Arctic Sea Ice Discussion 2016: Melt Season

[Relativistic]

2 hours ago, Ed Stone said:

I'm inclined to think (any thoughts based on one year's data can only be a guess ) that a weaker PV might allow Euro/Bartlett HP's to become even more entrenched? That ought to go down well!

I was thinking that less in the way of rampant westerlies due to a much warmer Arctic would lead to more blocking scenarios full stop. So more Greenies and Barties?

Edit: Knocker's post seems sensible.

Edited May 24, 2016 by Relativistic

[Gray-Wolf]

Is the thinning , from KARA ,across the pole toward Greenland for real or just an artifact? I have been watching Fram as winds appear to have favoured losses from there but not seen the scale of movement I'd expected. Could this be a fault line as the ice finally gives way to the forcing? The forecast for the next period shows forcings for Fram exits still at large so if this split is real it will become apparent over the next week.

Just imagine if that ice were to break free and make a bee line for Fram???? 

That would expose a lot of dark water to max insolation and a killing zone for ice would emerge there with anything coming in from the trans polar Drift doomed.

[knocker]

ASI 2016 update 1: both sides

Quote

May 27th 2016

After an unprecedented warm winter and an unprecedented early opening of the Beaufort Sea, the 2016 melting season isn't showing any signs of shrugging off the 'unprecedented' label. What has struck me most so far, is that unprecedented things have been happening on both the Pacific and Atlantic side of the Arctic.

I've been closely observing events in the Arctic for almost a decade now, and have been writing about them since 2010, and during that time I have gotten used to this sort of see-saw, where fast melting on one side of the Arctic would be compensated by events unfolding slowly on the other side of the Arctic. But this year is different. This year the ice pack is under attack on both sides of the Arctic.

I have written separate blog posts to describe these events (see here and here), and in weeks to come these ASI updates will provide a comprehensive overview on what is happening to the sea ice in the Arctic, and how this melting season is unfolding.

http://neven1.typepad.com/blog/2016/05/asi-2016-update-1-both-sides.html

[Singularity]

Dipole alert for day 5 going by the ECM 12z, as per many of the recent runs. The magnitude of this hasn't been modelled with such great consistency though - it involves a shortwave rapidly developing in conjunction with a cross-polar ridge, so timing is critical.

The dipole persists thereafter, and the trough becomes alarmingly deep:

  

That'd bring some strong winds to shove the sea ice toward the FRAM strait.

At the same time there's a three-pronged attack from warm air advection (western U.S., NW Europe/UK, East Asia):

 

Now, GFS is not quite so vigorous with the trough on the Eurasian side, but the overall pattern is concerning in its similarity:

 

We also see the three-pronged attack, but a little less pronounced in our part of the world:

 

That's actually pretty remarkable agreement for 10 days out and with the westerlies so very reduced. But then - there is perhaps truth in the idea that once momentum becomes extremely low, the value of persistence in weather patterns, with only slight adjustments needed, can improve the consistency between models - though not necessarily the accuracy of what they produce!

 

Edited May 27, 2016 by Singularity

[BornFromTheVoid]

So far this year, according to the NSIDC daily values, may has lost about 13.12% of the April 30th extent. This is already the 3rd largest % loss for May on record, with 2010 having the largest at 14.99%.
If we can average a loss of 61.2k/day for the remainder of the month, we'll just about beat the 2010 %.

[Singularity]

So I've been watching with much concern the exploration of a strong and prolonged dipole pattern by the NWP models over the past few days.

 

Here we have today's 00z GFS on the left and the 12z on the right.

Now, I actually thought the 00z had stepped off quite a bit thanks to a low splitting off and heading toward the Beaufort, limiting the cross-polar flow and hence draw of relatively warm air from the Pacific. Yet reading the ASI forum it has become apparent that the extent of support for FRAM export meant it was still a pretty dire run.

The 12z allows that low to split off around day 5, but then quickly recaptures it. This seems to be largely down to the blocking over Greenland being stronger and better aligned to drive such reverse-zonal movement.

This has brought the model in line with the ECM 00z, which was about as dipole-fanatic as I've ever seen. It was quite a shock after yesterday's 12z, which was more like the GFS 00z but with a less well defined flow through the FRAM strait.

        

The left and middle images show the very strong cross-polar flow at +144 and the sustained nature of this pattern by way of the +216 chart (and +240 did not improve things much!).

The right-hand image is the GFS 12z at +216. The cross-polar flow continues, while the flow through the FRAM takes a brief rest - but it's soon back. In fact we can look nearly two weeks ahead and still find a dipole pattern in place:

I'm going to go ahead and imply it; if a run like this transpires, the Arctic sea ice is as good as fudged.

 

Edit: for the heck of it, here's the +12 day GFS 12z chart showing dual-plumes (of heat) sneaking in via Alaska and East Asia, then the +15 day chart, showing a large area of 10*C+ 850 hPa temperatures invading the Arctic from East Asia, with a peak of around 15*C just off the coast.

 

Ouch.

