The 2016 melting season

[JayW]

Yes, according to both of the main weather models the Arctic Basin weather will be dominated by a large low pressure system for at least the next 10 days.

Well they do agree, but I wouldn't say the arctic is "dominated" by low pressure.   

ECMWF and GFS 8-10 day 500mb mean first attachment.

And the most reliable of all models, the ECMWF ensembles, has been moving towards move ridging in the Canadian archipelago, and even extending towards Greenland.  Perhaps even a negative NAO.

Second attachment is the ECMWF ensemble forecast fir hour 96.
http://www.tropicaltidbits.com/analysis/models/?model=ecmwf-ens&region=nhem&pkg=z500_mslp&runtime=2016070200&fh=96&xpos=0&ypos=23
http://www.tropicaltidbits.com/analysis/models/?model=ecmwf-ens&region=nhem&pkg=z500_mslp&runtime=2016070200&fh=96&xpos=0&ypos=23

[Lord M Vader]

Well, to cite Neven: "It's crunch time"

I think we can expect century breaks soon. Hudson Bay is roasting right now and CAA/Beaufort should see great damage. Not to mention the areas which will be impacted by the "BIG MAC" by next week.

[BornFromTheVoid]

If the weather models are to be believed, from about next Wednesday onward, weather patterns strongly conducive to rapid area and extent losses look like coming, with a chance of a mega melt week in the offing.

The area and extent losses look like having 3 main aspects;(a) Melting across Hudson, Baffin and the CAA, (b) melting across Chukchi, Beaufort and Central Arctic (c) compaction mainly across the Pacific side.

a. At this time of year, we would expect the melt out of Hudson and Baffin to be some of the biggest contributors to the overall losses, with a smaller contribution from the CAA. Over the next 10 days or so, none of these areas see any significant cold that would be expected to change this.

b. By Wednesday, the ECM shows significant warmth and clear skies getting pulled up through the CAA and into Beaufort, Chukchi and the central Arctic, with widespread upper air values above 4C and surface temps well above 0C. This should increase melt rates, especially surface melt, resulting in drops in extent and area.







c. At the same time, the combination of high pressure across the N. American side and a strong depression along the Eurasian side promotes a +ve dipole pattern, with a cross-polar air flow driving much of the ice toward the Barents sea area. This will cause compaction of the loose rubble-like ice on the Pacific side, resulting in further area and extent losses.









Given that these forecasts are still for a few days off, things can change. However, if the come to fruition, we will very likely keep in the race with 2012.

[slow wing]

BFTV "This will cause compaction of the loose rubble-like ice on the Pacific side, resulting in further area and extent losses."

True in the short term, but compaction helps preserve that ice, which should increase the expected minimum area and extent at the end of the melt season. It gets destroyed when it is instead blown into the regions of open water.

[BornFromTheVoid]

I don't think it's so straight forward, slow wing. Both 2012 and 2007 featured patterns favourable for compaction, with +ve dipoles and strong cross polar flows.

[slow wing]

True. It's also mobile ice being pushed around, which is bad for it.

[A-Team]

Here is a followup on #2794 which compared projected 07 July 16 with those of 2012-15. The images below show the differences with respect to 2016 (computed as 'grain extract' = 2016 - 201x + 128 within the RGB color cube).

[A-Team]

get the impression RobD doesn't know what radiation balance is. Could you provide a link for Screen 2010?

