Ice-free Arctic (Cryosphere Today SIA)

[Juan C. García]

I appreciate your comments 

[slow wing]

Interesting question and very difficult to predict even for those more knowledgeable than I. Just entering into the spirit though, this is my probability distribution by year...

2013 - 10%
2014 - 30%
2015 - 25%
2016 - 15%
2017+ - 20%

So I took the first bin - representing a 40% summed probability, though I could equally have taken the second bin.

To set the scale, last year was a record low minimum area, at 2.234 million km^2, so the area has to go below about 45% of that.

That is unlikely this year as the weather conditions have been unfavourable up until now, at least away from the PAC 2013. Nearly all of the East half of the Arctic Ocean might go but there is probably still too much multi-year ice left on the West side.

If this year isn't below 1 million km^2 then I would give next year about a 1-in-3 chance of meeting that, and so on.

[Neven]

Juan, I modified your title to 'ice-free'.

I'm of the opinion that this could happen any year now, depending on the circumstances. With 2007 weather conditions there's IMO a very good chance for this to happen. Whether chances increase because volume continues to go down, is something we'll learn a bit more about this year.

It's a guess, but I voted for 2017-2018.

[Pmt111500]

Sorry (bad humor follows). I factored in the worst case scenario. All the data receiving stations and satellites fail and a total economic crash occurs since all the food futures have been sold. Oceanic circulation moves the Arctic amplification to mid-latitudes after the Nuclear Winter caused by E.Snowden & J.Assange ('war games'-movie -scenario). This leads to discontinuation of CT SIA in 2015 (NSA will only feed us false info, this goes down to 1000100, but not lower, so the republicans can stay in power), so we cannot get any info about arctic ice, which despite the fallout vanishes completely in 2028, when the circulation returns to normal. This is noticed  in 2033 by the Icelandic fishing expedition which is trying to find out if walruses still exist while surveying the least radioactive breeding areas of fish and squids. Otherwise sticking to my original 2017-18.

[Juan C. García]

Hi everybody. Thank you for your comments and thanks, Neven, for the correction.
I find very different to talk about ice-free Arctic on NSIDC SIE monthly values than to talk about it measuring with CT SIA on a single day. Even that until this day, the SIA has not melted as quickly as I was expecting on 2013, my perception of the Arctic in the medium term is still the same.
So if NSIDC SIE I was voting for the 2021-2023, in CT SIA I will vote on 2017-2018.

[Tor Bejnar]

The 2017-18 voters are speaking up and I'm one of them.  PIOMAS exponential projection says zero ice volume in 2015,  but I expect a little tail to materialize as Arctic ice just north of Canada seems to be somewhat resilient (still).

[Tor Bejnar]

The north polar region could be ice-free by midcentury
Christa Marshall, E&E reporter - Published: Tuesday, July 16, 2013

The Arctic could experience an ice-free September by 2054, according to a study published yesterday in the Proceedings of the National Academy of Sciences.

The research uses two new modeling techniques to narrow the range of predicted dates for an ice-free Arctic, which can differ by 50 years or more. But some scientists say that the revised estimates are too conservative and that the Arctic could experience an ice-free state in a decade or so.

The study:  http://www.pnas.org/content/early/2013/07/10/1219716110.abstract?sid=3b49090f-fef8-4f5d-993c-01e16902b5eb

I fully expect we will see a functionally ice-free Arctic for a day or ten within five years, but we could wait much more than 10 years for an ice-free September - late September gets mighty cold up on top of the world! 

[ChrisReynolds]

2017-2018 but only for a week or so at most.

[Juan C. García]

Hi Tor and Chris:
I expect to have ice-free September before 2020, if we define it in terms of less than one million km2 average with Cryosphere Today sea ice area. The reason is simple: volume is the real property that is leading the Arctic sea ice and it seems that it has been dropping pretty fast, so volume will finally have an impact in extent and especially in area. At 2007 and 2012 the old records were break before August ended. On the other side, the Arctic sea will get warm without ice and it will take some time before it loses the heat and starts to freeze. So even that we could have some values above 1 million km2 on the beginning and on the ending of September, on average we can have a SIA with less than 1 million km2. But anyway, this is just my opinion.

I invite everybody to vote on this poll. It is interesting to find out the opinions after the slow start that we had at the beginning of the 2013 melting season.

[TerryM]

2015-2016


I've long felt that 2015 + 2 years was reasonable. I'm thinking that 2013 is out of the running but that still leaves 14,15,16 & 17 as possibilities. I can't imagine that we won't have one bad year between now and 2018, and one bad year is all that it will take.


