Cryosphere Today: 2010 Sea Ice Minimum 3,072,000 km2, area up only 2.6% from 2007
Veli Albert Kallio
"Researchers say projections of summer ice disappearing entirely within the next few years increasingly look wrong."
According to Cryosphere Today run by the University of Illinois, the 2010 sea ice area minimum was 3,072,000 km2 which was only 2.6% above the record sea ice area loss of 2007 which stood at 2,992,000 km2 (a bare 80,000 km2 or 2.6% above 2007 sea ice area minimum).
The National Snow and Ice Data Centre (NSIDC) at the University of Colorado has a different method of calculating the sea ice from Cryosphere Today at the University of Illinois. NSIDC reports 2010 sea ice minimum at 4.760,000 km2 whereas 2007 minimum was 4,130,000 km2. The NSIDC figure shows an increase of 15.3% or 630,000 km2 from 2007. At the same time, Pan Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) of Polar Science Center at the University of Washington recorded in 2010 a sustained loss in the Arctic sea ice volume progressing since 2007 with the sea ice loss maximum peaking at a new record of 4 standard deviations away from the mean value. This shows the summer 2010 was a rare event that should not occur more frequently than once in every 15,570 years if it were just a random event. Against this light the NSIDC figures appear particularly out of line and misleading.
NSIDC system is an old system that was set up before the era when the sea ice break up and resulting ice scattering of so-called rotten ice in the Arctic Ocean was far smaller due to a more resilient nature of multi-year or two year ice only some years ago. It was more stiff and had a good resistance against both melting and stresses from pounding waves.
When the ratio of open sea to ice covered sea has grown with ever greater amount of open water surfaces, the waves form more readily and they also do their damage on increasingly thinned ice. In addition, a localised vertical overturing of the ocean takes place as the wind push water against obstacles such as ice ridges or floes that deflect surface currents and waves pushed by wind that gets a far better grip on watery surface than smooth and melted, flat ice surfaces.
Consider this: when the Arctic Oceans sea ice melted and softened this summer, the waves broke the melted ice up and the broken ice then spread around by winds and sea currents. As the broken ice spread, what once was 85%-ice-covered-sea turned suddenly into 15%-ice-covered-sea as the broken pieces of ice floated to nearby open waters. NSIDC reported the melting and resulting break up as growth of sea ice area rather than loss of ice what it was in reality.
In NSIDC system the sea ice is growing until the ice floes on sea fall below 15% surface cover when it suddenly flops to zero. As the Arctic Ocean keeps thinning and increased open water surfaces generate larger waves we can only expect the softer and weaker sea ice to become more widely carried around and the overturning and mixing of sea water to become more intensive each year the sea ice thickness decreases and the more there are seasonal ice that contain some residue of salt in it in comparison to the older ice. The increased sea ice break up and scattering explains why NSIDC thinks the sea ice was 15.3% larger than in 2007 while Cryosphere Today saw it only 2.6% above 2007 ice area.
The sea ice area growth of 630,000 km2 from 2007 by NSIDC and the very meagre 80,000 km2 growth by Cryosphere Today (only 1/40th more ice than 2007) means that the ice area was essentially the same as back in 2007 but due to the more dynamic ocean and the weakened (more melted) sea ice the remaining 550,000 km2 with NSIDC indicate that the sea ice had become this much more distributed on the Arctic Ocean. If the sunlight receiving surface area is increased where the ice is spread, this creates enhanced conditions for the ice melting, just reverse when two packets of ice cream stay colder longer when they are packed closely together. Therefore, 2010 was a very bad year for sea ice melting and the statement suggested by NSIDC that there is a clear reversal of fortunes for the sea ice is entirely wrong.
After all the above Walt Meier's statement of optimism "But the 2040/2050 figure that's been quoted a lot - that's still on track. It could end up being wrong, of course, but the data we have don't disprove it." is not accounting above factors. NSIDC has recognised the problem of "rotten ice", the kind of spring-time "floating ice which has become honeycombed in the course of melting, and which is in an advanced state of disintegration". It is not right to call this as improved ice season and then suggest the ice area is growing and we may not probably see the sea ice vanishing until sometime between 2040-2050 and the people suggesting earlier dates for ice-free ocean are wrong. I suggested 2005 that the ice would be all gone by the end of decade due to the increasingly dynamic ocean taking over the melting processes.
During the first ten days of September it was notable that the adjacent areas to the North Pole were largely open with the sea ice covering only 15-60% of the ocean's surface. One area was between the North Pole and the Fram Straight and the other was a slighly smaller patch just behind the North Pole on the opposite direction from the North Pole towards the Bering Straight direction. According to Cryosphere Today this stopped only last 3-4 days ago when the freezing finally overtook the reverse processes that had been holding back the ice cover taking over the sea area there. This is important.