While neither of JA Screen model papers of that year -- which both address Arctic amplification of global atmospheric warming -- provides or utilizes experimental information about Arctic sea ice radiation balance, the first citing land-based weather stations and the other 1989–2008 ERA-Interim reanalysis, the links to free full text are here:

Increasing fall-winter energy loss from the Arctic Ocean and its role in Arctic temperature amplification
JA Screen and I Simmonds
GRL DOI: 10.1029/2010GL044136
http://onlinelibrary.wiley.com/doi/10.1029/2010GL044136/full 50 cites

The Central Role of Diminishing Sea Ice in Recent Arctic Temperature Amplification
Nature 464(7293):1334-7 · April 2010 DOI: 10.1038/nature09051  552 cites
JA Screen and I Simmonds
http://tinyurl.com/z7bebmw

Open water can have a low albedo (depending on wavelet scattering and incident angle of solar energy) but if the water is very clear, Raleigh scattering has the effect of distributing the heat along a substantial vertical water column. If the water is opaque from river or bottom sediment, the algal ecosystem algae on the underside of the floes, or open water algal bloom, heat is absorbed at comparatively small depth

Right. The Arctic system is extremely complex, every component of it, and changing rapidly. The notion that amateur back of the envelope calculations or cherry-picked papers can substitute for the full scientific literature and current experimental data from on the ice strikes me as preposterous.

[Magma.]

The Arctic system is extremely complex, every component of it, and changing rapidly. The notion that amateur back of the envelope calculations or cherry-picked papers can substitute for the scientific literature and current experimental data on sea ice strikes me as preposterous.

And this can be extended to many positions of climate cranks and contrarians, right down to the bottom of the barrel "CO2 is plant food" or engineers 'disproving' 40 years of atmospheric physics and radiative transfer studies based on old rules of thumb for furnace gases.

[A-Team]

Laurent writes in #2771: Big Block is weaker ! Tic Tac Tic Tac

Right, looking back from the July 02 surface melt features to determine what is stably present (not cloud artifacts), the clock has been ticking since the 24th of June. It's fair to say Big Block has not been in Gyrating lately nor is it drifting west into the Chukchi.

The motion in this 47600 km² section of the Beaufort does not lend itself to simplistic description.

However other floes in worse shape can be seen to still hold together for weeks. On the left side of the animation on June 29th, a game of bumper cars ends with a good-sized floe breaking up after a leveraging collision. Two days were unavailable because of clouds, the 26th and 28th, accentuating the apparent drama.

[seaicesailor]

Laurent writes in #2771: Big Block is weaker ! Tic Tac Tic Tac

Indeed, looking back from the July 02 surface melt features to determine what is stably there (not cloud artifacts), the clock has been ticking since the 24th of June. It's fair to say Big Block has not been in Gyrating lately nor is it drifting west into the Chukchi.

The motion in this 47600 km² section of the Beaufort does not lend itself to simplistic description.

However other floes in worse shape can be seen to still hold together for weeks. On the left side of the animation on June 29th, a game of bumper cars ends with a good-sized floe breaking up after a collision. Two days were unavailable because of clouds, the 26th and 28th, accentuating the apparent drama.

Great animation. What impresses me most is the 180° rotation of a big floe at the top left of the image. The floe translation of 50 km radius is not solidary wrt the movement of floes around. The floe is probably sitting on top of a vortex, which is mixing water elements that were 100 km apart one week before! Now let's put that into the energy conservation equation!

[seaicesailor]

...
Open water has even lower albedo but as you say absorbs over a large volume of water (unless water is very opaque,  sediment rich waters absorb within a comparatively small depth and surface temperatures rise quickly). So SW balance is  more positive and LW balance is a little less negative because surface temperatures are less, if cloudiness is the same above sea and land.

This is a point that puzzled me. If extra solar energy because of ice loss is buried into deeper ocean layers, the question is if this energy will surface out during the current melting season or not. If it doesn't, unless heat is being accumulated in the Arctic ocean, the extra heat will affect future freezing/melting seasons, and conversely the current  season is being affected by previous seasons.

My 'hunch' was that the Arctic is closed and the active layer sufficiently thin to avoid heat accumulation; also that all heat absorbed was transferred back to the ice (bottom melt) or to the atmosphere before refreezing.

Otherwise the ice may be paying the excesses of 2012 but that sounds irrealistic ( or not?)

