Arctic Ice Discussion (the Refreeze)

[BornFromTheVoid]

On CT Arctic sea ice has been on the up the last few days and has cleared the lowest maximum on record, 2011. Current area is 13.231 million km2. Other low maximum years include 2007 (13.317m) and 2006 (13.358m), so they're targets to look out for.

Conditions look set to remain good for ice growth over the next 72 hours.

850hPa Temperatures T0

850Hpa Temperature T72

Cold air over the Bering sea, sea of Okhotsk, Baffin sea and Kara sea should allow for the area to continue growing, possibly surpassing 2006 and 2007.

After T72, a reverse dipole anomaly appears with high pressure across the Eurasian side of the Arctic and low pressure across the Canadian Archipelago and Greenland. This causes milder southerlies to flood the central Arctic, but should minimise sea ice export and thicken things up which are positives.

Should be interesting to see if the reverse dipole pattern comes off and what impact it has.

[knocker]

GREENBELT, Md. -- A new NASA study revealed that the oldest and thickest Arctic sea ice is disappearing at a faster rate than the younger and thinner ice at the edges of the Arctic Ocean’s floating ice cap.

The thicker ice, known as multi-year ice, survives through the cyclical summer melt season, when young ice that has formed over winter just as quickly melts again. The rapid disappearance of older ice makes Arctic sea ice even more vulnerable to further decline in the summer, said Joey Comiso, senior scientist at NASA Goddard Space Flight Center, Greenbelt, Md., and author of the study, which was recently published in Journal of Climate.

The new research takes a closer look at how multi-year ice, ice that has made it through at least two summers, has diminished with each passing winter over the last three decades. Multi-year ice "extent" – which includes all areas of the Arctic Ocean where multi-year ice covers at least 15 percent of the ocean surface – is diminishing at a rate of -15.1 percent per decade, the study found.

There’s another measurement that allows researchers to analyze how the ice cap evolves: multi-year ice "area," which discards areas of open water among ice floes and focuses exclusively on the regions of the Arctic Ocean that are completely covered by multi-year ice. Sea ice area is always smaller than sea ice extent, and it gives scientists the information needed to estimate the total volume of ice in the Arctic Ocean. Comiso found that multi-year ice area is shrinking even faster than multi-year ice extent, by -17.2 percent per decade.

"The average thickness of the Arctic sea ice cover is declining because it is rapidly losing its thick component, the multi-year ice. At the same time, the surface temperature in the Arctic is going up, which results in a shorter ice-forming season," Comiso said. "It would take a persistent cold spell for most multi-year sea ice and other ice types to grow thick enough in the winter to survive the summer melt season and reverse the trend."

Scientists differentiate multi-year ice from both seasonal ice, which comes and goes each year, and "perennial" ice, defined as all ice that has survived at least one summer. In other words: all multi-year ice is perennial ice, but not all perennial ice is multi-year ice (it can also be second-year ice).

Comiso found that perennial ice extent is shrinking at a rate of -12.2 percent per decade, while its area is declining at a rate of -13.5 percent per decade. These numbers indicate that the thickest ice, multiyear-ice, is declining faster than the other perennial ice that surrounds it.

As perennial ice retreated in the last three decades, it opened up new areas of the Arctic Ocean that could then be covered by seasonal ice in the winter. A larger volume of younger ice meant that a larger portion of it made it through the summer and was available to form second-year ice. This is likely the reason why the perennial ice cover, which includes second year ice, is not declining as rapidly as the multiyear ice cover, Comiso said.

http://www.nasa.gov/topics/earth/features/thick-melt.html

[BornFromTheVoid]

Another big jump in northern hemisphere sea ice area on CT. Now up to 13.311 million km2, just a few thousand behind 2007. A similar sized gain today and we'll be away from the 3 lowest maxima on record.

[BornFromTheVoid]

Things going very well lately on CT. Ice area now up to 13.537km2, well above the bottom 3. If growth continues at this rate, we'll be at mid pack in 3 days and up to average by the weekend.

http://arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html

Shall have a more detailed look at things later.

[Geordiesnow]

Things going very well lately on CT. Ice area now up to 13.537km2, well above the bottom 3. If growth continues at this rate, we'll be at mid pack in 3 days and up to average by the weekend.

http://arctic.atmos....nteractive.html

Shall have a more detailed look at things later.

