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Kevin McKinney

Yes, another milestone; the season has definitely turned. And it is another interesting point in an interesting melt season. The spreadsheet gives the impression of a trend to later 'first upticks,' but it's pretty noisy data. (And we already know the season has lengthened.)

A bit amusing that the survey breakpoint was 4.5 million km2, and that's right where the extent is teetering. The anthropomorphically-inclined would think the season was trying to wring the maximum suspense: will the 26.7% or the 55.6% end up being correct? If I had to guess right now, I'd say we'll probably just sneak under the mark, but those fickle Arctic weather gods love to surprise, it would seem. . .

Andrew Xnn

From the Healy's webcam, it's clear that there is plenty of cold in the far north and has been for a while. Melt ponds are frozen and snowed over and the wind has picked up. Ice has been forming for a few weeks now.

So, this is the season for compaction, which is weather dependent. The delay in positive upticks maybe because compaction is more important than it has been in the past until it peters out.

However, compaction will never result in an ice free arctic. That has to occur from melting, which has ended.

Right now, we are witnessing the beginning of the conversion of 1st year ice to multi-year ice. Of course, there may also be dispersal going on near the peripheral, but that is weather dependent too.

Andrew Xnn

Here is a view from the Healy on Sept 1st.
87 North; 25F

Philiponfire

I disagree. Modis, Bremen and CT all clearly show expansion/dispersal of the pack in the central Arctic. large cracks everywhere. some many miles long and perhaps a mile or more wide. This is not over. my opinion is the current "increase" in the extent is in fact just a pack movement that with a wind change will vanish as rapidly as it happened.

Neven

Andrew, (bottom) melting isn't over until the water starts to release heat to the atmosphere. That's when we see a large uptick on the DMI 80N temperature chart.

There just isn't any compaction, or hardly any. With this kind of weather, in a normal, pre-2007 year, we'd have seen an uptick on the IJIS well before now, and the minimum would have been hit at least 10 days ago.

crandles

Re "in a normal, pre-2007 year" and
"and the minimum would have been hit at least 10 days ago."

Well in 1995 the minimum on GSFC wasn't reached until 4 Oct so I don't see how you get to "minimum ... at least 10 days ago".

Neven

crandles, I mean with the current weather situation in the Arctic.

In 1995 the minimum would have been reached a month earlier - at the least - with this kind of weather, even though the edge of the ice pack was probably much further south. Here's the ECMWF forecast, see for yourself.

I wouldn't be surprised to see the IJIS SIE minimum reached before the end of the week. It's amazing that it still has gone down so much.

Lord Soth

The Canadian ice service is showing the first signs of freeze.

At the top of Baffin Bay, ice crystals are begining to form in the bays of Ellsemere Island at 78 North. This is the first sign of ice formation, and is about a week behind schedule. This is just ice crystals in suspension with the water, but solid ice should form in the next few days.

http://ice-glaces.ec.gc.ca/prods/WIS34CT/20110911180000_WIS34CT_0006013438.gif

There is no signs of new ice in the Western Canadian Arctic.

I figure that by the end of the week, ice melt will be in balance with ice formation; and we will be at the total mercy of which way the winds blows for further declines.

crandles

"I mean with the current weather situation in the Arctic." Ahh OK.

A month ago in 1995 temperatures would have been above freezing and there would have been melt regardless of weather. Possible dispersion of pack could counteract melting but only by setting up low concentrations that would melt out later. So I don't think 12 Aug is a possible minimum date.

10 days ago, ie 2 Sept with current weather could be a minimum.
.

Incidently,
1995 managed to lose 472k after 11 Sep. I think there must have been some pretty intense lows late Sept and early October. There were lots of hurricanes in 1995, so I wonder if it was remnants of hurricanes.

Neven

10 days ago, ie 2 Sept with current weather could be a minimum.

Yes, I meant a month before the minimum in 1995, reached on October 4th. Should express myself more clearly.

