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Robert S

One (simplistic) way to think about this may be that May/June melt ponds equate to X cm more thickness loss, thereby causing thicker ice to melt out where there is extensive melt ponding. I have this suspicion that melt ponds will be less critical on thinner ice (all other things being equal... which they never are), because that ice will melt out in any case. So the question for 2017 may be how the combination of thinner ice and fewer melt ponds impacts the final extent. I'm tempted to think that melt ponding may be less critical this year, because that thinner ice may be going no matter what...

Robert S

Where some of the thick ice has gone: http://www.cbc.ca/news/canada/manitoba/climate-change-study-1.4157216


Another factor pointing to a possible rebound: concentration is looking better than the same time last year: https://sites.google.com/site/arcticseaicegraphs/concentration-maps/sic0613

I know this doesn't show thickness, but still... reason for hope that things might not go all runaway melt this year.

I'm tempted to think that melt ponding may be less critical this year, because that thinner ice may be going no matter what...

That could very well be true, Robert. And I'm definitely not saying that this is putting a spanner in the works of a new record.

Let me put it this way: If there was extensive melt ponding going on right now, building up lots of melting momentum for July and August, I'd be willing to bet (big) money that this year all records will be broken. As it is, everything is still open.

Melt ponding could still get going, or like you say, it may not matter all that much because so much of the ice is thin.

One other thing speaking for 2017 staying a very serious contender, is the current weather forecast. Although the spell of (relatively high) high pressure is now coming to an end, it's not like low pressure is taking over. In fact, it seems a weak dipole is going to form over the coming week.

SSTs are also on the rise. I'm waiting for June 15th to come around, as I have DMI SST anomaly maps for that date from 2012 and 2016.

Another factor pointing to a possible rebound: concentration is looking better than the same time last year:

Paddy, I think that this is another indication of low melt ponding. Normally, when the ice starts to turn bluish, that's also the start of large swathes of green/yellow/pink on the Uni Bremen SIC map. Because these swathes do not stay in the same place (most of the time), they're not really an indication sea ice concentration (ie open water vs ice), but rather of melt ponding.

Jim Hunt

Robert - Surely whether a particular area of sea ice "will melt out in any case" has no bearing on its albedo today?

If that area of ice is currently covered with snow instead of melt ponds it's reflecting most of the short wave radiation it receives, rather than absorbing most of it.

For those that follow such things, JAXA/IJIS/ADS Arctic sea ice extent for 2012 just dropped below 2017:



And then there was a huge hole in the ice around the border between the Chuchki and the CAB. Not much melt ponding, but, significantly, that area has been showing on off signs of melt ponds. Possibly that the ponds are forming and draining, all in one day, due to the fragmented nature of the ice.

They could, of course, also be forming and freezing all in one day too. I guess we won't know though unless someone goes and looks.

This, to me, is an indication of times to come. We saw this back in the autumn of the 2000's where the summer melt impacted the pack so badly that holes just opened up before the freeze set in again.

Now, though, it would appear it is happening in early summer. Which means we're seeing late summer ice conditions in early summer.

Not something which bodes well for the ice.


A thought for you Jim, 2017 crossed 2012 two days after 2007 and 0.5mkm^2 lower. 7 days later 2016 touches 2012 and is about the same difference, today, between 2017 as 2017 is from 2007.

I see it's 26F and has been snowing at Barrow. Yet the melt ponding is advancing rapidly and the landfast ice appears to be almost on the point of destruction. Might take a few more weeks though.

Sadly we lost the forecast and the data after 2011.


Susan Anderson

That CBC thing about Bell Isle icebreaking is interesting. Here was wunderground (Henson, including cite of Jim Pettit) a few days back.

I'm keeping an open mind, but observe in my most recent check of Nullschool that almost the entire Arctic Ocean surface temperature is above 0C. Since the melt point of saltwater is about -2C, doesn't that affect things as well? I realize warmth alone doesn't do the trick in a hurry, but it seems something that might affect the rest. Daylight will remain static until mid-July (yes, I know, cloud cover and weather ...).

Susan Anderson

Ah, for comparison I should have been looking at this.


Jim, Although 2012 has now passed 2017 it has also completed its' June dive and now declines at a very sedate rate for the next two weeks.

2011 crosses below 2012 in two days and it is likely that 2017 will do so within three. 2017 is only 76K behind 2012 and has the second greatest loss this month.

