MOTION-CONTROLLED MIDNIGHT SUN

Midnight Sun | Iceland from SCIENTIFANTASTIC on Vimeo.

I suppose we'll tire of motion-controlled time-lapse videos one of these days. But not yet. 

WAS THIS YEAR'S ARCTIC SEA ICE THE LOWEST EVER?

Ice ponds atop the melting Arctic Ocean. As ice melts, liquid water collects in depressions on the surface, deepening them to form melt ponds. These freshwater ponds are separated from the salty sea below until the ice breaks. Credit: NASA photograph by Kathryn Hansen.

  
As autumn approaches, the National Snow and Ice Data Center (NSIDC) reports that Arctic sea ice is near or at its seasonal low.

So how did 2011 fare?

Well, the data are still being collected. But according to the NSIDC algorithm, this year's minimum is unlikely to surpass 2007's record low:

On September 10, Arctic sea ice extent was 4.34 million square kilometers (1.68 million square miles). This was 110,000 square kilometers (42,500 square miles) above the 2007 value on the same date. The record minimum Arctic sea ice extent, recorded in 2007, was 4.17* million square kilometers (1.61 million square miles).

Ice extent in 2011, along with daily ice extents for the previous three lowest extent years. Sea Ice Index data. About the data. Credit: NSIDC.

  
However a different algorithm used by the University of Bremen concludes this year beat out 2007 for the lowest sea ice extent ever recorded. Here's what NSIDC has to say about the finer resolution of the Bremen calculations:

The University of Bremen employ an algorithm that uses high resolution information from the JAXA AMSR-E sensor on the NASA Aqua satellite. This resolution allows small ice and open water features to be detected that are not observed by other products. This year the ice cover is more dispersed than 2007 with many of these small open water areas within the ice pack. While the University of Bremen and other data may show slightly different numbers, all of the data agree that Arctic sea ice is continuing its long-term decline. 

Sea ice concentration maps of the minimum on 17 Sept 2007 and of the first day of historic minimum on 8 Sept 2011. The 2011 sea ice minima could reduce further in the next days. Credit: University of Bremen (pdf).

  

In the image from Bremen above you can see the nature of the lowest ice extent appears differently in the two years�with 2007 presenting as a consolidated pack, and 2001 as a scattered one. As Bremen (pdf) points out, this year's record low is likely the lowest extent since the end of the last Ice Age:

The extent of the Arctic sea ice shows a pronounced yearly cycle, with about 15 million km2 in March and five million km2 in September. In 2007 however, it was only 4.267 million km2, the previous smallest value since start of satellite observations in 1972, and most probably since the last climate optimum about 8000 years ago. The current value is 27,000 km2 or 0.6% lower and could even be undercut in the next weeks.

Northwest Passage. Via.

 
In the shipping news, retreating sea ice opened the Northwest and Northeast passages simultaneously in 2011�following the first ever dual openings in 2008 and 2009.

Consequently this year the northern crossing was made in record time�only 8 days�by a tanker travelling from Houston to Thailand.

Sea ice extent of the years 2003 to 2011 with minima in September and maxima in March. Credit: University of Bremen (pdf).

  
The Bremen report sums up the impacts of years of dwindling ice cover:

The retreat of the summer sea ice since 1972 amounts to 50%. For algae and small animals living at the lower side of the ice, less and less living environment remains since they need a certain time to settle there. They are at the beginning of the food chain for fishes, mammals and also man.

Credit: Ansgar Walk via Wikimedia Commons.

ARCTIC TIDES

The Arctic Light from TSO Photography on Vimeo.

Another beauty from Terje S�rgjerd.

NEW RECORD ARCTIC MELT

(Polar bears investigate the USS Honolulu 280 miles from the North Pole. Credit: Chief Yeoman Alphonso Braggs, US-Navy.)

Tweet this!
Arctic sea ice volume just reached its lowest on record ever for early July. This according to data and modelling from the University of Washington Polar Science Center.

Sea ice is an important climate indicator. It's composed mostly of frozen seawater and forms at lower temperatures than freshwater�at or below -1.8 �C/28.8 �F.

Typically in the Arctic, sea ice ages and thickens from winter to winter. Most scientists agree that perennial ice cover in the Arctic dates back at least 700,000 years. Some calculate 4 million years.

These days it's thinning and disappearing. I wrote in February about how bad the 2011 winter Arctic sea ice was looking�and how poorly this boded for our current summer ice conditions.