I'll go and find a SLP map for that period.

crandles

Sorry I am mis-reading. You meant a month before 4 Oct. Yes that sounds quite possible with current weather patterns.

crandles

Possibly Luis headed up there 11 Sept but I don't see others after that.

http://en.wikipedia.org/wiki/File:1995_Atlantic_hurricane_season_map.png

Neven

Here's a map with SLP for the month leading up to October 4th 1995:

And here's one for the past two weeks:

Where there's white in the middle, there's blue and purple now and it's forecasted to get worse the coming 5 days.

So again, despite the never before seen (in the satellite era) combination of thin ice and warm waters, I think weather conditions are finally going to have their way and a new record minimum won't be reached in the IJIS and NSIDC data sets.

Phil263

At this stage, minimum extent for 2011 could still be 4,526,575 on Sept 9, if tonight's revision brings us above that figure!!!

Considering the ECMWF forecast, I agree with Neven that we are not far off the minimum, in time and in extent figure +/- 4,500,000 just over rather just under I think.

Neven

And here's 2007 from September 10th to the minimum on the 24th:

With a perfect set-up like this a new record would've been reached already this year. Easily. As it is, 2007 has been equaled in some data sets, and almost in some others.

I will do a post on this, so consider this an appetizer. :-)

none

You forgot to make green in your spreadsheet September 1 and 7-9 in the year 2006 with their positive values

Neven

Thanks a lot, none, but the green cells are for the first positive value at the end of the melting season. Another thing I should have worded better. :-)

Andrew Xnn

There is still a significant potential for compaction. It is difficult to say when it will be over; especially with the ice being as thin as it it.

It may be a while before we get those huge pressure gradients and corresponding winds.

Neven

There is still a significant potential for compaction.

Definitely. 2011 is behind 2007 by more than 2% on the CAPIE chart.

Philiponfire

If you look at the ice drift map and CT concentration map for the last 2 days you can clearly see that there is ice moving out of the central Arctic towards the East Siberian sea. Central Arctic concentration going down East Siberian going up and the edge moving out. so this is all about ice movement not growth. clearly it depends on sensor sensitivity but I do not think there will be a corresponding increase in SIA on CT.

Seke Rob

Into crazy stats: CT Area days below 3 million square km...

2007 had 15 days, first Aug 23, last Sept. 19
2011 has had 8 through Sept.9, first Aug 24.

Through Sept.9, 2011 has had one more sub 3 million than 2007 :O)

Through Sept.9, both have a sub 3 million mean of 2.96

CT not updated yet as at 15:24 CET

Peter McGrath

I take it the vast majority of people writing on here are sheep, or have the complete inability to make decisions for themselves? How on earth can the above table prove anything about the late formation of ice this year as there hasn't been an upturn until now? That is nothing more than picking the figures you want to show, and then you are only picking very shaky figures as there is nothing to support your statement. I want to point out that from 2005-2010 on the 10th September the ice loss was still happening and only in 2011 was it increasing proving without doubt that we are in a new ice age. Is that a fact i could have stand up to scrutiny, no of course not but as with any figures they can be manipulated to whatever you want them to be. This isn't a balanced website, everyone knows that but please try to be a little less brazen in your attempts to show we'll be sunbathing in siberia soon.

Neven

How on earth can the above table prove anything about the late formation of ice this year as there hasn't been an upturn until now?

My point is that "[t]his is another one of those small signs that the combination of ice thickness and warm waters are overruling the influence of weather conditions". First sentence of the post.

I'm not claiming it's proof, I'm claiming it's one of those small pieces of evidence. Despite the weather which wasn't conducive to extent decrease at all, IJIS SIE kept going down, quite a bit longer than previous years that had an uptick as soon as the weather switched (2008 comes to mind).

It's not far-fetched to think this has to do something with the state of the ice, as there is other evidence of that as well.

But anyway, this post was mostly to inform readers that IJIS has shown its first uptick in this phase of the melting season. I don't need to prove anything. The Arctic sea ice can do that pretty much by itself. Doesn't need any distortion or exaggeration.

This isn't a balanced website,

Thanks for the compliment! :-p

we'll be sunbathing in siberia soon.

Make that Greenland and you have a point.

---

IJIS reports another uptick: 9,375 square km.