Edited May 30, 2016 by Singularity

[BornFromTheVoid]

NSIDC extent now below 11 million km2. This is 10 days earlier than the previous record holders of May 11th, in 2012 and 2010.

[Geordiesnow]

Goodness me, looks like the Siberian sea area is taking a right battering with the hot spell there at the moment, it does look like things may turn colder and with a more favorable wind direction but looks like it will only be tempory.

Eastern half of the Arctic turn to take a battering, I do honestly think we are heading into uncharted terrotory here as to where the extent will end up come September.

One is hoping this mornings ECM is right which shows the most favourable set up for sea ice,

[knocker]

Quite a deep depression forecast for the next few days/

[Gray-Wolf]

Well Knocks , i suppose this is where we find out about all this 'pre-conditioning' to the ice we've been hearing about? Watching Modis over the open water in Beaufort it appears that the water there is already melting ice so maybe we do not need anything forcing the ice into that area?

Nor do we need any disruption of the central ice? There is way too much room in Kara/Barentsz for it to migrate into lower latitudes and more challenging conditions?

Damned if we do.... damned if we don't!

[BornFromTheVoid]

I think we should be keeping a close eye on Kara and Laptev over the next 2 days.

A pretty deep depression is currently developing over the Kara sea and will reach it's peak in about 24 hours, with surface air temps generally above 0C too

 

The ice over northern Kara and into Laptev looks quite fragmented and weak, leaving it easily open to attack from the storm.

I think there's a reasonable chance of sea ice in the southern Kara sea getting cut off from the rest of the pack soon.

[knocker]

 

[stewfox]

Mean while you can see the dramatic slow down in the loss of Artic ice extent

This was to be expected given the dramatic start to the season.

https://ads.nipr.ac.jp/vishop/vishop-extent.html?N

I know many folk still expect to see the Artic close to being ice free by end of the summer but all to play for

 

 

 

[BornFromTheVoid]

3 hours ago, stewfox said:

Mean while you can see the dramatic slow down in the loss of Artic ice extent

This was to be expected given the dramatic start to the season.

https://ads.nipr.ac.jp/vishop/vishop-extent.html?N

I know many folk still expect to see the Artic close to being ice free by end of the summer but all to play for

 

 

 

 

Don't think many expect it to be close to ice free by September. But yeah, quite a slow down in extent. Area still dropping, which suggests ice being spread out and concentration dropping. Good in the short term for extent only, not great in the longer term for the other measures. Still, there's a good 3 months of melt remaining, much can happen.

[knocker]

 

[Geordiesnow]

Bit of an important period coming up I feel, the weather upto around 96 hours does have low pressure in charge mainly on the Pacific side of the Arctic but it what happens after that is what the models are struggling with. 

Some runs suggest one big(in terms of size rather than intensity) low pressure system will more or less stay over the central basin and the set up allows only limited warmth on the outskirts whilst the stationary low could potentially become slightly colder as its persists. Another scenario is for the low to start drifting SE'wards opening the doors to the warmth in Siberia and we could end up with a dipole like the GFS is kind of showing. 

Do kind of hope it will be the ECM that is closer, do want an even battle and it would make things more interesting in terms of will we get near or pass the 2012 mark. 

[Gray-Wolf]

With ice so low and long open waters to both Pacific/Atlantic sides of the basin I wonder if this low will be the 'saviour' for the ice that we hope? MODIS shows the pack, throughout the basin, well broken apart. We know small floes move easier than large ones so will we see enhanced transport into warmed waters by ice? Fram has virtually melted away so plenty of room our side for major losses should ice be spun out this way? We also have 'mechanical degradation' of floe bumping floe either leading to ice rubble of braking the floe into still smaller pieces?

I have to say I really do not know whether to cheer or feel concerned!!!

[Singularity]

An alarmingly warm ECM 00z run in the longer term this morning, as low pressure is displaced from the pole by intrusive ridges - but GFS does not follow suit so we can keep the bell in the cabinet for now.

Still waiting for any sudden step up in daily losses following the dispersal period that we are in. If those don't show up soon, I'll have to revise my June expectations to something more positive!

[Gray-Wolf]

I'm also wondering whether we are seeing the saving of the basin for another year or whether the 'early start/low ice levels' will have left the pack in too poor a condition to deal with the next 3 months?

[Geordiesnow]

11 hours ago, Gray-Wolf said:

I'm also wondering whether we are seeing the saving of the basin for another year or whether the 'early start/low ice levels' will have left the pack in too poor a condition to deal with the next 3 months?

All will depend on the weather really, if it gets too stormy with not much in the way of cold air then the pack could start to weaken that way, of course high pressure with high upper air temps is another way. If we get more in the way of low pressure set ups but fairly slack then in theory the pack should hold up well. 

Beaufort has certainly seen a shift in the weather type from the very warm May to a more chiller first part of June so you could say some sort of balance has been reached but ice levels here are still well down from previous years. 

