Polar Ice Extent

[stewfox]

EDIT: Bring Back an Antarctic thread!!! Both poles are key to our futures and both areas need our exploration/attention!!! (IMHO)

Yes I agree it would be nice to have them both again.

[Gray-Wolf]

Yes I agree it would be nice to have them both again.

Indeed Stew! Bring Back the Antarctic Thread!!!

Ice concentration seems to continue to reduce apace even if 'extent' appears to have slowed. The 'variable wind patterns' seem to have had most of the ice 'hold station' over the past week but as these concentration maps show the Bering end of the pack has lost it's high 80% concentration in favour of low 70% concentration (esp. the 12th and 13th)

http://www7320.nrlssc.navy.mil/pips2/archive/retrievepic.html?filetype=Concentration&year=2010&month=7&day=16

(just scroll back through 'previous plots')

This end of the basin suffers from Pacific water ingress over summer so the ice gets melted out from above and below. Looks like bothe the NW and N passage will be navigable this Aug!

[4wd]

Near the pole, temperatures have taken a dive recently.

http://psc.apl.washington.edu/northpole/POPS13_atmos_recent.html

The GFS from 3rd July was onto something maybe.

First signs of 'Autumn' cooling with -10C reappearing on the forecast chart by 17th July.

[Gray-Wolf]

Yet we still see ice loss across the central region 4wd? Could it be warm water melts ice better than air?

I've often said that 2m temps mean nought when the waters below are +5 or more. If anything the ice above insulates the warm waters below until ice cover is lost and then we have the 'dark water' positive feedback loop appear.

[Thundery wintry showers]

But as I mentioned earlier ice melt has slowed considerably and the ice extent is now back above where it was in 2007. That doesn't mean that we can be complacent about it- we're still at the second-lowest extent on record for mid July- but it shows that the synoptics have made a big difference.

[SteveB]

Yet we still see ice loss across the central region 4wd? Could it be warm water melts ice better than air?

I've often said that 2m temps mean nought when the waters below are +5 or more. If anything the ice above insulates the warm waters below until ice cover is lost and then we have the 'dark water' positive feedback loop appear.

I would be interested in your view on were ice levels are heading, as it seems at this stage we are not looking as bad as what it could have been.

[Gray-Wolf]

I would be interested in your view on were ice levels are heading, as it seems at this stage we are not looking as bad as what it could have been.

Hi Steve!

I think it's another bit of smoke and mirrors. If you check how the ice 'looks' (esp the central and Bering side) you'll see a well broken pack with rounded off edges to the floes.

http://rapidfire.sci.gsfc.nasa.gov/subsets/?mosaic=Arctic.2010196.terra.4km

Zoom in to the 250m resolution for a proper look.

The recent 'weather' has had ice movement a bit stalled

http://www7320.nrlssc.navy.mil/pips2/archive/retrievepic.html?filetype=Displacement&year=2010&month=7&day=16

trawl back a few days and you'll see what I mean.

Ice 'concentration', though, has continuede to plumet

http://www7320.nrlssc.navy.mil/pips2/archive/retrievepic.html?filetype=Concentration&year=2010&month=7&day=16

(again ,trawl back a few days)

and ice thickness still reduces

http://www7320.nrlssc.navy.mil/pips2/archive/retrievepic.html?filetype=Thickness&year=2010&month=7&day=17

Any talk of 'slowdown' is by folk who primarily rely on 'ice extent' as a measure of the situation across the pole and this is both myopic and misleading!

I've posted a 4 million 'min' but can see a sub 4 million if the weather turns back to an 07' type synoptic.

We have lost the 'sturdy' ice and the means (apart from wind/current) of trapping ice in the central arctic so once the weather settles back down you'll see ice levels start to increase in their 'extent' losses but more importantly the losses will continue past previous slow down points as some of that 'slow down' was merely the impact of the spread of collapsing 'old perennial' which is now lost and so cannot happen this year.:lol:

[4wd]

If anything the ice above insulates the warm waters below until ice cover is lost and then we have the 'dark water' positive feedback loop appear.

