Polar Ice Extent

[Gray-Wolf]

I think you are on a hiding to nothing if you expect that slab of ice to remain all the rest of melt season b.b.<BR><BR>Look at the drift on the recently calved ice at either end of the 'blockage' and then down the passage towards Baffin. You'll note the flow of the tributary inlets flowing out into Baffin and also the counter flow at the western end of the blockage. My guess is that the western end will be the last to go but this will be eaten away from the eastern end (as we see happening today). you must realise that there is a current now flowing through the passage (from Bering out to Baffin) so we have warmed waters flushing the ice out into Baffin melting the ice from below as it flows. With all of Hudson now melted (over a month early) there are no 'ice jams' in Baffin just lots of dark water (warming nicely) to welcome the remnant ice from the passage.<BR><BR>We will see but it's only going in one direction sadly.

Edited July 4, 2010 by Gray-Wolf

[sunny starry skies]

Hi G-W, just responding to your comment on my last post, no worries about your 'squiffiness' when writing it! I understand that it is all about the state of this year's pack that will make the progression towards the next minimum particular to this year, and not predictable purely based on previous years, and that's not even including the vagiaries(sp?) of weather! My aim with that little piece of data analysis was twofold - one to correct the erroneous information I posted earlier, and second to provide boundary conditions to what we might expect come this September given the same amount of extent loss to melt as those years (those boundaries came out at between ~3,800,000km2 and 4,500,000km2). Something I didn't mention, perhaps because I specifically didn't want to come across as 'alarmist' was that the volume measures this year are way down on previous years, and you've seen my videos of the Nares strait and you correctly identify the unusually high mobility of the pack this year as another factor. Thos observations would make me predict the ice extent to be in the lower range of the estimates based on previous years come September. And low volume values don't preclude a dramatic retreat leading to a record low value by a large margin through in situ melt-out, as well as transport out of the Arctic basin.

The Antarctic is a totally different system, and so there are other processes involved there, some of which G-W points to, and some I mentioned (I think) in an earlier post. It's interesting that the global sea ice albedo is presently approximately constant due to the sea ice increase in the Antarctic, but we need to treat them as two completely separate systems - the Antarctic has little effect on our weather, and does not have the same stores of methane contained within nearby permafrosts. Each area has a susceptible ice sheet nearby (WAIS, Greenland), which are independently capable of adding large quantities of water to sea level. We lose the Arctic cap, and sea ice increases in the Antarctic are not going to compensate!

sss

[Gray-Wolf]

Thanks both for the reply and the understanding S.S.S.!

A quick update on the NW Passage. The ice is now fracturing in such a way (in the last 'plug' blocking the channel) that I believe the flow from west to east, through the channel, is effecticely pulling the ice apart. You can see on the latest MODIS that the ice has pulled away from the shore at the western end but all the fragmentation is going on east to west.

I'd imagine a channel full of fragmented ice by weekend. Quite amazing really?

Mr Serezze appears to be spot on with his 'choked with melting perennial for 3 years' prognosis back in 07'!

[4wd]

Melt has slowed considerably of late, Low Pressure dominates up there through the next crucial week or two.

I expect the 2010 line will be nearer 2006 than 2007 now.

[Gray-Wolf]

From looking at the images the only 'slowdown' in ice is the relaxation of the central pack (from pole towards Svalbard), If you check C.T. for the Arctic Basin etc. then you'll see that the 3 areas within the basin show an 'increase' in area (Esp, East Siberian) as the ice 'stretches out over more ocean. Sadly, though within the 15% or more criterea, this spreading leads to more 'dark water between the ice and so a more rapid melt.

We either face a 'pick up ' in melt rates (as we see today) or the melt will slow/stall until it suddenly 'vanishes' as the 15% or more barrier is compromised by the melting.

[Richie V]

Because it shows an increase?

Maybe the decrease in the north is wrong also?

Ironic that were close to an all time record high extent in antartica!

