Arctic Ice

[osmposm]

Which one is telling the truth? Something's changed............I think I'll remain 100% skeptic/non-believer.

Delta, I agree that there is an inconsistency. The lower one, which I assume is an image you (usefully) saved, shows an ongoing slowing of the melt for about six days up to the 30th or 31st July. The upper (?current) one shows the slowdown lasting a shorter time, and being replaced by a renewed steeper fall line from the 27th or 28th.

I suspect the answer lies in this phrase - used in a slightly different context - from the NSIDC Ice Data FAQs: 'the images in our “Daily Image Update” have not yet undergone rigorous quality control to correct for conflicting information that is especially likely along coastlines'

Why not email them to ask? It's an absolutely valid question, and I would like to know the answer. Their email address is: nsidc@nsidc.org

If you don't, I probably will....but of course I don't know exactly when the lower one dates from.

You see - when you come up with a valid factual point I am very, very willing to listen?!

Ossie

Edited August 6, 2008 by osmposm

[Gray-Wolf]

To me the answer is quite simple. All of the thin, impoverished, single year ice is rapidly failing. Though a matter of 2 weeks astray in my prognosis you can now expect the 'fall off' I suggested and a very different 'end of melt season' to last years.

The energy of the warm waters last year went into the 'eating away' of the multiyear ice ,both on the Russian sector (the drifted multiyear that choked the Eastern passage) and the area to the NW of Greenland ( which broke free of it's 'land fast' nature and drifted off into open waters over the final 3 weeks of melt last year).

I for one would not be in the least surprised to see, over the next 3 weeks, the graph (NSIDC) steepen further before the final plateau.

[osmposm]

I think you've slightly missed the point, GW.

The problem is not that the line is now dropping away fast again (not unexpectedly, and probably in part or whole for the reasons you describe). It is that the previous line for the period of c. Jul 27th-30th shown on the graph from a few days ago has apparently been altered on the latest version.

As I said, I'm sure the answer lies in later quality control adjustments to suspect data (as we are very used to with the CET figures, for example). But I would like to have that confirmed.

[Mondy]

Delta, I agree that there is an inconsistency. The lower one, which I assume is an image you (usefully) saved, shows an ongoing slowing of the melt for about six days up to the 30th or 31st July. The upper (?current) one shows the slowdown lasting a shorter time, and being replaced by a renewed steeper fall line from the 27th or 28th.

I suspect the answer lies in this phrase - used in a slightly different context - from the NSIDC Ice Data FAQs: 'the images in our "Daily Image Update" have not yet undergone rigorous quality control to correct for conflicting information that is especially likely along coastlines'

Why not email them to ask? It's an absolutely valid question, and I would like to know the answer. Their email address is: nsidc@nsidc.org

If you don't, I probably will....but of course I don't know exactly when the lower one dates from.

You see - when you come up with a valid factual point I am very, very willing to listen?!

Ossie

By all means email them - I haven't the time at the moment. Be interested in their response.

[doctormog]

By all means email them - I haven't the time at the moment. Be interested in their response.

For a complete comparison I have superimposed the two images and this merged image is below:

[Devonian]

For a complete comparison I have superimposed the two images and this merged image is below:

I think "the images in our “Daily Image Update” have not yet undergone rigorous quality control to correct for conflicting information that is especially likely along coastlines" explains it, but perhaps it's just another of those evil scientist's conspiracies to deceive us eh :lol:

Edited August 6, 2008 by Devonian

[Iceberg]

Thanks Doctormog that's a useful little comparision.

We are only talking about 2 or 3 days worth of data here. It could be anything from a computer glitch to a sat issue to a problem with the formula they use, or even use bad plotting on a graph(something as simple as a cut and paste going wrong into excel.

[osmposm]

By all means email them - I haven't the time at the moment.

So you won't be have time to post on here for a while then? :lol:

I don't really have time either, or for the endless detailed ice analyses I produced for you, Bluecon & co in the last few weeks - which is why I did most of them in the middle of the night. But like the analysis, I will do it because I think it needs to be done.

For a complete comparison I have superimposed the two images and this merged image is below...

Thank you very much for that, Doc. I desperately wanted to do it, but had no idea how to go about it.

We are only talking about 2 or 3 days worth of data here. It could be anything from a computer glitch to a sat issue to a problem with the formula they use, or even use bad plotting on a graph(something as simple as a cut and paste going wrong into excel.

Absolutely, Iceberg; and Doc's merged image shows the difference as being even smaller than I'd thought from trying to read the difference using a set square, a ruler and felt tip pen marks on my screen!

