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Arctic Ice Data And Stats.


pottyprof

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Posted
  • Location: Hadleigh, Suffolk
  • Weather Preferences: An Alpine climate - snowy winters and sunny summers
  • Location: Hadleigh, Suffolk

Every picture tells a story, and whilst the headline is that the Arctic Ocean Basin minimum Sea Ice Extent this autumn is the 3rd lowest since records started in 1979, the graph highlights how the minimum extent has been on a downward trend over the period 1979 - 2018. This from Zack Labe:

Sea ice extent is currently the third lowest on record for the inner Arctic Ocean basin. Each line is one year of @NSIDC daily data over the satellite era [purple (1979) to white (2017)]. 2018 is shown in red.

2133015004_ArcticBasinSeaIceextentOct2018.thumb.jpg.270b903dc05f5602151a20083c9bac80.jpg

https://twitter.com/ZLabe/status/1045793536849862656

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Posted
  • Location: Leigh-on-Sea
  • Location: Leigh-on-Sea
8 hours ago, Blessed Weather said:

Every picture tells a story, and whilst the headline is that the Arctic Ocean Basin minimum Sea Ice Extent this autumn is the 3rd lowest since records started in 1979, the graph highlights how the minimum extent has been on a downward trend over the period 1979 - 2018. This from Zack Labe:

Sea ice extent is currently the third lowest on record for the inner Arctic Ocean basin. Each line is one year of @NSIDC daily data over the satellite era [purple (1979) to white (2017)]. 2018 is shown in red.

2133015004_ArcticBasinSeaIceextentOct2018.thumb.jpg.270b903dc05f5602151a20083c9bac80.jpg

https://twitter.com/ZLabe/status/1045793536849862656

I must be missing something, but I'm confused as to how its the 3rd lowest on record? Surely it should be 3rd lowest on record for this time of year? Which is quite a bit different to 3rd lowest on record?

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Posted
  • Location: Hadleigh, Suffolk
  • Weather Preferences: An Alpine climate - snowy winters and sunny summers
  • Location: Hadleigh, Suffolk
16 minutes ago, Rambo said:

I must be missing something, but I'm confused as to how its the 3rd lowest on record? Surely it should be 3rd lowest on record for this time of year? Which is quite a bit different to 3rd lowest on record?

Good spot Rambo. I've a high opinion of Zack Labe but his tweet does mislead, giving the impression that the 2018 3rd place was based on the season's minimum extent. Of course he may not have intended to mislead, but the words of his tweet certainly did and I will message him about this.

This post from Arctic Sea Ice News two days ago gives clarity about this years minimum and the provisional 2018 ranking of 6th lowest:

Arctic sea ice extent arrives at its minimum

On September 19 and 23, Arctic sea ice appeared to have reached its seasonal minimum extent for the year, at 4.59 million square kilometers (1.77 million square miles). This ties 2018 with 2008 and 2010 for the sixth lowest minimum extent in the nearly 40-year satellite record. 

Please note that this is a preliminary announcement. Changing winds or late-season melt could still reduce the Arctic ice extent, as happened in 2005 and 2010. NSIDC scientists will release a full analysis of the Arctic melt season, and discuss the Antarctic winter sea ice growth, in early October.

Table - 12 lowest Minimum Sea Ice Extents 1979 to date:

699784702_ArcticSeaIceMinimumExtent2018.thumb.jpg.359b6b6019c7ecfa4bdbfbbec2321b57.jpg

http://nsidc.org/arcticseaicenews/category/analysis/

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Posted
  • Location: Leigh-on-Sea
  • Location: Leigh-on-Sea

Yeh, I mean it could still melt considerably again and go lower, but as it stands at this point in time, I just thought it worth pointing it out :)

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Posted
  • Location: Ireland, probably South Tipperary
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Ireland, probably South Tipperary

Assuming the tweet hasn't been edited since, it doesn't appear misleading at all if you read it, but here's the quote:

"Sea ice extent is currently the third lowest on record for the inner #Arctic Ocean basin."