The importance of localised fluid dynamics on the phase boundary surfaces are very important and I quote the following that should explain the potential dangers of the increased thermal inertial transfers on the windier and more open ocean:
"Baikal, world's deepest lake (depth over 1,700 metres) freezes only in January although the severe winter frosts begin already in November. Over 400 metres deep Lake Superior in the United States has its mid parts open throughout the winter despite of the fact that January mean temperature is -20C and the worst winter frosts see the thermometer falling to -40C. This is a consequence of continuing strong winds and that the large masses of water beneath surface store large quantities of heat. Lake Superior is over three times of Gulf of Finland."
Jouko Alestalo: Jaalla on Voimaa (Ice Has Power) Tiede 2000 (Science 2000) 2/1988, page 29 column 1.
The Arctic Ocean beneath the North Pole is even deeper then the Lake Baikal and therefore its water has a greater capacity to store heat beneath. As the sea remains open and the sun starts to disappear the thermal gradients grow large between ice covered areas and where this area of ocean was ice-free. As per this, I believe that in current situation with high amont of wind and sea ice scattering producing a wide occurrence of the end-of-season "rotten ice", the PIOMAS and Cryosphere Today form a better basis for accounting the condition of the Arctic Ocean sea ice cover. They simply are are more suited to current situations with even predominanly more broaken, loose and rotten ice and waves around to spread this porridge of semi-melted ice around and to push it in low surface area densities the ice-free areas of ocean.
As an anecdotal evidence, the Arctic Ocean sea passages around both continents have been open facilitating the Arctic Ocean circumnavigation second season in succession and there are two teams attempting to manage the feat this year. So I am not going to see any argument to support that the sea ice situation would be "improving" when the terrestrial snow cover and permafrost melting have both also become earlier and more extensive melt seasons. In essence for the snow, the sea ice in the north is just a mere extension of land further to the north which rests on top of warm water tank.
I stick to my position that 2.6% increase in the area of ocean sea ice cover, 1/40th increase in the 2007 melt record is not enough to justify optimism and we need geoengineering and also to think about if we could prevent the increased vertical mixing of the Arctic Ocean that transfers heat due to themal intertia of water lying beneath the floating sea ice on just next to the North Pole. Any suggestions to stop the increase in winds, or to cover the widening leads between ice floes?
Kind regards,
Veli Albert
Date: Thu, 16 Sep 2010 07:39:13 +0100
Subject: [geo] NSIDC update
From: and...@andrewlockley.com
To: geoengi...@googlegroups.com
Original report http://nsidc.org/arcticseaicenews/
Ice floating on the Arctic Ocean melted unusually quickly this year, but did not shrink down to the record minimum area seen in 2007.
That is the preliminary finding of US scientists who say the summer minimum seems to have passed and the ice has entered its winter growth phase.
2010's summer Arctic ice minimum is the third smallest in the satellite era.
Researchers say projections of summer ice disappearing entirely within the next few years increasingly look wrong.
At its smallest extent, on 10 September, 4.76 million sq km (1.84 million sq miles) of Arctic Ocean was covered with ice - more than in 2007 and 2008, but less than in every other year since 1979.
Walt Meier, a researcher at the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado, where the data is collated, said ice had melted unusually fast.
"It was a short melt season - the period from the maximum to the minimum was shorter than we've had - but the ice was so thin that even so it melted away quickly," he told BBC News.
The last 12 months have been unusually warm globally - according to Nasa, the warmest in its 130-year record.
This is partly down to El Nino conditions in the Pacific Ocean, which have the effect of raising temperatures globally.
With those conditions changing into a cooler La Nina phase, Nasa says 2010 is "likely, but not certain" to be the warmest calendar year in its record.
Ice madeArctic ice is influenced by these global trends, but the size of the summer minimum also depends on local winds and currents.
Walruses have claimed parts of the Alaskan coastline as the sea ice they use was absentThis means ice can be concentrated in one region of the Arctic in one year, in another region the next.
This year, the relative absence of ice around Alaska has brought tens of thousands of Pacific walruses up onto land recently.
In terms of the longer-term picture, Dr Meier said the 2010 NSIDC figures tally with the idea of a gradual decline in summer Arctic ice cover.
But computer models projecting a disappearance very soon - 2013 was a date cited by one research group just a few years ago - seem to have been too extreme.
"The chances of a really early melt are increasingly unlikely as the years go by, and you'd need a couple of extreme years like 2007 in a row to reach that now," he said.
"But the 2040/2050 figure that's been quoted a lot - that's still on track. It could end up being wrong, of course, but the data we have don't disprove it."
NSIDC will release a full analysis of the 2010 data next month.
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