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Arctic Sea Ice Discussion 2015-2016: The Refreeze.

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How have we ranked in terms of the date for recovery?

 

Equal earliest  recorded in the last 15 years.. Doesn't mean that much as its only 35years since records began and earlier years are thought of as unreliable.

Possibly indicates reasonable weather conditions at the end of the melt season!.

 

MIA

Edited by Midlands Ice Age
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Earlier records are not thought of as "unreliable" they are used in confidence by the worlds top climate scientist. Stop spinning nonsense to suit.

Equal earliest  recorded in the last 15 years.. Doesn't mean that much as its only 35years since records began and earlier years are thought of as unreliable.

Possibly indicates reasonable weather conditions at the end of the melt season!.

 

MIA

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Earlier records are not thought of as "unreliable" they are used in confidence by the worlds top climate scientist. Stop spinning nonsense to suit.

 

Ingham,  A fan at last!

 

No spin involved, the NSIDC  stated it in their comments they couldn't be certain because of changes to better satellites that occured about the change of the century!!! Are you calling that  'nonsense'?

 

In fact it was the equal earliest for the last 35 years. So quite the reverse to your allegations - I was actually understating the position to fit what the NSIDC said.

.

Ok - what did I say to exaggerate to suit my position. It actually weakens it!

 

So please try and be constructive, not forever destructive.

 

What do you think caused the ice to start to re-freeze early! I have given my own opinion above with a qualifying 'possibly'. You obviously know  better however so lets hear it, or cut out snide remarks!!!

 

MIA 

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What do you think caused the ice to start to re-freeze early! 

MIA 

Getting cold sooner mostly :)  

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Getting cold sooner mostly :)  

 

You need to go back to 1959 to see such a sustained drop in temps in the high Arctic for this time of year.

 

I know some folk don't see that 'core' as important but its where most of the ice by volume comes from.

post-7914-0-90370100-1442864154_thumb.pn

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How have we ranked in terms of the date for recovery?

 

In reality, this question depends on the metric and the organisation measuring it (and by recovery I assume refreeze is meant).

Extent, area or volume?

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Ingham,  A fan at last!

 

No spin involved, the NSIDC  stated it in their comments they couldn't be certain because of changes to better satellites that occured about the change of the century!!! Are you calling that  'nonsense'?

 

In fact it was the equal earliest for the last 35 years. So quite the reverse to your allegations - I was actually understating the position to fit what the NSIDC said.

.

Ok - what did I say to exaggerate to suit my position. It actually weakens it!

 

So please try and be constructive, not forever destructive.

 

What do you think caused the ice to start to re-freeze early! I have given my own opinion above with a qualifying 'possibly'. You obviously know  better however so lets hear it, or cut out snide remarks!!!

 

MIA 

 

Any links to back that up, MIA?

 

You need to go back to 1959 to see such a sustained drop in temps in the high Arctic for this time of year.

 

I know some folk don't see that 'core' as important but its where most of the ice by volume comes from.

 

Of course, when you start off at a high point it's easy to get a large drop, even if that drop is only taking you back to slightly below average. Even still, so far this Autumn we've spent more time above than below average.

Also, N of 80N has only become the region with most volume, at the very end of the melt season, only in the last decade or so. This is because most of the other areas now melt most summers. If you want to protect 80N, you need to build volume outside of that region. Luckily, it's been a pretty chilly Autumn so far across much of the Arctic compared to recent years, and sea ice extent and area is responding accordingly.

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Any chance of any links...

etc

 

BFTV

 

Here is the link.

http://nsidc.org/arcticseaicenews/

 

The whole of it is interesting , but for the section involved consult the section on 'Previous MINIMUM Arctic sea ice extent',  also see the description link for much more detailed information on the changes.

 

It now just refers to the improved spaciality of the current satellites, whereas before it said the improved extent coverage in the Polar areas in the early 2000's in terms of improvements in satellites have meant that further adjustments are being made. I guess they were referring to the new Grunman satellites which were put into orbit in the early  2000's. I think it refers to the POLAR HOLE adjustments which are continually being made to compensate for the improved extent sweeping by the satellite compared to the earlier years. 

 

Hardly any difference really, but they have now removed any date indications they had previously mentioned!!

 

In any case their  tabled data only shows data since then and shows the dates of earliest start of refreeze.

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BFTV

 

Here is the link.

http://nsidc.org/arcticseaicenews/

 

 

 

Interesting to see the summer of 2015 had a similar wind pattern to 2007 and favoured less ice spread and a more compact ice sheet but extent still ended up much larger then 2007. Explains why the 'perception' it was a poor summer given starting volume doesn't ring true.Had the wind pattern been favorable for ice extent rather the compaction we might have ended up 500k higher in extent.

