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.

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