Jon Torrance

Since Neven focuses on 2005 to present, I'll point out that in 2003 the first uptick in JAXA extent wasn't until September 12th. It was of 64375 and was followed by another uptick of 74688 the next day and yet the minimum still hadn't been reached, although it came on the 18th and was only about 9000 lower than the value for the 11th.

Peter McGrath - if you can't handle someone making a simple observation about the observational data, perhaps you should stay off the climate blogs. Or at least stay quiet - now we know reality is getting under your skin :)

Newcrusader

I guess some in the 'outer-world' where not expecting to see a decline as close to the 2007 low.

In any case- they will have to except the fact that in the next few years we are likely to see a large drop below this year and 2007.

Lord Soth

Remember that we already had a record low extent this year from one respected source.

It would be nice if all the sources reported below 2007, so the climate change denial group would not cherry pick.

I believe the only reason, we are fixated on IJIS, is because we get daily updates, with actual values; not because it is any better or worse than the other extent models.

Correct me if im wrong, but didn't we get a newer area record today at 2.905 million km^2

Lucia (The Blackboard)

Peter--
It's true the balance of views varies from blog to blog. But in fairness, people at my blog are also looking at every snippet of evidence snippet of data to see whether they think we might be 1 day off or 20 days off from the minimum. If you don't like the 'balance' at Neven's stop by mine-- or some other blog.

Andrew Xnn

Peter;

Rather than insulting most everybody on this blog, it would make more sense to point out where "balance" is needed in a constructive way.

Neven

Thank you, Lucia, I agree. Everyone is free to choose his own echo chamber.

But again: we might be mostly alarmists/warmists/whatever here, but there really is no need for us to exaggerate what is happening up North. What is happening there is alarming. This is not because we are giving it an alarmist twist. We don't have to.

Reality/nature is doing it, and as long as she continues with it (she might, she might not), we don't have to twist facts, or distort, or lie. I don't think we would if we felt we had to, but that is irrelevant.

I hope this is clear.

I believe the only reason, we are fixated on IJIS, is because we get daily updates, with actual values; not because it is any better or worse than the other extent models.

Yes, it has become popular because of the daily updated csv file, and I personally find it the best looking graph.

Peter McGrath

Edit Neven: Thanks for stopping by, Peter. Good luck in finding an echo chamber that suits your tastes better. We like ours the way it is just fine.

I would appreciate it if you would refrain from posting further. This thread is about IJIS SIE.

Jon Torrance

Peter McGrath,

Quoting one Peter McGrath "...I for one like to read a balanced point of view so why should that stop me reading this Jon,..."

Also quoting the same Peter McGrath "This isn't a balanced website..."

I think the reason why you might want to stop reading this blog is obvious based on those two statements. But if you want to punish yourself by forcing yourself to read things you don't like, I have no objection.

A Rambler

I was just about to say, this Peter McGrath fellow seems really angry about something and is ruining my zen. Thanks Neven for fixing that.

Espen

You cant win them all!!

Neven

Yeah yeah, enough already. On-topic please. Any new records out there? (one is getting close again)

Ned Ward

We've updated our intercomparison of the extent data from IJIS, MASIE, and Bremen. Note that (as explained below) the Bremen data are unofficial and differ slightly from the official totals.

Time series since 1 July: png

Time series for the past month: png

IJIS data are from the daily CSV file. MASIE data for the most recent 28 days are from the daily CSV file, plus earlier data from crandles's spreadsheet.

The Bremen data were derived (by a colleague) from processing the TIFF version of daily maps in their archive, as follows:

(1) Download the maps from the UB archive (e.g., asi-n6250-20110911-v5.tif for 11 Sept. 2011).

(2) Classify pixels as ice if their concentration is at least 15%.

(3) Classify all pixels in the north polar gap as ice (some year this will no longer be reasonable...)

(4) Count the number of pixels of ice and multiply them by the pixel area (6.25 km x 6.25 km).

The resulting extents should accurately reflect the data provided in the maps. They do not exactly match the occasional totals that have been posted. For example, last week's press release said that the extent on 8 Sept. was 4.240 million km2. Processing the map this way yields an extent of 4.276 million km2.