I agree with this idea - open water loses heat fast, ice cover insulates the ocean trapping heat.

So open water cools the Arctic Ocean area.

Not sure about any positive feedback loop once the sun starts to lose power rapidly as it is doing now.

The warming from sun at low angle up there is minimal - about like at our latitude in March I would think.

[SteveB]

Hi Steve!

I think it's another bit of smoke and mirrors. If you check how the ice 'looks' (esp the central and Bering side) you'll see a well broken pack with rounded off edges to the floes.

http://rapidfire.sci...10196.terra.4km

Zoom in to the 250m resolution for a proper look.

The recent 'weather' has had ice movement a bit stalled

http://www7320.nrlss...&month=7&day=16

trawl back a few days and you'll see what I mean.

Ice 'concentration', though, has continuede to plumet

http://www7320.nrlss...&month=7&day=16

(again ,trawl back a few days)

and ice thickness still reduces

http://www7320.nrlss...&month=7&day=17

Any talk of 'slowdown' is by folk who primarily rely on 'ice extent' as a measure of the situation across the pole and this is both myopic and misleading!

I've posted a 4 million 'min' but can see a sub 4 million if the weather turns back to an 07' type synoptic.

We have lost the 'sturdy' ice and the means (apart from wind/current) of trapping ice in the central arctic so once the weather settles back down you'll see ice levels start to increase in their 'extent' losses but more importantly the losses will continue past previous slow down points as some of that 'slow down' was merely the impact of the spread of collapsing 'old perennial' which is now lost and so cannot happen this year.

So not looking good at all then. It's possible we could be ice free in the next few years then?

[Gray-Wolf]

So not looking good at all then. It's possible we could be ice free in the next few years then?

My honest answer has to be " no-one knows for sure" but I'd like to qualify that with the 'facts' of the matter.

Ice volumes have done nothing but fall through the period (and probably since the turn of the 1900's?) no matter how 'cold' or what 'ice extent' we have had. Something is rotten in the Arctic climate system (and it's not just the ice!!!).

The 'old workings' of the Arctic depended on the 'old perennial' ,plastered against Greenland and the Canadian Archipelago, to trap ice from the Arctic Gyre and trans polar drift both summer and winter to make these fantastic masses of sub glacial ice that could endure many 07' type summers. this ice is gone and no ice is thickening in the old strongholds any more. This year the only ice that 'grew' this way was a teeny blob off Siberia (wind and current riding ice floe over ice floe) but nowhere else. The 5m thick ice to the north of Greenland flushed into the N. Atlantic mid June so now we have sub 2m ice which just bobs around and melts. It does not haver the physical mass to plaster itself to itself and instead just floats around itself smashing itself into ever smaller bits (exposing ever greater surface areas to the ocean below).

I do not want to see what we are seeing but we are seeing it.

Another 07' type summer (on top of this years melt) and who knows? The numbers are 1 million sq km or less for the pack to be classed as 'seasonal'.

I do not think that the 2030 date is reasonable any more and ,personally think, a sun 2020 date more accurate.

[sunny starry skies]

I'd agree with that G-W - it's very important to consider the difference between a pack with a lot of thick ice and a pack with virtually no thick ice left. At the rate of volume decline, a seasonal pack is moving pretty rapidly towards the present, and 2020 would hardly be implausible. I think the accelerating trend seen in September minima is consistent with a progressively thinner pack, which is more and more prone to spectacular melts. They won't happen every year, as weather conditions dictate whether spectacular melts can occur, but the ice is now thoroughly preconditioned for big melts. It will be very interesting to see the rate of melt if favourable melt conditions return in the next 6-8 weeks. We can hope for the current (2 week) slowing of extent melt to continue, but that doesn't do anything much for the long-term decline in ice volume.

sss

[Gray-Wolf]

I think we'll find the Beaufort Gyre turning positive again this coming week and 'normal service will be resumed'. Ice authorities have noted that whilst loss of 'extent' has stayed static the ice has continued to melt/thin and any resumption of the di-pole (h.p forecast over Beaufort and L.P. over Siberia) will lead to a rapid increase in the rate of extent decrease.