Quite a lot of uncertainty in what the weather will do after this low pressure cell, the low is forecast to fill and things could slacken off but there have been some hints we could see a less favourable set up whilst other runs look a bit more favourable. Just how much warm air will hit the Pacific side of the Arctic is far from clear although the models seem to agree a bit more on some warmth heading northwards on the Atlantic side of the Arctic. Hudson Bay is set to get hit by well above average temperatures so ice loss here could be quite dramatic so I shall expect extent figures to take more of a nose dive during next week just for that reason alone.

[Gray-Wolf]

From the looks of Beaufort over the past two weeks I don't think we should be thinking of any 'slowdown'? Recent studies have shown how important down welling radiation is to conditioning ice for melt out later and this depends on an 'opaque' atmosphere above ( not clear skies) . Couple that with the 'relaxation and spread' the low provided by reversing the gyre and spread of MY ice into the warmed coastal stretch where we can see the periphery melting out? Extent may appear 'near stalled' but concentration provides us with an explanation as a well broken pack relaxes apart as the lows pass over.

As with the Beaufort Gyre we may well be seeing a thing that once 'helped' stay ice loss becoming a potent reason for losses?

 

[BornFromTheVoid]

2 hours ago, Gray-Wolf said:

From the looks of Beaufort over the past two weeks I don't think we should be thinking of any 'slowdown'? Recent studies have shown how important down welling radiation is to conditioning ice for melt out later and this depends on an 'opaque' atmosphere above ( not clear skies) . Couple that with the 'relaxation and spread' the low provided by reversing the gyre and spread of MY ice into the warmed coastal stretch where we can see the periphery melting out? Extent may appear 'near stalled' but concentration provides us with an explanation as a well broken pack relaxes apart as the lows pass over.

As with the Beaufort Gyre we may well be seeing a thing that once 'helped' stay ice loss becoming a potent reason for losses?

 

The longwave downwelling is more important further away from the summer solstice, I think. At the moment, our surface melt is much more similar to the last 3 years than to 2012 or 2007, regardless of whether short or longwave energy is the most important factor.
It's not longer just an extent slowdown either, 2012 has caught up with this year already according to Wipneus' shadow CT data and his homebrew area, and without some big losses, both NSIDC and ADS extent will be above 2012 by the weekend.

Things in the Arctic still look bad, but they could have been a whole lot worse at this stage considering the state of things only 3 weeks ago.

[Geordiesnow]

7 hours ago, BornFromTheVoid said:

The longwave downwelling is more important further away from the summer solstice, I think. At the moment, our surface melt is much more similar to the last 3 years than to 2012 or 2007, regardless of whether short or longwave energy is the most important factor.
It's not longer just an extent slowdown either, 2012 has caught up with this year already according to Wipneus' shadow CT data and his homebrew area, and without some big losses, both NSIDC and ADS extent will be above 2012 by the weekend.

Things in the Arctic still look bad, but they could have been a whole lot worse at this stage considering the state of things only 3 weeks ago.

Indeed they do and there is a long way to go in the melt season for things to change for the worse thats for sure. 

The outlook does look low pressure dominated but it does not mean its all plain sailing, some very warm/hot air over Chukchi at the moment and whilst the winds don't look like persisting for too long nor do they look strong, some melting is still possible aatswell as warming the SST's up which do look well above average in the Pacific at the moment. 

Kara is another area which is going to experience hot conditions, infact I just wonder if it could actually be record breaking for June? there is not much ice left there but surely it will be wiped out in the near future and unlike in 2013/14, the current ice situation is more akin to 2011/12 and 15 so again, open water with warm uppers will only mean increased SST's which of course could make bottom melt more potant.

Hudson Bay is warming up and although the sea ice there can be a bit more stubborn, I still believe large drops here will occur here. 

I can't help but feel because we got quite low at one point, despite on paper the better weather conditions, the ice is still in quite a lot of trouble and I would not rule out a record low occuring. 

[Relativistic]

An interesting article fom the BBC this morning.

Essentially, experts at the University of Reading have developed a model based on the distribution of melt ponds in the Arctic which tries to predict the sea ice minimum come September. The model predicted the minima in 2014 and 2015 to a good degree of accuracy, and it is not predicting a record low this year.

Melt ponds suggest no Arctic sea-ice record this year - http://www.bbc.co.uk/news/science-environment-36560548

Edited June 18, 2016 by Relativistic

[BornFromTheVoid]

1 hour ago, Relativistic said:

An interesting article fom the BBC this morning.

Essentially, experts at the University of Reading have developed a model based on the distribution of melt ponds in the Arctic which tries to predict the sea ice minimum come September. The model predicted the minima in 2014 and 2015 to a good degree of accuracy, and it is not predicting a record low this year.

Melt ponds suggest no Arctic sea-ice record this year - http://www.bbc.co.uk/news/science-environment-36560548

That's what I'm thinking too, unless the weather turns quite bad in July and August. Current surface melt extent is down around the bottom of the last few years. If the warm weather since the winter had continued into June, we would have been in a really bad place, but this month has been relatively cool compared to 2012.
Daily NSIDC extent is now above 2012 too.