(Narwhals tusking. Credit: Glenn Williams, NIST.)

In 2003 NASA predicted perennial ice could be gone by the end of the 21st century. Since then, the melting continues to accelerate faster than the models can keep up.

Here's what the Polar Science Center has to say about chasing after the superdynamic realities of sea ice in a warming world:

Sea ice volume... depends on both ice thickness and extent and therefore more directly tied to climate forcing than extent alone. However, Arctic sea ice volume cannot currently be observed continuously.  Observations from satellites, Navy submarines, moorings, and field measurements are all limited in space and time.  The assimilation of observations into numerical models currently provides one way of estimating sea ice volume changes on a continous basis. Volume estimates using age of sea ice as a proxy for ice thickness are another useful method (see here and here).  Comparisons of the model estimates of the ice thickness with observations help test our understanding of the processes represented in the model that are important for sea ice formation and melt.

(Credit: National Snow and Ice Data Center.)

The graph above shows the following sea ice data: 

• The 1970-200 average (solid gray line)
• The 2007 all time low (dotted line)
• The 2011 data, so far (blue line)

You can see how this year's sea ice extent dipped below the record-low 2007 extent a few days ago.

(Credit: National Snow and Ice Data Center.)

Here you can see how last month�June 2011�sea ice extent was reduced by 47 percent, nearly half, compared to its maximum in 1979. That's when we first began examining these things via the eyes of satellites.  

Arctic sea ice extent for June 2011 was 11.01 million square kilometers/4.25 million square miles. The magenta line shows the 1979 to 2000 median extent for that month. The black cross indicates the geographic North Pole.  

(Credit: Environment Canada.)  

As to which villains are driving this year's steroidal melt, Jeff Masters at WunderBlog explains masterfully (you can see what he's talking about in the weather map above):

The latest surface analysis from Environment Canada shows a 1039 mb high pressure system centered north of Alaska, which is bringing clear skies and plenty of ice-melting sunshine to the Arctic. The combined action of the clockwise flow of air around the high and counter-clockwise flow of air around a low pressure system near the western coast of Siberia is driving warm, southerly winds into the Arctic that is pushing ice away from the coast of Siberia, encouraging further melting. This pressure pattern, known as the Arctic Dipole, was dominant over the Arctic during June, leading to June having the 2nd lowest extent on record, and the record low extent observed at the beginning of July. The Arctic Dipole began emerging in the late 1990s, and was unknown before then; thus climate change is suspected as its primary cause. The Arctic Dipole has become increasingly common in the last six years, and has contributed significantly to the record retreat of Arctic sea ice.

(Walrus in the Chukchi Sea. Credit: Sarah Sonsthagen, US Geological Survey.)

HOW TO CROSS A FROZEN OCEAN

Ben Saunders - Living on Ice from Ben Saunders on Vimeo.

LIFE INSIDE THE ICE

(Seal tracks on sea ice. Photo by Jason Auch, courtesy Wikimedia Commons.)

There's a fascinating paper in PNAS examining the relationship between Arctic sea ice and the single-celled algae that live in sea ice.

These tiny players account for 57 percent of the primary productivity�that is, the business of making life from nonlife via photosynthesis�in springtime Arctic waters.

The authors turned the predictable question�How will dwindling Arctic sea ice affect ice-dwelling algae?�inside-out:

Here we ... ask instead whether organisms�in particular sea-ice algae�have evolved means to alter ice physical properties to their bene?t, mitigating impacts of climate change.

 

(Frazil or grease ice, an early stage in the formation of sea ice. Photo by Mila Zinkova, courtesy Wikimedia Commons.)

Some background: Although sea ice forms from seawater, it's composed largely of freshwater. That's because in the course of freezing most brine is expelled from the ice crystals�though some remains trapped in microscopic channels and pockets known as brine inclusions.

Amazingly, brine inclusions support tiny but rich ecosystems of  bacteria, viruses, unicellular algae, diatom chains, worms, and crustaceans�a near-frozen ecosystem inside a frozen world known as a sympagic environment (Greek syn: with; pagos: frost). 

We know a lot of lifeforms inhabit Arctic sea ice�and we hear a fair amount about the big guys, like seals, walruses, and polar bears. 

(Photo by Ansgar Walk, courtesy Wikimedia Commons.)