So it's made quite clear that it's neither the entire Arctic nor the record annual minimum extent - it is the current extent in the inner Arctic basin
The graph even has, in an unusually large font "ARCTIC BASIN SEA ICE" on the top of it.

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Posted
  • Location: Leigh-on-Sea
  • Location: Leigh-on-Sea
19 hours ago, BornFromTheVoid said:

Assuming the tweet hasn't been edited since, it doesn't appear misleading at all if you read it, but here's the quote:

"Sea ice extent is currently the third lowest on record for the inner #Arctic Ocean basin."

So it's made quite clear that it's neither the entire Arctic nor the record annual minimum extent - it is the current extent in the inner Arctic basin
The graph even has, in an unusually large font "ARCTIC BASIN SEA ICE" on the top of it.

Its clearly misleading, and makes a better headline, but thats not to say it isnt just a simple mistake!

You cannot make a claim that certain data is the highest or lowest on record, without stating it in context. As a random example, "the temperature in July was the hottest on record" vs "the hottest July month on record".........can you see the difference?

You can spin it how you like, but saying "Sea ice extent is currently the third lowest on record for the inner #Arctic Ocean basin." is NOT correct!

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Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.
1 hour ago, Rambo said:

Its clearly misleading, and makes a better headline, but thats not to say it isnt just a simple mistake!

You cannot make a claim that certain data is the highest or lowest on record, without stating it in context. As a random example, "the temperature in July was the hottest on record" vs "the hottest July month on record".........can you see the difference?

You can spin it how you like, but saying "Sea ice extent is currently the third lowest on record for the inner #Arctic Ocean basin." is NOT correct!

It might be misleading to those who can't understand it, I suppose... Then again, you might be attempting to use an 'argument from incredulity'? Who knows, when folks start playing silly buggers with words?

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Posted
  • Location: Leigh-on-Sea
  • Location: Leigh-on-Sea
17 minutes ago, Ed Stone said:

It might be misleading to those who can't understand it, I suppose... Then again, you might be attempting to use an 'argument from incredulity'? Who knows, when folks start playing silly buggers with words?

Well look who it is ?

How exactly am I unwilling to believe it lol??? Where have I said that arctic sea ice isnt the 3rd lowest on record for October?? Nope, I cant find it either.....perhaps I didnt say it? But then why would you make a comment like that if I didnt say it?.....hmmm

There's "playing silly buggers with words", and then there's outright lying, so you've beaten me hands down on this one :)

Unless of course you've used "incredulity" in the wrong context, in which case, I'll let you off!

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Posted
  • Location: Ireland, probably South Tipperary
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Ireland, probably South Tipperary
8 minutes ago, Rambo said:

You cannot make a claim that certain data is the highest or lowest on record, without stating it in context. As a random example, "the temperature in July was the hottest on record" vs "the hottest July month on record".........can you see the difference?

You can spin it how you like, but saying "Sea ice extent is currently the third lowest on record for the inner #Arctic Ocean basin." is NOT correct!

I think the issue lies with the word currently. I read that as the same as "for the time of year", where as I guess other may not. But I think given that he provided a nice clear graph of the ice with the current extent highlighted with the big red dot should help with the confusion.

 

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Posted
  • Location: Leigh-on-Sea
  • Location: Leigh-on-Sea
1 hour ago, BornFromTheVoid said:

I think the issue lies with the word currently. I read that as the same as "for the time of year", where as I guess other may not. But I think given that he provided a nice clear graph of the ice with the current extent highlighted with the big red dot should help with the confusion.

 

Trouble is, just relying on "currently" isn't enough as it can have two meanings! 

Obviously it's clear to anyone who looks at the graph what the current state is, I just dislike this type of "spin" where it makes the "headline" sound more exciting than it is. As I said, I'm not saying it was done deliberately, but people should know better. Without the graph, it sounds far worse! 

