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NeilT

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Re: The 2015 melting season
« Reply #3250 on: August 11, 2015, 08:46:37 AM »
I did also notice, from the DMI volume/thickness charts, that the Laptev bite seems to be blocked by an arm of 3m thick ice which has curled around right in front of the normal bite location.

If that melts, the ice thickness diminishes rapidly thereafter, setting the potential scene for a late and very rapid bite to appear.

Ditto the blocking band of 2m ice on the Atlantic side, backed by 0.5m thick ice.

Whilst I don't expect some dramatic last minute rush of massively melting thin ice in the CAB, it can't be discounted.
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F.Tnioli

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Re: The 2015 melting season
« Reply #3251 on: August 11, 2015, 10:06:17 AM »
...
Whilst I don't expect some dramatic last minute rush of massively melting thin ice in the CAB, it can't be discounted.
Define "rush", though... Don't we see areas of <80% (yellow-ish) appearing in the last Slow Wing's animated feature, located in 1) 60...75°W ~85°N, 2) ~150°E ~89°N? Don't we see much larger areas next to said <80% concentration ones also losing concentration in the same .gif animation, becoming <90% concentration (red color)?

Because i do. Is this a "rush" yet? If not, what would be? Genuinely curious.
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Re: The 2015 melting season
« Reply #3252 on: August 11, 2015, 11:52:56 AM »
I never got the comparisons  to 2012.

I think we will end up slightly above 2007 and 2011.


I don't lime that area of dark ice over the Southern CAB tho.


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Re: The 2015 melting season
« Reply #3253 on: August 11, 2015, 11:57:04 AM »
Food for thought


Neven

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Re: The 2015 melting season
« Reply #3254 on: August 11, 2015, 11:57:42 AM »
Gonzo, that orange has now turned to an apple. Here's a comparison of 2015 today with 2012 on the same date (slightly warmer, I'd say):
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seaicesailor

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Re: The 2015 melting season
« Reply #3255 on: August 11, 2015, 12:06:18 PM »
And, more food for thought. This is only 3 days ahead, see Beaufort and CAA



Gonzo, that orange has now turned to an apple. Here's a comparison of 2015 today with 2012 on the same date (slightly warmer, I'd say):


Neven, that comparison is not totally fair, 2012 was open water in all that area. Of course it is warmer, there is no ice.

Said so, 2015 is extremely difficult will catch 2012 IMO


Neven

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Re: The 2015 melting season
« Reply #3256 on: August 11, 2015, 12:31:03 PM »
Neven, that comparison is not totally fair, 2012 was open water in all that area. Of course it is warmer, there is no ice.

I'm sorry, didn't mean to be unfair.  ;)

ECMWF now has 1025-1030 hPa over the Beaufort in days to come. Will these clear skies add some more solar radiation to ice and sea water, or will things cool down because of outgoing energy? GFS obviously thinks the former, so it looks like that region is going to get yet another slap in the face.
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Ninebelowzero

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Re: The 2015 melting season
« Reply #3257 on: August 11, 2015, 12:50:45 PM »
Hi, thought I'd join in and post before the name changed to Arctic Sea forum.  :)

Been watching the Nsidc site for some years now and lately this one.

http://weathernews.com/GIC/data/index.html

It was meant to be using winsat-1 data and although it seems to be processing data (which goes back to 2012) from elsewhere and showed an odd hiatus last month by using the analysis box you can get a good idea of change in progress.

The retreat of 90% plus ice cover from the Russian islands at ~70 degrees seems quite fast. Any chance someone here could animate the last few weeks?




greatdying2

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Re: The 2015 melting season
« Reply #3258 on: August 11, 2015, 02:14:10 PM »
Even more food...
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NeilT

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Re: The 2015 melting season
« Reply #3259 on: August 11, 2015, 02:53:59 PM »
Define "rush", though...

A week with 300-500k lost in thin ice due to massive atmospheric heat, sea encroachment on fragmented ice and warm seas.

