA started to put out data. Alexander Beitsch from the University of Hamburg's KlimaCampus optimized the processing of this data, improving grid resolution to a stunning 3.125 km. This was part of his PhD in the framework of the IRO2 project that is being funded through the German Federal Ministry of Economics and Technology (BMWi). Sehr gut und danke schön!

There was just one problem with the sea ice concentration map that was produced, and that was that it was huge. 17 MB for just one image makes it difficult for us amateurs to play around with it. Luckily, the Arctic Sea Ice blog has some very smart bunnies on its member list, and it was Wipneus (well-known for his work on PIOMAS data) who managed to reduce the file size by ten times. For the time being he is putting those images on a separate Google Site. Thank you, Wipneus!

If this is real...

As usual, it's all about the if. Allow me to explain what this is about:

In the first Arctic Sea Ice update of the 2013 melting season that was posted a couple of days ago, I announced that a cyclone was forecasted to move over the Arctic Basin and stay there for a while. It's been there for a couple of days now as can be seen on this animation of Danish Meteorological Institute SLP images:

It's not particularly strong (especially not compared to GAC-2012), but it stays in the same spot for quite a while and so is bound to have some effect on the ice below. Now, according to the Naval Research Laboratory's ACNFS forecast model, this effect is quite pronounced. And to show you just how pronounced, here's their sea ice concentration animation from May 22nd, with a forecast up to June 6th:

Everything you want to know about the jet stream

...but are afraid to ask.

Skeptical Science contributor John Mason has outdone himself this time - which says a lot after his great pieces on Arctic methane and other subjects - by writing a comprehensive article about the jet stream, what it is, what it does and why that is important. Here's the introduction and table of contents, but I'd advise everyone to go read the whole thing over at Skeptical Science:

A Rough Guide to the Jet Stream:
what it is, how it works and how it is responding to enhanced Arctic warming

Posted on 22 May 2013 by John Mason

Barely a week goes by these days in the Northern Hemisphere without the jet stream being mentioned in the news, but rarely do such news items explain in detail what it is and why it is important. As a severe weather photographer this past 10+ years, an activity which requires successful DIY forecasting, I've had to develop an appreciation into what makes it tick. This post, then, is a start-from-scratch primer based on that knowledge plus some valuable assistance from academia into where the current research is heading. Because of its length and breadth of coverage, I've broken it up into bookmarked sections for easy reference: to come back here click on 'back to contents' in each instance.

Contents:

Earth's Troposphere - an introduction

Weather systems aloft - the Polar Front and the jet stream

Waves on the jet stream - upper ridges and troughs

Positive vorticity - a driver of severe weather - and the jet stream

Wind-shear - a driver of severe weather - and the jet stream

Jetstreak development along the jet stream - a driver of severe weather

Northern Hemisphere atmospheric circulation patterns: the Arctic and North Atlantic Oscillations

Climate change and the future: how will the jet steam and pressure-patterns respond?

Conclusion