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Antarctic sea ice saga

by Judith Curry

The drama and the irony of  the Antarctic expedition stuck in summertime sea ice.

The aim of the Spirit of Mawson expedition:
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The Antarctic remains one of the last great unexplored regions on Earth. In spite of a century of discovery, Antarctica and the Southern Ocean remain a unique place to monitor the health of our planet. The Australasian Antarctic Expedition – the AAE – will truly meld science and adventure, repeating century old measurements to discover and communicate the changes taking place in this remote and pristine environment.
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On Dec 30, expedition leader Chris Turney writes:
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It has been a sobering week. At the time we were initially caught by the sea ice, the Shokalskiy was just 2 to 4 nautical miles from open water. Now the sea ice distance has become even greater with the continued winds from the east, putting our nearest point of exit at some 16 nautical miles. 
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Meanwhile on board the Shokalskiy, morale remains good and the team are pulling together in an extraordinary way. Everyone is working hard to support one another. Take a look at the video diaries on the Intrepid Science YouTube Channel to see what we are up to. We are all keeping busy, with twice daily briefings outlining all the information we have to hand, alongside classes through the day (knot tying, languages, yoga, photography and many others) while the science programme has continued as best we can.
Photos can be found at:  Daily Mail
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The skeptics are having fun with this:
  • Marc Morano refers to this as ‘Clitanic
  • Josh has a cartoon
  • BishopHill sums it up with this statement: “the sheer majesty of the propaganda failure that Prof Turney and his colleagues have achieved.

JoNova has a comprehensive discussion, as does WUWT

Rescue efforts
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A summary of the recent rescue efforts:
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An Antarctic blizzard has halted an Australian icebreaker’s attempt to reach a Russian ship trapped for a week with 74 people onboard, rescuers said on Monday. A first rescue attempt by a Chinese icebreaker, the Snow Dragon, had to be halted because the ice was so thick.

Now another attempt, by the Aurora Australis, has been hampered by the weather. It has had to return to open waters about 18 nautical miles from the Akademik Shokalskiy because of poor visibility, the Australian Maritime Safety Authority (AMSA), which is co-ordinating the rescue, said.

The BBC provides the latest on the rescue mission:

A rescue mission for a ship trapped in ice in Antarctica is under threat as reports have emerged that one of the assisting vessels may itself be stuck.

Fifty-two passengers and four crew members were due to be evacuated by helicopter from China’s Xue Long ship as soon as conditions allowed.

However, the Xue Long has barely moved in a day and may be stuck in the ice.

The Aurora Australis, is now understood to be planning to carve through the dense thick pack to assist the Xue Long.

The initial plan had been for a helicopter from the Xue Long to carry people in groups of 15 up from the pack ice next to the Shokalskiy.

The airlifted passengers would then be transferred by a small boat, deployed from the Australian icebreaker, onto the Aurora Australis.

The expedition members would then have travelled to Australia’s Antarctic base at Casey some four days’ voyage away.

However, if the Chinese vessel is also stuck and the Australian vessel cannot help it reach clear water, there will be no airlift.

Under the initial plan, the remaining crew members would have stayed on board until another, more powerful US icebreaker arrived in up to 10 days’ time, the BBC’s Andrew Luck-Baker reports from on board the Akademik Shokalskiy

However, it may now be that all of those on board may have to wait for the US icebreaker, the Polar Star, he adds.

A tweet from sadmaninagame sums it up:  Just as I suspected. The escape plan is to form a line of ships from the Antarctic to South America, and walk home.

Andy Revkin points out that these diversions of resources for the rescue are disrupting serious Antarctic science.
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Stuck in their own experiment

FoxNews interviews expedition leader Chris Turney:

But Chris Turney, a professor of climate change at Australia’s University of New South Wales, said it was “silly” to suggest he and 73 others aboard the MV Akademic Shokalskiy were trapped in ice they’d sought to prove had melted. He remained adamant that sea ice is melting, even as the boat remained trapped in frozen seas.

“We’re stuck in our own experiment,” the Australasian Antarctic Expedition said in a statement. We came to Antarctica to study how one of the biggest icebergs in the world has altered the system by trapping ice. We … are now ourselves trapped by ice surrounding our ship.

“Sea ice is disappearing due to climate change, but here ice is building up,” the Australasian Antarctic Expedition said in a statement.

Turney later told FoxNews.com the ice surrounding his ship is old, rather than recently formed, and likely from a particular 75 mile-long  iceberg that broke apart three years ago. Climate change may have prompted the iceberg to shatter and float into the previously open sea where the mostly Australian team finds itself stranded, Turney said.

“The ice was swept across to this area by the South-East wind, its pieces creating a knock-on domino effect,” Turney told FoxNews.com, speaking from a tent erected on the stranded ship’s top deck. “We were just in the wrong place at the wrong time.”

From an article at SFGate:

Turney had told journalists that his expedition wanted to collect data that could be used to improve climate models. Too bad the folks who are supposed to predict climate decades into the future are guided by scientists who could not manage to avoid ice floes during a five-week trip.

Climate changers usually warn about Arctic ice, which has been receding over the last few decades, but rarely address the overall growth of ice in Antarctica.