We shall see over the next week.

As it is our FI seems to be very variable atm (I'm on holiday from 26th and it looks like being anything from cold and wet to 31c with burning sun!!!) I'm not thinking anything is set in stone here!

[CJWRC]

Sorry can you post ice thickness anomlie graphs, it's hard for the ordinary folk like me to know if the thickness shown in the above images is much below/above average?

Edited July 17, 2010 by CJWRC

[sunny starry skies]

Sorry can you post ice thickness anomlie graphs, it's hard for the ordinary folk like me to know if the thickness shown in the above images is much below/above average?

Hi CJWRC (and everyone else of course), try these for size:

Thickness anomaly graphs don't so far as I am aware, exist in the way you suggest, though I think there are outputs from the PIPS (and PIOMAS?) models that suggest thicknesses?

Good graphical resources of various kinds here:

http://sites.google.com/site/arcticseaicegraphs/

The most important of which for your question is perhaps the PIOMAS volume graph:

http://psc.apl.washington.edu/ArcticSeaiceVolume/images/BPIOMASIceVolumeAnomalyCurrent.png

It hasn't been updated since June, and it will be very interesting to see what the volume estimates for the past few weeks were. Obviously thickness is a function of area and volume!

http://www.science20.com/chatter_box/arctic_ice_july_2010_update_2

Patrick Lockerby has some intriguing observations on the recent slowing of the extent curves. Basically the ice is thinning and spreading out in situ, and that has in the last few days become painfully obvious in the central Arctic basin with sizeable patches of open water appearing in an obviously highly degraded pack. Consequence: not much change in the extent figures (they've slowed down because there is no compression of the pack to produce large areas of open water), but ice melt and pack degradation has visibly continued apace. Once the wind blows, compression of the pack will quite likely produce a very rapid apparent decline in ice extent, as extent is defined as >15% concentration, so thin, spread out ice is not much different to thick ice, but thin ice compressed into thicker ice will produce a very large drop, the cost of producing some slightly thicker/more concentrated ice.

Similar observations from NSIDC in this post by Neven:

http://neven1.typepad.com/blog/2010/07/sea-ice-extent-update-16-back-to-the-30s-again.html

sss

[J10]

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.

Time for the latest update. The Current figures are at 7,946,875, this is 364,955 below recent term averages, with 1,238,860 below longer term averages. We are around 4 days ahead of recent averages in terms of ice loss. (i.e current figures = 22th July Average figures)

There continues to be an improvement with ice melt rates now below 50,000sqft per day. (However current ice extent is still the lowest apart from 2007 in both series going back to 1979.)

We are now over 440,000sqft over 2007, which is the very least to be expected. Assuming the figures of 2002-2004 are long gone, we might see this years figures come close to last years figures by next week and perhaps also the figures for 2008 by the end of July, I will be checking the progress in relation to this in next weeks update.

[Yorkshiresnows]

Hi Folks,

Check out the following site:

http://wattsupwiththat.com/sea-ice-page/

It puts all the graphs and charts for the Arctic and Antarctic all together.

Currently ...... well looking a lot better than I would have thought. Arctic below, but currently slowing on the melt and Antarctic up (could be a record in the making), ....... overall ice extent = bang on average.

Y.S

[BLAST FROM THE PAST]

Well with El Nino now gone and La Nina forming a fairly big global cool down is kicking in. The lag of the El Nino is used up and we currently see a record low July ice melt develop. Like I said weeks back we will IMO be well above 2007. I look forward to see how the next 2 months pan out but I'm liking what I'm seeing.

BFTP

[Devonian]

I think what we're seeing is the noise in a long term downward trend. Few things, few trends, are absolutely linear. In spring the trend is clearly a warming one, but it's not by exactly the same amount every day, indeed it might cool for a few days before returning to trend. Likewise when Autumn comes it's not a absolutely linear cool down, it's is fits and spurts but the trend is clear.