As I said, I'm not expecting it, but if the 2m blockage does melt out, it can't be completely discounted.
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Re: The 2015 melting season
« Reply #3260 on: August 11, 2015, 03:26:24 PM »
.... in today's U. Bremen update, showing ice pack disintegration in several regions that have gone beyond the day-to-day fluctuations ....
The band of rain across Beaufort might have exaggerated the melting effect in the U. Bremen image - something to keep an eye out for next week, as there will be a lot more rain over the ice arm if the forecast holds.

Even more food...
Indeed, if the low tracks over the Chukchi Peninsula, the winds and moisture in front of it will flow right through the Bering Strait.  Big question is whether the advected heat will stay mainly over open water or push into the central ice pack.
http://i.imgur.com/MQmYzSd.png

F.Tnioli

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Re: The 2015 melting season
« Reply #3261 on: August 11, 2015, 03:28:47 PM »
...
ECMWF now has 1025-1030 hPa over the Beaufort in days to come. Will these clear skies add some more solar radiation to ice and sea water, or will things cool down because of outgoing energy? GFS obviously thinks the former, so it looks like that region is going to get yet another slap in the face.
Things cool down somewhat slower than they ever were cooling down at the same date, i believe. I mean things like highest mean CH4 mean athmospheric content, which at 04 august 2015 was some 1840 ppb, i read. And, of course, most of sunlight is visible and thus the amount "going in" is affected much less...
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Re: The 2015 melting season
« Reply #3262 on: August 11, 2015, 03:39:09 PM »
Quote
Neven: Gonzo, that orange has now turned to an apple. Here's a comparison of 2015 today with 2012 on the same date (slightly warmer, I'd say):
Not sure what that sentence means? Can you clarify?
It looks warmer on the Atlantic side this year. Warmer at the Pacific. The Beaufort is covered up with floating debris, so about the same, and warmer this year where the ice was joined to Siberia in 2012.

F.Tnioli

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Re: The 2015 melting season
« Reply #3263 on: August 11, 2015, 03:40:49 PM »
Define "rush", though...

A week with 300-500k lost in thin ice due to massive atmospheric heat, sea encroachment on fragmented ice and warm seas.

As I said, I'm not expecting it, but if the 2m blockage does melt out, it can't be completely discounted.
So average of ~43...71k daily loss for 7 consequetive days? Of thin ice around the Arctic (doubt you meant that), or of thin ice confined in just a single region (i think you meant this one)? Latter less likely than former, but in either case, i somehow feel that such a rush could easily happen sooner than the melt of such a 2m blockade. After all, 2m is 2m, even in warm waters it'll survive for quite a while, while being thinned down. Already thin parts are so much more vulnerable. Send 'em some GAC or alike, see them poof rush off quick - quite in something like a single week, yes. Again, that's a feeling only, though...
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Gonzo

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Re: The 2015 melting season
« Reply #3264 on: August 11, 2015, 03:49:54 PM »
Quote
Neven: Will these clear skies add some more solar radiation to ice and sea water, or will things cool down because of outgoing energy?
Chances are it will be heating still. Too early to be a cold high. I also think if the clouds ever clear enough over the Arctic Ocean, we will see a mess over the whole icesheet. I think that cloud has been largely the result of evaporation since it lost its association with any well defined pressure system about a week ago, and the cloud is a sign of warmth and evaporation.

F.Tnioli

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Re: The 2015 melting season
« Reply #3265 on: August 11, 2015, 04:07:12 PM »
Quote
Neven: Will these clear skies add some more solar radiation to ice and sea water, or will things cool down because of outgoing energy?
... I think that cloud has been largely the result of evaporation since it lost its association with any well defined pressure system about a week ago, and the cloud is a sign of warmth and evaporation.
Likely. When i see things like this, i recall that when water and surface air are at ~8C, there would be about half as much evaporation as when water/air are at ~23C, which seems quite significant thing to me. And of course, thick enough clouds are excellent in throwing IR radiation back to the Earth surface (reflection, and also absorption plus re-radiation - the part which goes downwards). My primitive understanding is that when daily insolation is high, thick clouds cool; but when it's low, clouds warm the surface. It'd be very helpful for the ice if we'd have cloudy July this year, but it wasn't. Now, clouds might even do more warmth than cooling for CAB (if there's much heat import to the CAB with water currents and surface winds), at least if it's clouds with rather low upper boundary (below 5km), which i think is the case with the vast majority of Arctic clouds year-round. They can be rather gray, absorbing more sunlight than your usual cloud would, and IR they emit upwards from such relatively low altitude is already a subject to much of greenhouse effect.