Edit: by the Arctic is closed I mean for practical purposes in the problem of solar energy heating open water; that little of that energy is taken away by ocean currents during the melting season

[A-Team]

the translation of the 50 km radius floe is not in solidarity with movement of floes around it, probably sitting on top of a vortex

Interesting idea, ocean current vortices. Floe motions don't correlate notably with the 1000 hPa wind field at nullschool. Those have been erratic in June compared to a textbook May clockwise gyre.

The nullschool wind animation below covers the same date range as floe animation above.

[Tealight]

[edit] Does anyone want to make an adjustment to my calculations of bottom-melt in the Beaufort ?

I don't want to contribute an exact calculation, but a visual aid. On Worldview the 'Brightness Temperature Band' shows very clearly warm ocean water. When an ice floe drifts over this warm water the brightness temperature is drastically reduced. This means most of the ocean heat went towards bottom melt and not lost to the atmosphere/space.

 It is best visible by switching between a few days or having two browser windows at the same time.

https://worldview.earthdata.nasa.gov/?p=arctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,MODIS_Terra_Brightness_Temp_Band31_Day(palette=rainbow_1,min=270.4,max=285.6,squash),Reference_Labels(hidden),Reference_Features(hidden),Coastlines(hidden)&t=2016-07-01&v=-2595018.9332532175,-207628.2966213263,-1643722.9332532175,375539.7033786737

[jdallen]

Yes, according to both of the main weather models the Arctic Basin weather will be dominated by a large low pressure system for at least the next 10 days.

Well they do agree, but I wouldn't say the arctic is "dominated" by low pressure.   

ECMWF and GFS 8-10 day 500mb mean first attachment.

And the most reliable of all models, the ECMWF ensembles, has been moving towards move ridging in the Canadian archipelago, and even extending towards Greenland.  Perhaps even a negative NAO.
<snippage>

The forecast does appear to suggest Fram export may get a kick, as well as movement across the central pack pushing towards the "hot" ocean along the whole Fram/Svalbard/Franz Joseph/NE Barents front.  If it continues, that will be worth keeping an eye as its turned into a killing zone for the ice.

[Laurent]

I do not see much, may be it from too far away... ?

[A-Team]

On Worldview the 'Brightness Temperature Band [31 Day, Terra]shows very clearly warm ocean water. When an ice floe drifts over this warm water the brightness temperature is drastically reduced. This means most of the ocean heat went towards bottom melt and not lost to the atmosphere/space.

No, it doesn't mean anything of the sort. You are in way over your head on infrared false color imagery. Go back and at least read the abstracts of the Perovich papers, #2784.  Go back and read up on what AndreasT has been posting on that forum topic.

[seaicesailor]

the translation of the 50 km radius floe is not in solidarity with movement of floes around it, probably sitting on top of a vortex

Interesting idea, ocean current vortices. Floe motions don't correlate notably with the 1000 hPa wind field at nullschool. Those have been erratic in June compared to a textbook May clockwise gyre.

I'll upload the nullschool wind animation on Tuesday when the forum server handling attachments gets repaired.

That'd be awesome. Also it would interesting how it looks against the ACFNS model. The 30-day animation of SSS shows big eddies indeed being generated

http://www7320.nrlssc.navy.mil/hycomARC/beaufort.html

I attach a piece of today's prediction. Rather than the salinity itself, the idea was to visualize the eddies. From the animation, the coastal current (big red arrows) is seen to generate many eddies from Barrow (where the ocean current has to bend in order to follow the coast). I believe the one with an "A" travels more than 200 km from the time is formed at the beginning of the animation (30 days ago).

The Big Block location and approximate size is represented by the cyan oval.

Along the left side of the coastal current similar eddies appear. I add a red arrow in a few I could identify.
In fact the simulation does not show much Beaufort clockwise current.  It is mainly the coastal current mixing like a jet.

Edit: to start with, the floe in A-Team visualization is rotating in the opposite direction than the eddies from the model :-( 

[seaicesailor]

Far in the horizon:


This setup looks bad for the ice. Uncertain as it is, the worrying thing is that the weather pattern is similar during the previous days.