Edited by stewfox

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Interesting to see the summer of 2015 had a similar wind pattern to 2007 and favoured less ice spread and a more compact ice sheet but extent still ended up much larger then 2007. Explains why the 'perception' it was a poor summer given starting volume doesn't ring true.Had the wind pattern been favorable for ice extent rather the compaction we might have ended up 500k higher in extent.

But we didn't!

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BFTV

 

Here is the link.

http://nsidc.org/arcticseaicenews/

 

The whole of it is interesting , but for the section involved consult the section on 'Previous MINIMUM Arctic sea ice extent',  also see the description link for much more detailed information on the changes.

 

It now just refers to the improved spaciality of the current satellites, whereas before it said the improved extent coverage in the Polar areas in the early 2000's in terms of improvements in satellites have meant that further adjustments are being made. I guess they were referring to the new Grunman satellites which were put into orbit in the early  2000's. I think it refers to the POLAR HOLE adjustments which are continually being made to compensate for the improved extent sweeping by the satellite compared to the earlier years. 

 

Hardly any difference really, but they have now removed any date indications they had previously mentioned!!

 

In any case their  tabled data only shows data since then and shows the dates of earliest start of refreeze.

 

Cheers, MIA.

 

Unfortunately, I don't see anything to support your claim of the earliest minimum in 35 years. Perhaps you misread the tables? For example, 1987 had it's minimum on the 5th, and 1995 on the 9th.

 

With regard to the improved sea ice coverage, the improvements they note don't change the long term trends or older values in significant ways. Many of the improvements they apply are also applied to older data (much like the hated adjustments to global temperature data sets).

 

 

Interesting to see the summer of 2015 had a similar wind pattern to 2007 and favoured less ice spread and a more compact ice sheet but extent still ended up much larger then 2007. Explains why the 'perception' it was a poor summer given starting volume doesn't ring true.Had the wind pattern been favorable for ice extent rather the compaction we might have ended up 500k higher in extent.

 

Missed a bit, Stew.

 

However, it was not nearly as favorable as the 2007 pattern, when the area of unusually high pressure was located further south and east (over the northern Beaufort Sea), and unusually low pressure extended along much of the coast of northern Eurasia. This led to a pattern of warm winds from the south over the East Siberian and Chukchi Seas, promoting strong melt and transport of ice away from the coast. 

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BFTV..

 

Thanks for the response.

 

I have never suggested that the extents had changed noticeably. They said in the article that a couple of small differences had appeared, but nothing of note, that would effect the extent trends.

 

Re the dates - if you look back to my original reply  to Summer Blizzard,  I stated that it was the  equal earliest for the last 15 years.(not 35 years). I obtained this from the link I gave you.,

 

They (NSIDC) had suggested that it may have been one of the earliest since records began  They mentioned the cutoff date of early 2000's for the changes. This seems to have been removed and the report updated in this area. They still show only the cutoff dates in this report from 2005, indicating that they have not removed all the evidence of their incorrect original information. Why do they still state it is equal earliest for the last 15 years? It is a meaningless piece of information on its own, without reference to the 35 year tables?

 

The report was altered, but some of the original comments still remain  to prove my point.

 

PS I suspect that even that will be gone by tomorrow!.

 

MIA

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Neven

 

2015 minimum overview, part 1

 

A week has passed by since the melting season ended and the minimum on all sea ice extent and area graphs has been reached. During this week I've been collecting images that show various aspects of this year's melting story, which will be accompanied by short explanations/interpretations.

Such an overview must inevitably start with an image showing the shape of the ice pack, and the University of Bremen has put up a great sea ice concentration map that also shows the ice pack outlines at the end of record melting seasons 2007 and 2012, as well as the 1981-2010 average:

 

 

http://neven1.typepad.com/blog/2015/09/2015-minimum-overview.html

post-12275-0-82035200-1443074656_thumb.j

Edited by knocker
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Great discussion folks, I've been following it for maybe 10 years now (has it been going that long??). Thanks to all for the information and explanations, some amount of research and thought gone into it.

 

I have a quick question, it is widely agreed (isn't it?) that the northern hemisphere goes through cycles of warmer and colder climate of about 30 years because of (most likely?) activity on the sun. My main question is, given that as far as I've heard and observed, we currently are in a colder period, does that mean the small increase in minimum sea-ice extent since 2007 is most likely to be down to that? Or at least, that is the main reason?

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Re the dates - if you look back to my original reply  to Summer Blizzard,  I stated that it was the  equal earliest for the last 15 years.(not 35 years). I obtained this from the link I gave you.,

 

 

Mmmmmm.....