Problem I see though BFTV is the main reason for the sharp increase and quite high extent(looking at the NSIDC figure, it looks like extent wise for the 4th March is the highest for 9 years) could be down to the above average seasonal sea ice rather than any above average in the basin itself, e.g the Atlantic side of the Arctic is way below average and it looks unlikely it will increase much more this refreeze season with the models forecasting continious southerly direction winds. Obviously the Bering Sea has been way above average for most of the winter season but now the Labrador Sea has really gained in extent and so has the Gulf of St Lawrence to some extent. The ice has also rapidly grown in the Sea of Okhotsk where some parts are above average.

However, the Kara and Barents sea areas have been dominated by mainly southerly direction winds thanks to a persistant russian high and low pressure in the Norweigan sea, really unusual and as I said previously, the Svalbard isles must be experiencing one of its mildest winters on record. From what I learnt, northerly winds is a poor direction because thicker ice tends to leave the Arctic but southerly winds will pump very mild air towards the pole as the models are once again indicating so it will be interesting how much thicker ice has left the Arctic and whether more thicker ice has survived because of the continious southerly direction winds.

Of course extent in the winter season does not always paint a true picture of how the melt season will unfold, 2006 had a very low winter extent but no years have been higher than that at the end of the melt season. Will the persistant mild southerlies put the ice towards the pole under threat, will the above average ice extent in the Bering sea help a slower melt than last year on the other side of the Arctic. Also how vulnable is the ice in the Laptev Sea as thats been another mild area because of winds coming from a southerly direction and also the fact that winds have also been blowing from east-west alot this season aswell. I suppose weather will play alot in answering those question but it will be interesting if conditions this winter will play a major part in the final melt figure.

Looking at the charts, the extent figure may start to fall a little bit, depends how much ice will be pushed back by those southerlies in the Barents sea and how any milder weather at lower latitudes will affect the ice. May see some melt in the Gulf of St Lawrance for example as milder air looks like moving back in if albeit perhaps not for very long and conditions looks a bit mixed in the Bering Sea with low pressure systems moving across giving a mix of winds coming from the Pacific and the Arctic.

I still expect around mid April-May the extent figure could be at record breaking lows because of how weak the ice is in the Kara Sea and the below average ice conditions on the Atlantic side of the Arctic.

Edited March 5, 2012 by Geordiesnow

[BornFromTheVoid]

Problem I see though BFTV is the main reason for the sharp increase and quite high extent(looking at the NSIDC figure, it looks like extent wise for the 4th March is the highest for 9 years) could be down to the above average seasonal sea ice rather than any above average in the basin itself, e.g the Atlantic side of the Arctic is way below average and it looks unlikely it will increase much more this refreeze season with the models forecasting continious southerly direction winds. Obviously the Bering Sea has been way above average for most of the winter season but now the Labrador Sea has really gained in extent and so has the Gulf of St Lawrence to some extent. The ice has also rapidly grown in the Sea of Okhotsk where some parts are above average.

However, the Kara and Barents sea areas have been dominated by mainly southerly direction winds thanks to a persistant russian high and low pressure in the Norweigan sea, really unusual and as I said previously, the Svalbard isles must be experiencing one of its mildest winters on record. From what I learnt, northerly winds is a poor direction because thicker ice tends to leave the Arctic but southerly winds will pump very mild air towards the pole as the models are once again indicating so it will be interesting how much thicker ice has left the Arctic and whether more thicker ice has survived because of the continious southerly direction winds.

Of course extent in the winter season does not always paint a true picture of how the melt season will unfold, 2006 had a very low winter extent but no years have been higher than that at the end of the melt season. Will the persistant mild southerlies put the ice towards the pole under threat, will the above average ice extent in the Bering sea help a slower melt than last year on the other side of the Arctic. Also how vulnable is the ice in the Laptev Sea as thats been another mild area because of winds coming from a southerly direction and also the fact that winds have also been blowing from east-west alot this season aswell. I suppose weather will play alot in answering those question but it will be interesting if conditions this winter will play a major part in the final melt figure.

Looking at the charts, the extent figure may start to fall a little bit, depends how much ice will be pushed back by those southerlies in the Barents sea and how any milder weather at lower latitudes will affect the ice. May see some melt in the Gulf of St Lawrance for example as milder air looks like moving back in if albeit perhaps not for very long and conditions looks a bit mixed in the Bering Sea with low pressure systems moving across giving a mix of winds coming from the Pacific and the Arctic.