“Sea ice is disappearing due to climate change, but here ice is building up,” the Australasian Antarctic Expedition acknowledges. It’s a conundrum. If warming is melting ice in the North, why isn’t it melting ice in the South?

Turney told the Australian Broadcasting Corp. that his goal is to excite the public about science. As for climate change, “in the scientific community, it’s remarkably solid.” And “self-evident.”

He pushes a framework of science being data-driven and free from politics. And yet it’s hard to escape the suspicion that whatever the icebound researchers experience, they will frame it as proof that climate change is unassailable.

Climate implications

In case you haven’t been following the Antarctic sea ice story, the Antarctic sea ice  extent shows a positive trend, with large positive anomalies the past two years.  A paper by Liu and Curry addressed this issue:  Accelerated warming of the Southern Ocean and its impact on the hydrological cycle and sea ice.   The punchline for why Antarctic sea ice extent has been increasing:

For the last half of the 20th Century, as the atmosphere warmed, the hydrological cycle accelerated and there was more precipitation in the Southern Ocean surrounding Antarctica.  This increased precipitation, mostly in the form of snow, stabilized the upper ocean and insulated it from the ocean heat below. This insulating effect reduced the amount of melting occurring below the sea ice. In addition, snow has a tendency to reflect atmospheric heat away from the sea ice, which reduced melting from above.

Jinlun Zhang published a recent paper in Journal of Climatology entitled Modeling the Impact of wind intensification on Antarctic sea ice volume, which is discussed in an article by Michael Lemonick.  The punchline:

Zhang argues that about 80 percent of the growth can be explained by changes in the prevailing winds around the frozen continent; the remaining 20 percent, he suspects, might be the result of changes in ocean circulation.

There are a number of contrasting points and asymmetries between Arctic and Antarctic sea ice.  Why is the Antarctic sea ice extent so high when the Arctic sea ice has been so low?  Well, natural variability combined with the fundamentally different geographies.

A paragraph from my text Thermodynamics of Atmospheres and Oceans:

At its maximum seasonal extent, sea ice covers approximately 8% of the surface area in the Southern Hemisphere and 5% in the Northern Hemisphere.  In the Southern Hemisphere, sea ice forms a seasonally-varying ring around the Antarctic Continent with relatively small meridional variations.  Most of the Antarctic sea ice is seasonal, with 80% of the ice disappearing by the end of the austral summer.  In the Northern Hemisphere, a perennial sea ice cover exists in the Arctic Ocean, which is essentially a landlocked ocean basin.  Strong meridional variations in the Arctic Ocean sea ice cover arise from the complex configuration of the Northern Hemisphere land masses and from variations in ocean currents.  In winter, the sea ice extends as far south as 45°N to the coast of Japan, while the warm Atlantic water flowing northward keeps the ocean ice free as far north as 80°N near Spitsbergen.

The Arctic ice is generally thicker than Antarctic ice, because most of the Antarctic  ice is first year ice.  The thickest most dangerous ice is icebergs calved from nearby glaciers.  The impact of sea ice on climate is through influencing surface albedo, influencing the exchange of heat between ocean and atmosphere (and the ocean surface temperature), and influencing the circulation patterns of both the atmosphere and ocean.  Hence there is a complex dance between the oceans, atmosphere and sea ice whereby their interactions both influence and are influenced by global climate change.

The predominant focus has been on Arctic sea ice, but the Antarctic sea ice is arguably equally interesting and important.

JC comments

While the stranded passengers seem to be partying like this is Gilligan’s Island and enjoying the adventure,  the rescue risk/cost is substantial. A post at WUWT reminds us of the ships that have sunk in Antarctic waters in the past decade.  As FoxNews reports:

Icebergs pose an even greater danger to the ship than the surface ice that now has the ship in its grip, because they can pierce the hull of a ship like the Akademic Shokalskiy, in a Titanic scenario. Lisa Martin, of the Australian Maritime Safety Authority, which is coordinating rescue attempts from their New South Wales headquarters told FoxNews.com icebergs have been seen in the area.

While science does not seem to be the predominant motive for this expedition, the expedition may serve to highlight the increasing extent of Antarctic sea ice, the importance of natural variability in influencing sea ice extent, and the role of weather processes in determining the variability of ice in any given year.  I don’t think this was part of any scientific objective for this expedition.

The expedition failure also highlights concerns about logistics of such expeditions, and why/how this happened in the first place.  I am familiar with the extensive efforts, planning, and superb logistics undertaken by the US National Science Foundation (NSF) for U.S. funded expeditions, somehow I don’t see this happening if this had been a U.S. expedition.  Perhaps since this expedition was more motivated by civic than scientific reasons, the same efforts were not undertaken.  But the influence of this expedition failure on canceling scientific research as vessels are diverted in rescue attempts has implications for international science and its coordination.

And finally, I return to the issue raised by BishopHill:  “the sheer majesty of the propaganda failure that Prof Turney and his colleagues have achieved.”  This angle seems to be downplayed in the media reports, but it seems fairly obvious that CAGW PR was a major part of this expedition.

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