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Posted
  • Location: Ireland, probably South Tipperary
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Ireland, probably South Tipperary
15 minutes ago, Rambo said:

Trouble is, just relying on "currently" isn't enough as it can have two meanings! 

Obviously it's clear to anyone who looks at the graph what the current state is, I just dislike this type of "spin" where it makes the "headline" sound more exciting than it is. As I said, I'm not saying it was done deliberately, but people should know better. Without the graph, it sounds far worse! 

Calling it "spin" and then saying it wasn't done deliberately is a little inconsistent, don't you think?
Keep in mind, it's the twitter account of one guy, a PhD student, rather than some media organisation. I doubt he's considering the headline value or possible interpretations of every word and phrase used. Much the same way none of use would have the time or resources to consider that stuff with every public comment made!

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Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.
7 minutes ago, BornFromTheVoid said:

Calling it "spin" and then saying it wasn't done deliberately is a little inconsistent, don't you think?
Keep in mind, it's the twitter account of one guy, a PhD student, rather than some media organisation. I doubt he's considering the headline value or possible interpretations of every word and phrase used. Much the same way none of use would have the time or resources to consider that stuff with every public comment made!

You have the patience of a saint, Sam...Do you ever get the idea that you are deliberately being sidetracked, into discussing the polysemous nature of certain words?

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Posted
  • Location: Hadleigh, Suffolk
  • Weather Preferences: An Alpine climate - snowy winters and sunny summers
  • Location: Hadleigh, Suffolk
On 30/09/2018 at 00:09, BornFromTheVoid said:

Assuming the tweet hasn't been edited since, it doesn't appear misleading at all if you read it, but here's the quote:

"Sea ice extent is currently the third lowest on record for the inner #Arctic Ocean basin."

So it's made quite clear that it's neither the entire Arctic nor the record annual minimum extent - it is the current extent in the inner Arctic basin
The graph even has, in an unusually large font "ARCTIC BASIN SEA ICE" on the top of it.

Hi BFTV. Strictly speaking you are correct, but IMHO I still think the tweet misleading. Zach chose a particular date some days after the minimum for 2018 when clearly the ranking with other years ON THAT DATE had changed (due to the different 'melt timing' graph lines for each year) and then uses the description “the 3rd lowest on record” in his tweet. Yes, the knowledgeable and/or alert may have spotted what was being said. I regret I didn't. I interpreted the tweet as comparing the 2018 absolute minimum with other years. So to me the important news is that 2018 (subject to no further melt) is actually the 6th lowest on record and my inattention led to a misleading post (for which apologies).

While I'm on, may I ask whether there would be any difference in "Arctic Basin" (meaning Arctic Ocean?) sea ice extent and sea ice remaining in the "entire Arctic" at this time of year? (I'm not an expert on this topic so still learning about these subtleties). Thanks.

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Posted
  • Location: Leigh-on-Sea
  • Location: Leigh-on-Sea
1 hour ago, BornFromTheVoid said:

Calling it "spin" and then saying it wasn't done deliberately is a little inconsistent, don't you think?
Keep in mind, it's the twitter account of one guy, a PhD student, rather than some media organisation. I doubt he's considering the headline value or possible interpretations of every word and phrase used. Much the same way none of use would have the time or resources to consider that stuff with every public comment made!

Hardly inconsistent lol.... spin can happen by accident! 

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Posted
  • Location: Leigh-on-Sea
  • Location: Leigh-on-Sea
1 hour ago, Ed Stone said:

You have the patience of a saint, Sam...Do you ever get the idea that you are deliberately being sidetracked, into discussing the polysemous nature of certain words?

I'm sorry, but you need to sort your bias out! 

This is science, and science relies on words that aren't ambiguous! 

And how am I deliberately sidetracking lol? Sidetracking away from what lol? 

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Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.
6 minutes ago, Rambo said:

I'm sorry, but you need to sort your bias out! 

This is science, and science relies on words that aren't ambiguous! 

And how am I deliberately sidetracking lol? Sidetracking away from what lol? 

