Arctic Ice Discussion (the Refreeze)

[jethro]

I've core data back up my view as well as old transcripts. So my view is a proven, scientific one. I find it a little strange and almost dillusional the fact you are trying to disprove an already proven fact. It's like trying to tell people gravity doesn't exist and no matter how many times people tell you it's a proven fact you still feel obliged to argue the toss..

If the scientists involved with the ice core data have questions and issues with the accuracy of time and scale (which they do) I wonder why and how they can be presented as absolute proof. There is data available to prove every view point but you do have to read all the data, not stop at the point you find something which supports your view - that's confirmation bias at it's best. Having read all the data, it's wise to add the caveat of "as far as we know" because that's the best that is currently available. 'Proof' when applied to climate, and in particular past climate is something beyond the reach of current understanding, a Tardis would be handy but we haven't got one so we'll have to make do with vague ideas; vague ideas leave room for discussion which is a long way from arguing the toss.

[Radiating Dendrite]

I've core data back up my view as well as old transcripts. So my view is a proven, scientific one. I find it a little strange and almost dillusional the fact you are trying to disprove an already proven fact. It's like trying to tell people gravity doesn't exist and no matter how many times people tell you it's a proven fact you still feel obliged to argue the toss..

Earths history is 4.5 billion years!

I do not think that Ice Cores go back that far

[BornFromTheVoid]

I've core data back up my view as well as old transcripts. So my view is a proven, scientific one. I find it a little strange and almost dillusional the fact you are trying to disprove an already proven fact. It's like trying to tell people gravity doesn't exist and no matter how many times people tell you it's a proven fact you still feel obliged to argue the toss..

Ice core data can't be used to prove whether sea ice existed and in what quantities with a huge degree of certainty. The ice simply doesn't last long enough for those techniques to be effective.

It's certainly not backed up by observations, because we don't have accurate observations even before the 1950s.

There's little doubt the ice has receeded considerably more as recently as the Medieval warm period, and the 1940s saw dramatic reductions in a short period.

You can't really claim that observations before 1950 are inaccurate and then use "evidence" from that time to argue you point though.

If the scientists involved with the ice core data have questions and issues with the accuracy of time and scale (which they do) I wonder why and how they can be presented as absolute proof. There is data available to prove every view point but you do have to read all the data, not stop at the point you find something which supports your view - that's confirmation bias at it's best. Having read all the data, it's wise to add the caveat of "as far as we know" because that's the best that is currently available. 'Proof' when applied to climate, and in particular past climate is something beyond the reach of current understanding, a Tardis would be handy but we haven't got one so we'll have to make do with vague ideas; vague ideas leave room for discussion which is a long way from arguing the toss.

I agree with much of what you say. But it isn't just ice-core data used to estimate past temperatures, there are a myriad of other techniques that are used in conjunction with each other to work out past climates.

[Isolated Frost]

Very interesting debate. Arctic sea ice is still looking disappointing. As usual however, we are doing well in Greenland (E), but bad in Canada and woeful in Alaska/Siberia. Is there any synoptic changes in recent years that would back up a theory in which certain areas are losing much more than others, or maybe a change in ice flow.

Another question, what synoptic flow generally optimizes arctic ice area/extent, and which one least does? Thanks

[BornFromTheVoid]

Very interesting debate. Arctic sea ice is still looking disappointing. As usual however, we are doing well in Greenland (E), but bad in Canada and woeful in Alaska/Siberia. Is there any synoptic changes in recent years that would back up a theory in which certain areas are losing much more than others, or maybe a change in ice flow.

Another question, what synoptic flow generally optimizes arctic ice area/extent, and which one least does? Thanks

To me it seems as though the Arctic dipole may have been a large player in recent years. http://en.wikipedia...._dipole_anomaly

I've been doing some work on it for my dissertation this year and have made a dipole index going from present back to 1979. it shows quite a lot of variety from '79 to about 2005, then it turns very positive for the recent years.

Some of the effects of the strong positive dipole include a tendency for more ice to get shipped out through the Fram strait, which may account for some of the extra ice along eastern Greenland (or may not!).

What was interesting to note this year, was that the minimum this September was the joint earliest since 1995, and it was also only the 3rd negative dipole month since 2006, the first negative September since 2000 and the most negative September since 1992.

Also, the melt season of 2007 had the highest dipole in the series. The difference between the melt season of 1995 (+50 dipole) and 1996 (-20 dipole) is quite startling.

Of course it doesn't work for every month or every year, as there are plenty of other factors at play, and maybe it's even just a coincidence!

