Showing posts with label NSIDC. Show all posts
Showing posts with label NSIDC. Show all posts

Thursday, January 28, 2010

Rotten Sea Ice







This is further confirmation that the decades long sea ice decline is continuing.  Field observations describing the collapse of apparent multiyear ice sheets last fall supported that prognosis, but this will tighten it up.

This winter I believe we had much colder conditions so if there is to be a halt in the ice loss process, then this summer could show it.  That is assuming that the cause of the sea ice loss is significantly related to atmospheric conditions which I no longer subscribe to at all.

The little evidence we have supports the idea that a shift in the geometry of the circum polar current cause an increase of surface water flowing into the Arctic.  The cycle itself appears to be a full millennia long and is barely understood to exist by myself let alone anyone else.

In the meantime, this shows that even badly rotten ice can mask the actual losses.  In fact the press has constantly jumped on areal extent as a measure of total ice.  It is not.  The low of 2007 came about because of exceptional wind conditions.  The problem is that the ongoing disintegration of the sea ice has prevented much of a recovery taking place, but normal winds have allowed a more regular area to be covered.

We really have doubtful proxies for multiyear ice and it is problematic to just send out parties who can only assess a modest non representative sample.

The longer picture is of sea ice decline that has entered its last stages of collapse.  As I posted in 2007, I expect it to be glaringly obvious by 2012.  Certainly two more years anywhere like the past decade or so will have eliminated the multiyear ice pretty well completely.

This year promises to shed significant insight on the role of atmosphere on sea ice loss and perhaps strengthen the case for the global circum polar current paradigm.

It would be immeasurably ironic if it could be shown that atmospheric conditions are driven by the variation of sea conditions everywhere rather than blithely assuming that warm weather is the cause of declining ice.  That any apparent climate warming or change is mostly reflecting ocean changes we know little about.

 Ice Is 'Rotten' in the Beaufort Sea


ScienceDaily (Jan. 23, 2010) — Recent observations show that Beaufort Sea ice was not as it appeared in the summer of 2009. Sea ice cover serves as an indication of climate and has implications for marine and terrestrial ecosystems.

In early September 2009, satellite measurements implied that most of the ice in the Beaufort Sea either was thick ice that had been there for multiple years or was thick, first-year ice.

However, in situ observations made in September 2009 by Barber et al. show that much of the ice was in fact "rotten" ice -- ice that is thinner, heavily decayed, and structurally weak due to a uniform temperature throughout.

The authors suggest that satellite measurements were confused because both types of ice exhibit similar temperature and salinity profiles near their surfaces and a similar amount of open water between flows. The authors note that while an increase in summer minimum ice extent in the past 2 years could give the impression that Arctic ice is recovering, these new results show that multiyear ice in fact is still declining.

The results have implications for climate science and marine vessel transport in the Arctic.

The research appears in the journal Geophysical Research Letters.

Authors include David G. Barber, Ryan Galley, Matthew G. Asplin, Kerri-Ann Warner and Mukesh Gupta, Centre for Earth Observation Science, Faculty of Environment, Earth and Resources, University of Manitoba; Roger De Abreu, Canadian Ice Service, Environment Canada; Monika Pućko, Centre for Earth Observation Science, Faculty of Environment, Earth and Resources, University of Manitoba, and Freshwater Institute, Fisheries and Oceans; Simon Prinsenberg, Bedford Institute of Oceanography, Fisheries and Oceans; Stéphane Julien, Laurentian Region, Canadian Coast Guard.


Looking for Above Normal Temperatures? They are in the Arctic.
Submitted by Nick Sundt on Tue, 01/05/2010 - 20:58

Despite the cold air gripping much of the U.S., Europe and Asia, there is a very large area in the Northern Hemisphere where temperatures are well above normal: the Arctic.  The National Snow and Ice Data Center (NSIDC) reported yesterday (5 January 2010) that "average air temperatures over the Arctic Ocean were much higher than normal" during December 2009.  The extraordinary atmospheric conditions may be tied to climate change and  to the rapid decline in Arctic sea ice, as well as other factors that cause climate to vary.

In our 24 December 2009 post (Don't be Fooled by Weather's Ups and Downs: The Climate is Warming -- Rapidly ) we explained that the odds of below normal temperatures are lower than they used to be -- but such conditions can still occur.  More importantly, we emphasized that it is necessary to look at the big picture -- what is happening globally and over a longer period of time. 

December is a case in point.  While most of us experienced cold conditions and heard in the news only about similar conditions elsewhere in the Northern Hemisphere, vast and sparsely populated regions of the Arctic were well above normal.  In Extreme negative phase of the Arctic Oscillation yields a warm Arctic (5 January 2010), the NSIDC included the figure below that dramatically contrasts above normal conditions in the Arctic with below normal temperatures in populated areas to the south.