With the much thinner ice this year it is easy to envisage 2017 with a substantial gap below 2012 by the end of the month.


Talking about melting momentum and melt ponding, a huge area of ice went from ice to water and back to red/yellow on the concentration charts in two days on Bremen. Right on the Chuchki/CAB border.

I'm wondering if the ice is so thin now that it can melt pond and drain again in 24 hours. Which would invalidate the 3 day scenario and would produce much more unpredictable ice conditions.

It could, of course, just be freezing up again, but it must be pretty close to 24 hour sun there. Unless the weather closed in. But even then I'm seeing melt ponding at Barrow staying melt at 26F with snow.

I guess we'll know if someone decides to overfly or sail there and investigate.

Robert S

Jim Hunt: Your point about the albedo impacts is certainly accurate. I guess that the impact of melt ponds/more radiation absorption would be earlier melt, followed by more heat entering the arctic ocean, which certainly could be significant over the longer term, and would probably show up most during the refreeze.

The current fragmentation of the ice is also having some pretty interesting albedo impacts.

Wade Smith

[snip, too off-topic, too long, go to the ASIF; N.]

Wade Smith

[snip, see previous comment; N.]

Wade Smith

[snip, see previous comment; N.]

Hans Gunnstaddar

Ok, big prediction time:

Within the next 7-10 days there will be a sharp drop in extent below 2012 level. If this prediction is correct I'll explain later how it was forecast.

Rob Dekker

Why not explain your prediction beforehand ?
Is it PIOMAS record low volume ?

Also, 2012 doesn't decline that much over the next 10 days. Only 67 k/day if I recall. If you claim a significant decline over the next 10 days, why not go with 2010 ?

Hans Gunnstaddar

"Why not explain your prediction beforehand?"

Because it's unknown how accurate this predictive system is, but to put it to the test it has to be documented with a post (on 6/16). In fact, should this succeed the 1st time, 2nd and 3rd predictive posts will also be needed to establish increasing probability of accuracy. If it works for a 3rd time in a row, the method will be divulged.

John Christensen

Thank you very much for the melting momentum update Neven!

I would agree with Dr. Schroder that we should see slightly below average sea ice meeting this season due to lower melt pond fraction, seeming caused by lower than average high north temps (DMI 80N).

I am also very curious about the impact of Greenland, which often is given little space for consideration for the sea ice: The relentless storms last fall has caused much higher precipitation than usual (http://polarportal.dk/groenlands-indlandsis/nbsp/isens-overflade/ ), and the measured albedo of Greenland has improved as a consequence.
In 2012 we saw the heat dome over Greenland, which caused very warm air to flow down to surrounding sea surfaces, but this year the ice cap will help keep things temperate.

Back to lurking.


Thanks, John.

Since 2012, we haven't seen a melting season with a high amount of preconditioning through melt ponds. Maybe it's a sign of some negative feedback kicking in.

Last year still went low despite this lack of melting momentum, and this year the ice is supposedly thinner than it has been (although the gap between 2017 and 2012 has rapidly disappeared, according to the latest information on the ASIF). And there's already a substantial amount of open water in the Beaufort, Chukchi, East Siberian and Laptev Seas.

So, while there's a lack of melt pond formation, it may be that the influence thereof is becoming less of a factor. In this sense, and as always, it will be interesting to see how things play out this year.

Of course, once we get a year that is low volume-wise and heavy preconditioning at the start of the melting season...


Whilst the Beaufort and the Chuchki seemed to have slowed down (for now), the Kara continues to be low area and the ESS and Laptev have large melt areas just starting to grow. Also the Hudson Bay is now in serious terminal decline.

All of which leads to an accelerating melt for the next week or two. Not radical but it doesn't need to be.

I'm watching extent right now as it's much easier, for me, with chartic, to do comparisons with prior years.

For me it looks like 2017 will drop below 2016 and 2010, in about 7 days. It is then likely to continue on that track without excessive melting.

Whilst this is not volume, volume will be impacted by the significantly lower extent especially as there is a lot of broken ice, with melting going on, where there should be extremely thick ice and firm pack ice.

Barrow looks to be likely to lose it's landfast ice in the next week or two. Putting it firmly in the 2003/04/07 bracket.

The most interesting thing here is that, so far, the only thing which has really been exceptional is the prior winter ice conditions.

Which leads me to wonder just how much of the final demise of the summer ice pack will come from exceptional winters rather than exceptional summers.