Edited August 6, 2008 by osmposm

[trevw]

Thanks Doctormog that's a useful little comparision.

We are only talking about 2 or 3 days worth of data here. It could be anything from a computer glitch to a sat issue to a problem with the formula they use, or even use bad plotting on a graph(something as simple as a cut and paste going wrong into excel.

must admit I've noticed all summer that the curve always looked like it was turning upwards at the 'end' but come back a week later and it had been straightened up at the point of the previous upturn but had a new upturn at the new 'end'. It got to the point where I wondered if it was a statistical issue to do with their calculation of rolling means they use.

Of course if the same is holding true now then the fact that the end is straightish means that the 'upturn artifact' is hiding a downturn :lol:

[osmposm]

I have just emailed NSIDC pointing out the graph discrepancy, and requesting an explanation/clarification. I will of course come back here with any reply.

Ossie

Edited August 6, 2008 by osmposm

[J10]

I have downloaded the figures from the http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm website, to show the current figures, both in tabular and chart form, and full details shown in the spreadsheet below. The figures represent the Sea Ice in the Arctic Ocean in km squared.

Current Figures Are 6909063 on the 3rd August,

this is well up on last year which was 6109844.

The other available figures are 7458594 (2003), 7693750 (2004), 6866719 (2005), and 6967188 (2006).

So the figures are well below 2003 and 2004, and close to 2005 and 2006.

Looking at recent years, at the end of August between 75% and 85% of Sea Ice at 3 August remains at the 31st August, so on this basis, we should be looking at Sea Ice Extent on the 31st August 2008, in the region of 5.2 to 5.9m sq km.

I will be updating this regularly to see how accurate this is, and that the likely position should be.

The Ice Extent has fallen to 6724844 sq km, based on the 5th August figures, which remains above the 2005 figures but below the 2006 figures.

Based on this and the range of output on the 31st August stands at 5,259,500 (2007 Melting Rate) to 5,913,155 (2006 Melting Rate) with a average of 5,592,380 (based on average Melting Rate over last 5 years.

The Minimum Ice Extent for this year ranges from 4,857,355 to 5,722,170 with an average of 5,336,164.

So on this basis, the minimum ice extent is set to be higher than 2007, There is a chance it will be above the 2005 figure of 5315156, but it is set to be below 2003,2004 and 2006.

[Roger J Smith]

A discontinuous open water boundary is slowly developing around 77 N from the Beaufort west towards the New Siberian Islands. This looks like it could develop into a more permanent boundary in a week or so given the current weather pattern of blocked southeast flow into that region. Not quite as spectacular as last year's events but those continued to develop into September as I recall. I think we'll see the second largest ice-free anomaly but there is only a very slight chance of the ice boundary exceeding 81 N anywhere in the western to Siberian part of the basin this year, last year 84 N was reached in places before the re-freeze began. This will be the interesting part of the situation, really, to observe how much similarity there will turn out to be in winter 2008-09 to the "big rebound" phenomenon and all the regional weather events that came with it (the colder and snowier arctic, the extension of cold into Asia and central N America, etc). Perhaps this year it will be Europe's turn to feel the power of the rebound.

[osmposm]

Here's hoping, Roger....but I'm not holding my breath

[Iceberg]

The Ice Extent has fallen to 6724844 sq km, based on the 5th August figures, which remains above the 2005 figures but below the 2006 figures.

Based on this and the range of output on the 31st August stands at 5,259,500 (2007 Melting Rate) to 5,913,155 (2006 Melting Rate) with a average of 5,592,380 (based on average Melting Rate over last 5 years.

The Minimum Ice Extent for this year ranges from 4,857,355 to 5,722,170 with an average of 5,336,164.

So on this basis, the minimum ice extent is set to be higher than 2007, There is a chance it will be above the 2005 figure of 5315156, but it is set to be below 2003,2004 and 2006.

The latest value : 6,582,344 km2 (August 6, 2008)

That's one heck of a fall in a single day.

Based on the falling experienced this month so far the 2005 figure will almost certainly go(particularly when looking at the state of alot of the ice left), the 2007 figure looks out of reach but the minimum for all of the years has occured in September so plenty of time to go yet.

As I mentioned on the other thread both Bremen and CT now show the opening of the shallower NW passage the AMSR used at Bremen also shows that the deeper NW passage is almost open, it shows the state of the ice north of 80N as quite precarious.