Yet sea ice is critically important at a more foundational level too:

• It provides a habitat for photosynthetic algae to overwinter during the dark months when the water column can't support phytoplankton growth
• It provides nursery grounds for invertebrates and fish
• During the spring melt, it releases its overwintering organisms into the surface waters to seed the algal blooms that power Arctic waters through summer and fall�until the next freeze-up

(The sympagic ecosystem. Credit: Christopher Krembs, Jody Deming, University of Washington, courtesy of NOAA.)  

To survive in brine that's at or even below the freezing point of seawater, Arctic algae secrete mucuslike glues that function as their antifreeze and antidessicants. Biologists call this goop extracellular polysaccharide substances, or EPS.

The authors wondered what effects EPS might have on sea ice formation or durability. 

To answer that, they examined natural sea ice and compared it with sea ice they grew in the laboratory�to some of which they added EPS from a culture of the sea-ice diatom, Melosira arctica, one of the Arctic's dominant diatoms. 

For controls, they grew lab ice with no added EPS. 

(Arctic ice diatoms, Melosira arctica, with ephytic diatoms [the spiky parts]. Image courtesy of Arctic Exploration 2002, Rolf Gradinger, NOAA/OER.) 

The findings, based on microscopic analysis (and my extreme simplification):

• Lab-grown ice with algal EPS was more porous than the control ice by as much as 15 percent
• Lab-grown ice with algal EPS had higher bulk salinities than the control ice by between 12 and 35 percent

Which means the EPS-endowed sea ice resembled and behaved more like natural sea ice than the EPS-free controls. The authors describe the significance:

EPS effects on ice and pore microstructure improve sea ice habitability, survivability, and potential for increased primary productivity, even as they may alter the persistence and biogeochemical imprint of sea ice on the surface ocean in a warming climate.

(Krill larvae feeding on sea-ice algae in Antarctic waters. Photo courtesy Wikimedia Commons.)

This has some broad�maybe really broad�implications in a warming climate:

Sea ice that retains more salt will also retain more of the dissolved constituents of the source water, from carbon dioxide and other greenhouse gases to iron and other nutrients essential to primary production. Their retention, alteration, and eventual release determine the biogeochemical imprint of sea ice on the surface ocean (and atmosphere). The reduction of ice permeability by EPS must also in?uence the role of sea ice as an inorganic carbon pump from atmosphere to underlying ocean, as well as its seeding and fertilization of surface waters during the melt season.

(Phytoplankton bloom in the Barents Sea. The bright blue colors are likely from coccolithophores, the green colors from diatoms. NASA image courtesy Norman Kuring, NASA Ocean Color Group.)

In other words, the power of the tiny briny world is potentially profound, rippling across the "barriers" between ice, ocean, and atmosphere.

Though whether or not algal EPS helps or hinders sea ice melting awaits further research. The authors conclude:

Although this study has provided clear evidence that EPS alter the growing sea-ice matrix, the impacts of EPS on the melting of ice remain to be documented. The mechanical strength of sea ice depends on salinity, with saltier ice, as generated from EPS-rich source waters, being weaker. The persistence of sea ice, however, and its rate of melt re?ect a complexity of factors, including that clogged pores and EPS-coated ice surfaces may retard the advection of warmer saline water and reduce melt rates. Such a potential positive feedback to ice persistence would be of considerable importance to primary production in the ice, its dependent ecosystem, and the ultimate fate of ice in a warming climate. Answering this question requires more investigation, but a potent biological mechanism worth exploring further for its alterations of the physical properties of sea ice has been identi?ed.

(Ursus maritimus. Photo courtesy the US Fish & Wildlife Service, via Wikimedia Commons.)

The paper:

Krembs, C., Eicken, H., & Deming, J. (2011). Exopolymer alteration of physical properties of sea ice and implications for ice habitability and biogeochemistry in a warmer Arctic Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1100701108

MYSTERY OF THE ICE WHALES

(The whale within the iceberg. 1884. By George R. Halm. From the New York Public Library Digital Gallery.)

Believe it or not, whales sometimes end up frozen in glaciers, some of which may then calve out with icebergs to float around the ocean for a spell. 

The illustration above, by New York artist George R. Halm (1850-1899), tells a visually compelling story�though the words to this tale have been forgotten, as best I can tell.

So what could the picture be about? Well, the engraving includes images of men at work on the sea. Maybe whalers.

Handwritten at the bottom of the print is the word "Whaling"�perhaps a catalogue notation from an early librarian.