[Tigertown]

Not quite a century drop today but we did get 90k in extent loss per JAXA

[Paladiea]

It's interesting to note that people talk about heat shed to the atmosphere as being "lost". Isn't it true that the atmosphere also radiates heat to the ocean, especially if it is warmer?

I understand that the heat capacity of air is much less than water, but isn't it fair to assume that if the atmosphere above a certain part of the ocean is cooling (or even not warming), then it is transferring its heat to the ocean?

[bbr2314]

The low is now getting going, T-48 til it gets into the 970s, and another 48 hours til it re-enters the 980s...

[Rob Dekker]

Rob, your comment is demonstrating the dangers of thinking you can get to grips with heat transfer without "overanalysing". Unless you have just expressed your thoughts poorly, I get the impression you don't know what radiation balance is. Could you provide a link for Screen et al?

I'm sorry, Andreas, re-reading my own comment I can see that indeed I was sloppy with my words.
Let me rephrase.

All I wanted to do was to come up with a ballpark number for how much bottom melt is happening in the Beaufort, and how much goes to warming the water.

Making some simple assumptions (20 meter mixing layer, 280 W/m^2 SW insolation, 3 C warming of the Beaufort since it opened up) I concluded that some 17% goes to warming the water, and thus that more than 80% must have gone to bottom melt.
I am perfectly open to adjustments to these assumptions, but only with supporting evidence.

Now somebody said that I should subtract 40 W/m^2 because of surface LW imbalance.

There I mentioned two issues :

1) If we are going to bring in LW imbalance, then we should also bring in regular atmospheric heat transfer. After all, if there is a significant LW radiative imbalance, then even the surface temperature of "white" (reflecting SW) areas like these floes that are drifting in the Beaufort should cool down. But since these  floes are now also top-melting suggests that any LW imbalance is compensated by plain old atmospheric heating.

2) I questioned that 40 W/m^2 LW loss. Just seems quite a lot.
There I found fig 3 in the Screen et al 2010 paper ""The central role of diminishing sea ice in recent Arctic temperature amplification" in your "Radiative balance in the Arctic" thread :
https://farm3.staticflickr.com/2936/14234219758_372564238c_o.png
which suggests that indeed in spring there is a radiative imbalance of some -40 W/m^2 while in summer there is a surplus (atmosphere radiatively warming the surface) of something like +30 W/m^2. I figured that are the transition time between spring and summer (over the past month) there would not be much or LW radiative imbalance.

However, I now realize that this Screen 2010 figure is total net surface radiation (SW plus LW) over all latitudes in general. That means the figure is not very useful for determining LW imbalance for specific surfaces in specific locations.

Your CERES figures are more useful there, although it is very hard to determine the LW imbalance over open water, the last CERES graphs your posted show something very useful :



The very interesting part there is the "Surface Net Total Flux", specifically over the open water areas in June 2015 (which was the Bering Strait). There CERES reports about 200 W/m^2, which is a very useful adjustment to my 280 W/m^2 insolation number.

But if we go there, we should really try to determine heat input from lower latitudes (my point (1)) too. After all, the land areas are much above 0 C and thus the winds blowing over ocean have quite a bit of heat that WILL warm the water too.

[Rob Dekker]

On Worldview the 'Brightness Temperature Band [31 Day, Terra]shows very clearly warm ocean water. When an ice floe drifts over this warm water the brightness temperature is drastically reduced. This means most of the ocean heat went towards bottom melt and not lost to the atmosphere/space.

No, it doesn't mean anything of the sort. You are in way over your head on infrared false color imagery. Go back and at least read the abstracts of the Perovich papers, #2784.  Go back and read up on what AndreasT has been posting on that forum topic.

A-team, this is not like you. Your sound upset. What's going on ?

In general, it is not very helpful to tell somebody to "Go back and at least read" the abstracts to dozens of papers or tell them that they are "way over your head".