If it does have as much of an effect as it appears, we could easily see ice minimums near the early 00s with a negative summer dipole imo.

[jethro]

I agree with much of what you say. But it isn't just ice-core data used to estimate past temperatures, there are a myriad of other techniques that are used in conjunction with each other to work out past climates.

Agreed but all proxy measurements are subject to such large degrees of error that they cannot possibly support the assertions made by Scottyboy earlier.

[yido]

One thing I've noticed is that the Baltic between Finland and Estonia is already frozen according to NSIDC. This is incredibly early and certainly early when there hasn't been a great deal of cold as of yet. I take it this must be a mistake?

http://nsidc.org/data/seaice_index/images/daily_images/N_daily_extent_hires.png

[Richie V]

Easily the lowest ever (recent times) ice extent recorded for this time of year according to CT. A truley whopping -2.206 Km Sq anomaly.

I thaught it was a joke when I saw 4.8 ML KM coverage. Should we be not nerear 7.3 ML KM in mid october???

[Gray-Wolf]

http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png

Seems to be about to cross the 07' line ( according to NSIDC?) which doesn't bode well when you look at past years? If we have got a lot of ocean having to shed heat before ice can form then we have the atmospheric impact of this 'shedding' to look forward to. This would also have an impact on how thick the ice can form over the winter season?

Here's a thing;

http://www.arctic.io/2011/10/see-thick-ice-vanishing-in-the-beaufort-gyre

Shows you how the old ice Nursery has now turned into it's killing fields.....

[knocker]

Extreme Melting on Greenland Ice Sheet, Reports CCNY Team

Glacial Melt Cycle Could Become Self-Amplifying, Making it Difficult to Halt

The Greenland ice sheet can experience extreme melting even when temperatures don’t hit record highs, according to a new analysis by Dr. Marco Tedesco, assistant professor in the Department of Earth and Atmospheric Sciences at The City College of New York. His findings suggest that glaciers could undergo a self-amplifying cycle of melting and warming that would be difficult to halt.

“We are finding that even if you don’t have record-breaking highs, as long as warm temperatures persist you can get record-breaking melting because of positive feedback mechanisms,” said Professor Tedesco, who directs CCNY’s Cryospheric Processes Laboratory and also serves on CUNY Graduate Center doctoral faculty.

Professor Tedesco and his team collected data for the analysis this past summer during a four-week expedition to the Jakobshavn Isbræ glacier in western Greenland. Their arrival preceded the onset of the melt season.

Combining data gathered on the ground with microwave satellite recordings and the output from a model of the ice sheet, he and graduate student Patrick Alexander found a near-record loss of snow and ice this year. The extensive melting continued even without last year’s record highs.

http://www1.ccny.cuny.edu/advancement/news/Extreme-Melting-on-Greenland-Ice-Sheet.cfm

[karyo]

Good to see a sharp rise in sea ice extent over the last few days. Still close to the 2007 levels but the speed of increase is faster than the average.

http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png

Karyo

[Gray-Wolf]

We must be mindfull that , if we have a low start point ,rapid ice extent increases ( to reach 'normal' levels) are really what we ought to expect?. Every year since 07' we have had folk trying to peddle 'catchup re-freeze' as sign of the fabled 'recovery'.

Before we start getting 'clap happy' I'd check the average extent growth rate as averaged over 07', 08', 09',10' for Late oct /Early Nov? I think we'd find them more 'average' than we'd like to think?

As for Greenland, wait until the 'grounding line' of the major outlet glaciers hits the basin beyond!

[BornFromTheVoid]

The average daily increase for October from 79-10 is 73,221km2/day

The average October increase from 07-10 though is 99,720km2/day

As for November the 79-10 average is 61,190km2/day

And the 2007-2010 the average is 64,400km2/day

[karyo]

The average daily increase for October from 79-10 is 73,221km2/day

The average October increase from 07-10 though is 99,720km2/day

As for November the 79-10 average is 61,190km2/day

And the 2007-2010 the average is 64,400km2/day

How does the average daily increase for this October compare with the 07-10 average?

Today's update continues with the rapid refreeze: http://nsidc.org/dat..._timeseries.png

Karyo

Edited October 28, 2011 by karyo

[songster]

Indeed - a quite remarkable rise over the last couple of weeks which has brought it to the dizzying heights of still being the second worst on record for the time of year. Or maybe it's just about made it to third, it depends which site you're looking it. Important to keep an eye on the context, I feel >.<

[karyo]

Indeed - a quite remarkable rise over the last couple of weeks which has brought it to the dizzying heights of still being the second worst on record for the time of year. Or maybe it's just about made it to third, it depends which site you're looking it. Important to keep an eye on the context, I feel >.<

What did you expect to see? Cross the average after such a low point?