What 'bias' is that? The sort that enables me to both extract data from a graph and interpret the word 'currently'?

currently
ˈkʌrəntli/
adverb
 
  1. at the present time.
    "the EC is currently attempting greater economic integration"
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Posted
  • Location: Ireland, probably South Tipperary
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Ireland, probably South Tipperary
37 minutes ago, Blessed Weather said:

Hi BFTV. Strictly speaking you are correct, but IMHO I still think the tweet misleading. Zach chose a particular date some days after the minimum for 2018 when clearly the ranking with other years ON THAT DATE had changed (due to the different 'melt timing' graph lines for each year) and then uses the description “the 3rd lowest on record” in his tweet. Yes, the knowledgeable and/or alert may have spotted what was being said. I regret I didn't. I interpreted the tweet as comparing the 2018 absolute minimum with other years. So to me the important news is that 2018 (subject to no further melt) is actually the 6th lowest on record and my inattention led to a misleading post (for which apologies).

While I'm on, may I ask whether there would be any difference in "Arctic Basin" (meaning Arctic Ocean?) sea ice extent and sea ice remaining in the "entire Arctic" at this time of year? (I'm not an expert on this topic so still learning about these subtleties). Thanks.

Hi Malcolm,

I can see why some might be a little confused by the ambiguity in the term "current", but I posted more to dispel the idea that it was an attempt to generate a sensational headline or that it was in any way a form of spin. Misunderstandings are only human but, as I'm sure you've noticed, lately in general science or political discussion, but especially in climate science, there's a tendency for a certain side of the debate to link everything to ploys, conspiracy theories and "fake news".

The Arctic ocean and peripheral seas make up the measurements of Northern Hemisphere sea ice, which is often just called Arctic sea ice. The map below shows roughly where the different regions are, though there will be slight variations depending on who's doing the measurements.

2017_sio_call_figure1.png

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59 minutes ago, Blessed Weather said:

Hi BFTV. Strictly speaking you are correct, but IMHO I still think the tweet misleading. Zach chose a particular date some days after the minimum for 2018 when clearly the ranking with other years ON THAT DATE had changed (due to the different 'melt timing' graph lines for each year) and then uses the description “the 3rd lowest on record” in his tweet. Yes, the knowledgeable and/or alert may have spotted what was being said. I regret I didn't. I interpreted the tweet as comparing the 2018 absolute minimum with other years. So to me the important news is that 2018 (subject to no further melt) is actually the 6th lowest on record and my inattention led to a misleading post (for which apologies).

While I'm on, may I ask whether there would be any difference in "Arctic Basin" (meaning Arctic Ocean?) sea ice extent and sea ice remaining in the "entire Arctic" at this time of year? (I'm not an expert on this topic so still learning about these subtleties). Thanks.

Hi Malcolm @Blessed Weather, not much time but if I may attempt to clear up some of the misunderstanding here as the debate that the Zach Labe tweet produced demonstrates a spread of views. This is one of the downsides of a tweet – so abbreviated that unless the wording is 100% clear, the meaning can be distorted and create a range of interpretations or misinterpretations. If a tweet links to a wider blog or report then at least the tweet can be put into its full context. At first sight, the chart does "appear" to be referring to minimum ice extent and if it's showing anything else (as indeed it is), then that must be made clear. Zach is guilty of not making that clear.

If common sense prevails (which it rarely does these days!), then one can clearly see what the chart is showing. It “was” the 6th lowest at the time of previous minimum extents all measured against the exceptional record low 2012 extent. At the time of the tweet, 3 of those 5 lower years started recovering earlier than in previous "recent" years while 2018 had actually drifted marginally lower and is struggling to recover and it's currently (at the time of the tweet) the 3rd lowest on record. This is a misleading timing issue.