Caption (from NSIDC):  Map of air temperature anomalies for December 2009, at the 925 millibar level (roughly 1,000 meters [3,000 feet] above the surface) for the region north of 30 degrees N, shows warmer than usual temperatures over the Arctic Ocean and cooler than normal temperatures over central Eurasia, the United States and southwestern Canada. Areas in orange and red correspond to strong positive (warm) anomalies. Areas in blue and purple correspond to negative (cool) anomalies.
—Credit: National Snow and Ice Data Center courtesy NOAA/ESRL Physical Sciences Division


Beyond giving us a more complete picture of temperatures in the Northern Hemisphere, there are other reasons why Arctic conditions matter.  They not only affect the region's wildlife, ecosystems and communities, they have consequences that spill beyond the Arctic into the rest of the northern hemisphere -- and the entire planet.  We explore many of these connections inArctic Climate Feedbacks: Global Implications (PDF, 10.3MB).


Atmospheric pressure conditions in the Arctic have a lot to do with the temperature anomalies we are seeing.  The atmospheric pressure in the Arctic and its relationship to mid-latitude pressure can fluctuate in a pattern known as the Arctic Oscillation (AO) and its status is quantified as an index value.  When pressures are higher than normal in the Arctic and lower than normal in mid-latitudes, the AO is in its negative phase and the index is negative. The NSIDC reports that December's AO index value was -3.41, "the most negative value since at least 1950."

There is mounting evidence that atmospheric pressure patterns are changing in mid-latitudes and in the Arctic, that atmospheric circulation -- the large scale movement of air -- is changing, and that these changes are related to the rapid buildup of greenhouse gases in the atmosphere and to the associated decline in Arctic sea ice.  While some are using the recent frigid conditions in the U.S. and other regions to raise doubts about climate change science, a wider perspective instead reinforces the science and the need to seriously address climate change by reducing emissions and preparing for the impacts that are increasingly evident. 

For a recent discussion of the connection between Arctic climate change and weather changes in the northern hemisphere, see The Climate is Changing: The Arctic Dipole Emerges (Dr. Jeff Masters' WunderBlog, 11 December 2009).  According to Masters:

"The dramatic loss of Arctic sea ice in recent years has created a fundamental new change in the atmospheric circulation in the Northern Hemisphere that has sped up sea ice loss and is affecting fall and winter weather across most of the Northern Hemisphere, according to several recent studies. " [emphasis added]

Stu Ostro at the Weather Channel also is raising the alarm about the anomalous atmospheric patterns that are emerging and how those changes are reflected in unusual weather, including extreme events such as flooding rains.  As Ostro says in his posting, Off the Chain without a 'Cane (3 October 2009), climate change is altering the thickness (or depth) of different parts of the atmosphere, thereby "setting the table" for the unusual and sometimes extreme weather we are seeing.  Ostro says:

"What we've been observing over and over again in recent years is exceptionally strong ridges of high pressure, sometimes accompanied by strong, persistent "cutoff lows" (upper-level lows cut off from the main jet stream) to the south of the ridges. The upshot: many weather events/patterns in recent years which have been topsy-turvy and/or produced precipitation extremes and temperature anomalies."

Ostro concludes that "[w]hile it's important to consider what may happen in 50 or 100 or 200 years, and debate what should be done about that via H.R. 2454 or other measures, we need to get a grip on what's happening *now*." (Ostro's emphasis).

See also:
·                   How Did this Happen?  Blame the North Pole and the Equator.   Capital Weather Gang (Washington Post), 21 Dec 2009.
·                   Study Links Low Arctic Sea Ice Levels to Drier Winters in the U.S.  WWF Climate Blog (6 October 2009)
·                   Where on Earth is it Unusually Warm?  Greenland and the Arctic Ocean, which is Full of Rotten Ice.  Climate Progress, 6 January 2010.
·                   It's cold outside. What happened to global warming?  Christian Science Monitor, 7 January 2010).
·                   The U.S. and European Cold Blast: Blame the NAO. By Jeff Masters, Wunder Blog (7 Jan 2010)
·                   Winter Temperatures and the Arctic Oscillation.  NASA Earth Observatory, 9 January 2010.
·                   Feeling That Cold Wind? Here’s Why. New York Times, 9 January 2010.
·                   Frozen In France? Thank The Arctic Oscillation.  National Public Radio, 16 January 2010.
·                   It's Cold so There is No Global Warming.  Video "Climate Denial Crock of the Week" by Peter Sinclair, 16 January 2010.

