Sea Ice Thickness

What this makes clear is that the decline in ice thickness has been ongoing since 1980. Prior work gave us only two points of reference between 1959 and 2000. This is a more detailed study from 1959 on and assures us that the ice loss has been ongoing after 1980 which represented a peak. This is a surprise.

This means that I can ignore the pre 1980 data and focus on the decline since.

The measured thickness has declined by 53% which easily explains the sharp drop in areal extent also. It has all happened in twenty five or so years and is accelerating because the heat been absorbed has progressively less ice to work with. Also the process has not ended yet. Today’s ice I believe is the thinnest yet.

The real point that must be made is that this process has not ended or reversed.

This continues to be the one tangible bit of evidence that is indisputable about so called global warming. It also suggests that we could be on the verge of quite warm Arctic summers. Real vegetation in the Arctic?

This also allows us to fine tune our calculations and we find that multiyear ice will likely be gone in about a decade at most. We are now in the visible melt out phase of this Arctic clearing event. A good wind system like 2007 will also accelerate it just as a strong cooling event will reverse the process.

Which means that the open seas will take a bit longer but not much longer and expect another surprise in the decline of areal extent.

Satellites And Submarines Give The Skinny On Sea Ice Thickness

http://www.terradaily.com/reports/Satellites_And_Submarines_Give_The_Skinny_On_Sea_Ice_Thickness_999.html

http://www.terradaily.com/images/change-sea-ice-thickness-1988-2008-bg.jpg

Patterns of average winter ice thickness from February to March show thicker ice in 1988 (left), compared to thinner ice averaged from 2003-2008 (right). Thickness information in Antarctica is limited to an irregular polygon shape that outlines the area where declassified submarine data are available. Credit: Ronald Kwok/NASA

by Kathryn Hansen

Pasadena CA (SPX) Sep 10, 2009

This summer, a group of scientists and students - as well as a Canadian senator, a writer, and a filmmaker - set out from Resolute Bay, Canada, on the icebreaker Louis S. St-Laurent. They were headed through the Northwest Passage, but instead of opening shipping lanes in the ice, they had gathered to open up new lines of thinking on Arctic science.

Among the participants in the shipboard workshop (hosted by Fisheries and Oceans Canada) was Ron Kwok of NASA's Jet propulsion Laboratory in Pasadena, Calif. Kwok has long provided checkups on the health of Arctic sea ice - the frozen sea water floating within the Arctic Ocean basin. He also knows that some important clues about ice changes can't be seen from a ship.

Extending the Record

While satellites provide accurate and expansive coverage of ice in the Arctic Ocean, the records are relatively new. Satellites have only monitored sea ice extent since 1973. NASA's Ice, Cloud, and land Elevation Satellite (ICESat) has been on the task since 2003, allowing researchers to estimate ice thickness as well.

To extend the record, Kwok and Drew Rothrock of the University of Washington, Seattle, recently combined the high spatial coverage from satellites with a longer record from Cold War submarines to piece together a history of ice thickness that spans close to 50 years.

Analysis of the new record shows that since a peak in 1980, sea ice thickness has declined 53 percent. "It's an astonishing number," Kwok said. The study, published online August 6 in Geophysical Research Letters, shows that the current thinning of Arctic sea ice has actually been going on for quite some time.

"A fantastic change is happening on Earth - it's truly one of the biggest changes in environmental conditions on Earth since the end of the ice age," said Tom Wagner, cryosphere program manager at NASA Headquarters. "It's not an easy thing to observe, let alone predict, what might happen next."

Sea ice influences the Arctic's local weather, climate, and ecosystems. It also affects global climate. As sea ice melts, there is less white surface area to reflect sunlight into space. Sunlight is instead absorbed by the ocean and land, raising the overall temperature and fueling further melting. Ice loss puts a damper on the Arctic air conditioner, disrupting global atmospheric and ocean circulation.

To better identify what these changes mean for the future, scientists need a long-term look at past ice behavior. Each year, Arctic ice undergoes changes brought about by the seasons, melting in the summer warmth and refreezing in the cold, dark winter.

A single extreme melt or freeze season may be the result of any number of seasonal factors, from storminess to the Arctic Oscillation (variations in atmospheric circulation over the polar regions that occur on time scales from weeks to decades).

But climate is not the same as weather. Climate fluctuates subtly over decades and centuries, while weather changes from day to day and by greater extremes.

"We need to understand the long-term trends, rather than the short-term trends that could be easily biased by short-term changes," Kwok said. "Long-term trends are more reliable indicators of how sea ice is changing with the global and regional climate."

That's why a long-term series of data was necessary. "Even decadal changes can be cyclical, but this decline for more than three decades does not appear to be cyclical," Rothrock said.

All the Ice Counts

Arctic sea ice records have become increasingly comprehensive since the latter half of the 20th century, with records of sea ice anomalies viewed from satellites, ships, and ice charts collected by various countries. Most of that record, kept in the United States by the National Snow and Ice Data Center at the University of Colorado, Boulder, describes the areal extent of sea ice.

But a complete picture of sea ice requires an additional, vertical measurement: thickness. Melting affects more than just ice area; it can also impact ice above and below the waterline. By combining thickness and extent measurements, scientists can better understand how the Arctic ice cover is changing.