I still think the artic extent is in deep didery doo this year though.

Edited July 6, 2010 by Chassisbot

[Thundery wintry showers]

Melt has slowed considerably of late, Low Pressure dominates up there through the next crucial week or two.

I expect the 2010 line will be nearer 2006 than 2007 now.

The map you posted suggests that it's still marginally below 2007, so it certainly isn't closer to 2006 than 2007. Forecasts for the next two weeks have a "cold low" over the pole which should restrict melt in that area, but parts of Siberia are currently exceptionally warm with >20C at 850hPa and surface temps well over 30C.

But it is possible that we could have a similar "melt summer" to 2006 which would leave us well short of the 2007 record. It remains to be seen.

[Gray-Wolf]

But it is possible that we could have a similar "melt summer" to 2006 which would leave us well short of the 2007 record. It remains to be seen.

If we still held the 'volume' of 06' T.W.S. that might be true but have a quick shufftie at how much less 'volume' we have today compared with then?

That extra thin ice is somewhere and it won't like melt season.

If we've had three years of collapsing perennial spreading a cloak over the final figure by it's then this year will not 'slow up' as the loss has in past years. If I'm right it'll continue to loose sq km's, into Sept ,at a rate that we're not accustomed too.

Ironic that were close to an all time record high extent in antartica!

I still think the artic extent is in deep didery doo this year though.

:)Please read up on Antarctica?

[4wd]

http://www.accuweather.com/video/73146202001/icing-on-summers-cake.asp

Joe B predicts ice minimum similar to 2006 also

Edited July 6, 2010 by 4wd

[Gray-Wolf]

http://www.accuweath...ummers-cake.asp

Joe B predicts ice minimum similar to 2006 also

Joe B ,as per his 'strike ' record, is wrong.

Come Sept 19th I'll either owe an apology or need a bit of Kudos?

We do not retain the ice volumes to compare with the past 30yrs. We have less ice volume than ever in fact so surely this 'thin spread ice' , to be comparable with other years, is lacking in areas where it used to have bulk

What we are seeing in Viscount Melville Sound is a consequence of such 'thinness'.

Even the channels feeding into to it (McClintock,Peel etc, are shallower ,and of past times, were ice filled [well nearly] but are now just 'skim ice' and breaking like the front of a glacier before it first calves that summer!

They used to be like an ice pop in a wrapper and just 'relax' back a little over summer NOT flush out into the sound like pack ice!!!

EDIT: Well it's GdGdGdGoodnight Folks for the ice at Melville!

http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2010187/crefl1_143.A2010187193500-2010187194000.250m.jpg

As predicted, you can see both the failures (where the ice breaks apart) butalso, on this image ,the faults where the ice will fail and you can trace it through the last remaining portion of the sheet!!!

Maybe I'm out done in my 'weekend ' prediction?

Edited July 6, 2010 by Gray-Wolf

[4wd]

OK, let's see who is nearest :lol:

[Gray-Wolf]

OK, let's see who is nearest :lol:

LOL!

Drag me up to a 'just sub' 4 million an' I'll be happy!!!

[sunny starry skies]

Put me down for something close to 2007, finishing a little higher (say around 4.2-4.5million sq km). Though I doubt the weather will be as favourable as in 2007, the thinner ice, as G-W notes will do the rest for loss in area given an average melt season. With the lower ice volume than 2006, you're asking for a truly remarkably low melt this year 4wd. Weather will, of course play a significant role in which of us all will be closest to the actual figure!

Oh, if Joe B is predicting a low melt, it probably means it'll be a record high melt given his 'track record' - see this article and links within:

http://climateprogress.org/2010/07/06/joe-laminate floori-worst-long-range-forecaster-accuweather-global-warming/

how good are his weather forecasts?:

http://groups.google.com/group/uk.sci.weather/msg/c1c2bd6e12d9e7c6

If he can't even predict weather, what on earth will he know about Arctic ice?