What is your point ? Are you claiming that the waters in the Beaufort are not "warm" (relatively speaking) ? Or that there is no bottom melt happening ? Or that the "Brightness Temperature" does not say anything about either Beaufort water temps or how they affect bottom melt ? And why ?

[jdallen]

On Worldview the 'Brightness Temperature Band [31 Day, Terra]shows very clearly warm ocean water. When an ice floe drifts over this warm water the brightness temperature is drastically reduced. This means most of the ocean heat went towards bottom melt and not lost to the atmosphere/space.

No, it doesn't mean anything of the sort. You are in way over your head on infrared false color imagery. Go back and at least read the abstracts of the Perovich papers, #2784.  Go back and read up on what AndreasT has been posting on that forum topic.

A-team, this is not like you. Your sound upset. What's going on ?

In general, it is not very helpful to tell somebody to "Go back and at least read" the abstracts to dozens of papers or tell them that they are "way over your head".

What is your point ? Are you claiming that the waters in the Beaufort are not "warm" (relatively speaking) ? Or that there is no bottom melt happening ? Or that the "Brightness Temperature" does not say anything about either Beaufort water temps or how they affect bottom melt ? And why ?

I think he was saying the false color infrared imagery does not provide adequate proof of heat entering the water and causing bottom melt. This does not preclude bottom melt, but precludes some of the conclusions being drawn by way of the imagery.

[Rob Dekker]

On Worldview the 'Brightness Temperature Band [31 Day, Terra]shows very clearly warm ocean water. When an ice floe drifts over this warm water the brightness temperature is drastically reduced. This means most of the ocean heat went towards bottom melt and not lost to the atmosphere/space.

No, it doesn't mean anything of the sort. You are in way over your head on infrared false color imagery. Go back and at least read the abstracts of the Perovich papers, #2784.  Go back and read up on what AndreasT has been posting on that forum topic.

A-team, this is not like you. Your sound upset. What's going on ?

In general, it is not very helpful to tell somebody to "Go back and at least read" the abstracts to dozens of papers or tell them that they are "way over your head".

What is your point ? Are you claiming that the waters in the Beaufort are not "warm" (relatively speaking) ? Or that there is no bottom melt happening ? Or that the "Brightness Temperature" does not say anything about either Beaufort water temps or how they affect bottom melt ? And why ?

I think he was saying the false color infrared imagery does not provide adequate proof of heat entering the water and causing bottom melt. This does not preclude bottom melt, but precludes some of the conclusions being drawn by way of the imagery.

Thanks Jdallen, but which "conclusion being drawn by way of the imagery" would be precluded, then ?
After all, of course infrared imagery does not provide any proof of heat entering the water, since that is mostly SW.

But infrared imagery DOES provide evidence of the temperature of the surface. So the question is why did A-team take off against a claim that the Beaufort sea is relatively warm at this point and causing bottom melt ?

[Tealight]

No, it doesn't mean anything of the sort. You are in way over your head on infrared false color imagery. Go back and at least read the abstracts of the Perovich papers, #2784.  Go back and read up on what AndreasT has been posting on that forum topic.

When I read the Abstract from Preconditioning of the 2007 sea-ice melt in the eastern Beaufort Sea, Arctic Ocean then it confirms exactly Robs bottom melt thesis:

During summer 2007, perennial sea ice in the Beaufort Sea, Arctic Ocean, experienced an unprecedented amount of basal melt. It has previously been shown that this basal melt was linked to an increase in open-water fraction, increasing absorption of solar radiation into the ocean.

Also why are infrared images suddenly not suited for studying ocean heat? A few weeks ago we discussed the effect of river discharge into the Arctic and the scientific papers mentioned in this thread used the exact same images to show the heat input of the Mackenzie river. Why is it wrong when I use these images?

So the question is why did A-team take off against a claim that the Beaufort sea is relatively warm at this point and causing bottom melt ?

I don't know. A-Team uses in general a very different approch then me when studying the Arctic and has a different goal with his contributions. A-Team reads through hundreds or thousands of scientific papers puplished by universities or other institutions and tries to help them by providing high quality real time images.