Karyo

[BornFromTheVoid]

How does the average daily increase for this October compare with the 07-10 average?

Today's update continues with the rapid refreeze: http://nsidc.org/dat..._timeseries.png

Karyo

The AMSR-E sensor has been down for the last month, so I don't have access to the daily data I'm afraid. Would be interesting to see how large those daily gains have been though.

[BornFromTheVoid]

Just looking at what 2007 averaged between the 17th and 31st, a pretty impressive 162,000km2/day.

Seen as we're a little ahead of that, I'd say we could be averaging close to 200,000km2/day the last week.

[BornFromTheVoid]

NH sea ice extent continuing to increase rapidly, which while a good sign, is rather unsurprising for the time of year and after the low minimum.

Around the end of October over all years since 1979, most years are grouped together, but 2007,2009 and 2010 (and now 2011) are in their own sub-group behind the rest with the closest to them being 2006 with about 300,000km2 more. They continues to bunch together with the rest further into November usually.

Here's the latest sea ice comparison with 2006 which is roughly where we should be aiming towards at this point in the year.

And for anyone who might be interested, I extended the dipole index back to 1948.

In doing so, I found that 4 of the strongest 8 dipole melt seasons occurred between 1949 and 1968, while the other 4 occurred between 1995 and 2010.

1968 now takes the title as strongest dipole over the melt season from 2007.

Will be doing some new analysis over the coming weeks, but even before that I found some fascinating stuff while doing correlations for each melt season month separately for each decade, to get a decadal correlation. Might post it up later after a bit more work

[Isolated Frost]

NH sea ice extent continuing to increase rapidly, which while a good sign, is rather unsurprising for the time of year and after the low minimum.

Around the end of October over all years since 1979, most years are grouped together, but 2007,2009 and 2010 (and now 2011) are in their own sub-group behind the rest with the closest to them being 2006 with about 300,000km2 more. They continues to bunch together with the rest further into November usually.

Here's the latest sea ice comparison with 2006 which is roughly where we should be aiming towards at this point in the year.

And for anyone who might be interested, I extended the dipole index back to 1948.

In doing so, I found that 4 of the strongest 8 dipole melt seasons occurred between 1949 and 1968, while the other 4 occurred between 1995 and 2010.

1968 now takes the title as strongest dipole over the melt season from 2007.

Will be doing some new analysis over the coming weeks, but even before that I found some fascinating stuff while doing correlations for each melt season month separately for each decade, to get a decadal correlation. Might post it up later after a bit more work

We seem to be doing better across e greenland and the canadian arctic- but notably worse in alaska/nw canada-e siberia area. Also not as good near the european arctic (svalbard, nw russia).

Weird gap of no sea ice just of the n siberian coast?

[oldsnowywizard]

Seems to be one hell of a vortex developing over the arctic in the next week or so .... Cold and lots of snow on the agenda ... Should help with the ice development nicely

[karyo]

The refreeze is continuing at a faster than average rate!

http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png

Karyo

[Isolated Frost]

The refreeze is continuing at a faster than average rate!

http://nsidc.org/dat..._timeseries.png

Karyo

And yet it's only marginally above the dire 2007, well below the average. What terrible times for the arctic.

[karyo]

And yet it's only marginally above the dire 2007, well below the average. What terrible times for the arctic.

Are you expecting a baby to run before it can walk?

[BornFromTheVoid]

An interesting statistic (or not perhaps) is that we've now recorded the longest period of below average global sea ice area on record.

You can check here

http://arctic.atmos....a.withtrend.jpg

A little hard to eyeball it, but if you measure the distances between the periods below average, the current one is still on going and the already the longest.

Also, with the dipole I used rolling average for each month for every melt season (Apr-Sept) from 80-11 to get a rolling anomaly, then got then averaged the anomaly for the whole melt season and averaged the dipole for each melt season.

I then did a correlation between the 2 for each decade (well, the 10 years of each decade), here are the results

80s +0.63

90s -0.73

00s -0.42

80-11 -0.52

Seems as though something may have changed in the late 80s or early 90s with how the sea ice deals with dipole patterns. Moving along and comparing each set of 10 years I found this correlation

92-01 = -0.90

Unfortunately, the correlations are somewhat skewed by the fact that the sea ice has been in something of an accelerating decline over all. So I plan to get the monthly change in sea ice from the beginning to the end of the month from Apr-Sept instead and then get anomalies and averages with these to use for the correlations so they should be more accurate.

Edited November 4, 2011 by BornFromTheVoid