NSIDC June report:

http://nsidc.org/arcticseaicenews/2010/070610.html

Fastest June loss on record, lowest June extents. Very interesting analysis, and a suggestion of a somewhat slower melt in July due to melt reaching slightly thicker ice. Interesting talk on the Arctic dipole weather pattern and on the Nares Strait.

sss

[Gray-Wolf]

Yup, a bit of a worry to see the spectre of the 07' weather pattern emerging with the ice volumes of 2010!

It is now the period of time that we see the more 'durable' central pack ice starting to melt so I guess we'll fine out pretty soon just how 'tough' it is.

[Gray-Wolf]

Though I'm not yet positive the glimpses from the 1:30pm MODIS (cloudy at the western end) shows Viscount Melville Sound now fragmented!!! Amazing if true.

Will check tonight (the images are 4 or 5 hrs behind times and the 'Terra' pass is about 6:30 (ish) with Aqua earlier(?).

With any luck the cloud bank will have shifted and revealed the western end of the sound.

[The PIT]

Though I'm not yet positive the glimpses from the 1:30pm MODIS (cloudy at the western end) shows Viscount Melville Sound now fragmented!!! Amazing if true.

Will check tonight (the images are 4 or 5 hrs behind times and the 'Terra' pass is about 6:30 (ish) with Aqua earlier(?).

With any luck the cloud bank will have shifted and revealed the western end of the sound.

Mmmm are we beginning to slow down??

http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

[Gray-Wolf]

Mmmm are we beginning to slow down??

http://www.ijis.iarc...aice_extent.htm

We are both getting into the 'thicker' , more resilient ice and into 'drifting pack' where the 15% or more criteria starts to mess around with the 'facts' of the matter.

Seeing as we have the same set up as 07's summer (Arctic dipole anom [DA])

"The Arctic dipole anomaly

The record low ice extent of September 2007 was influenced by a persistent atmospheric pressure pattern called the summer Arctic dipole anomaly (DA). The DA features unusually high pressure centered over the northern Beaufort Sea and unusually low pressure centered over the Kara Sea, along the Eurasian coast. In accord with Buys Ballot's Law, this pattern causes winds to blow from the south along the Siberian coast, helping to push ice away from the coast and favoring strong melt. The DA pattern also promotes northerly winds in the Fram Strait region, helping to flush ice out of the Arctic Ocean into the North Atlantic. The DA pattern may also favor the import of warm ocean waters from the North Pacific that hastens ice melt.

June 2010 saw the return of the DA, but with the pressure centers shifted slightly compared to summer 2007. As a result, winds along the Siberian coastal sector are blowing more from the east rather than from the south. Whether or not the DA pattern persists through the rest of summer will bear strongly on whether a new record low in ice extent is set in September 2010."

there's a lot of clear skies up their to actually have a look at the ice/framentation/melt ponds/dark water

[BornFromTheVoid]

The ice over the central arctic seems to be breaking up quite a bit.

This image has the Laptev sea on the upper right, Kara sea bottom right, the central Arctic basin to the left, almost at the north pole.

At center left you can see the broken ice. I'm guessing this is the kinda ice area that shouldn't be breaking up at all?

Larger image here

http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r04c04.2010189.terra.500m

[stewfox]

We are both getting into the 'thicker' , more resilient ice and into 'drifting pack' where the 15% or more criteria starts to mess around with the 'facts' of the matter.

I'm afraid that always happens from July onwards

Real data conflicts with your 'facts'

[Gray-Wolf]

I'm afraid that always happens from July onwards

Real data conflicts with your 'facts' :lol:

And always will Stew (if there's any ice left by July in future years).

Now about this 'data' and my 'facts'?

If we are still on Viscount Melville and McClure opening 6 weeks earlier than the last time (and 'first time') they last opened I think you'll need check your 'data'.