Edited August 7, 2008 by Iceberg

[osmposm]

As I mentioned on the other thread both Bremen and CT now show the opening of the shallower NW passage the AMSR used at Bremen also shows that the deeper NW passage is almost open, it shows the state of the ice north of 80N as quite precarious.

Yup, agreed - the shallow one now seems quite clear on both; and the ice in the southern & eastern part of the (deep water) McClure Strait/Visc Melville Sound area seems to be breaking up/retreating northwards rapidly. It looks like there will soon be clear water along the whole of the northern edge of Victoria Island, as there already is along Banks Is.

Interestingly, it looks as if last year the passage melted the other way round - from the north southwards, and the inleted N edge of Victoria Island never lost its ice:

http://arctic.atmos.uiuc.edu/cryosphere/IM...VE/20070815.jpg

Incidentally, for those unfamiliar (as I was) with the geography, here's a (not great) image from a good atlas I have showing the western end of the NW passage, which is the area under discussion. I've marked in the approx line of the main deep (red) and shallow (mauve) water routes:

Note, incidentally, the edge of the permanent ice pack as shown in the atlas (it's a 1972 one with some revisions to 1988): the edge on the left hand side is now way, way further north.

Edited August 7, 2008 by osmposm

[J10]

The latest value : 6,582,344 km2 (August 6, 2008)

That's one heck of a fall in a single day.

Based on the falling experienced this month so far the 2005 figure will almost certainly go(particularly when looking at the state of alot of the ice left), the 2007 figure looks out of reach but the minimum for all of the years has occured in September so plenty of time to go yet.

As I mentioned on the other thread both Bremen and CT now show the opening of the shallower NW passage the AMSR used at Bremen also shows that the deeper NW passage is almost open, it shows the state of the ice north of 80N as quite precarious.

Indeed Quite a drop, I'll update the figures again over the weekend, but it's safe to say, that the averages will fall based on this. Also the figures are now lower than on this date in 2005.

[Iceberg]

The fall of a 100+K a day is continuing (.25Million km2 is two days ! )

The latest value : 6,477,344 km2 (August 7, 2008)

[Gray-Wolf]

For those of us who need the pretty pictures the graph above (and it's 'steepness' of decline) shows well how quickly the small 'raftletts' of single year that now predominate across the arctic pack fail in the ever warming arctic ocean.

a glimpse at the sst anoms at the moment around the remaining pack give no hope of the recent declines will slow over the coming 3 weeks, this is without any 'weather' shipping up warm air to attack the remaining ice from above.

The July reports from NSIDC put a (reduced) figure of an 8% change of equalling or exceeding last years ice min figure, they did say that this could rapidly alter though!

[BLAST FROM THE PAST]

The arctic hasn't had a warm summer yet the ice keeps melting away...it has to do with all that volcanic activity below along the Gakkel Ridge, yet more have been discovered....its like a gas hob down there on full burn.

BFTP

[Iceberg]

Apart from they found that the Gakkel ridge hadn't erupted for quite a few years......... And that No scientist agree's with this view.

And the fact that many scientists predicted that even an average summer would lead to mass arctic melt due to the nature of the ice that existed up there.

[Gray-Wolf]

The arctic hasn't had a warm summer yet the ice keeps melting away...it has to do with all that volcanic activity below along the Gakkel Ridge, yet more have been discovered....its like a gas hob down there on full burn.

BFTP

Surely , were this true, we'd see the effect mirrored around Antarctica with it's mid oceanic ridges, terrestrial volcanics ( with open lava pools at the summit of the worlds southernmost active volcano!) and the Ross ice shelf unable to extend into the areas it presently does. I think some guys are still getting their minds muddled as to how insignificant the heat output from mid oceanic ridge systems are in the great scheme of things.

We've all seen the wonderful footage of pillow lava ( Pa Hoe-Hoe) being formed beneath the ocean so why wasn't the diver boiled in his suit if these temps are so invasive?

I'm not looking to insult/offend anyone here but I do think that some folk could do with popping back to basics to re-build their knowledge/understanding of the geomorphology we find shaping our planet to allow them a more meaningful perspective on things.

Apart from they found that the Gakkel ridge hadn't erupted for quite a few years......... And that No scientist agree's with this view.

And the fact that many scientists predicted that even an average summer would lead to mass arctic melt due to the nature of the ice that existed up there.

Thanks iceberg.

The sad reality is that we are in a 'new' climate phase in the arctic/high arctic.

