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2011 Arctic Ice Nears Record Low source - ESA/University of Bremen

#1 User is offline   Bazmundo 

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Posted 14 September 2011 - 11:27

http://www.esa.int/e...SG_index_0.html

Posted ImagePosted Image
Envisat image of the Arctic
Arctic ice nears record low
14 September 2011
A new record low could soon be set for ice in the Arctic. The past five years have seen the lowest extent of sea ice since satellite measurements began in the 1970s.

Earth observing satellites make it possible to measure the amount of sea ice in inaccessible areas such as the Arctic.This year, the extent of Arctic sea ice is comparable to the record low set in 2007.

According to scientists at the University of Bremen in Germany, sea ice extent in early September has dropped below even that record.

Their maps are based on observations made by Japan’s microwave sensor on NASA’s Aqua satellite.

According to other teams, like the US National Snow and Ice Data Center, the 2007 record has not yet been reached but is very close.

International teams use various methods to measure sea ice based on different satellite observations, but the slight differences in their results are trivial.







Posted Image
Posted Image
This graph, based on data from the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) on NASA’s Aqua satellite, shows the Arctic sea ice extent for each year from 2003 to 2011. The Bremen sea-ice maps are generated as part of their involvement in the ESA-funded project Polar View.

Credits: University of Bremen

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#2 User is offline   ldavidcooke 

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Posted 14 September 2011 - 12:43

Hey Bazmundo,

This is as would be expected. Based on tbe conditions of the Arctic Oscillation to have the Polar vortex to actually reposition over the Canadian Martimes this past Winter it was clear that warmer winds and ocean currents would penetrate deep into the Arctic region. When we look at the positioning of the Bermuda/Azores High to have been over the Eastern Seaboard of the US for most of the Summer it would of been hard to miss that the flow of heat to the Poles wuld have been extreme this year.

When we add into the mix a general reduction of ITCZ cloud cover due to the extreme Northerly path of the Southerly Jet Stream this year, in association with the marked deviation of the Northern Jet Stream it was clear that the Northern Hemisphere was going to be in for a year of extremes. It looks like this Fall will likely follow suit.

To me the issue remains as to what could drive these changes, History/geology shows that 134ppm of CO2 is insufficient to drive these extremes. At best the condItions we are seeing map fairly well with the seasonal deviations seen 10kya as the Earth was emerging from the last ice age. It is likely that the only major difference between then and 7500 ya was the difference in vegetation cover. The advancement of the Forests into the former glacier valleys and plains speaks volumes wrt both the former CO2 uptake that has been lost, and the former soil moisture and aquafir capacities.

When we look at the former Forestation and the current we can see nearly 1/2 removed for farms, housing and transportation. Given that the former forests withheld nearly 90Gt more CO2 then today there is a major cause of change in the CO2 isotope balance. The C12-13 ratio change just goes to demonstrate the displacement of one system for another.

Now I am no tree hugger, I believe there should be a rich lumber industry; however, I do not condone the clear cutting and the invasion of land developers without the return of former housing or tailed out farms being returned to Forests. By the same token if you are going to cut down wide swaths of Oak, Elm, Chestnut and Ash, you should be replanting Oak, Elm, Chestnut and Ash. At worst case in wide flat regions subject to seasonal flooding we should be planting Willow, Persimmon, Birch..., not scrub pines and the planting rate should be 10 to 1, so that in 40 years at least one seedling makes it to maturity. (Note: Even with selective cutting strong healty specimens should be left standing otherwise we leave weak, disease prone, sources as the follow up generations. Hence, we can only reap what we sow. The largest and strongest every few acres must remain untouched within their drip line.)

In the past natural turnover may have run at about 10-15% for the worlds Forests, however the average Carbon sequestration was fairly flat, the biggest deviations surrounded volcanic or geologic activity resulting in either massive erosion or broad regional fires. After these passed the land would eventually return to forests, (reseeded by the mix of seeds already in the ground, including examples of the strongest specimens). We need to do a better job of returning our slums and fallow farm lands back to nature. Give them a couple generations to heal and then feel free to harvest the bounty of our efforts. Then replant and return them to nature; but, not as isolated blocks or strips; but, as whole regions which interlock with other regions.