Friday, October 9, 2009

Record Low for Multi Year Ice



As stated, during the last five years, the areal extent has clocked in with the five lowest readings. While this is all happening, it has also been getting thinner. In fact, this report tells us we lost 2.2 feet of thickness over the past four years or we are losing thickness at the rate of over five inches per year. The ice itself is spreading itself out thinner to sustain areal coverage thanks to cooperating winds.


Critically, the supply of ice over two years old is now at a record low of 19 % of total. On the good news side, we have a somewhat larger carry over into next year, but that may actually be illusionary.


The combination of conditions experienced in 2007 will rip this pack up terribly because it will be picking up where 2007 left off with a foot less ice. We have recovered no net ice mass since then and the prospects for such recovery must be low. It will take several years of ice growth before this changes. We have had the opposite for possibly two decades and all evidence until now has been for continuation. It barely slowed down this year though I have some reason to anticipate a really good ice forming year this year.


Of course the overdue sunspot cycle might just kick in and cloud cover will thus reduce and a resultant warm arctic summer will tear up the ice.


Otherwise, I simply do not see any other reason to think that conditions are anything other than stable and we will continue to lose five inches of ice per year. This really means that collapse is imminent over the next three years and should become more visible this coming year unless we form an extra several inches of ice this winter.


As posted earlier, we will stress test the cosmic ray hypothesis this winter and maybe it will shape up convincingly. I am not nearly so convinced because such a signature as the related sunspot cycle is not convincingly showing up in the Antarctic record I just posted on. Thus I am definitely in a wait and see position there.



Arctic sea ice extent remains low; 2009 sees third-lowest mark


At the end of the Arctic summer, more ice cover remained this year than during the previous record-setting low years of 2007 and 2008. However, sea ice has not recovered to previous levels. September sea ice extent was the third lowest since the start of satellite records in 1979, and the past five years have seen the five lowest ice extents in the satellite record.


NSIDC Director and Senior Scientist Mark Serreze said, "It's nice to see a little recovery over the past couple years, but there's no reason to think that we're headed back to conditions seen back in the 1970s. We still expect to see ice-free summers sometime in the next few decades."


The average ice extent over the month of September, a reference comparison for climate studies, was 5.36 million square kilometers (2.07 million square miles). This was 1.06 million square kilometers (409,000 square miles) greater than the record low for the month in 2007, and 690,000 square kilometers (266,000 square miles) greater than the second-lowest extent in 2008. However, ice extent was still 1.68 million square kilometers (649,000 square miles) below the 1979 to 2000 September average. Arctic sea ice is now declining at a rate of 11.2 percent per decade, relative to the 1979 to 2000 average.


Sea surface temperatures in the Arctic this season remained higher than normal, but slightly lower than the past two years, according to data from Mike Steele at the University of Washington in Seattle. The cooler conditions, which resulted largely from cloudy skies during late summer, slowed ice loss compared to the past two years. In addition, atmospheric patterns in August and September helped to spread out the ice pack, keeping extent higher.


The ice cover remained thin, leaving the ice cover vulnerable to melt in coming summers. Scientists use satellites to measure ice age, a proxy for ice thickness. This year, younger (less than one year old), thinner ice, which is more vulnerable to melt, accounted for 49 percent of the ice cover at the end of summer. Second-year ice made up 32 percent, compared to 21 percent in 2007 and 9 percent in 2008. Only 19 percent of the ice cover was over 2 years old, the least in the satellite record and far below the 1981–2000 average of 52 percent. Earlier this summer, NASA researcher Ron Kwok and colleagues from the University of Washington in Seattle published satellite data showing that ice thickness declined by 0.68 meters (2.2 feet) between 2004 and 2008.


NSIDC Scientist Walt Meier said, "We've preserved a fair amount of first-year ice and second-year ice after this summer compared to the past couple of years. If this ice remains in the Arctic through the winter, it will thicken, which gives some hope of stabilizing the ice cover over the next few years. However, the ice is still much younger and thinner than it was in the 1980s, leaving it vulnerable to melt during the summer."


Arctic sea ice follows an annual cycle of melting and refreezing, melting through the warm summer months and refreezing in the winter. Sea ice reflects sunlight, keeping the Arctic region cool and moderating global climate. While Arctic sea ice extent varies from year to year because of changeable atmospheric conditions, ice extent has shown a dramatic overall decline over the past thirty years. During this time, ice extent has declined at a rate of 11.2 percent per decade during September (relative to the 1979 to 2000 average), and about 3 percent per decade in the winter months.


NSIDC Lead Scientist Ted Scambos said, "A lot of people are going to look at that graph of ice extent and think that we've turned the corner on climate change. But the underlying conditions are still very worrisome."


To read the full press release and view figures, see


http://nsidc.org/news/press/20091005_minimumpr.html.

Wednesday, August 27, 2008

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.