Kwok and other researchers used ICESat's Geoscience Laser Altimeter System to estimate the height of sea ice above the ocean surface. Knowing the height, scientists can estimate how much ice is below the surface.

Buoyancy causes a fraction (about 10 percent) of sea ice to stick out above the sea surface. By knowing the density of the ice and applying "Archimedes' Principle" - an object immersed in a fluid is buoyed by a force equal to the weight of the fluid displaced by the object - and accounting for the accumulation of snowfall, the total thickness of the ice can be calculated.

In 2008, Kwok and colleagues used ICESat to produce an ice thickness map over the entire Arctic basin. Then in July 2009, Kwok and colleagues reported that multiyear 'permanent' ice in the Arctic Ocean has thinned by more than 40 percent since 2004. For the first time, thin seasonal ice has overtaken thick older ice as the dominant type.

Submarines and Satellites

To put the recent decline in context, Kwok and Rothrock examined the recent five-year record from ICESat in the context of the longer history of ice thickness observed by U.S. Navy submarines.

During the Cold War, the submarines collected upward-looking sonar profiles, for navigation and defense, and converted the information into an estimate of ice thickness. Scientists also gathered profiles during a five-year collaboration between the Navy and academic researchers called the Scientific Ice Expeditions, or "SCICEX," of which Rothrock was a participant. In total, declassified submarine data span nearly five decades-from 1958 to 2000-and cover a study area of more than 1 million square miles, or close to 40 percent of the Arctic Ocean.

Kwok and Rothrock compared the submarine data with the newer ICESat data from the same study area and spanning 2003 to 2007. The combined record shows that ice thickness in winter of 1980 averaged 3.64 meters. By the end of 2007, the average was 1.89 meters.

"The dramatic decrease in multiyear ice coverage is quite remarkable and explains to a large degree the decrease in total ice area and volume," Kwok said.

Rothrock, who has worked extensively with the submarine data, agrees. "This paper shows one of the most compelling signals of global warming with one of the greatest and fastest regional environmental impacts."

Ice Through Human Eyes

While it is critical to keep monitoring the Arctic with satellites and aircraft, Kwok believes there is also a benefit in physically standing in a place and seeing the changes through human eyes-particularly for non-scientists, who do not keep a close watch on sea ice.

The August 2009 workshop in the Northwest Passage brought together an eclectic group of politicians, artists, and scientists to see the ice firsthand. The challenge was to see the problem of a changing Arctic environment from a variety of scientific, political, cultural and human perspectives and to discuss the future of collaborative study in the Arctic. The science of sea ice has implications for people's livelihoods, for long-established ecosystems, and for opening a new part of the world to exploration and exploitation.
The workshop participants now take their experiences and observations back to warmer climates, where there is sometimes less urgency about ice retreat.

"Sea ice is about more than just hard science; it's a geopolitical and human issue," Kwok noted. "There is a big personal impact when you get away from your desk and see it in person."

Late August Sea Ice

Winds have abruptly cleared a lot of the western ice away and sharply reduced the areal extent of the sea ice. I do not know now it stacks up against the past two years but the lateness of the winds has surely allowed for more areal extent than normally expected.

We also get a sense that the thickness is continuing to decline strongly. Therefore if no reversal is experienced or even a substantial slowing of the thickness loss, we are on the way to sea ice dramatics in a couple of years.

A combination of essentially one season ice throughout and a return of 2007 wind conditions would possibly even clear the ice pack out of the Arctic.

This year those same lack of winds kept the Northwest Passage blocked off and have also kept the Northeast Passage closed. Both needed just a bit of luck to be open though. The swift recent clearing of the Bering sea shows that.

One thing that I would like to point out is that the ice is pulling way back from the Russian coast pretty consistently, so while a clear passage is not conveniently available, it is possible for smaller prepared vessels to approach the edge of the ice almost everywhere and to be in position to force their way through the area blocking the Northeast Passage with a slight break in the winds.

Again the map is at:

http://www.socc.ca/cms/en/socc/seaIce/currentSeaIce.aspx

And the graphic chart pretty well tells us that the three year ice is now effectively gone. From now on our sea ice will consist of one and two year ice rotating through the Arctic Gyre. This should grind down to a region of consistent two year ice with a generally smaller region of coverage that will be stable.

We may not get total removal of the ice in any given year but we will also not have any three year ice.

It may also turn out that minimum ice cover looks largely like this. Strong winds may concentrate the ice in a smaller area but do little to the annual coverage produced by the winter freeze.

Arctic is Melting even in Winter

This item says a lot about what is happening with the sea ice and informs us that there is more to the story.

The sea ice is actually collapsing in the same way spring breakup hits and suddenly cleans out the river.

We had forgotten that an accelerating melt will tend to create a layer of warmer fresh water on the surface of the denser salt water. This layer appears to be a lot more influential than we supposed and likely carries over the warming impact of previous seasons in some way.

I do not think that mixing is encouraged with the ice protecting most of the fresh water layer from the winds.

What this does suggest is that the actual sea ice removal that we are experiencing may have to go to completion in order for the fresh water layer to be completely remixed. From there on we would see the winter sea ice been easily built up again because of the lack of much fresh water that could insulate the forming ice from the normal salt water.