I quite think that after sunny July, the usual "max cloud" phase which usually is September could already begin in quite many parts of the Arctic. Difference is, the Sun is not September's sun yet, so those will be quite warmer clouds than usual September's, i guess. Which means they'll probably persist for longer, and would delay re-freeze more than normal. Up to three months of slushing back and forth (initially more forth than back) for the Arctic as a whole, starting from now, anyone?
« Last Edit: August 11, 2015, 04:48:43 PM by F.Tnioli »
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Neven

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Re: The 2015 melting season
« Reply #3266 on: August 11, 2015, 04:07:17 PM »
Quote
Neven: Gonzo, that orange has now turned to an apple. Here's a comparison of 2015 today with 2012 on the same date (slightly warmer, I'd say):
Not sure what that sentence means? Can you clarify?

Two days ago you asked for a SST comparison with 2012. I showed you one, but there was a two-day difference. I thought I'd update the comparison now that I had the map for 2015 August 11th.
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Gonzo

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Re: The 2015 melting season
« Reply #3267 on: August 11, 2015, 04:14:10 PM »
Quote
Neven: Two days ago you asked for a SST comparison with 2012.
I know, I didn't know what you meant by apple. Just trying to figure out what you are referring to?

Neven

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Re: The 2015 melting season
« Reply #3268 on: August 11, 2015, 04:17:59 PM »
I didn't mean the colour orange, but the fruit. Two days ago the comparison was apples to oranges. But now both maps are apples (because the same date).

Sorry for the confusion.  :)
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Gonzo

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Re: The 2015 melting season
« Reply #3269 on: August 11, 2015, 04:22:04 PM »
I get it. Thanks. Great to see those comparisons by the way.

F.Tnioli

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Re: The 2015 melting season
« Reply #3270 on: August 11, 2015, 04:22:24 PM »
Neven, that's one excellent thing about fruits, i wasn't initially getting it too, but now i do. Good one! :)
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Re: The 2015 melting season
« Reply #3271 on: August 11, 2015, 05:29:09 PM »
Certainly will be interesting watching the weather this week. Big highs and big lows usually bring strong winds somewhere!

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Re: The 2015 melting season
« Reply #3272 on: August 11, 2015, 05:55:45 PM »
The retreat of 90% plus ice cover from the Russian islands at ~70 degrees seems quite fast. Any chance someone here could animate the last few weeks?

A bit like this one you mean? From:

http://GreatWhiteCon.info/resources/arctic-regional-graphs/northern-sea-route/



Showing more of the Atlantic though?
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Re: The 2015 melting season
« Reply #3273 on: August 11, 2015, 06:10:18 PM »
I didn't mean the colour orange, but the fruit. Two days ago the comparison was apples to oranges. But now both maps are apples (because the same date).

Sorry for the confusion.  :)

Sorry for going further OT but: http://www.improbable.com/airchives/paperair/volume1/v1i3/air-1-3-apples.html

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Re: The 2015 melting season
« Reply #3274 on: August 11, 2015, 06:45:50 PM »
.....

A bit like this one you mean? From:

http://GreatWhiteCon.info/resources/arctic-regional-graphs/northern-sea-route/



Showing more of the Atlantic though?


With those the unnecessary use of primary colours, fiddly depiction of ice concentration and too fast a framerate change makes parts of my brain switch off.  8)

A frame rate change of 1.5 seconds to 2 seconds per day, ice concentrations using lines with a colour grading of deep blue to white for the sea would show things with more clarity I believe.

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Re: The 2015 melting season
« Reply #3275 on: August 11, 2015, 07:01:34 PM »
Anyway, both extent and area in the peripheral seas continues to show level anomalies (extent), or climbing anomalies (area).