I'm not sure why the totals that UB reports appear to differ slightly from the extent shown on their maps. As you can see in the second link above (the time series for the past month), there are some pretty large "noise" swings in the single-day extent data shown in the maps (large areas of ice can disappear one day, and reappear the next).

This suggests it might be a good idea to use caution when interpreting the maps, and to avoid drawing too many conclusions from comparisons of maps from one day to the next.

Chris Biscan

Big compaction day in the Beaufort. Not surprising. given the wind shift that took place.

also holes opening up in the Fram and the Eastern side of the ice pack has took some more beatings from historically warm waters pounding it.

Chris Biscan

we will likley see the CT SIA drop another 100,000L the next 3-4 days.

crandles

Re "Big compaction day in the Beaufort."

I would suggest it is more a case of the melt slowing down so very few small pieces are breaking off larger pieces. The small pieces were always going to melt out; it is just a case of when they stop breaking off bigger pieces.

Wayne Kernochan

Neven - I'm not sure this qualifies as a new record, but I thought it was interesting. In the Sept. 12 International Business Times article referenced on your site, they quote researcher Axel xxx, apparently of Bremen, as saying that ice volume was going down faster than ever for this time of year. The interview of Axel was clearly some time between the 8th and the 12th, suggesting either that he's talking about their volume figures a couple of days ago, or the PIOMAS ones.

According to the PIOMAS figures as L Hamilton has them, on Aug 31 the volume value was 4.275 mm3, which was about 150K lower than the 2010 minimum. It appears that in 2010, volume lost about 300-350K between August 31 and the minimum. So what Axel seems to be saying is that, so far at least, volume seems to be aiming at a minimum south of 3.9 mm3, and maybe below 3.8 mm3 -- which would mean a 12 % drop from last year.

It might also, given what we're seeing in area right now, yield an average thickness well below 1 meter at minimum -- certainly a new record.

Jon Torrance

crandles,

Looking at today's preliminary Bremen concentration map compared to yesterday's map, I think "Big compaction day in the Beaufort." is a much better explanation that your suggestion. The only plausible alternative I can see is that a whole lot of the edge spread out to less than 15% concentration while refreezing simultaneously filled in a lot of polynyas, which really doesn't sound very plausible when I try saying it out loud.

crandles

100,000 area drop sounds a lot. I accept there is time for 100,000 extent drop as edges sharpens up and southern Greenland melts out. Is there any time left for area decreases with the weather being so good for the ice to remain and area minimums have averaged about now?

crandles

Jon, I am certainly no expert so it is likely to be me that is wrong. My explanation would certainly require a lot of the small bits spreading out to less than 15% concentration as well as some melting out.

Would you expect compaction to leave shapes like little nodules connected to the main pack? I would have expected compaction to tend to smooth out sharp angles into slow curves particularly on upwind side of main pack. Maybe I am not appreciating the scale and likelyhood of eddies at this scale.

Neven

Crandles posted something over at Lucia's that made me have to think some more. Apparently 2003 had its first uptick on Septmeber 12th, which is later than this year, albeit the fact that 2003 was very close to having its uptick earlier (a drop of just 625 km2 for September 2nd and a drop of the same amount on September 8th)

What is even more interesting:

Looking at the SLP maps from that time, I see there's a huge cyclone in the 5-6 days leading up to the first uptick, pushing out the ice from the Beaufort Sea to what I assume were also warmer waters then.

Mind you, that ice in the Beaufort isn't there this year, as 2003 had about 2.35 million square km more ice than yesterday.

A big cyclone like that would be interesting to see now. Maybe we'll get one next week.

Neven

Wayne Kernochan, I had a post on the new volume record.

It might also, given what we're seeing in area right now, yield an average thickness well below 1 meter at minimum -- certainly a new record.

Agreed.

Yikes! CNN unleashed the masses!

Yes, that press release is doing the rounds alright. Good.

Jon Torrance

crandles,

No doubt we can both be wrong on some aspect of this and inexpert in solidarity with each other. I agree, that isn't the shape of ice edge I'd intuitively expect from compaction. Hopefully it's been a clear day and visible imagery will allow someone to enlighten us as to what's actually happened there.