These may be useful thoughts worth modeling to see were they take us.

We certainly are watching the sea ice go, while possible ignoring supposedly colder weather.

Arctic is melting even in winter

The polar icecap is retreating and thinning at a record rate

Jonathan Leake

The Arctic icecap is now shrinking at record rates in the winter as well as summer, adding to evidence of disastrous melting near the North Pole, according to research by British scientists.

They have found that the widely reported summer shrinkage, which this year resulted in the opening of the Northwest Passage, is continuing in the winter months with the thickness of sea ice decreasing by a record 19% last winter.

Usually the Arctic icecap recedes in summer and then grows back in winter. These findings suggest the period in which the ice renews itself has become much shorter.

Dr Katharine Giles, who led the study and is based at the Centre for Polar Observation and Modelling at University College London (UCL), said the thickness of Arctic sea ice had shown a slow downward trend during the previous five winters but then accelerated.

She said: “After the summer 2007 record melting, the thickness of the winter ice also nose-dived. What is concerning is that sea ice is not just receding but it is also thinning.”

The cause of the thinning is, however, potentially even more alarming. Giles found that the winter air temperatures in 2007 were cold enough that they could not have been the cause.

This suggests some other, longer-term change, such as a rise in water temperature or a change in ocean circulation that has brought warmer water under the ice.

If confirmed, this could mean that the Arctic is likely to melt much faster than had been thought. Some researchers say that the summer icecap could vanish within a decade.

The research, reported in Geophysical Research Letters, showed that last winter the average thickness of sea ice over the whole Arctic was 26cm (10%) less than the average thickness of the previous five winters.

However, sea ice in the western Arctic lost about 49cm of thickness. This region saw the Northwest Passage become ice-free and open to shipping for the first time in 30 years during the summer of 2007.

The UCL researchers used satellites to measure sea-ice thickness from 2002 to 2008. Winter sea ice in the Arctic is about 8ft thick on average.

The team is the first to measure ice thickness throughout the winter, from October to March, over more than half of the Arctic, using the European Space Agency’s Envisat satellite.

Giles’s findings confirm the more detailed work of Peter Wadhams, professor of ocean physics at Cambridge University, who has undertaken six voyages under the icecap in Royal Navy nuclear submarines since 1976 and has gathered data from six more voyages.

The vessels use an upward-looking echo-sounder to measure the thickness of sea ice above the vessel. The data gathered can then be compared with previous years to find changes in thickness.

Wadhams published his first paper in 1990, showing that the Arctic ice had grown 15% thinner between 1976 and 1987.

In March 2007 he went under the Arctic again in HMS Tireless and found that the winter ice had been thinning even more quickly; it was now 50% of the 1976 thickness.

“This enormous ice retreat in the last two summers is the culmination of a thinning process that has been going on for decades, and now the ice is just collapsing,” Wadhams said.

The scale of the ice loss has also been shown by other satellite-based observations that are used to measure the area of the Arctic icecap as it grows and shrinks with the seasons.

In winter it normally reaches about 5.8m square miles before receding to about 2.7m square miles in summer.

In 2007, however, the sun shone for many more days than normal, raising water temperatures to 4.3C above the average. By September the Arctic icecap had lost an extra 1.1m square miles, equivalent to more than 12 times the area of Britain.

That reduced the area of summer ice to 1.6m square miles, 43% smaller than it was in 1979, when satellite observations began.

At the heart of the melting in the Arctic is a simple piece of science. Ice is white, so most of the sunlight hitting it is reflected back into space. When it melts, however, it leaves open ocean, which, being darker, absorbs light and so gets warmer. This helps to melt more ice. It also makes it harder for ice to form again in winter. The process accelerates until there is no more ice to melt.

Wadhams said: “This is one of the most serious problems the world has ever faced.”

2008 Sea Ice Volume

I almost missed reading this item, but took a double take when I understood that they are addressing volume.

They have even stated the year 2013 as a possibility. This is very early confirmation that the gross ice volume is even lower than 2007 which I thought probable in my earlier postings.

My readers can expect all the experts to pile on to this date now that it is clear that the Northern sea ice is in collapse unless a drastic cold spell hits soon. After all, once the decline is completely discernable it is a surety that it is in the end game already and you are no longer waiting for decades.

Again, a minimal mathematical analysis as I have described in earlier posts shows that a persistent loss of ice will terminate as a collapse.

If we have a reasonable winter and an early start to the spring, we can expect even more dramatics next year.

For the past two seasons, the Northwest Passage was very navigatable provided an ice breaker was on standby to provide assistance if necessary. That alone is hard to believe. This year, friendly winds opened the Northeast Passage.

They do make the comment that the Arctic could become ice free. I do not think that will be totally possible because the rotation of the gyre will retain some ice every season, but that ice will be destroyed in the coming season as the rotation takes the ice away from the colder zones.

Whether an over the pole route ever becomes feasible seems unlikely because of this.

Arctic Sea Ice Shrinks to Record Low

Experts Say Thickness, Overall Amount of Ice at Troubling Low

By CLAYTON SANDELL

Oct. 3, 2008

Sea ice at the top of the planet has apparently reached the lowest volume ever recorded, say scientists, with conditions declining toward a point where the Arctic Ocean may soon be completely ice-free in summertime.