So...  If the peripheral seas had completely melted out today, we would still see rising anomalies while we waited for the historic average to catch up.  I'm not sure I like using this anomaly approach.  It leads to you saying stuff which sounds like its devastating to certain points of views, but which doesn't mean anything if we take it out of context.  And in order to supply the context, we pretty much ignore the sentence and study the graph for awhile to see how 2015 compares to 2012, 2011, and 2007.

Well area is acting pretty much like 2007 and 2011, not 2012. Although the impact of the GAC2012 hit through the recent period.

Anomalies need to be considered in their context, what metric doesn't? But since I have moved to the same baseline as NCEP/NCAR the weather driven components fall out easily.

Take the plot of extent through the summer.



OK. So Central has started to drop, Canadian and Atlantic continue their drops, Siberian is level, then drops after late June. But is any of this unusual, and when you add all those together what roles do various regions play in the overall summer decline? That graph is pretty but, frankly next to useless.

Now consider the same regions (except Pacific which is left out due to phantom ice in the source data), but express those regions as difference from the long term average for each region (for each day), i.e. anomalies.



The seasonal cycle has been removed so we can see the wood (forest) not just the trees.

As the different regions are stacked, and the amounts of positive anomalies are negligible, the lower edge shows the overall departure from the average, and we can see what causes the departure. So the feature that screams out is the strongly above average loss in July, before July regions were below average but the losses were about average, so with a constant offset the overall anomaly was level, and the contributions from various regions remained about the same. But from early July / late June overall loss went well ahead of normal, and with the regions stacked it is clear where that was happening.

So I turn to weather data for that period. Temperature at the surface is next to useless, we cannot tell whether warmth causes ice loss or warmth is due to ice loss. So we can look at sea level pressure, or the surface result; winds.

1) What caused the severe above average loss in the Siberian sector (ESS & Laptev) in July?

The drop in anomalies happened from around 1 July to 23 July, so what were surface winds doing in that period? We have a very unusual drop in extent in the context of the 1981 to 2010 average in the conglomerate region of ESS and Laptev, we're looking for something equally unusual in the winds expressed as an anomaly from the same baseline period over the same area.



2) What caused the levelling after 23 July?

We're looking for some reason why losses returned to normal levels, whatever was unusual in the weather for question 1 should have returned to more normal levels.



So question 1 is answered by the strong dipole anomaly winds, as discussed in various papers in the literature. Question 2 is answered by a lessening of the dipole driven winds, and likely a change to winds pushing ice into the ESS and Laptev acting against retreat of the ice edge and keeping losses at more average levels.


It is just my opinion, you may disagree, but speaking for myself: Anomalies beat the crap out of just plain unadjusted metrics. Yes, they take a bit more work, but they repay that work. When the tandem of weather / ice to the same baseline fails, mostly there is reason to suspect another factor, like multi-year ice or ocean heat.

ChrisReynolds

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Re: The 2015 melting season
« Reply #3276 on: August 11, 2015, 07:06:46 PM »
Sea Ice Sailor,

I thought you made a reference in passing to JD Allen seeing the predicted storm impact, that was what made me scroll up thread.

It was exciting, maybe another year we'll see the same scenario play out for real, ideally in late July after a June Dipole, with thinner winter ice cover...  ;D

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Re: The 2015 melting season
« Reply #3277 on: August 11, 2015, 09:20:14 PM »
With those the unnecessary use of primary colours, fiddly depiction of ice concentration and too fast a framerate change makes parts of my brain switch off.  8)

A frame rate change of 1.5 seconds to 2 seconds per day, ice concentrations using lines with a colour grading of deep blue to white for the sea would show things with more clarity I believe.

Evidently you can't please all of the people all of the time. My initial version was criticised with "You could speed it up slightly"!

http://forum.arctic-sea-ice.net/index.php/topic,1149.msg50163.html#msg50163

The colour scheme is the default supplied by the University of Hamburg. Perhaps we should run a poll of a few alternatives?
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Re: The 2015 melting season
« Reply #3278 on: August 11, 2015, 09:32:21 PM »
About the Nares straight today. Satellite imagery has about 3/4 of the ice gone in the straight however Cyoshphere Today shows it has about 100% of the ice is left today. It has been this way a few days now.  Why the discrepancy? Also same for the Nansen sound... ,   .
« Last Edit: August 11, 2015, 09:45:49 PM by 12Patrick »

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Re: The 2015 melting season
« Reply #3279 on: August 11, 2015, 10:06:03 PM »
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12Patrick

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Re: The 2015 melting season
« Reply #3280 on: August 11, 2015, 11:11:45 PM »
Why the discrepancy?