So, the evidence still is of a long term downward trend in Arctic ice extent, volume, area whatever. And there is no reason this trend should be linear - how that trend behaves only time will tell but I don't see any reason to doubt the prediction. I'd still expect ice free Arctic summers sometime in the first third of this century.

[stewfox]

Similar observations from NSIDC in this post by Neven:

http://neven1.typepa...-30s-again.html

sss

I found this the most interesting.

Of course if we have all this thin ice up there , even a return to a 'average conditions' should see a rapid ijis fall ??

[Yorkshiresnows]

I think what we're seeing is the noise in a long term downward trend. Few things, few trends, are absolutely linear. In spring the trend is clearly a warming one, but it's not by exactly the same amount every day, indeed it might cool for a few days before returning to trend. Likewise when Autumn comes it's not a absolutely linear cool down, it's is fits and spurts but the trend is clear.

So, the evidence still is of a long term downward trend in Arctic ice extent, volume, area whatever. And there is no reason this trend should be linear - how that trend behaves only time will tell but I don't see any reason to doubt the prediction. I'd still expect ice free Arctic summers sometime in the first third of this century.

You could be right Dev, ... but if natural cycles do have any weight, then we should see a reversal of fortunes for the arctic (and antarctic) once the PDO and AMO swing to negative.

Exciting times.

Y.S

[BLAST FROM THE PAST]

You could be right Dev, ... but if natural cycles do have any weight, then we should see a reversal of fortunes for the arctic (and antarctic) once the PDO and AMO swing to negative.

Exciting times.

Y.S

Unless we enter an ice age the southern hem will lose ice with the switch to -ve PDO and La Nina domination as the arctic increases as part of the natural phase. AMO still about 10 yrs away from -ve phase but PDO already there.

Exciting times indeed and I will heat my hat if 2010 becomes warmest year on record. Silly NOAA counting their chickens....6 months of data yet to come and July anomaly has shown large cooling globally thus far and massive slow down in icemelt. Blip? or signs of La Nina and PDO doing their work.

BFTP

[Gray-Wolf]

Had we not lost the majority of our 'old perennial' nor had large areas of the Arctic Ocean lose it's 'zoning' then I'd be tempted to agree with a 'natural' driven' Renaissance in ice. Because I see all that we have lost over the past 100yrs (or so) I cannot hold out such hopes. The Arctic has changed now for this Arthropocene period and we will see it limp on into a seasonal pack (should 'natural' prove a strong driver) with only 'Milankovich' type forcings driving the carbon cycle back into 'cool' mode.

The conservatives are giving 2030 or 2050 as the time for a seasonal pack to be fully established but they are being very 'conservative' and maybe 'unrealistic'?

There will be a swap between the cycles we know driving the Arctic to the Arctic driving the 'cycles' we know (or at least modifying them?)

For the guys who live by 'extent' alone I can see a cold winter bringing 'extents' within 2 standard dev's of what we are used to but 'Volume'?, only downhill I'm afraid (IMHO).

Edited July 19, 2010 by Gray-Wolf

[Devonian]

Unless we enter an ice age the southern hem will lose ice with the switch to -ve PDO and La Nina domination as the arctic increases as part of the natural phase. AMO still about 10 yrs away from -ve phase but PDO already there.

Exciting times indeed and I will heat my hat if 2010 becomes warmest year on record. Silly NOAA counting their chickens....6 months of data yet to come and July anomaly has shown large cooling globally thus far and massive slow down in icemelt. Blip? or signs of La Nina and PDO doing their work.

BFTP

OT, but I've missed NOAA counting their chickens wrt the year 2010 rather then report on the first six months, where did they do that?

Edited July 19, 2010 by Devonian

[Gray-Wolf]

http://www.terradaily.com/reports/Russia_swelters_amid_drownings_and_drought_999.html

Bet you're glad you're not in Siberia then BLAST!!!

[4wd]

No reason to assume current long term downward trend will continue.

Even if AGW added a couple of degrees, natural cycles could still easily cool enough for ice to increase.

No trend in the natural world goes one way only long term.