The Advanced Microwave Scanning Radiometer (AMSR-E), a high-resolution passive microwave Instrument on NASA's Aqua satellite shows the state of Arctic sea ice on September 10 in this image released September 16, 2008.

While final numbers are still coming in, experts at the National Snow and Ice Data Center in Boulder, Colo., believe the overall volume of Arctic sea ice -- determined by measuring the area covered and the thickness of ice -- has reached the lowest level since satellite measurements began in 1979.

"We're pretty confident this is a record low," said Walt Meier, a research scientist at the center.

Meier and his colleagues monitor the health of Arctic sea ice by looking at many factors, including the extent of sea ice -- how much can be seen from space -- and the thickness of ice hidden underwater, to calculate the overall volume.

"It's like a building and a Hollywood set of a building," Meier said. "You take a picture of both of those, and they look exactly the same. But if you go and peer around the corner, one is thick, and one isn't. And so, what we're seeing now is that ice, that used to be like a building, is kind of becoming more like a Hollywood movie set."

Experts say that much of the thicker Arctic sea ice -- which takes years to develop but is more robust -- has been replaced by younger, "first year" ice that is thinner and more prone to melting. In March 2008, data showed that a record 73 percent of the sea ice in the Arctic was made up of the thinner ice.

"The arctic is fundamentally changing in character, and we're going to continue this downward trend and eventually reach the point when we have entire sea-ice melts during the summertime," Meier said.

Experts warn that, without Arctic sea ice, there will be major, if unknown, consequences far beyond the top of the planet. The region acts as a giant air conditioner for the planet, helping stabilize global temperature and weather patterns in lower latitudes, like the jet stream.

"You're changing the equation," Meier said. "And that's going to potentially change traditional wind patterns, ocean currents, and storm tracks. And which way the wind blows has tremendous impact in certain areas, particularly on where it rains and when it rains."

Less sea ice also exposes darker water, which absorbs more energy from the sun. That, in turn, melts even more ice.

2007 broke the record for the lowest extent of sea ice, and 2008 came in second. The third-lowest year on record is 2005, part of a dramatic downward trend that has lasted three decades and doesn't appear to be slowing.

Going forward, experts say, there may be some cooler years when the sea ice may not melt as much. But the long-term trend toward warmer temperatures makes a recovery unlikely.

"We don't see it turning around," Meier said.

He believes that the Arctic could be ice-free in summertime by around 2030 or 2040, but he says more pessimistic estimates predict that could happen as soon as 2013.

"Five years ago, if you'd gone to a conference of scientists and said, 'by 2013 the Arctic sea ice in summertime is going to be gone,' you might have been laughed out of the room," he said.

"No one is laughing now."

Consensus Emerging on 2012

The scientific community is slowly waking up to the reality that this current collapse of long term sea ice, unless reversed and that is also no small trick now, is going to be complete as early as five years or by 2012. It took them a year from my own postings last year, but then it was reasonable to see what happened this year. What happened is that there was no significant reversal.

We may now be about to embark on a decadal strong chilling of the northern hemisphere but that is the minimum requirement to reverse what is going on. If not and with only a normal climate as of the past twenty years, we can expect to see the majority of the long term ice to be gone by 2012.

Meanwhile, this year as of a few days ago, both the Northwest Passage and the Northeast Passage opened up for navigation for the first time ever. I am pleased to see that the Northeast Passage opened. This was a normal year in terms of winds and the like and I had despaired of this passage ever been opened. In fact the map as of Sunday showed the Northeast Passage cleared back from land by huge distances and taking the presence of a major island whose name I have not checked to partially present a risky choke point if the winds were to shift.

http://www.socc.ca/seaice/seaice_current_e.cfm

This could mean that we are entering an era in which it will become normal for both passages to open up for a month or so. This fact has not been lost on ship owners who are contemplating a short direct route between the Atlantic and the Pacific for the first time.

Some of the more enthusiastic are calling for an ice free Arctic. I do not see that at all. I expect to see winter ice driven into packs that survive the summer and then migrate and get broken up the next summer. What we have lost is stable areas of accumulating sea ice that become very thick and steel like.

Actual navigation to the area of the North Pole will continue to be an adventure while the two passages can become busy and successful ocean routes.

While the areal extent is still likely slightly more than last year, it is distributed more normally this year and I have little reason to think that the loss of gross perennial ice is not continuing.

In the meantime we continue to get opining over the fate of the Greenland ice cap. My answer to that is nothing much. It did not disappear during the Bronze Age which was warmer for two thousand years, although that may also reflect the persistence of extensive remnants of the Laurentide ice sheet in the Arctic. If that is in fact the case, then perhaps we need to worry.

However, it looks more stable than that and the most we need fear is a modest retreat of the glaciers which we are in fact seeing. And again, the only way that the sea level is going to rise is if we see an abrupt collapse of a major part of the Greenland ice cap. We are nowhere near that.

This winter promises to be major test of competing ideas about global temperatures and the next five years will determine a lot about the relationship to sunspot activity. We will need to revisit this theme, but in the meantime we can enjoy the last days of the arctic summer.

Arctic ice may melt completely within ten years.