I still expect around mid April-May the extent figure could be at record breaking lows because of how weak the ice is in the Kara Sea and the below average ice conditions on the Atlantic side of the Arctic.

You are of course right that the jump in area/extent recently has been seasonal ice, but that's generally what causes all the ups and down from Autumn to Spring. It's only really July, August and September where we're dealing with the multiyear ice (or what's left of it). CT gives the ice area for the Arctic basin also here and it's been pretty close to average, which is what we'd expect as it's generally "maxed out" for most of the year.

Since around 2000, the main area of negative anomalies has been around the Kara and Barents sea since the AO turned more negative, but clearly, this year, much of it has been down to the Russian high as opposed to the AO.

Here is the mean SLP from Dec 1st to March 2nd and the anomaly for pretty much the same time

You can clearly see were having the opposite to the dipole anomaly that's occurred so frequently the last few years and was responsible for flushing much of the paleocrystic ice out through Fram. I see the current pattern as being quite positive. With the dipole anomaly before, ice was being almost continuously shipped out of the Arctic during the winter, leaving less ice less time to thicken. This pattern will hopefully hold the sea ice in around the Arctic basin long enough to thicken and maybe even provide a little more resistance to summer melt.

As for the short term pattern, I don't expect Kara or Barents to take too much of a hit until the weekend. Barents mainly because its so low already and the southerlies are to slack to cause much damage in Kara, along with some very cold surface temps courtesy of a ridge thrown up from the Siberian high. I doubt the basin will lose much either as away from the east coast, the ice is already quite far N of Svalbard.

Where I'd be looking is towards the Bering sea. Some fairly big storms there over the next week. Could see a lot of variability there as the ice breaks, spreads and melts.

[Gray-Wolf]

Don't forget the 'Spring tides' this weekend as well? lets think how this will disrupt the ice and how that will aid/hinder the coming melt?

[The PIT]

Well after a disappointing year last year we approach another year where some members speculate over a complete melt/ the lowest ever while others speculate about a recovery.

We shall see although a complete melt will not really be on agenda.

[BornFromTheVoid]

I wonder if the peak occurred on the March 5th at 13.68m? We're now at 13.58m, which ain't too far off 5th, so probably 50/50 as to whether it can be beaten or not

The pattern over the last week (up to the 11th) has been almost identical to the winter pattern

Last week and Winter...

The pattern over the next 2 or 3 days is more of the same, which should keep things looking healthy. After about 4 day, things look like improving across Barents and Kara as winds turn easterly there with some cold uppers. If this occurs and Kara and Barents start producing more sea ice and the Bering sea maintains it's massive +ve anomaly, we could see another increase in northern hemisphere sea ice during the next week, possibly surpassing the max set on the 5th.

[karyo]

I like the sound of that Bornfromthevoid! It has certainly been a very good end to the winter season and start of spring.

Karyo

[Methuselah]

With global temps still high, I can't really imagine anything spectacular on the recovery front, this summer. Total meltdown? My guess is that we won't be seeing that either...

[Geordiesnow]

I wonder how vulnable Hudson Bay ice will be over the next week or so with the unseasonably warm weather that is across the US atm. The models have been predicting several very warm spells to hit parts of Hudson bay(one occuring now albeit only brief). I looked past in recent years and I have not seen a year where plus 10 upper air temperatures being over parts of Hudson Bay so should be interesting if any very early melt will occur there.

I still think we could see some record breaking low figures as we reach the end of Spring barring a miracle really with how weak the ice is in the Barants and Kara Seas, of course if favourable weather conditions could stop this.

I think this will be a very interesting melt season though with the frequent southerlies towards the poles this winter and if this stopped less ice from leaving the fram stright then we may see a more resistant pack. Of course, it could be announce that the pack is thinner still this year and if so, then hope and prey for a cool summer!

Edited March 14, 2012 by Geordiesnow

[stewfox]

Is there anyway to filter the attached to show just 10 years, its a very 'messy graph'

http://arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html

[songster]

Click on the year number to toggle any given line on/off.

[Gray-Wolf]

Well , that may well be it for the 'winter'?

Looks like being another 'interesting melt season' ?

We'll see if 'export' from the basin reaches 'average' amounts as the in-situ melts of last year would suggest a 'record low' this summer if we see export at normal levels alongside the way the young ice melts now?