As to homesteads, we need to abandon the idea of grass as a man made meadow in lumber regions. Sure surround your home with gardens whether flower or vegetable does not matter; but once you get 15 meters away from the house plant trees. As to homes, do we really need 2000sq feet under roof for two people? In my youth, yes I desired a 2300sq foot home, and yet I found plans for a 1384 sq foot house that offered every bit the level of comfort desired in a home... today 1140 sq ft is more then I and my bride can maintain..., maybe it is time for new types of home designs, that are flexible, that can accomodate changing needs, as our societies begin to reduce mobility requirements. (Information systems are going a long way to reducing the need to relocate.)

Sorry, Glyn, I did not intend to hijack this thread. However, we do need to start looking critically at the root cause of these changes. Simply changing the isotope ratios of Carbon do not explain it. That the anthropogenic Carbon load between 1800 and 1950 could have been met by nature suggests there had to be something at work in the 1800s for the CO2 levels to begin to rise. The most notable is the denuding of the land...
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#3 User is online   John Mason 

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Posted 14 September 2011 - 13:26

Neven's blog is a really interesting source of discussion on Arctic sea-ice:

http://neven1.typepad.com/

Well worth popping in for a read every now and then :)

Cheers - John
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#4 User is offline   Bazmundo 

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Posted 14 September 2011 - 14:33

Hey LDC,

No need to apologise, I think it's worth making a modest attempt to keep within the frame of reference of the thread (rather than 'go global'), but if I wanted a purely synoptic analysis I'd have posted somewhere other than Climate Chat. Posted Image

I just like the way these articles always come with caveats, ie: "since the advent of satellite technology" or "various methods to measure sea ice ... the slight differences in their results are trivial" - hmm, over such vast areas though?


Still, I'm glad they're doing it, and will always keep an eye on it.
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#5 User is offline   ldavidcooke 

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Posted 14 September 2011 - 15:29

Hey Baz,

Actually I am glad to see them applying caveats for a change. It would be very difficult to claim the current conditions are unique if they had not been measured before and yet we have evidence in the record of human history of similar past events. As to measurment methods in a sample size, it maybe trivial; yet' when applied to the entire Arctic Ocean it may not be. It is hard to deduce trivality when one of the factors in the equation is huge.
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#6 User is offline   Foxy2 

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Posted 28 November 2011 - 11:34

Did the Arctic sea ice ever reach that record low? Ice cover has recovered considerably in the last few weeks but still well below historic levels of course.

http://arctic.atmos....cent.arctic.png
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#7 User is offline   Andy Mayhew 

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Posted 28 November 2011 - 13:28

2nd lowest in the end

Arctic ice at 2nd lowest level since 1979
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#8 User is offline   ldavidcooke 

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Posted 28 November 2011 - 13:28

Hey Foxy,

There was a change in measurement techniques since 2007 so it may not be clear. As to 100% coverage in unmelted ocean ice it appears that 2011 had the least ice coverage since the Norse settlements in Greenland. As to the 85% density the ice coverage either tied or was slightly greater then the 2007 record.

Considering that the multi-year ice was much lower then in 2007, the melt was not as bad. However, synoptics were not as extreme as in 2007 either. So if you look at all the factors it was likely a wash.
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#9 User is offline   Foxy2 

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Posted 28 November 2011 - 13:55

As a scientist (of sorts) it annoys me when 'people' change the measuring technique. Did they have a period of overlap beyween old and new for the sake of consistency?
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#10 User is offline   ldavidcooke 

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Posted 28 November 2011 - 14:03

Hey Foxy,

Not really, just different agencies reporting ice melt differently. Once, all moved to satellite for remote measure all decided to adopt a universal measure. The end result 85% coverage became the rule, not unlike international martime storm designations. All part of globalization, kind of like the UN farmland report out today...
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