I can't do the same because during my bachlor studies I have seen what kind of crap people with professor or doctor titles can produce. My time is limited and I can't evaluate each scientifc paper about the arctic so I rely mostly on basic physical equations or measurements and do my own studies with them, like my arctic sea ice forcast model.

[Quantum]

Out of interest do people think there is a possibility the Northern route might stay closed this year? With rather thick ice on that side of the arctic and persistently cool weather in the forecast it seems there is at least a possibility.

[Laurent]

Fragmented ice on the North pole.

[Watching_from_Canberra]

Fragmented ice on the North pole.

This link shows ice fragmentation near the pole at the same time in 2013:
http://go.nasa.gov/29qBnIn

Looked much worse then.

[Tigertown]

If anyone has ever broken up concrete with a sledge hammer, they know that the hardest part is getting it started. Once it has a little space to give, the rest is easy. There are just so many areas that are breaking up in the ice, and as soon as some of these get open water, the pack is going to need sea sickness pills. The open waters are going to have a greater part this year in ripping up the remainder of the pack.

[Laurent]

In 2013 Beaufort was in better shape also the central area between Beaufort and Laptev. The Atlantic wasn't in the Arctic as obviously as it is now. The ice in the interface with Canadian Archipelago was still there, some remains but not much.

[iceman]

Any day now:

I think you could get a small boat through there. 

http://rammb.cira.colostate.edu/ramsdis/online/npp_viirs_arctic.asp[

Can't tell for sure with the clouds, but looks like there is now a (mostly) clear pathway from Beaufort through to Chukchi.

viirs_rgb3_remapped_alaska 20160703

[seaicesailor]

Maybe the coming storm does what warmth did not do this year, to open up the Laptev sea.

[epiphyte]

Right. The Arctic system is extremely complex, every component of it, and changing rapidly. The notion that amateur back of the envelope calculations or cherry-picked papers can substitute for the full scientific literature and current experimental data from on the ice strikes me as preposterous.

A heated vessel of hot water on the point of coming to the boil is a complex and rapidly changing system, about which there exist gigabytes of research and experimental data (... some of it highly classified , believe it or not) - but even I know how long it takes to make a cup of tea. Sometimes all an amateur needs to know is what to draw a black box around, and how to parameterize it!

Apologies for the OT interjection - but I was always taught that "Preposterous" is not a word which should be used in collegial debate, other than in jest.

[jdallen]

<snippage>

Thanks Jdallen, but which "conclusion being drawn by way of the imagery" would be precluded, then ?
After all, of course infrared imagery does not provide any proof of heat entering the water, since that is mostly SW.

But infrared imagery DOES provide evidence of the temperature of the surface. So the question is why did A-team take off against a claim that the Beaufort sea is relatively warm at this point and causing bottom melt ?

I'll leave it to A-Team to clarify, as past what I said, I believe the best I can do is speculate.  Over all, I don't think he was disagreeing that much of the Beaufort is dangerously warm, rather, again, not thinking you could derive the conclusions you did from the imagery.  A fine but pertinent distinction.

[Laurent]

The ice becomes rubble quickly all around the pole...
http://www.arctic.io/explorer/4Xa5A-8/2016-07-03;2015-07-03/9-N89.39875-W81.12672

[Tigertown]

Glad to see someone who has been on the forum a long time point that out. Everytime one of us relatively new ones say something like that, we get rebuked. It is starting to be obvious though, that more has been happening this year than what first meets the eye.

[FishOutofWater]

Tigertown, I have been lurking here forever. The spooky thing this year is when you finally get a really clear view you realize that many areas that looked solid were visually held together by thin clouds. Some of those thin clouds are heat trapping low clouds. It's very hard to figure how this summer is going to progress but most of us try to stick with the known science on melt ponds and the ice preserving effects of June storminess.

