319 replies to this topic

[songster]

Hum, I wouldn't be so certain. Yes, the southerlies have kept the pack low on the Kara/Barents side. However, they've also compressed (and thickened?) the central pack and shifted the distribution of thicker ice over into the Beaufort and Chukchi seas. To an untrained eye, it also looks as though there's also been less export through the Fram Strait than usual, aside from a couple of weeks near the start of the freeze when it was absolutely booking it out of there. If you're not careful, there's a danger of falling into the trap of seeing every possible wind direction as catastrophic. Winds blowing towards the Pole? Then the heat transport will be keeping the ice thin. Winds blowing away from the Pole? That's the old ice being flushed out to melt in warmer waters. Winds blowing round in circles? That's churning up the ice and proving it's in poor condition.

All told, there's been a lot of very cold air bottled up north of Canada for much of the winter, more than the last few seasons. I suspect therefore that melt in the Beaufort and Chukchi seas will be slower in 2012 than in 07-11. However, I agree that if losses in these seas are <i>not</i> substantially reduced this year, then yes, we're probably looking at a record or very near. That's simply a logical consequence of how low it it on the Atlantic side of things.

Edited by songster, 03 February 2012 - 10:19 .

[BornFromTheVoid]

Whatever the winds are up to this year songster, things are looking very poor across Kara and Barents with no favourable conditions for the next week.
CT has the Kara sea ice extent back to mid-November levels, while the conditions that have piled up a +ve 300,000km2 anomaly over the Bering sea is set to end in the coming days.
Current NH anomaly on CT is just below 1.1million km2.

[BornFromTheVoid]

A great new interactive ice area chart from Cryosphere Today
http://arctic.atmos....nteractive.html

2012 currently lowest on record.

[Gray-Wolf]

I think we can blame Kara and Barentsz for that and thank Bering that we are not a lot lower on the plot!! According to the folk over on Neven's Blog March 10th sees the sun high enough to melt the ice again there (15 degree rule?) so it's has not long to freeze and let the temps get down to there normal -30c and not the current 'above -1.8c'. It does look as though melt has already arrived there with ice levels dropping back over recent weeks (compaction?)

If this area remains as is then be prepared for a low start to the season with that 'supporting ice' over in the Bering sea disappearing quite fast leaving us with the absent ice from Barentsz/Kara and normal melt over on the Bering side?

I've heard folk saying that the ice (what there is of it) is thicker this year? anyone got any data?

EDIT: I'd ask again , is there anywhere else on the planet where an anom of 28c goes un-noticed by the media/masses???

Edited by Gray-Wolf, 07 February 2012 - 15:43 .

[BornFromTheVoid]

Things not looking great in the Arctic at the moment. The anomaly on CT is nearly at 1.3million km2, lowest on record.
On the northern hemisphere charts the cold air has left the Bering sea and the +ve anomaly it had built up is now falling away. Uppers of over 5C now over the Beaufort sea and surface temps around Kara and Barents above 0C in places.


Not a whole lot of change then until about t120, when colder air manages to reach the Kara and Barents seas.
Will be interesting to see how the NH area fares over the coming 4 or 5 days...

[Weather Ship]

I don't know whether this is of interest. The midday plots for the Arctic Ocean, Beaufort Sea, Barents Sea, Greenland Sea, Kara Sea,Laptev Sea Chuchi Sea.

Attached Thumbnails

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Edited by weather ship, 10 February 2012 - 17:46 .

[Devonian]

weather ship, on 10 February 2012 - 17:39 , said:

I don't know whether this is of interest. The midday plots for the Arctic Ocean, Beaufort Sea, Barents Sea, Greenland Sea, Kara Sea,Laptev Sea Chuchi Sea.

Those are interesting. I took a double take until I realised it's Farenheit? Even then some of the temperatures are as extraordinarily warm as the cold across parts of Europe have been - indeed given Svalbard has been 13C above normal for the last 30 days (and, I see, had a hugely anomalously warm last 12 months) rather more extraordinary perhaps. Anyway, are those plots available on the net or are they done via synops and a program?

[Weather Ship]

Devonian, on 10 February 2012 - 19:03 , said:

Anyway, are those plots available on the net or are they done via synops and a program?

The latter.

[BornFromTheVoid]

Just looking through CT, and spotted on the global sea ice graph that last year was the lowest maximum in the series, and the first not to reach 21,000,000km2.
Here's the CT graph with the 21 million line changed to solid black to make comparisons a little easier.



Original image here http://arctic.atmos....a.withtrend.jpg

[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.

[Weather Ship]

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/...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....nteractive.html
Shall have a more detailed look at things later.

[Geordiesnow]

BornFromTheVoid, on 05 March 2012 - 14:45 , said:

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 by Geordiesnow, 05 March 2012 - 20:38 .

[BornFromTheVoid]

Geordiesnow, on 05 March 2012 - 20:37 , said:

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

[Solar Sausage]

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...