Tags: arctic ice, sea level

There are worrying reports that the Arctic sea ice is melting at a faster rate than last year, despite the colder weather. Information from the US National Snow and Ice Data Center (NSIDC) shows that the year began with ice covering a larger area than at the beginning of 2007. However by the beginning of summer the ice had diminished to the same levels as June last year – breaking the records for sea ice loss. The ice is melting easily as it is so thin and scientists are now predicting that the Arctic seas may be ice-free during the summer within five to ten years.

“We had a bit more ice in the winter, although we were still way below the long-term average,” said Julienne Stroeve from NSIDC in Boulder, Colorado. “So we had a partial recovery. But the real issue is that most of the pack ice has become really thin, and if we have a regular summer now, it can just melt away”.

Despite NASA’s reports in March, that the area covered by sea ice had increased slightly from 2007, most of the ice is thin, formed during the previous winter. It is more fragile than the thicker, less saline floes that have been around for several years.A few years ago, scientists were predicting that the Arctic ice would have melted in the summer by about 2080. Then computer models started projecting earlier dates, around 2030 to 2050. In the summer of 2007 the Arctic sea ice reduced to the lowest amount ever recorded; 4.2 million sq km from 7.8 million sq km in 1980. By the end of last year, a research group had predicted the ice melting entirely as early as 2013.

“I think we're going to beat last year's record melt, though I'd love to be wrong,” said Dr Stroeve. “If we do, then I don't think 2013 is far off any more. If what we think is going to happen does happen, then it'll be within a decade anyway.”

Despite this eminent loss off ice being environmentally catastrophic, countries surrounding the Arctic are seizing up the economic opportunities that melting ice could expose. Canada and Russia are exploring sovereignty claims over tracts of Arctic seafloor, while President George Bush has recently encouraged more oil exploration in US waters, possibly with intent to extend the exploration to reserves off the Alaskan coast.

In their rush to maximize the situation economically, countries are not reflecting enough upon the climatic problems this will cause. Greenland has already lost ice into the ocean, contributing to the gradual rise in sea levels. The Arctic ice cap could increase sea levels globally by about seven metres if it all melted. Natural climatic cycles such as the Arctic Oscillation play a role in year-to-year variations in ice cover. Many scientists feel that the ice is now so thin there is little hope of preventing the melting cycle.

“If the ice were as thick as it was in the 1970s, last year's conditions would have brought a dip in cover, but nothing exceptional. But now it's so thin that you would have to have 0an exceptional sequence of cold winters and cold summers in order for it to rebuild,” said Dr Ian Willis, from the Scott Polar Research Institute in Cambridge. This does not bode well for the future of the Arctic ice.

For the first time in human history, the North Pole can be circumnavigated

Melting ice opens up North-west and North-east passages simultaneously. Scientists warn Arctic icecap is entering a 'death spiral'

By Geoffrey Lean, Environment Editor

Sunday, 31 August 2008

Open water now stretches all the way round the Arctic, making it possible for the first time in human history to circumnavigate the North Pole, The Independent on Sunday can reveal. New satellite images, taken only two days ago, show that melting ice last week opened up both the fabled North-west and North-east passages, in the most important geographical landmark to date to signal the unexpectedly rapid progress of global warming.

Last night Professor Mark Serreze, a sea ice specialist at the official US National Snow and Ice Data Center (NSIDC), hailed the publication of the images – on an obscure website by scientists at the University of Bremen, Germany – as "a historic event", and said that it provided further evidence that the Arctic icecap may now have entered a "death spiral". Some scientists predict that it could vanish altogether in summer within five years, a process that would, in itself, greatly accelerate.

But Sarah Palin, John McCain's new running mate, holds that the scientific consensus that global warming is melting Arctic ice is unreliable.

The opening of the passages – eagerly awaited by shipping companies who hope to cut thousands of miles off their routes by sailing round the north of Canada and Russia – is only the greatest of a host of ominous signs this month of a gathering crisis in the Arctic. Early last week the NSDIC warned that, over the next few weeks, the total extent of sea ice in the Arctic may shrink to below the record low reached last year – itself a massive 200,000 square miles less than the previous worst year, 2005.

Four weeks ago, tourists had to be evacuated from Baffin Island's Auyuittuq National Park because of flooding from thawing glaciers. Auyuittuq means "land that never melts".

Two weeks later, in an unprecedented sighting, nine stranded polar bears were seen off Alaska trying to swim 400 miles north to the retreating icecap edge. Ten days ago massive cracking was reported in the Petermann glacier in the far north of Greenland, an area apparently previously unaffected by global warming.

But it is the simultaneous opening – for the first time in at least 125,000 years – of the North-west passage around Canada and the North-east passage around Russia that promises to deliver much the greatest shock. Until recently both had been blocked by ice since the beginning of the last Ice Age.

In 2005, the North-east passage opened, while the western one remained closed, and last year their positions were reversed. But the images, gathered by Nasa using microwave sensors that penetrate clouds, show that the North-west passage opened last weekend and that the last blockage on the north- eastern one – a tongue of ice stretching down to Russia across Siberia's Laptev Sea – dissolved a few days later.

"The passages are open," said Professor Serreze, though he cautioned that official bodies would be reluctant to confirm this for fear of lawsuits if ships encountered ice after being encouraged to enter them. "It's a historic event. We are going to see this more and more as the years go by."