The detail in the lower left might be an image of a sunken ship. Maybe a whale-wrecked ship. With nothing left afloat but the crow's nest? I'm not sure. Was there once a story of a wronged whale and a haunted iceberg on an intercept course with a few doomed sailors?

Moby Dick was published 33 years before George R. Halm's engraving�priming the public mind for tales of vengeful behemoths.



moby dick intro from Carys Banks on Vimeo.

Interestingly, in his description about the the blubber of sperm whales, Herman Melville included an eerie reference to ice seamen:

For the whale is indeed wrapt up in his blubber as in a real blanket or counterpane; or, still better, an Indian poncho slipt over his head, and skirting his extremity. It is by reason of this cosy blanketing of his body, that the whale is enabled to keep himself comfortable in all weathers, in all seas, times, and tides. What would become of a Greenland whale, say, in those shuddering, icy seas of the North, if unsupplied with his cosy surtout? True, other fish are found exceedingly brisk in those Hyperborean waters; but these, be it observed, are your cold-blooded, lungless fish, whose very bellies are refrigerators; creatures, that warm themselves under the lee of an iceberg, as a traveller in winter would bask before an inn fire; whereas, like man, the whale has lungs and warm blood. Freeze his blood, and he dies. How wonderful is it then�except after explanation�that this great monster, to whom corporeal warmth is as indispensable as it is to man; how wonderful that he should be found at home, immersed to his lips for life in those Arctic waters! where, when seamen fall overboard, they are sometimes found, months afterwards, perpendicularly frozen into the hearts of fields of ice, as a fly is found glued in amber.

For another ice whale story only slightly less mysterious, I found a 1959 paper in Nature, about the 1958 discovery of a whale entombed in a glacial moraine beyond which the glacier had retreated in Svalbard (also known as Spitzbergen), north of mainland Norway.

(The Isefiorden, Spitzbergen, Norway, c. 1890-1900. From the Library of Congress' Flickr photostream.)

Disappointingly, I can only read the abstract, since even with my exorbitantly expensive personal subscription to Nature I am not entitled to read back issues from 1959. (O, ?less policy.)

The abstract is tantalizing:

THE preservation of Pleistocene or Recent land mammals in the Siberian permafrost has long been known, but the literature does not appear to include mention of marine mammals preserved in ice. Particular interest, therefore, is attached to the discovery in 1958 of part of a whale carcass entombed in the ice-cored moraine of Sveabreen, Ekmanfjord, in Vestspitsbergen. The north-eastern lateral moraine of Sveabreen projects into the fjord about two miles beyond the ice-front, and the find was made by members of the Birmingham and Exeter Universities Spitsbergen Expedition near the seaward tip.

(Bowhead whale. Photo by Ansgar Walk, courtesy Wikimedia Commons.)

 What species of whale was it? Were they able to determine? 

There was a huge whaling and walrusing industry in Svalbard beginning in 1604�a piratical affair between British, Dutch, Danish, and French mercantile companies, who built forts to defend their commercial interests.

(Photo from the BBC.)

Their primary targets were bowhead whales�the real ice whales.

(The whale-oil factory of the Amsterdam Chamber of the Greenland Company on Amsterdam Island near Spitzbergen. 1639. Cornelis de Man.)

In 1996 a bowhead whale melted out from another Svalbard glacier, bringing with it a few juicy clues about its past... including a death date circa end of the Little Ice Age... perhaps from the time of the earliest commercial whalers.

Here's the abstract of the 1997 paper in Polar Research:

An 8 m long carcass of a bowhead whale (Balaena mysticetus) melted out from remnant glacier ice in the lateral moraine of the Jemelianovbreen glacier in August 1996. Folded and sheared sediment bands in the ice suggest that the whale was incorporated during an advance of the glacier. The whale's longitudinal axis was oriented parallel to the direction of the ice-flow, with the thinnest posterior part dipping upflow. The posterior section was best preserved with muscles and blubber, although the entire skin surface was strongly decomposed and only a thick fibrous surface was left of the blubber. The abdominal wall was holed, most likely by marine organisms, and partly filled with a compacted mixture of well-sorted gravelly beach sediments and fat. the whale seems to have been incorporated into the glacier together with glaciomarine sediments and carried by the flowing ice to an altitude of ca. 15 m. Jemelianovbreen is a tidewater glacier with two known surge-episodes. The first and most extensive of these occurred ca. 1900 AD and reached ca. 7 km outside the present coast-line. Radiocarbon dating of a fragment of a caudal vertebra yielded 345 � 40 ¹⁴C years BP (1535-1660 cal. AD), suggesting that the whale lived some time during the last part of the cold period known as the Little Ice Age.