All melting seasons are different and they are drastically impacted by the weather. What is changing is the position from which they start.

I still believe we will get a more similar season to 2007, than any of the others. Whether it causes a new minimum with the same kind of impact remains to be seen.

My future forecast remains the same as it did last year. 2022 is my view for truly game changing events. Although I do expect a fairly dramatic melting season eventually in 2017.


I've been following the chat for a long time and eventually I decided to jump in.

There's a strong cyclonic circulation in the central Arctic going on since a few days ago:


a direct consequence of the low pressure over the area:


I'm curious about what effect will that have on the ice at the edge in the Kara and Barents Seas.

Jim Hunt

One intriguing recent development is the expansion of this year's "Laptev bite" towards 80N:

At 4 days out this is by no means a certainty yet, but ECMWF is currently forecasting that the low pressure will develop into a sub 970 hPa cyclone:


I'm curious about what effect that will have, if it comes to pass!

Jim Hunt

P.S. See also this post by Neven on the Arctic sea ice forum:


A comparison between the ECMWF deterministic and ensemble forecasts of the potential cyclone.


Thanks, Jim.

And next week I'll be showing how both these forecasts fared (for June 24-29), when compared to what happened from day to day. It's high time I learned some more about weather forecasting. ;-)



Jim , that Low is just about right indicating early stages of disintegration of the main pack ice, a tad earlier than I anticipated, I don't think it will persist as long as it will be in later August. Mean time I would trade some of my prediction skills for persuasion abilities, if I could, things are looking grim, many people don't know it, these are the voters of interest.


In the vast area of Arctic Ocean If there is more sea ice snow than 2016, as Neven's melt pond graphs suggest, the collapse of sea ice will appear unnerving, sudden, unexplainable, but if we study a smaller area, such as Baffin Bay, Hudson Bay and Barrow Strait:


the larger Arctic Ocean Pack becomes easily predictable by the machinations of macro regions. Is a fact of physics you can learn on such wonderful science shows such as PBS NOVA (one of USA's greatest jewels, to be cut off if dumb dumb Trump gets his way).
Water effects can be literally modelled on a very small scale. And so the Arctic Ocean mini models abound in nature, but having a lab would help further replicate.

http://www.pbs.org/wgbh/nova/earth/megafloods-of-the-ice-age.html .

John Bilsky

Just took a 12 second plunge in the Beaufort Sea at Prudhoe Bay. The air temperature is around 60ºF and I've been told that the sun won't set until Aug. 1st at this latitude. The shoreline is essentially ice free but not for far. However the ice looks horribly rotten. I suspect the majority of the melt ponds are highly disguised by snow slush and in my uninformed opinion may *appear* to be "solid ice" instead of what they likely are.... slush ponds. How far this can be applied to the entire Arctic is anyone's guess. Back to lurking and waiting.


John, the sat images since a few days ago show large extensions of the Beaufort sea ice no longer as pristine white floes but as ice clearly tinted in blue. In agreement with your in-situ observations. Mo more snow disguising melt, well, perhaps further North closer to the CAB

Bill Fothergill

@ John Bilsky "Just took a 12 second plunge in the Beaufort Sea at Prudhoe Bay ..."

If these "in-situ observations" are being supported by the NSF, I really think that you should significantly extend the plunge duration.


John Bilsky

Thanks guys.

@ Navegante.... We will see soon enough huh?

@ Bill F. :-) You funny guy. :-) The water was cold but looking back at the experience it was certainly possible to stay in longer. The initial shock was a bit much for the cranium. Surprisingly it was quite comfy after getting out.


It looks like the Barrow Landfast ice just started to exit. Whilst not all the point has gone, a significant portion in front of the camera has gone and, mostly, it seems to have melted out rather than been pushed away.

If the rest goes today, it will equal 2007.

Jim Hunt

Neil - Actually it would seem to have been "pushed away" by the recent easterly winds?


Meanwhile O-Buoy 14 has captured the onset of surface melt in the heart of the Northwest Passage:

Amongst other things!



Jim, I watch it daily over multiple times in the day. The near shore ice went first to melt. Then the ice outside of the ridges went second and melted out. It was only after the significant melting in the outer ice that the wind took over.

It's not like the 2016 events where the wind quite literally shunted the ice all up the coast.

I watched the last 24 hour video. Yes there was some drift from the wind, but no real solid push of all the ice like we've seen before.


I just looked again. It's pretty clear, that is melt.


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