And Methane?

Also another large Berg ready to drop out of Jacobson?

[loafer]

Lots of 'quotes', G-W...who are you quoting?

[Krakatoa01]

I really believe this year will see destructive melt. The pack is incredibly thin. 15% thinner than last years pack. Worrying times ahead

Well , that may well be it for the 'winter'?

Looks like being another 'interesting melt season' ?

We'll see if 'export' from the basin reaches 'average' amounts as the in-situ melts of last year would suggest a 'record low' this summer if we see export at normal levels alongside the way the young ice melts now?

And Methane?

Also another large Berg ready to drop out of Jacobson?

[Gray-Wolf]

Loafer, me! all my own work but watch this space for confirmation!!!

The pack is ever younger ,with ice that is far less durable than the old Paleocryistic that used to form the majority of any summer pack, and the odds of another summer of stalled export are even lower than encountering another 'perfect storm' synoptic so we can happily expect greater losses than last year which came close to being the lowest on record (with a 'stalled export' synoptic so all in-situ melt). An average export summer and a pack 15% thinner (for in-situ melt) with no 'babies arm' of thicker ice across the pole from Beaufort to Siberia tends to have me thinking of a record year so far as ice loss is concerned.

[karyo]

Are we heading for a new peak?

http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png

It seems that the spring melt is delayed this year.

Karyo

[BornFromTheVoid]

Are we heading for a new peak?

http://nsidc.org/dat..._timeseries.png

It seems that the spring melt is delayed this year.

Karyo

Almost there...

[Geordiesnow]

Are we heading for a new peak?

http://nsidc.org/dat..._timeseries.png

It seems that the spring melt is delayed this year.

Karyo

Delayed or not, parts of the Arctic has very thin ice most noticetably the Kara Sea which normally has a very slow melt but unless we have favourable set ups then this area will melt away quite quickly once the warm weather starts to make it presence felt or just simply by having a mild SW'ly will start to melt the ice away.

It does look like the set up at the moment looks fairly favourable for the extent to go up because ice is so low in the Barents sea but I guess that depends how the very warm weather will affect the ice in Hudson Bay in the next 3-4 days and if we do see some melt there(way to early for ice to melt normally there but we are in a warming world!) then will that balance things out somewhat.

Its funny how some comments above are saying that the ice is even thinner this year despite people on TWO saying that some of the pack is actually thicker than 2011 and the fact that we had more southerlies into the Arctic this year in theory should mean less ice leaves the fram stright? Are we at the stage where there is little hope for a recovery and whatever direction the winds come from, it does not make a difference because the story will be the same.

I suppose it will be an interesting melt season as it tends to be the Atlantic side of the Arctic which has more ice than the Pacific side of the Arctic and whether or not the ice is going to be more reluctant to melt because of this years weather set ups or not.

[The PIT]

LOL doom slayers are out total melt this year anybody or a repeat of this discussion next year? Take yer bets.

[karyo]

Delayed or not, parts of the Arctic has very thin ice most noticetably the Kara Sea which normally has a very slow melt but unless we have favourable set ups then this area will melt away quite quickly once the warm weather starts to make it presence felt or just simply by having a mild SW'ly will start to melt the ice away.

Surely the fact that the ice is still increasing in the second half of March is a big positive! I'd rather focus on that for now and worry about what may or may not happen much later in the season.

There was a post by another member on the 3rd February saying that the synoptics for the rest of the winter were not good and that no significant increase was expected! Despite that, the synoptics became favourable since then and where we are now must be a surprise for many people!

Karyo

Edited March 17, 2012 by karyo

[BornFromTheVoid]

I wouldn't consider gains in the second half of March as anything more than a frivolous plus. Both 2011 and 2007 saw gains late in March! As for the warm spell across southern Hudson bay, I doubt it will have much of an impact. The ice usually doesn't start melting there until May, so even if there are any small losses over the next few days, chances are there will still be time for it to re-freeze.

PIT, who's suggesting a total melt out this year?

[BornFromTheVoid]

Made a short animation of MODIS images over the last 5 days of sea ice breaking up and exiting through the Bering strait.

Would be interesting to know how much has been lost this way during the winter...

EDIT: Sea Ice Extent now at a new maximum

Edited March 18, 2012 by BornFromTheVoid