(Antarctic toothfish, Dissostichus mawson, a Nototheniid. Photo by Paul Cziko, courtesy Wikimedia Commons.)

Whales aren't the only mysteries trapped in ice. A 1962 paper in the Polar Record recounted all kinds of entombed marine life found by early Antarctic explorers. The abstract:

In February 1902, members of Scott's Discovery expedition found the remains of a fish 18 in. long on the surface of the "pinnacled ice" near the ice front of the Ross Ice Shelf in McMurdo Sound. In 1903, a party under Wilson found three Nototheniid fishes, sponges, shells, and seaweeds among similar ice on the floating section of the Koettlitz Glacier. The fishes, which were up to 48 in. in length, were all headless. They resembled a specimen caught in a seal blow-hole near the Discovery winter quarters, whose head was bitten off by a seal before it could be landed, but whose body weighed 40 Ib. and was 46 in. long. This fish was a Notothenia, close to N. colbecki Boulenger. In 1911, a party under Taylor found another large headless fish, which may have been as much as 4 ft. long, embedded in the ice of the Lower Koettlitz Glacier some 5 miles from its seaward end, and among the pinnacled ice near the Dailey Islands the same party found corals, shells, sponges, patches of sediment, and about a dozen small fish. The ice in this region was so rich in sponges that it was difficult to get spicule-free ice for cooking.

(The pinnacled ice of McMurdo Sound, photographed by Reginald Skelton for the British National Antarctic Expedition�aka Scott's Discovery expedition�1901-1904. From the Royal Collection.)

A news story out of Greenland in 1985 aroused the mystery again, along with a new round of theorizing:

A dead whale frozen in an iceberg 13 feet above the surface of the frigid waters off south Greenland is mystifying scientists and curious residents of a tiny Greenland settlement. No one can figure out how the 59-foot sperm whale died or how it ended up in an icy grave high above the water drifting a few miles off the tiny settlement of Alluitsup. First came speculation the beast was a prehistoric creature buried for eons in the ice cap that makes up 85 percent of Greenland. But examination showed that the whale, the size of which indicates it was a male, was identical to contemporary sperm whales. And it emitted a rank smell, making fossilhood unlikely... Close inspection reveals the whale may have been the victim of a hunter`s harpoon. In its neck is a cylindrical hole 15 inches in diameter and three feet. But that does not explain how the beast came to rest in an icy grave bobbing 13 feet above the water. One theory is that it sprang into the air and landed unluckily on a large iceberg, perhaps stuck in a narrow crevice. Marine biologists in Greenland theorize the whale may have been attacked by killer whales, or, stranded in a shallow area, became disoriented and died. They believe the whale, weakened or dead, could have drifted over the submerged portion of an iceberg and become an involuntary hitchhiker when the iceberg separated and a submerged portion rose under the whale.

Cutting Room Floor: "Deep at Sea" from Tristan Bayer on Vimeo.

(The filmmaker describes: "This cut is made with unused footage that we shot in Dominica which would otherwise be left on the 'Cutting Room Floor.''')

The papers:

• D. L. Dineley and P. A. Garrett. Whale Remains in Glacier Ice. Nature. 183. 272 (1959). DOI: 10.1038/183272a0.
• Ida L�nne and Eva Fuglei. Carcass of a bowhead whale (Balaena mysticetus) found in the lateral moraine of the Jemelianovbreen glacier, eastern Svalbard. Polar Research. (1997). DOI: 10.1111/j.1751-8369.1997.tb00723.x.
• M. W. Holdgate. Faunal remains on the Ross Ice Shelf in McMurdo Sound. Polar Record (1962), 11: 40-42. Cambridge University Press. DOI: 10.1017/S0032247400052554.
  
  

RANDOM EXCERPT FROM "DEEP BLUE HOME:" SEA TURTLES IN THE ICE REALM

"It's not surprising to see a leatherback up here
on the edge of the ice, since this is one of the most traveled
of all vertebrate species, perpetually on the move along
jellyfish highways between the tropics and the high latitudes."

DEEP BLUE HOME
-Chapter 14
The Distant Geography of Water

Photo courtesy COML.org