The fact that much of the single year ice did not exceed 70cm (instead of 2m) over large sectors of the pole last winter coupled with the December fracturing/sea channels that disrupted the Canadian sectors led to a very thin and patchy 'skin' of ice build over last winter. Feb/March helped to prop up the ice extent figures (it was a very cold winter across much of the arctic basin) but the onset of melt was up to 6 weeks early (and nobody 'turned the sun up early for a laugh) and this had led to us mirroring the 2005 melt up to the point that we are at now where the 'warm' water is ablating the thin patches of remaining 'single year' ice.

I for one would not be very surprised (though greatly saddened) to see the rate of ablation over the next 3 weeks exceed last years 'maximum rate of ablation'.

There surely can be no left out there who could forsee our current polar decline without mans input to help 'nudge' it along....can there? :lol:

[valiant]

We've all seen the wonderful footage of pillow lava ( Pa Hoe-Hoe) being formed beneath the ocean so why wasn't the diver boiled in his suit if these temps are so invasive?

I'm not looking to insult/offend anyone here but I do think that some folk could do with popping back to basics to re-build their knowledge/understanding of the geomorphology we find shaping our planet to allow them a more meaningful perspective on things.

My open fire is invasive. It heats my room by a catastrophic 10 degrees within an hour. I sit 10 feet away from it all night - but I don't boil inside my pajamas.

Has this post raised the interlectual bar in this discussion?

[osmposm]

....a glimpse at the sst anoms at the moment around the remaining pack give no hope of the recent declines will slow over the coming 3 weeks, this is without any 'weather' shipping up warm air to attack the remaining ice from above......

I don't know about other arctic areas, GW, but it has actually been unusually mild in the canadian Archipelago recently, and near the NW passage there's no cooldown forecast till Tuesday, http://www.weathercity.com/ca/nt/resolute . I seem to remember Roger(?) reporting exceptionally warm conditions much further north at Alert recently, too, though it seems to have dropped back down now.

So I think the NW passage melt, at least, is coming from both top and bottom.

My idea that the north coast of Victoria Island was about become ice-free now seems wrong. The latest Bremen image suggests that the ice is mobile, and is now being forced by wind/current south and east in towards Victoria Is, http://www.iup.uni-bremen.de:8084/amsr/arc...MSRE_visual.png .

This, on reflection, is perhaps what happened last year, too, and implies that when/if the deep water passage opens, it will happen as before along the northern (Melville Is) side of the waterway. I would caution against jumping the gun on this, however: the false-colour version of today's image shows plenty of 85%+ ice concentration still in Viscount Melville Sound, http://www.iup.uni-bremen.de:8084/amsr/arctic_AMSRE_nic.png .

Here, again, is the atlas page that shows where these place are:

My open fire is invasive. It heats my room by a catastrophic 10 degrees within an hour. I sit 10 feet away from it all night - but I don't boil inside my pajamas.

Absolutely, valiant

Sorry, GW, your illustration about the unboiled diver was nonsense, and badly undermined the rest of your argument. If "some folk could do with popping back to basics to re-build their knowledge/understanding of the geomorphology", then some other folk need to do the same with their basic thermodynamics!

Edited August 8, 2008 by osmposm

[Thundery wintry showers]

It isn't just the warm sea temperatures (although those certainly don't help). There's a pool of warm 850hPa temperatures, 5 to 10C, hanging around the area of the Arctic that is currently having the rapid melt.

[BLAST FROM THE PAST]

Surely , were this true, we'd see the effect mirrored around Antarctica with it's mid oceanic ridges, terrestrial volcanics ( with open lava pools at the summit of the worlds southernmost active volcano!) and the Ross ice shelf unable to extend into the areas it presently does. I think some guys are still getting their minds muddled as to how insignificant the heat output from mid oceanic ridge systems are in the great scheme of things.

We've all seen the wonderful footage of pillow lava ( Pa Hoe-Hoe) being formed beneath the ocean so why wasn't the diver boiled in his suit if these temps are so invasive?

I'm not looking to insult/offend anyone here but I do think that some folk could do with popping back to basics to re-build their knowledge/understanding of the geomorphology we find shaping our planet to allow them a more meaningful perspective on things. B)

GW

Well it ain't o.7c worth of warming which has all but been wiped out over the last 18 months? Antarctica has been having a very cold time down there but we have seen ice reduction, now that ain't AGW warmer temps is it...or does colder mean warmer? The oceans have warmed first, the air warmed next to the same degree as the oceans...it cannot work the other way.

Iceberg, much more activity has been witnessed down there than even thought of and more activity has been discovered in June/July

BFTP