The headline should be that 2018 is “currently” (at this time of the season) the 3rd lowest with a very slow/late recovery. This whole issue is dominated by those at either end of the global warming debate and there are so many misleading reports, blogs and tweets with distorted facts and figures and some very “political” manipulation of statistics. Zach is a highly respected and well qualified scientist and he “should” take great care to report his findings accurately with balanced comments whatever his personal views might be.  Scientists can be controlled by their employers or paymasters but Zach works on the educational side and should be neutral (which I believe is his intention).  He is also guilty of the graph “axis/scale” problem that I highlighted in my long history of ice extent post on another forum (I may cross-post one or two of them on here when I have time).  Starting a graph at 2 or 3, instead of zero, grossly exaggerates what is already a very worrying situation and can make it look like that there is practically no ice left at all!.  I’m not yet persuaded by those that claim we’ll see a completely ice free Arctic in the summer in 20 to 30 years’ time but we may well accelerate towards even lower minimums than the exceptionally low 2012 minimum.

I have no problem about anyone posting tweets providing that there are at least a few comments to put it into context. Otherwise, the messenger innocently becomes as guilty as the author by spreading the ambiguity around instant social media. This is a huge problem that will only get even worse. For those of us that have enough knowledge and understanding (not just the experts) then we have a duty to provide the balance and appropriate cautions and if we are uncertain we should either say so or think twice about posting a particular tweet. Perhaps PMing or emailing the author initially to confirm any aspect of their ambiguous tweet might help, providing one notices it and has the time to do so.

Zach Labe (who I really do respect btw and have often referred to his research and excellent papers) posted another tweet in mid-August, which was also a little misleading, as although it was comparing decadal changes, the presentation of the graphics make it look like 2018 was seeing the lowest ice extent. I almost always make at least a short comment below each chart that I post stating exactly what it’s showing. By coincidence, the NSIDC mid-month August update was published.  Until mid-July, 2018 was on target to be the lowest on record but then the rate of melting decreased to a snail’s pace (mostly due to circulation patterns).  Unfortunately, I already felt that the 2018 recovery may well be a real struggle.  With far more older ice melting and those huge +ve SST anomalies continuing, it will need prolonged periods of weak and favourable wind patterns to allow a faster recovery. Later in October we may well be seeing headlines that 2018 is the lowest ice extent on record “for that date”.  I’m hoping that the falling and more widespread –ve SSTs in the mid-north Atlantic will assist but it may take at least several more winters for those anomalously high Arctic SSTs to fall back.  They are partly a legacy of the 2015 super El Nino which blasted the Atlantic jet stream and warm ocean currents right up to the edge of the main ice sheet for prolonged periods.

Turning to the definition issue of what is the difference between “Arctic Ocean Sea Ice extent” and “Arctic Basin Sea Ice extent” - oceans are basins and there is absolutely no difference at all. It’s the misuse of the term basin by the author/poster that’s the problem.  If they said Arctic “region”, then we could include Greenland and all the islands + the Hudson Bay and other inland rivers and lakes (+ the north Baltic if/when it freezes up) which are inside the Arctic circle. There is also a distinction between the main continuous polar ice sheet and ice that forms outside of that, such as in the bays and inlets on the Canadian and Siberian sides before the main sheet engulfs them during the winter re-freeze. 

I will be back posting on both forums regularly quite soon with regular cross-posts.  Previously my main Arctic reports have gone on the either the model thread or the teleconnections thread but when they are purely Arctic related, I'll pop them on to this excellent thread.  keep the fascinating discussions going.  David  :)  

EDIT: In the time that it took me to prepare this post I see that 3 more posts have been added. I think that @BornFromTheVoid very nicely sums up the "basins" issue  D

 

 

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Posted
  • Location: Leigh-on-Sea
  • Location: Leigh-on-Sea
2 hours ago, Ed Stone said:

What 'bias' is that? The sort that enables me to both extract data from a graph and interpret the word 'currently'?

currently
ˈkʌrəntli/
adverb
 
  1. at the present time.
    "the EC is currently attempting greater economic integration"

You still don't get it, and I'm bored now, especially as bftv has turned this into a climate debate issue too lol. 