The broken ice pack can stick around for a very long time even when you know it's going to melt out. The thing to remember is that we are watching the fine details but what's important is the changes that are taking place over years and decades, not one melt season. The progressive change of much of the Barents sea into an ice free extension of the north Atlantic is apparently causing shifts in northern hemisphere weather patterns. That is important. Many of the details are apparently random.

Yes, today's MODIS images show areas around the pole that are highly fractured. It doesn't look as solid as it did 2 days ago. We might know in a month or two if it is an important observation.

[plinius]

Today's highlight: Sudden collapse of the ice in the southern arm of the north-west passage
https://worldview.earthdata.nasa.gov/?p=arctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor%28hidden%29,MODIS_Aqua_CorrectedReflectance_TrueColor%28hidden%29,MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels%28hidden%29,Reference_Features%28hidden%29,Coastlines&t=2016-07-03&v=-2533229.595531665,-1066522.543423484,-1859437.5955316648,-731162.5434234841

> 20C temperatures impacting on already weakened ice. Gives a nice taste for what is going to happen in the Canadian Archipelago when close to record heat spreads over the next week.

[bbr2314]

It should be noted that 2016's residual + vs. yrs like 2012 is entirely low-latitude (Hudson, Baffin, and Laptev).

Now the question should be *why* this is. Why has the Arctic proper taken a sledgehammer while areas low in latitude seem to be holding out much better than they did in the worst years from the mid-2000s through 2014-15?

I highly suspect that the melting of the CAA is crucial to allowing ++transport of cold freshwater south into Foxe Basin and Hudson Bay from the vicinity of Greenland. Without the melt, it seems like those areas stay cold enough to retain ice into June/early July, but with the melt... I am wondering whether much more ice than usual survives in Foxe Basin this year compared to normal.

It is *not* coincidental that these areas are now taking longer to melt vs. previous strong melt years. This would constitute a very strong and previously unknown tipping-point that seems to defy expectations, but it does seem that the more that high-latitude ice is damaged in summer/winter, the better the integrity of low-latitude ice, especially in Hudson & Baffin Bays.

Some satellites indicate this is now some of (if not *the*) thickest remaining ice in the entire Arctic... I wonder why?

[seaicesailor]

Tigertown, I have been lurking here forever. The spooky thing this year is when you finally get a really clear view you realize that many areas that looked solid were visually held together by thin clouds. Some of those thin clouds are heat trapping low clouds. It's very hard to figure how this summer is going to progress but most of us try to stick with the known science on melt ponds and the ice preserving effects of June storminess.

The broken ice pack can stick around for a very long time even when you know it's going to melt out. The thing to remember is that we are watching the fine details but what's important is the changes that are taking place over years and decades, not one melt season. The progressive change of much of the Barents sea into an ice free extension of the north Atlantic is apparently causing shifts in northern hemisphere weather patterns. That is important. Many of the details are apparently random.

Yes, today's MODIS images show areas around the pole that are highly fractured. It doesn't look as solid as it did 2 days ago. We might know in a month or two if it is an important observation.

Hi FishOutOfWater and Tigertown
I am relatively new. In this thread about the "2016 melting season", I find many people as myself gotten lost in the woods, not caring much about the big pic. There are other threads for the big pic too; nevertheless I enjoy reading some commenters here that give context within the big frame of things (as long as they don't derive in geo-engineering discussions or conspiracy theories about PIOMAS).

About the broken mobile ice from Pole to Siberia to CAA. Just my opinion: the Arctic has been subject to sun radiation, storms making holes, dipoles bringing warmth, floes ... floating. Same thing for centuries.
As the planet warms, everything happens sooner. Ice becomes thinner in average too. But, storms break up and separate 2.5 m thick ice very much as 1.0 m thick ice (look where the polynia are appearing no matter if 1.0 m or 2.5 m thick ice; use PIOMAS or the DMI model).