Chris Biscan

http://vortex.plymouth.edu/gifs/110912192402.gif


That is why the ice there compacted.

and this:

http://www.wetterzentrale.de/pics/Rhavn002.gif


it's warm and the winds are compacting.

the models were showing this lasting a week or more.

Now they have it for 2-3 days. Which is why it doesn't look as bad as it did.

Andrew Xnn

Please keep in mind that theoretically, when an ice free summer arctic is reached, the first uptick will occur as ice forms since there won't be any to compact. That formation will likely be north of 85 and may happen much earlier than Sept 12th.

Wayne Kernochan

Hi Neven -

Sorry I wasn't clear. Not a new volume record; a new thickness record. - w

Lord Soth

Yes it is good that CNN is reporting a minimun ice extent. CNN is considered liberal.

The real test will be the US Fox network, which is a cross between right wing and wing nut. If they report a minimun it will be the lowest since the beginning of time (ie 4004 BC).

dorlomin

http://www.uni-koeln.de/math-nat-fak/geomet/meteo/winfos/arcisoTTPPWW.gif

Umm there is a low near Alaska north coast that is rather intense in that map. Is that an error or am I reading it wrong?

Twemoran

dolomin

Bad sensor - Canadian charts don't show it.

Earlier in the season the same location showed as an extreme low and one of the other posters showed me the light.

Rob Dekker

One interesting feature over the past weeks has been the large 'hole' in the ice north of the Laptev, with open water all the way to 85N.

Since yesterday, it seems that at least the Bremen AMSR image shows this hole covered with 50-75% ice concentration. Cryosphere still shows low (25% or so) concentration with open areas.

I tried to find an image on Modis from the past week that shows the situation in that area, but cloud cover obstructs the view. It just seems that the ice/ocean is dirty (brownish).

Anyone knows what's going on there ?

Paul Klemencic

Rob Dekker, The ice pack has been pushed over 100km, and likely in places more, toward the Laptev Sea. This has closed on the hole, and along with a pincer movement, has put about 100 km of ice with over 90% concentration between the weak ice and the 85N parallel. Given this movement, it is unlikely we get open seas above 85N this year.

The ice pack was set up about a month ago, to rotate into the Fram, and in the Laptev region, move weak ice above 85N, but we didn't see the usual rotation. If we had, the E. Siberian region ice pack could have been separated from the main pack, and left to drift. Also, there has been very little movement of ice into the Fram.

However we did see the ice pack on several occasions pushed toward Svalbard and Zemlya Franceta Josefa, but the sea was warm enough to melt it out.

If we had even a week of a classic Arctic Dipole, this season could have seen much worse ice melt. As it is, a fairly large amount of ice in the E. Siberian, Laptev, and the central arctic basin should survive the season, even though very weak at this point.

I still think we have about a week for a bottom, but it could come earlier... the weather will determine.

Chris Biscan

Final Bremen map shows a 80,000km2 loss or so on it. Probably will send Bremen to a new low.

Kevin McKinney

. . . and back down again, at 4,529,844 km2. (Prelim for September 12.)

Rich and Mike Island

This pause surprised me. I still think we'll go down below 4.5 million sq km. Then it should be interesting to read about what kind of weather patterns help arctic sea ice grow and what patterns hold back the advance of the ice this fall.

We're still learning about this stuff :)

Phil263

and back down again, at 4,529,844 km2. (Prelim for September 12.)

If the upward revision is as big as last night , we might see another increase for Sept 12. Preliminary is higher than yesterday prelim by about 10k and we are still above the (temporary ?) minimum of 4,526,575 reached on the 9th.

Stevemosher.wordpress.com

Who needs balance? I come here for three reasons.

1. it's the only place that discusses the weather and its role.
2. the players have a long history of looking at this data.
3. they have a perspective that they are entitled to have and defend. perspectives are good.

The balancing happens in my head. err hopefully.

Phil263

True, most participants on this blog approach the problems of the arctic ice and the problem of climate change generally with a certain perspective. No researcher even the most dyed in the wool positivist researcher can claim full objectivity!
What I like about this site is the fact that while we may be what people with a different perspective wwould call "warmist", we have different points of view and there is an active and generally courteous discussion between participants.