Bring Back explains it perfectly (much better than me) 

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Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.
57 minutes ago, Rambo said:

You still don't get it, and I'm bored now, especially as bftv has turned this into a climate debate issue too lol. 

Bring Back explains it perfectly (much better than me) 

Do you always blame somebody else?

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  • 2 weeks later...

EXTREMELY SLOW ICE BUILD UP - THE RE-FREEZE HAS HARDLY BEGUN IN THE EAST

I shall be posting on this thread quite frequently from now on.  I'll start with the latest ice extent charts.

     ar1.thumb.PNG.823eed559b9f213ae6b9d176de08789e.PNG

Arctic sea ice is running far below the 30 year mean - nothing surprising about that. The re-freeze has been quite fast in the west on the Canadian side but has barely started on the Siberian side and ice extent has even declined further in the  Kara Sea!  To compare the exact date (October 12th) with 2017, I show the NOAA chart below (the October 2017 NSIDC archive report shows a chart to October 5th). Note that the ice sheet last year (still well below the mean) did extend right across to the Siberian coast (more below).

    sn2.thumb.PNG.9af1ac6d038d76eb19c984637357bc37.PNG

    ar2.thumb.PNG.5207fb3075b93a03f69f5e7ea15ce88b.PNG

This summer we saw even more older ice thinning and melting (as has been highlighted in several earlier posts on here). Note how little (white areas) 100% ice concentration there is, even around the pole. 

  ar3.thumb.PNG.c67c0c8c3f9c9c9b8893e13b82496240.PNG

2018 ended up as only the 6th lowest on record (see below) following a slow down in melting through August - it had been challenging the record low year of 2012 before then. Unfortunately, with such little re-freezing, 2018 is heading for the lowest mid/late October extent on record (for that date).  2012 was recovering quickly through October. Weather and circulation patterns vary considerably and these can impact on ice build up in the short term but there are other factors in play, such as the anomalously high SSTs in the Arctic, particularly on the Atlantic side - I'll examine these again in my next post on here. 

   ar4.thumb.PNG.f8e1227fd28b04a1c6c1a3be0393f321.PNG

Here we can see that 2012 was way below any other year but it reached its minimum extent in mid September. At that time, 2018 was the 6th lowest equalling 2008 (note that the previous 4 years + 2012 are shown but 2013 and earlier years are not as this chart is meant to be a 5 year comparison measured against the record low year). 2018 saw its lowest point in late September but has been slower to rise than in any of the earlier years. 2016 also had a slow recovery and that year saw the lowest extent on record from mid October and through into early winter. It looks like 2018 will see even lower levels within a few weeks unless a rapid re-freeze gets going very soon. 

This from the latest NSIDC report:

Arctic sea ice extent for September 2018 averaged 4.71 million square kilometers (1.82 million square miles), tying with 2008 for the sixth lowest September in the 1979 to 2018 satellite record. This was 1.70 million square kilometers (656,000 square miles) below the 1981 to 2010 average, and 1.14 million square kilometers (440,000 square miles) above the record low recorded for September 2012. Prior to September 19, sea ice extent declined at a relatively rapid 14,440 square kilometers (5,580 square miles) per day, significantly faster than in most years. The near-zero loss rate between September 19 and 23, and the very late onset of significant seasonal ice growth after September 23, were atypical of the satellite record.

Sea ice loss during the first half of September primarily occurred within the East Siberian, northern Laptev, and northern Chukchi Seas, in part because winds from the south brought warm air into the region and inhibited ice from drifting or growing southward. Retreat in these areas was partially offset by ice expansion in the eastern Beaufort Sea and the northern Kara and Barents Seas. The old ice that had been persisting in the Beaufort Sea near Prudhoe Bay mostly melted out by the end of September. While the Northern Sea Route opened again this year, as it has every year since 2008, ice lingered in the central section of the southern route of the Northwest Passage between Bellot Strait and Gjoa Haven.

