Arctic Sea Ice Discussion 2016-2017: The Refreeze.

[BornFromTheVoid]

Both NSIDC and ADS extent are sitting on the lowest March values on record, but there's still over a week of melting potential ahead...

[Methuselah]

Situation Dire, I would say?

[Gray-Wolf]

About this time of year i used to mull over just what a good ( high melt) summer would do to that pack. I am now no longer able to do this as last year showed us by having a high retention weather melt season nearly take record lows for extent/area.

The winter just past was even worse than last years for conditioning the ice into something that could face melt season and survive and we have record low volume so I know that an even worse summer ( for melt) will still leave us in a bottom 3 spot in the rankings. When even ice retentive years take our ice we know things are now different!

With the return of the perfect melt storm synoptic now possible what would such a melt season mean to our hemisphere???

[stewfox]

5 hours ago, Gray-Wolf said:

About this time of year i used to mull over just what a good ( high melt) summer would do to that pack. I am now no longer able to do this as last year showed us by having a high retention weather melt season nearly take record lows for extent/area.

The winter just past was even worse than last years for conditioning the ice into something that could face melt season and survive and we have record low volume so I know that an even worse summer ( for melt) will still leave us in a bottom 3 spot in the rankings. When even ice retentive years take our ice we know things are now different!

With the return of the perfect melt storm synoptic now possible what would such a melt season mean to our hemisphere???

Where do you think we will end up this year ?

Maybe time for a new thread

[knocker]

PIOMAS April 2017

Quote

Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

http://neven1.typepad.com/blog/2017/04/piomas-april-2017.html

[Geordiesnow]

Some interesting weather coming up into the Arctic with a WAA heading in via a strong low that is hitting the Bering sea and in turn we see quite a strong Beaufort high developing with a rather tight pressure gradient developing. Just how much ice will there be in the Bering sea in a few days time and just how much ice will come away from the coastline of Alaska and what will the situation be like this time next week?

Giving how thin the ice is in Chuckchi and no real Multi year ice in Beaufort then its certainly not going to be a good start to the melt season on the Pacific side of the Arctic.

I suppose at least the ice in the Kara Sea has been given a lifeline after unprecedented ice loss there during March, just imagine what the situation would be like there if the Southerlies continued!? Either way, the foreseeable does seem to suggest conditions should remain cold in the Kara but I still expect the ice there to retreat quite rapidly like it did in 2012.

[Gray-Wolf]

Yup GS, I don't see much of the Bering ice being there next week and we are past any chance of it reforming so I'd expect JAXA to see us bottom ( not 2nd bottom) by this time next week?

Beaufort will be interesting to watch though? We have never seen such young , poor ice dominate this region but we are all armed with what we have seen there over past seasons with very good ice ( the 'babies arm'?) taken over the season? I used to take it that an average season would take upward of 1.5m of ice so that alone would bring us a massive new record low across all measures even if only an 'average year'. To see this happen would seal the deal on ice free over the coming years.

At the moment we do see difference in CRYOSAT2 and PIOMAS thickness data and , until we get the ice bridge data, do not know which to trust? The ice could be this mass of 1.5 to 2m ice or it could be far thinner and capped with thick WACCy snow cover from both early winter snow ( like we saw across West Siberia?) or the frequent WAA into the basin throughout winter. If snow cover is making the freeboard appear much higher than it is then that up to 2m thickness could end up being 1.3 or 1.5m giving us a real potential of a sub million pack before re-freeze?

By the time we are into May we might have a better idea of just how healthy the pack is but even with today's values it is by far the poorest pack we have ever seen at the beginning of melt season and all of our best ice looks bound for Fram over the coming months leaving a near complete FY ice pack there after..

[Geordiesnow]

13 hours ago, Gray-Wolf said:

Yup GS, I don't see much of the Bering ice being there next week and we are past any chance of it reforming so I'd expect JAXA to see us bottom ( not 2nd bottom) by this time next week?

Beaufort will be interesting to watch though? We have never seen such young , poor ice dominate this region but we are all armed with what we have seen there over past seasons with very good ice ( the 'babies arm'?) taken over the season? I used to take it that an average season would take upward of 1.5m of ice so that alone would bring us a massive new record low across all measures even if only an 'average year'. To see this happen would seal the deal on ice free over the coming years.

At the moment we do see difference in CRYOSAT2 and PIOMAS thickness data and , until we get the ice bridge data, do not know which to trust? The ice could be this mass of 1.5 to 2m ice or it could be far thinner and capped with thick WACCy snow cover from both early winter snow ( like we saw across West Siberia?) or the frequent WAA into the basin throughout winter. If snow cover is making the freeboard appear much higher than it is then that up to 2m thickness could end up being 1.3 or 1.5m giving us a real potential of a sub million pack before re-freeze?

By the time we are into May we might have a better idea of just how healthy the pack is but even with today's values it is by far the poorest pack we have ever seen at the beginning of melt season and all of our best ice looks bound for Fram over the coming months leaving a near complete FY ice pack there after..

I kind of expect the ice in the Bering to get more compacted so whilst extent will reduce there, I would expect some ice to remain there by this time next week, perhaps more concerning is just how big those polynyas will get towards the Alaskan coast and exactly how much ice will push away from there, are temps going to be low enough to limit the extent of open water? Only saving grace is that this sort of set up has not yet happened in a month or two time when true warm air would of entered the Arctic. There is hints from the models that the winds along the Beaufort stretch itself could change so they are coming from the Arctic basin which may close any holes along the Alaskan coasts but they have only been hints and if anything, the trend does seem to be for the high to be quite persistant and stuck in more or less the same place. The Chuckchi sea looks the most vulnable to me in the coming week and I would not be surprised at all if we start seeing a lot of reds and yellows appearing on the Breman sea ice concentration charts soon.

I still think its too early to say whether we will get a record low or not but for me, even we end up near last years total, if we have a situation where the trend line is way off the others during the summer months then that will tell everything on the state of the ice that is up there at the moment. If we have a 2007/11 type of summer then a record low for the summer months will most defintely occur and we could see the trend line well away from the other years just because on how thin the ice is in thickness and volume.

[Gray-Wolf]

As ever ,at this time of year, all we can do is sit back and watch GS!

It is me who has altered over recent years in that I used to fear a return of 'The perfect Melt Storm' over the melt Season. Now I look at how the winter treated the ice and fear a better than average Summer!!!

[knocker]

 

[Geordiesnow]

On 13/04/2017 at 19:55, Gray-Wolf said:

As ever ,at this time of year, all we can do is sit back and watch GS!

It is me who has altered over recent years in that I used to fear a return of 'The perfect Melt Storm' over the melt Season. Now I look at how the winter treated the ice and fear a better than average Summer!!!

I think the biggest damage was caused during the Autumn season where refreeze was very slow and the PV almost non existing really as winds was blowing from the Pacific side of the Arctic in particular bring an awful lot of mild air, I never seen upper air temps across the Arctic being so warm before during October, it was quite unique to say the least!

I do think an ice free pole would be more or less an certainity if we get a 2007/11 type of summer but the ice already looks in such a bad shape that you feel when we get the first proper heat blast of the season then the ice will just melt right away, hopefully the early openings on the Pacific side can be filled back in before it will be too late even if albeit it will probably only cover the cracks so to speak.

Does look more certain there will be a pattern change from high pressure to more lower pressure over the Arctic although there is quite a lot of disagreement in terms of the details but with lower pressure, the PV should strengthen slightly which could bring colder air and more favourable winds to the areas of the Arctic that will need it.

[reef]

Closing this, please continue in the melt thread.

Cheers