On topic. Which extraordinary phenomena are happening this season that I would expect to be very unusual in the previous 500 seasons? I exclude the very direct consequences of a warmer climate extraordinary as they are (earlier onset of land snow and sea ice melting, thinner ice, overall extent lower ...)

  - The sheer size of the open water in Beaufort sea and whatever is stirring it up like a Martini.
  - The strength and warmth of the Atlantic currents around Greenland Sea, Svalbard, and Barentz
  - ... ... ... ...

There are more I guess, people add their ideas. More to come as well.

The broken polynya may become important, but I would expect the same to happen in a "healthier" Arctic, so I don't perceive them as extraordinary yet (we'll see).

[bbr2314]

Should also note that a phytoplankton bloom is now occurring north of Scandinavia/Russia and the area W of Kara about doubled in size over past two days... if it is any kind of proxy for how the season is going, it took til 7/23 or so in 2012 for similar amounts to appear.

[FishOutofWater]

At present sea ice levels in the Greenland sea are the most anomalous of all the regions in the Arctic. And the early bloom in the Barents is in the region that is becoming more like the Atlantic and less like the Arctic ocean. The June weather has pretty much stopped ice export out of the Fram but that situation is allowing rapid warming east of Greenland. The weather that helps preserve the central Arctic this summer may lead to a surge of warm water that affects the Arctic ocean sea ice over following years.

[Tigertown]

I think everyone has made good points, and my biggest thing has been that we can't really judge what has happened and will yet happen this year solely on the SIE numbers. These might be more of a reflection on the conditions later.Although I did not observe many past season in real time, I have reviewed them and read what others have shared on here,as well as Neven's blog. From what I have understood, this year is unique in many ways. I certainly think the effects will be far reaching.

[plinius]

@bbr: I have no clue how you want to transport fresh water from the CAB into the Hudson ?! As an alternative to spinning weird theories about salty CAB/Baffin water decreasing the salinity of sweet/brackish Hudson, you might just want to have a look at temperature anomalies: While the CAB had a very warm winter (record warm), the Hudson Bay area had impressively cold temperatures for the whole FEB-April period. That makes for a lot of new ice formation. No doubt that this can be well linked (look up "WACCy" for that), but it's a temperature/weather correlation, impacted by low sea ice, and no obscure fresh water flux.

[bbr2314]

@bbr: I have no clue how you want to transport fresh water from the CAB into the Hudson ?! As an alternative to spinning weird theories about salty CAB/Baffin water decreasing the salinity of sweet/brackish Hudson, you might just want to have a look at temperature anomalies: While the CAB had a very warm winter (record warm), the Hudson Bay area had impressively cold temperatures for the whole FEB-April period. That makes for a lot of new ice formation. No doubt that this can be well linked (look up "WACCy" for that), but it's a temperature/weather correlation, impacted by low sea ice, and no obscure fresh water flux.

Hudson Bay is shallow, if the CAA melts that liberates freshwater from the ice itself, and as Greenland melts during the summer, the freshwater lense atop the saltwater from runoff also grows. This is also somewhat dependent on the semi-permanent vortex that has established itself over Hudson/Baffin Bay, which acts to funnel the water through Foxe Basin and into HB (also the reason why HB has been so cold).

As the below animation shows, as CAA melts out its surface salinities drop to a level at or below the open water of northern Hudson Bay, and the Coriolis also helps shunt this through Foxe and into Hudson.

I think you may have just been conflating the CAA with the CAB? Was not implying the latter mattered to HB.

[Paladiea]

A possible mechanism for lower latitude ice endurance could be the weakening jet streams due to a reduction in the temperature gradient between the equator and the Arctic. As the streams are less able to hold in cold Arctic air, that air could be shifting to preserve ice further south.

Just a thought.

[bbr2314]

..........yikes

[abbottisgone]

A possible mechanism for lower latitude ice endurance could be the weakening jet streams due to a reduction in the temperature gradient between the equator and the Arctic. As the streams are less able to hold in cold Arctic air, that air could be shifting to preserve ice further south.

Just a thought.

Thoughts are good!