 

 

In fact it was the equal earliest for the last 35 years. So quite the reverse to your allegations - I was actually understating the position to fit what the NSIDC said.

 

They mention the last 15 years because before that there were earlier minima, I assume. Just as we might say the coolest September CET in 20 years, or something similar. It's an interesting tidbit, little more.

 

 

Great discussion folks, I've been following it for maybe 10 years now (has it been going that long??). Thanks to all for the information and explanations, some amount of research and thought gone into it.

 

I have a quick question, it is widely agreed (isn't it?) that the northern hemisphere goes through cycles of warmer and colder climate of about 30 years because of (most likely?) activity on the sun. My main question is, given that as far as I've heard and observed, we currently are in a colder period, does that mean the small increase in minimum sea-ice extent since 2007 is most likely to be down to that? Or at least, that is the main reason?

 

Welcome along Altohumorous. I think the globe tends to go through cycles of around 30 years, but that appears to be related to goings on in the Pacific, like the IPO/PDO, for which we don't really have a cause. Nowadays, rather than having ~30 years warming and ~30 years cooling, it's ~30 years rapid warming and ~30 years moderate warming!

 

The Arctic sea ice minimum, on a year to year basis, is controlled by the weather. From 2007 to 2012, we frequently had weather patterns that encouraged extra melt, compaction and export of sea ice from the Arctic (-ve AO, -ve NAO and +ve Arctic Dipole Anomaly). In 2013 and 2014, just after the record low of 2012, the weather patterns switched to cooler and more positive for ice retention. This summer, the pattern was more like the 2007-2012 period, though not nearly as mild as most of those years.

Figuring what causes or strongly influences the NAO, AO and Arctic Dipole Anomaly would be useful!

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Thanks BFTV. Like the film, it's complicated! Any evidence to show that sea-ice alters in line with those shorter periods of warming and cooling?

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Missed a bit, Stew.

 

However, it was not nearly as favorable as the 2007 pattern, when the area of unusually high pressure was located further south and east (over the northern Beaufort Sea), and unusually low pressure extended along much of the coast of northern Eurasia. This led to a pattern of warm winds from the south over the East Siberian and Chukchi Seas, promoting strong melt and transport of ice away from the coast. 

 

I said similar .

 

What was interesting and not often mentioned is the wind patterns

 

Anyway the refreeze is well under way now

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I said similar .

 

What was interesting and not often mentioned is the wind patterns

 

Anyway the refreeze is well under way now

 

It certainly is. The 5 day average extent growth over the last week is well above average too, at +26.4k/day compared to the 81-10 average of +17.6k/day, or the average of the last 5 years of 11.5k/day

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Thought it was worth bumping forward  Knockers 'find' in the 'New Research' thread to the sea ice thread.

 

I certainly found lots of references to this situation/problem when I was researching the North West Passage a couple of weeks ago when we were discussing volume and ice thickness in the recent completed 'melt'  thread.

 

There is still a lot of thick ice in this area, and the northern sea route has not been able to be fully opened to shipping this year.

People can get through on the more southerly track all round the islands, but not in reasonable sized ships and not without ice breaker assistance.

 

The other thing to note is that in some years the ice has continued melt until late October in this area. So there could just about be time, but the ice is now reforrming /thickening so unlikely to happen this year.

 

 

The quote and reference is here ------

 

 

Quote Despite climate change, sea ice in the Northwest Passage (NWP) remains too thick and treacherous for it to be a regular commercial Arctic shipping route for many decades, according to new research out of York University. "While everyone only looks at ice extent or area, because it is so easy to do with satellites, we study ice thickness, which is important to assess overall changes of ice volume, and helps to understand why and where the ice is most vulnerable to summer melt,"

 

Prior to this research, there was little information about the thickness of sea ice in the NWP, which meanders through the Canadian Arctic Archipelago.

 

Yet, next to ice coverage and type, sea ice thickness plays the most important role in assessing shipping hazards and predicting ice break-up. "says lead researcher York Professor Christian Haas, the Canada Research Chair for Arctic Sea Ice Geophysics.

 

Read more at:

 

http://phys.org/news/2015-09-arctic-sea-ice-thick-regular.html

 

 

 

 

 

 

The article hints that in future more warming may make it more difficult not easier for transport in the area..

 

-- So perhaps not good to use this area as a proxy for warming.

 

MIA

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The article hints that in future more warming may make it more difficult not easier for transport in the area..

 

-- So perhaps not good to use this area as a proxy for warming.

 

MIA

 

No indeed that would be very silly and unnecessary. Although not quite as silly as using it as a proxy that it wasn't. On a par with using the glaciers in the Karakoram range whilst the rest of the world's glaciers are busy melting.

Edited by knocker
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