Resolution.
So the satellite image shows it clear and ice free but the computer doesn't because of resolution?

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Re: The 2015 melting season
« Reply #3281 on: August 11, 2015, 11:27:37 PM »
That's the first reason I could think of. Cryosphere Today sea ice area is based on a 25 km x 25 km grid which is pretty coarse (compared to JAXA's 6.25 or the Uni Hamburg 3.125 resolution). And then there's the land mask as well, lots of land nearby in such a narrow strait. If you want more details, you could ask Wipneus.

This is the reason I stopped using the CT concentration maps a few years ago. I usually go for Uni Bremen.
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AmbiValent

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Re: The 2015 melting season
« Reply #3282 on: August 11, 2015, 11:49:09 PM »
Congratulations for 2000 helpful and informative posts, Neven!
Bright ice, how can you crack and fail? How can the ice that seemed so mighty suddenly seem so frail?

12Patrick

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Re: The 2015 melting season
« Reply #3283 on: August 11, 2015, 11:49:46 PM »
That's the first reason I could think of. Cryosphere Today sea ice area is based on a 25 km x 25 km grid which is pretty coarse (compared to JAXA's 6.25 or the Uni Hamburg 3.125 resolution). And then there's the land mask as well, lots of land nearby in such a narrow strait. If you want more details, you could ask Wipneus.

This is the reason I stopped using the CT concentration maps a few years ago. I usually go for Uni Bremen.
That's the first reason I could think of. Cryosphere Today sea ice area is based on a 25 km x 25 km grid which is pretty coarse (compared to JAXA's 6.25 or the Uni Hamburg 3.125 resolution). And then there's the land mask as well, lots of land nearby in such a narrow strait. If you want more details, you could ask Wipneus.

This is the reason I stopped using the CT concentration maps a few years ago. I usually go for Uni Bremen.
So does JAXA and Uni Hamburg sites have the Northern sea ice area less than the Cryosphere Today? .

ivica

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Re: The 2015 melting season
« Reply #3284 on: August 11, 2015, 11:57:38 PM »
Congratulations for 2000 helpful and informative posts, Neven!
AmbiValent , the observer, I envy you :)

AmbiValent

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Re: The 2015 melting season
« Reply #3285 on: August 12, 2015, 12:04:53 AM »
Congratulations for 2000 helpful and informative posts, Neven!
AmbiValent , the observer, I envy you :)
Unfortunately, I'm no expert in any way on Arctic melting, so I mostly just read and observe while others do the work...
Bright ice, how can you crack and fail? How can the ice that seemed so mighty suddenly seem so frail?

ivica

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Re: The 2015 melting season
« Reply #3286 on: August 12, 2015, 12:10:18 AM »
Congratulations for 2000 helpful and informative posts, Neven!
AmbiValent , the observer, I envy you :)
Unfortunately, I'm no expert in any way on Arctic melting, so I mostly just read and observe while others do the work...
You do the good job, humanity needs more such people :)

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Re: The 2015 melting season
« Reply #3287 on: August 12, 2015, 12:13:57 AM »
Congratulations for 2000 helpful and informative posts, Neven!

Thanks, AV!

So does JAXA and Uni Hamburg sites have the Northern sea ice area less than the Cryosphere Today?

JAXA doesn't do area, they do extent. Wipneus does UH area in the dedicated thread, but I forgot about the details wrt differences etc.
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Re: The 2015 melting season
« Reply #3288 on: August 12, 2015, 12:28:39 AM »
Quote
Jim Hunt : The colour scheme is the default supplied by the University of Hamburg. Perhaps we should run a poll of a few alternatives?
The colour scheme is easy to follow, and the timing is just fine. Thanks.