If you refer to something else on the thread then you'd need to point me at it as I 'believe' many things to be 'facts' (the eventual loss of summer ice in the Arctic being one).

EDIT: This site does ice over '30%' as solid ice and we can see a rapid downturn which ,I imagine will prelude the same on the 15%= solid ice sites.....

07' had 4 days of low ice loss around now, better hope that 10' isn't going to open up a gap again eh? For me 10' has the better 'legs' for the final dash not having the added 'prop' of slumping/collapsing perennial to bolster the final figure.

Sadly cloudy over Melville/McClure so we wait to see how fast the fragmented ice clears the channel. I bet it heads East into Baffin/Newfoundland (and melt).

http://rapidfire.sci...201000.250m.jpg

the best for today but it does give a glimpse behind the big chunks at the eastern end of the old blockage showing how shattered the mid section now appears? I wonder if this comes from wave action from the western end and we can expect that section to appear similar to the middle??

All in all it won't take such mangled ice long to clear/melt.

EDIT:EDIT: this shot

http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2010190/crefl2_143.A2010190171000-2010190171500.250m.jpg

shows an early view and the fissures appear to run east /west. The McClure end was terminated by a fractured slab across the ice front so I guess this went and allowed the ice to 'fan out' into the melted shore areas. It does not signify very thick ice should this be the case. Solid pack (3m+) would hold together as a solid floe (like the one Dr Barber encountered?).

Edited July 9, 2010 by Gray-Wolf

[BornFromTheVoid]

Looks like the Nares Strait has become blocked, at least temporarily

http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r03c03.2010190.terra.250m

Middle left.

[Yorkshiresnows]

Hi Folks,

Don't want to interrupt the dooms-day posts too much ....... but you've always got to look on the bright side of life .......

...... perhaps we may be about to see a change in pattern .... PDO from +ve and Northern hemispheric warmth to PDO negative and a colder out-look (much as has been touted as a possibility on previous threads) ... and with it the possible start of a recovery in Arctic ice ...... perhaps ... perhaps not

Guess we have to wait and see.

http://www.accuweath...ummers-cake.asp

http://www.accuweath...y-worldwide.asp

http://www.accuweather.com/video/110914873001/more-on-the-coming-cooling.asp

Y.S

Edited July 10, 2010 by Yorkshiresnows

[BLAST FROM THE PAST]

ice melt slows, Polar region is cooler than average and will get colder and projected global temps to fall too. Here is where we'll go, no record ice melt in fact we'll not be in bottom 2 and we're in for a harsh autumn winter.

Enolugh for now, lets see where we go.

BFTP

Edited July 10, 2010 by BLAST FROM THE PAST

[J10]

Time for my first update on this thread for the summer.

Not good figures so far this month with the latest figures for the 26th June at 9,216,563, which is 700,736 below recent averages, and 1,436,171 below longer term averages. It is also the lowest on both series. So we are around 8 days ahead of recent averages in terms of ice loss. (i.e current figures = 5th July Average figures)

The next update will be a fortnight today, and hopefully we will see an improvement before then.

As promised, the fortnight is up and this is the latest update. The Current figures are at 8,258,594, this is 580,290 below recent term averages, so a slight improvement with 1,456,448 below longer term averages. The figures have now gone above 2007, which is the minimum expected at this time of year. We are around 7-8 days ahead of recent averages in terms of ice loss. (i.e current figures = 17-18th July Average figures)

Going forward we would like to see the deficit to recent average continue to be cut over the next week, and also the surplus over 2007, to be extended.

[SteveB]

ice melt slows, Polar region is cooler than average and will get colder and projected global temps to fall too. Here is where we'll go, no record ice melt in fact we'll not be in bottom 2 and we're in for a harsh autumn winter.

Enolugh for now, lets see where we go.

BFTP

I'm sure it's been said before, but there seems a lot of blue on the 850's on GFS up in the Artic for this time of year, I saw some -10 in FI on today's 06z..