Since the seasonal minimum extent, reached on September 19 and again on September 23 at 4.59 million square kilometers (1.77 million square miles), ice cover has expanded in the Canadian Archipelago, the northern Chukchi and Beaufort Seas, and the East Greenland Sea, while retreating slightly within the Kara Sea.

We can examine the circulation patterns and the other reasons for the unusually slow build up on here - such as the persistent southerly winds in the east.  For the Siberian coast to be ice free and for the entire eastern Arctic to still be navigable in mid October is almost unheard of. I hope to bring some better news before too long but I am really concerned about this delayed re-freeze.  David ☹️

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Posted
  • Location: Solihull, West Midlands. - 131 m asl
  • Weather Preferences: Sun, Snow and Storms
  • Location: Solihull, West Midlands. - 131 m asl
1 hour ago, Bring Back1962-63 said:

EXTREMELY SLOW ICE BUILD UP - THE RE-FREEZE HAS HARDLY BEGUN IN THE EAST

 I hope to bring some better news before too long but I am really concerned about this delayed re-freeze. 

David ☹️

BB..

 I will look forward to your reporting.

I perform a similar operation over on Two on a daily basis so not quite as detailed as this your first report.

Can I make a couple of suggestions?

1)  Also take a look at volume/thickness of the ice, as this will determine the longevity of the ice.

I recognise that the extent is important for current weather forecasting implications.

2)  I think this is a review of the last few months and general I agree with it.

The last 3 days have seen strong increases in extent. (back up to the normal rates for this time of year).

 

index.php?action=dlattach;topic=2223.0;a      ack to ASIF

 

This has mainly been occurring in the areas of Arctic which are still well below their average extent for the time of year.

As you have stated it is important to realise that the Arctic temperatures are now (although anomalies are +4.3C),  well below the freezing point of the ocean.

We now need to watch to see whether the fact that this area (which is abnormally close to the pole), proceeds to refreeze quickly, as has happened in other years (notably 2007), when the shortage of the ice in this area was extreme.

 CICE_combine_thick_SM_EN_20070930.png

 

MIA

Edited by Midlands Ice Age
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3 hours ago, Midlands Ice Age said:

BB..

 I will look forward to your reporting.

I perform a similar operation over on Two on a daily basis so not quite as detailed as this your first report.

Can I make a couple of suggestions?

1)  Also take a look at volume/thickness of the ice, as this will determine the longevity of the ice.

I recognise that the extent is important for current weather forecasting implications.

2)  I think this is a review of the last few months and general I agree with it.

The last 3 days have seen strong increases in extent. (back up to the normal rates for this time of year).

This has mainly been occurring in the areas of Arctic which are still well below their average extent for the time of year.

As you have stated it is important to realise that the Arctic temperatures are now (although anomalies are +4.3C),  well below the freezing point of the ocean.

We now need to watch to see whether the fact that this area (which is abnormally close to the pole), proceeds to refreeze quickly, as has happened in other years (notably 2007), when the shortage of the ice in this area was extreme.

 MIA

SNIPPED (charts removed to save space)

Hi MIA, I have also been active elsewhere, on a US weather forum where I started an Arctic thread. I will cross-post quite regularly on both of them. Malcolm @Blessed Weather and I got my library idea going on there building a Research Portal (link to index: https://www.33andrain.com/topic/996-index-to-papers-and-articles/).  We had wanted to do that on here but things moved far too slowly. We will be reviewing many papers on both forums.  There are plenty of Arctic papers and presentations in there.

I note your points above.  I will be producing separate posts on the long term ice and on Arctic SSTs. These are both more important than merely the extent of 15% ice accumulations and even more of a concern going forward. In fact I did a couple of posts on these 2 months ago on the US forum and I'll copy them across on to this thread during this week to go on with and I or someone else can provide an update.