Shipping companies are already getting ready to exploit the new routes. The Bremen-based Beluga Group says it will send the first ship through the North-east passage – cutting 4,000 nautical miles off the voyage from Germany to Japan – next year. And Canada's Prime Minister, Stephen Harper, last week announced that all foreign ships entering the North-west passage should report to his government – a move bound to be resisted by the US, which regards it as an international waterway.

But scientists say that such disputes will soon become irrelevant if the ice continues to melt at present rates, making it possible to sail right across the North Pole. They have long regarded the disappearance of the icecap as inevitable as global warming takes hold, though until recently it was not expected until around 2070.

Many scientists now predict that the Arctic ocean will be ice-free in summer by 2030 – and a landmark study this year by Professor Wieslaw Maslowski at the Naval Postgraduate School in Monterey, California, concluded that there will be no ice between mid-July and mid-September as early as 2013.

The tipping point, experts believe, was the record loss of ice last year, reaching a level not expected to occur until 2050. Sceptics then dismissed the unprecedented melting as a freak event, and it was indeed made worse by wind currents and other natural weather patterns.

Conditions were better this year – it has been cooler, particularly last winter – and for a while it looked as if the ice loss would not be so bad. But this month the melting accelerated. Last week it shrank to below the 2005 level and the European Space Agency said: "A new record low could be reached in a matter of weeks."

Four weeks ago, a seven-year study at the University of Alberta reported that – besides shrinking in area – the thickness of the ice had dropped by half in just six years. It suggested that the region had "transitioned into a different climatic state where completely ice-free summers would soon become normal".

The process feeds on itself. As white ice is replaced by sea, the dark surface absorbs more heat, warming the ocean and melting more ice.

Arctic Calm

My favorite sea ice maps came up again after a three week absence. The winds have not done what they did last year and the sea ice is more broadly distributed this year. Therefore, it looks like any movement in the Northwest Passage is problematic this year. There is plenty of ice at various points that are usually clear by now. It is not tight packed but it is certainly a navigation hazard. It will take good luck this year to move anything large although small vessels may have no problem.

More interestingly only a negligible amount of the sea ice is showing one hundred percent coverage. That means that all that ice has also warmed up to ambient ranges for ice and little retains the steel like cold of winter that large blocks might be expected to do. I see no evidence that the annual loss of net ice mass has abated at all. The downward spiral is continuing. We unfortunately do not have a reliable proxy for ice mass but breaking the trend line now will need a very dramatic increase in the thickness of winter ice with a cool summer that retains a lot of that ice. In short we need a volcano to blow up.

In the meantime, I see little evidence that the discharge of atmospheric heat that took place between 2005 and 2007 is been replenished very fast if at all. The sunspot crowd would certainly argue against any replenishment whatsoever. In fact it is reported a couple of months back that global temperatures dropped three quarters of a degree. Whatever that meant, it has certainly silenced a lot of the run away global warming crowd.

What is becoming more evident to me is that the Earth’s heat engine is operating on far longer cycles than anyone gives it credit for. The reason for that conjecture is the measurable lag between the heating spell of the nineties and the heat discharge event of 2005 to 2007. Certainly the long warm spell has been followed by a protracted warming of the Arctic. This could be simply the result of a transfer mechanism that is not overly robust except in extremis.

Without question our atmosphere is very good at correcting local heat disturbances through mechanisms such as hurricanes. We should have anticipated a long period of low hurricane activity after the blowout of 2005. That was the historic record. And it all shows us that the resolution of our climate models is still hopeless.

In any event, we did not have a very warm summer. I wonder if the winter will be as surprising as last year’s.

The Arctic has had almost a hundred years free from major volcanic activity. The last such event was Novarupta/Katmai, in 1912 in Alaska. It was during this time that the Peace River area of Alberta was opened up to settlers and I have it on good report that the winters were unusually long and awful. The point is that there has been no forced cooling on the Arctic since. So perhaps it is not surprising that we now have enough surplus heat in the Arctic to maintain pressure on the sea ice every year.

As my readers are aware, I think that there is ample indication that the primary cooling mechanism for the Arctic outside of the normal seasonal cycle is the occasional injection of volcanic gas and dust directly into the polar zone. We certainly have a convincing culprit standing by.


In the meantime this news story is waxing somewhat more enthusiastic than I can justify with the areal maps of the fifteenth. Here is hoping that a nifty algorithm is at work and this is not simply journalistic license. Otherwise it is a good update on current coverage and we have plenty of eyeballs this year.

U.S. scientists sound alarm over Arctic ice as Harper poised for visit

Randy Boswell , Canwest News Service

Published: Monday, August 25, 2008

With an election-primed Stephen Harper poised to touch down Tuesday in Inuvik to begin a three-day visit to northern Canada, scientists tracking the ongoing Arctic meltdown are sounding new warnings about the state of the polar environment in an era of evidently rapid climate change.

The latest satellite analysis of this summer's sea-ice retreat, released Monday by the U.S. National Snow and Ice Data Center, showed a decline close to matching last year's record-setting thaw, and experts at the Colorado-based centre noted that key Arctic shipping routes have now opened in both the Canadian Arctic archipelago and in Russia's northern waters.