This year has been an eye opener as I really thought we'd be far ahead of where we are in terms of sea ice volume, north of 80 temperatures and Greenland's ice sheet. I wonder how much effect the SSW had on the Arctic?


Terry

[ChrisReynolds]

Juan,

I view this year as driven primarily by the failure of the Greenland centred summer atmospheric pattern, and the preceding cold May (which may have caused the failure of the pattern. I don't think we've seen the last of that pattern. It has dominated the Arctic summer for the last 6 years, and on the seventh it's not appeared (so far). And it first appeared after the 2007 sea ice crash.

This year is a step back, it remains to be seen to what degree the atmospheric set up will lead to increased second year ice this coming winter. But this year will probably represent little more than a small uptick with further losses in the years to come. Hence it's not changed my opinion about when we'll drop below 1M km^2.

[James Lovejoy]

2015-16 is the most likely in my opinion.

As stated above, it only will take one year with the weather conducive for ice melting/transport.  This is unlikely to be the year, but its better than even for one of the next 3 to be. 

One thing that might make me shift the time out to the 2020s is if last year's pattern of warm fall/winter & cool spring/early summer persists during the next few years.  If it does I'll figure that there is a physical basis for the pattern, instead of it being just random.  I'll also figure that the pattern is a negative feedback for ice melting.

[icebgone]

I believe 2017 is the first sub 1MM year.  This year the SSW really had a powerful impact on temperatures as oceanic heat was vented early and is not now available for bottom melting.  Next year I expect area to dip into the 1.7-1.8 range if no early venting happens.  2015 could be a possibility but you would need an early spring start followed by a warmer than average 80N.  If not 2015 then 2017.  Once you get to sub 1MM the trend line looks like 2030 for the first ice free summer.  The tail could be long after that.  The long-term CO2 record becomes important for an ice free Arctic.  If we reach 500ppm by Mid-century then an ice free Arctic may be possible. 

[dorlomin]

Personally I would only give it 50/50 before 2020. But 75/25 before 2030.

I seem a lot more conservative than most but I cant help but think that every winter the surface ice will always be exposed to the cold deep emptiness of space, barring a few CO2 molecules and the odd cloud for many long hard cold months. I think this will put something of a 'floor' under the volume melt. After a while it will slow down.

This may be the only group of people on the planet where Id be considered very conservative for that projection!

[Shared Humanity]

Personally I would only give it 50/50 before 2020. But 75/25 before 2030.

This may be the only group of people on the planet where Id be considered very conservative for that projection!

We can use this.

[ChrisReynolds]

Personally I would only give it 50/50 before 2020. But 75/25 before 2030.

I seem a lot more conservative than most but I cant help but think that every winter the surface ice will always be exposed to the cold deep emptiness of space, barring a few CO2 molecules and the odd cloud for many long hard cold months. I think this will put something of a 'floor' under the volume melt. After a while it will slow down.

This may be the only group of people on the planet where Id be considered very conservative for that projection!

You may very well be right. If the 'early' camp are wrong, this is almost certain to be the reason why. The root cause being the power of winter ice growth.

[kynde]

Where we end up this year should give us some hints as to what lies ahead given the reasonable freeze except for cracking and the sluggish start.

Although I'm a member of the early camp and have argued against all gompertz fits and such, I must admit that what dorlomin said is still very much a possibility. I think the MYI is done for but the coming changes in the ocean currents and layering as well as in weather patterns remain undetermined and they certainly have the capacity to swing it either way.

[Juan C. García]

Four and a half days left to vote. I appreciate your long term perception on SIA, even though it would be shorter than what it seems to be the official perception... 

[Anne]

I voted 2017-18, though I wouldn't be astonished if it were earlier or later. It depends on wind and weather. I agree with what dorlomin says about the exposure to the long cold arctic night putting a floor under it.  But with less ice cover, won't the surface become increasingly turbulent and harder to freeze?

[Vergent]

13 -14

Obviously not 13. There has been a negative temperature anomaly in the high arctic this year. this has significantly shortened the melting season. But if this fall there is an Atlantic inrush into the CAB due to the extreme Atlantic side melting this year, it will go "ice free" next year. We can watch the ITP buoys for the inrush, so we will know for sure in the fall. The Met office global model modeled an inrush last year, the result was a convection that melted an ice free patch near the pole in early January, this surely would be a harbinger of an ice free arctic.

Vergent