Wrt to the recent changes we are rather talking cross purposes here and it's always important to explain exactly what the charts are showing and what we are commenting on. The NSIDC ice extent and concentration charts that I referred to were up to 12th October - so they were up-to-date. Their last written report was on 8th October - still pretty up-to-date.  I quoted from the main part of the report but here's a snip of their intro for completeness:

ar5.thumb.PNG.1e3681b6de03bb198e4597b11782c110.PNG    

I referred to their narrative which explained that while ice extent was recovering quite well in the west (on the Canadian side) it had hardly started to recover in the east (on the Siberian side) and had actually declined further in the northern Kara Sea. The latter charts, comparing previous years are usually updated once a month. 

Now your first chart refers to "daily overall ice extent changes" (with weekly groupings) and it would not be at all surprising to see some periods of rapid recovery in the years having the latest start to the re-freeze - ie; playing something of a catch up from a low starting position. The chart compares 2018 to 2017 which had a rather different recovery pattern - ahead earlier on but with some major setbacks later on (eg: for much of November).  I was comparing 2018 to 2016 which also had a very late recovery  It is true that the patterns have recently changed and those Siberian southerlies have gone during the last few days, snow cover has started to accumulate there and surface temps have fallen substantially. The recovery in the eastern Arctic has still hardly started (with most of the recent freezing still in the west) but with the more favourable patterns, let's hope that the east does start to re-freeze much more quickly.  Your chart is very useful for showing extremely short term overall extent changes and for signs of developing trends over a few weeks. 

Now your excellent second chart.  Let's compare it to exactly one week ago: 

                       October 6th 2018                                              October 13th 2018

    ar6.thumb.PNG.2b48e6c068c7a86741475dc8ef99f28d.PNG            ar7.thumb.PNG.8bb7e0b45d63935f4d4ddbb428f83fef.PNG

This confirms what I was saying, despite the recovery in the last week, 2018 is even closer to becoming the lowest year on record for mid/late October. Right now it almost exactly matches the second lowest set in 2016 but until late October, 2012 was still the lowest, after that it was 2016 but 2018 needs to get its skates on (almost literally!). In other words, if we compare 2018 and 2016 (see below), 2016 was recovering at an even faster rate at this stage than 2018. The main question now is, just how quickly can the more continuous ice sheet reach right across to the Siberian side.  Once that is achieved, further growth (north and south) should be more easily achieved with those open waters being dammed. 

So, we are not in any disagreement here - just needing to ensure that we are comparing like with like.  I think that you agree with me that we need to make sure that we take a balanced approach and show the facts and not take a political view at either end of the climate change debate. This thread was set up to provide Arctic statistics - so the more the better and let's get a good like for like comparison and thorough analysis going.  With that in mind, I'll sign off with your excellent charts but for this time last year and in 2016 too:

                     October 12th 2017                                              October 12th 2016

    ar8.thumb.PNG.4251e3efea24022245febe9c942c9318.PNG             ar9.thumb.PNG.9cdb2bdfed9e5aa98d9997ad32caafd4.PNG

In 2017 the ice had just extended across to the Siberian side (there was very early Asian snow cover build up last year and more favourable circulation patterns).  Even 2016, with similar overall ice build up had more ice in the east.

David :) 

   

Edited by Guest
check charts and correct typos
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  • Location: Solihull, West Midlands. - 131 m asl
  • Weather Preferences: Sun, Snow and Storms
  • Location: Solihull, West Midlands. - 131 m asl
3 hours ago, Bring Back1962-63 said:

Hi MIA, I have also been active elsewhere, on a US weather forum where I started an Arctic thread. I will cross-post quite regularly on both of them. Malcolm @Blessed Weather and I got my library idea going on there building a Research Portal (link to index: https://www.33andrain.com/topic/996-index-to-papers-and-articles/).  We had wanted to do that on here but things moved far too slowly. We will be reviewing many papers on both forums.  There are plenty of Arctic papers and presentations in there.

David :) 

   

Hi David..

 Thanks for the link to the portal. There sure is a lot of data on there already.

I will be a fan of your postings on here.

MIA 

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