I would like in particular to congratulate Neven for his balanced and factual comments about the sea ice situation and evolution in the Arctic. I particularly commend him for posting links to papers that go somewhat against the grain of what people on this blog would like to believe. This is something I could not say about other popular climate change sites that share the same perspective as this site.

Chris Biscan

Who wants to see badassness?


I created with HDF tools an animation of Jaxa/Bremen exact to scale using the NSIDC grids so they are exactly the same size. So the overlap is perfect.

We can use this to do some validation on extent with the Modis terra and aqua satellites.

http://i174.photobucket.com/albums/w109/frivolousz21/131588326627945.gif

Rob Dekker

Paul Klemencic, thanks a lot. That explanation makes a lot of sense, especially considering the position of the lows right now. Also, if the lows are stable, and compaction continues in that hole, we should see more extent decrease there.

Neven

Thanks, Phil!

I have always tried to be open here about being an alarmist/warmist. I like to think I don't have a real agenda, but if I do I try to be transparent about it.

If people want to know where I'm coming from, they can read my word of welcome on this blog and the guest blog Michael Tobis was so kind as to post last year (and goes much further than just AGW).

Here are a few answers I gave to some questions recently:

Why do you fight?

Because I can't stand ugliness. I don't want to be part of it.

What are your dreams?

Having a garden and a library.

What are your ethics?

No violence, and thus trying to prevent situations that make violence likely.

I'll have a disclaimer at the top of this site at the end of the melting season.

Paul Klemencic

I haven't been putting comments up comparing sea ice maps, since I am traveling and have limited time. But I did update my graph showing IJIS versus MASIE versus estimates of Bremen, mixed with a few actual Bremen numbers from various sources.

The MASIE sea ice extent reported for day 253, supposedly September 10th, fell 111k, which clearly doesn't fit observations. However, using a six day lag, this big decline is the day before the decline observed on September 5.

I have updated my spreadsheet comparing the different SIE's, and have posted a picture of my graph comparing the SIEs on google docs.

As we can see on the graph, the divergence between the IJIS (adjusted to the date representing the end of UTC day closest to middle of duration of the 48hr temporal sampling period), and date/ time corrected MASIE data continues. The graph of Bremen extent data is my rough estimate using hints from Larry H. with a few points where he was kind enough to share the number for a specific day, or from the recent Bremen press release.

The date-corrected MASIE numbers are approaching the record low minimum extent, with MASIE only about 100k sq km from that level (for whatever date the last data point represents). If the data is from six days earlier than labeled on the MASIE site downloadable spreadsheet, then MASIE is almost certainly going to confirm the Bremen data point showing SIE below 4.25 million sq km.

Paul Klemencic

Chris Biscan, you said in a comment earlier, that you had spent some time looking into the accuracy of the different ice concentration measurement systems.

Could you share a few comments comparing the IJIS report with 12.5 km grid compared to the Bremen 6.25 km grid versus the MASIE 4 km grid. Am I correct in assuming that because of a lot of dispersed ice, the IJIS report picks up more ice extent, the Bremen less, and MASIE similar to Bremen?

Paul Klemencic

Ned Ward, regarding this comment:
We've updated our intercomparison of the extent data from IJIS, MASIE, and Bremen. Note that (as explained below) the Bremen data are unofficial and differ slightly from the official totals.

... The Bremen data were derived (by a colleague) from processing the TIFF version of daily maps in their archive, as follows:

(1) Download the maps from the UB archive (e.g., asi-n6250-20110911-v5.tif for 11 Sept. 2011).

(2) Classify pixels as ice if their concentration is at least 15%.

Nice work. The only thing I would caution, is that the Bremen map light blue areas go down to 10% ice extent (if the legend is correct). So your pixel count extent for Bremen should be slightly higher than the Bremen report; and that appears to be the case for your results.

But at least we are talking on the same page now. If MASIE does correct the date issue, or at least explain the rather bizarre swings in their data ( A 111k decline on September 10 ???), then the graphs you linked to in your comment are looking much like mine.

Ned Ward

Paul writes: The only thing I would caution, is that the Bremen map light blue areas go down to 10% ice extent (if the legend is correct). So your pixel count extent for Bremen should be slightly higher than the Bremen report; and that appears to be the case for your results.