"Sea ice extent is declining at a fairly brisk and steady pace," the NSIDC said, reporting a total retreat to about 5.5 million square kilometres with up to three weeks of melting left to go.

Sea ice extent is declining at a fairly brisk and steady pace, the U.S. National Snow and Ice Data Center has warned.

Last year's retreat reached an all-time low of about 4.3 million square kilometres by mid-September, a melt that has stoked unprecedented international interest in Arctic shipping, tourism and oil and gas development.

"Amundsen's Northwest Passage is now navigable," the centre said, referring to the southerly route near the Canadian mainland first traversed by Norwegian explorer Roald Amundsen in 1906. "The wider, deeper Northwest Passage through Parry Channel may also open in a matter of days. The Northern Sea Route along the Eurasian coast is clear."

That news follows a series of reports in recent days highlighting the impact of rising temperatures across the world's northern latitudes - a newly discovered crack threatening a Greenland glacier; eroding shorelines in communities across the Canadian Arctic; and polar bears swimming in dangerously open waters of the Chukchi Sea north of Alaska, far from the safe harbour of any land or ice floe.

"There were some years when some bears may have had to swim as far as 100 miles," Steven Amstrup, the senior polar bear scientist with the United States Geological Survey in Alaska, told the New York Times this week. "Now the ice is much farther offshore, more consistently and for longer. So the possibility of long distances between land and sea ice is much greater."

Meanwhile, a U.S. study published Sunday in the British journal Nature Geoscience suggests thawing permafrost in polar regions will unlock up to 60 per cent more carbon dioxide than previously believed, potentially amplifying the greenhouse effect already widely blamed for the current Arctic warming.

Andrew Freedman and Sea Ice

Those tracking this summer’s sea ice melt can see that it is the retreat on the eastern edge is well ahead of past seasons, while the western edge is showing little change as yet. This is hardly surprising considering the massive retreat of last year.

This past winter created a thicker than expected first year ice, but the melting taking place appears to also have been faster this April. In short, I see nothing stopping the removal of most of last years sea ice this summer. Then if the winds rise, we will catch another sharp reduction in the remaining sea ice this August. The scientists are quite right to quote short odds on this event.

I observe also that there will be a number of cruise ships standing by to run the Northwest Passage. That will still need a cooperative wind at the best, but we certainly could have done it last year. I wonder if there will be any brave merchant ships making the attempt? I suspect it will not be permitted yet.

We continue to get froth over the polar bears, primarily driven by the need of environmentalists for a salable cause. The bears can essentially hibernate a full five months as they must do in southern Hudson’s Bay. At this moment, even that is still covered with ice, although I am pretty sure it is pretty rotten now. Anywhere further north they are still feeding and will be largely retreating to land now as the ice continues to fail. Their hibernation period is more like three months. Also the observation that the bears are getting slightly smaller is a strong indicator of overpopulation problems, since the population has sharply expanded over the past forty years.

We need to actually declare the Blue fin Tuna as endangered since it is in decline thanks to aggressive over fishing. Oh well!

Andrew Freedman: Arctic Sea Ice May Set Record Low

The Interior Department's decision last week to list the polar bear as a "threatened" species under the Endangered Species Act (ESA) may soon be seen as either a prescient move, or possibly even as too little too late, if scientists' ominous predictions for this summer's Arctic sea ice melt and for future seasons prove correct. A number of predictions have been issued in the past several months, all indicating that 2008 has at least a decent chance of beating out 2007 for the title of the greatest summer sea ice loss on record.

In fact, some experts have concluded that the North Pole itself may be covered by water, rather than ice, during the peak of the annual melt season at the end of the summer, and that the Northwest Passage could be ice-free for a time as well.

The recent predictions offer an unsettling picture of the astonishing rate of environmental changes that have been taking place in the far north. Sea ice loss also puts the pace of climate change policymaking into perspective, since there is a stark disparity between the rapidly melting Arctic and the slow pace of Washington policymakers.

An examination of new information about Arctic sea ice dynamics illustrates this point. According to recent analyses of Arctic sea ice, the ice that is entering the 2008 summer melt season is thinner and younger than the ice that melted like butter on a frying pan last summer. With sea ice, the opposite of the Hollywood ideal of young and thin is desirable, since new and thin ice melts more rapidly than thicker, older ice.

Late last month, University of Colorado at Boulder researchers found that only two percent of Arctic sea ice was older than normal (defined in that study as the period between 1982 to 2007), while 63 percent was younger than average. Consistent with this assessment, National Snow and Ice Data Center (NSIDC) researchers reported in April that first-year ice covered a whopping 72 percent of the Arctic Basin, including the area around the North Pole. The NSIDC noted that Arctic sea ice had recovered in terms of geographic extent from last summer's record melt, but that last summer's decline was so large that there was precious little older ice left over to build up during the winter.

Recent atmospheric conditions have also contributed to the Arctic sea ice's young and thin problem, including a positive phase of the Arctic Oscillation in which pressure patterns steer storms farther north, bringing stronger surface westerly winds in the North Atlantic and warmer and wetter than normal conditions to the Arctic and northern Europe. Such winds helped to flush older ice out of the region this winter, leaving a large expanse of younger and thinner ice to enter the 2008 melt season. Last summer, unusually sunny weather during portions of the summer season contributed to the record melt.

Although it remains to be seen whether atmospheric and ocean conditions will combine to create another record sea ice melt this year, most predictions indicate that there is a high likelihood that this year's melt season will at least result in well below average Arctic sea ice extent (average here refers to the 1979-2000 period).

"Even if more first-year ice survives than normal, the September minimum extent this year will likely be extremely low," the NSIDC stated on April 7.

The University of Colorado's sea ice forecast indicated that there is a three-in-five chance that the 2007 record low for Arctic sea ice extent will be exceeded this year due to the combination of warming temperatures and the preponderance of younger, thinner ice. And the NSIDC has declared that it is "quite possible" that the North Pole will be ice free during this melt season.

According to a study published in February in Geophysical Research Letters, computer model predictions show a 50 percent chance that the Northern Sea Route and the Northwest Passage will be "nearly ice free" in September of 2008. The study indicated that sea ice loss this year is likely to progress more slowly than last year, and reach a low but not necessarily record-breaking minimum.

The NSIDC's May 5 sea ice news and analysis stated that only 30 percent of first-year ice typically survives the summer melt season, compared to a 75 percent survival rate for older ice. NSIDC scientists compared survival rates from past years with the 2008 April sea ice coverage and determined that in order to avoid breaking last year's record, more than 50 percent of this year's first-year ice would need to make it through the melt season. To put this into further perspective, only 13 percent of first-year ice survived last year's record melt.

Last year, sea ice melted to a record low that far exceeded 2005's record melt. In September of 2007 (September marks the end of the summer melt season), the sea ice cover was 23 percent below the 2005 level and 39 percent below the long-term average from 1979 to 2000.

The melt was so rapid last year that, according to Sheldon Drobot of the University of Colorado, during a two-week period the area of sea ice lost was equivalent to losing the area of Kansas every day.
Scientists blame human emissions of greenhouse gases for much of the Arctic sea ice decline, but natural factors are also at work in the region, such as variations in ocean currents and atmospheric cycles including the Arctic Oscillation. The interactions between natural cycles and human influences is a key research area during the current International Polar Year.

Whether or not sea ice cover hits a new record low this year, however, it's likely that the overall decline in sea ice will have negative repercussions on polar bears and other ice-dependent species. This is, of course, the reason for the Interior Department's begrudging polar bear listing last week. The Interior Department's press release stated as much when it said, "loss of sea ice threatens and will likely continue to threaten polar bear habitat. This loss of habitat puts polar bears at risk of becoming endangered in the foreseeable future, the standard established by the ESA for designating a threatened species."

However, assuming a strong relationship exists between sea ice loss and species decline, after looking at the latest predictions and the recent Arctic sea ice data, I wonder how soon it will be before polar bears are pushed into the endangered category. Hopefully policymakers will catch up to the scientists, who are themselves struggling to stay abreast of the rapidly changing environment. According to NSIDC, one sea ice expert, Ron Lindsay of the University of Washington, has cautioned that "sea ice conditions are now changing so rapidly that predictions based on relationships developed from the past 50 years of data may no longer apply." In other words, we're now in uncharted territory.

Current Polar Sea Ice Maps 2008

Current Polar Sea Ice Maps 2008

One of my favorite sites is:

http://www.socc.ca/seaice/seaice_current_e.cfm

We get a map of current sea ice coverage and a second map showing the variation from the thirty year medium and is vastly more significant.

Last year we got a huge surprise when an unexpected wind system emerged and helped shift a lot of perennial ice out into the Atlantic and opened the Northwest Passage. We can reasonably conjecture that this was a release mechanism whereby surplus heat already built up in the higher latitudes as shown by unusually warm winters over the past five years, is suddenly disposed of. A result is the return this winter of rather cold conditions with plenty of snow.

After all this activity and speculation we come to the 2008 season which should help answer a few questions or prove that we are still clueless. Although we have had a very unusual winter, I see little reason to see that it was colder than the averages set before the turn of the century. That grants that the several years since have been warm and that was the source of the heat buildup that discharged last summer.

If that model holds up, then we should expect several years of heat recharge before we see another strong attack on the Artic sea ice.

This brings me to another issue. We know that the globe has been slowly warming since the onslaught of the little ice age whose cause has been attributed to the sunspot minimum and other non earthly causes. We know this because worldwide glaciers have been retreating for the past two hundred years.

The only way in which this is possible is for the atmosphere to get warmer. That does not necessarily mean hotter at surface so much as more heat is contained in the air mass itself. Presumably that also means a very slight increase in sea temperatures.

An increase in sea temperature is usually concentrated in the tropics and is discharged by increased hurricane activity. This system seems to have a thirty to forty year cycle by itself, and yes, we caught a peak with Katrina.

In the meantime the atmosphere is able to deliver extra heat onto the glaciers, or perhaps less than sufficient snow onto the glaciers. Of course it will take years to figure out which is correct. Myself, I hope enough snow landed on the Columbia snow field this winter to cause an advance.

The sea ice should breakup quickly this year and while it has the potential to be pushed back to the same line as last year, I am expecting a lot less and that a lot of this winter’s ice will get to be two year ice. We shall see.