Sorry, but I'm not quite following this. The calculation we used is based on the actual numerical concentration values (0-100%) not the colors of the pixels. Maybe that wasn't clear in my summary.

D

Theres this hot spot south of svalbard, which is at 16/18 degc i have no idea how extensive this could be but feel there must be a substantial flow for it to show up this far north.
http://polar.ncep.noaa.gov/sst/ophi/color_sst_NPS_ophi0.png
Looking at this it would appear to be making it's way form the latitude of spain, but more or less due south of greenland.
http://polar.ncep.noaa.gov/sst/ophi/color_sst_NW_ophi0.png
To submerge and travel 4-5000 miles and retain enough heat to surface at 16 degc+ makes me think this is huge certainly too big for it all to be sucked down the 'plughole'. Or is this a normal feature, just warmer? where else does this current carry too?

Kevin O'Neill

It's really difficult to get meaningful 'apples-to-apples' comparisons on first uptick day. If you think about it, the first uptick day should be happening earlier.

While the Atlantic edge hasn't shown a lot of movement over the years, the Laptev/East Siberian/Chukchi/Beaufort side has seen the autumn ice edge move more than 5 degrees north in many places. With an edge that much further north random cold weather events should be likelier to happen earlier calendar-wise; which should lead to earlier 1st upticks.

That the data isn't adjusted for latitude and still we see generally later minimums and 1st upticks is another indication the ice-loss is beyond linear.

Ned Ward

Phil263 wrote: and back down again, at 4,529,844 km2. (Prelim for September 12.)

If the upward revision is as big as last night , we might see another increase for Sept 12.

Yep, looks like yesterday was another uptick, which makes three in a row.

There have been a few times in the past decade when there were three consecutive increases in Sept. before the minimum. So this is not necessarily the end, in spite of three consecutive increases.

Nightvid Cole

The first Bremen map for today seems to show a rim of new ice growing around the "Beaufort bite", indicating that the freezing process has begun in earnest. So it would take some pretty heavy compaction to get a "2010 style" "double dip", but of course it could still heppen if the Transpolar Drift starts drifting and the Beaufort Gyre starts gyrating...

Lucia (The Blackboard)

Ned--
My 'predictometer' says the 50%50% point for the minimum in the 7-day average of JAXA is 4.443; the current value is 4.547. The daily minimum would be somewhat lower. So, based on the condition of the ice, we should expect some more drops. That said, my 95% confidence intervals are 4.318 to 4.532. (The reason for the excess decimals is merely to show people how sensitive various features are to the assumptions under my statistical model.)

Chris Biscan

: Nightvid Cole,

New ice is not forming in the Beaufort sea. I am not trying to be a jerk but the Beaufort is actually torching right now. for this time of year.

http://ocean.dmi.dk/arctic/satellite/index.uk.php

You can see the SSTs in one day warmed up dramatically on the surface. This can vary but real time obs show there is quite a bit of warm water out there in that area on the surface and under it.

http://www.wetterzentrale.de/pics/Rhavn122.gif

Ice isn't going to form there under 12-14C 850 temp anomalies. and 4-10C ssts flowing in that direction.

also if you look at the coast the prelim maps do not account for satellite wobble. This helps create delusions in the prelim maps that make ice seem to be moving much more then it really did. They often later correct this, which peer reviewed studies show it can be corrected upwards of 30KM.


A Rambler

What are these IJIS revisions based on, fudging?

Nightvid Cole

:Chris Biscan,

I was talking about the ice edge from 78N 145W to about 79N 165W on the Uni Bremen map, away from the SST "hotspots" and with 850 mb temp near -5 C on your maps. When it goes from a rugged edge of ice with holes to a smoother, gradient fringe of ice expanding outward, this is new ice indeed.

Nightvid Cole

:A Rambler,

I think that the IJIS revision is a result of taking a moving average which includes several hours of the next day, in order to smooth out the data (compare IJIS to Bremen extent graphs!)

Chris Biscan

You might want to look at a satellite image.

ice didn't blow up today in that area.


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