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Re: The 2015 melting season
« Reply #3289 on: August 12, 2015, 12:36:48 AM »
Great job showing that big yellow-red fissure on the concentration map, from NE Greenland out to far "west" (whatever these maypole dancers want to call it).
That thing goes way west, and could be a fissure from Atlantic side, all the way to Beaufort for the first time ever.
It shows up in all concentration, satellite, and extent/area maps right now, and goes all the way across.
It is gonzo I think, all the way through, by mid September I think.

It should be called the "Gonzo Passage".

Looking again to this "passage" today in MODIS; I had been kind of dismissive with u, but I must say you really had spotted a weak area; today I saw that it has some polynia and open water (sorry it is late and on the mobile, no pics). I had thought it was tainted ice before, but might be very thin ice. People spotted other marks weeks ago closer to Kara, but after some days I lost interest.

Truth is, the models show really thin ice there. But I still believe that this feature will refreeze and will be transported away during Winter.

Yeah, I just a noob that writes too much.  :-X

EDIT: the two bands actually may be the borders between regions of ice of different age. See the Fowler et al map of ice age, northeast of Greenland.
« Last Edit: August 12, 2015, 12:54:48 AM by seaicesailor »

Nick_Naylor

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Re: The 2015 melting season
« Reply #3290 on: August 12, 2015, 12:54:29 AM »
I had been kind of dismissive with u, but I must say you really had spotted a weak area . . .

Nice find, but let's not encourage these artistes who are always trying to name phenomena after themselves.  :P

budmantis

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Re: The 2015 melting season
« Reply #3291 on: August 12, 2015, 01:33:06 AM »
I had been kind of dismissive with u, but I must say you really had spotted a weak area . . .

Nice find, but let's not encourage these artistes who are always trying to name phenomena after themselves.  :P

Agreed, look what happened with Tommy and the "Tommy Gap"!

cesium62

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Re: The 2015 melting season
« Reply #3292 on: August 12, 2015, 01:36:01 AM »
Neven, that's one excellent thing about fruits, i wasn't initially getting it too, but now i do. Good one! :)

Isn't idiomatic English fun! ;-)

greatdying2

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Re: The 2015 melting season
« Reply #3293 on: August 12, 2015, 01:41:45 AM »
Hasn't been a clear view north of Svalbard for about a week. Certainly does seem to be melting out, and ready for more. SSTs remain high.
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

wili

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Re: The 2015 melting season
« Reply #3294 on: August 12, 2015, 03:27:55 AM »
Quote
    Neven, that's one excellent thing about fruits, i wasn't initially getting it too, but now i do. Good one! :)

Isn't idiomatic English fun! ;-)

Time flies like an arrow;

Fruit flies like...bananas!

(Sorry, couldn't resist!)

Now back to ice melt: Any bets on when the NW passage will really open up? I see a path that looks like one would just have to go through a bit of very loose ice, already.
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

12Patrick

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Re: The 2015 melting season
« Reply #3295 on: August 12, 2015, 03:37:51 AM »
Congratulations for 2000 helpful and informative posts, Neven!

Thanks, AV!

So does JAXA and Uni Hamburg sites have the Northern sea ice area less than the Cryosphere Today?

JAXA doesn't do area, they do extent. Wipneus does UH area in the dedicated thread, but I forgot about the details wrt differences etc.
Correct but the satellite shows nothing so either way it should still show up as nothing in the calculations...

slow wing

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Re: The 2015 melting season
« Reply #3296 on: August 12, 2015, 03:58:38 AM »
Just incremental changes in today's U.Bremen update, plus the usual fluctuations between yellow, orange, red and crimson.

The Beaufort Arm disintegrated a little more, as did the rest of the Beaufort Sea ice.

That extraordinary long linear feature just off the North coast of Greenland is peeking again, showing as yellow concentration.

The ice off Greenland's East coast is currently being battered by 40 mph winds, particularly the Southern end of the ice where, unsurprisingly, some loss is evident.

Click to crossfade between yesterday's and today's maps:
« Last Edit: August 12, 2015, 04:07:01 AM by slow wing »

cesium62

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Re: The 2015 melting season
« Reply #3297 on: August 12, 2015, 04:14:54 AM »
Anyway, both extent and area in the peripheral seas continues to show level anomalies (extent), or climbing anomalies (area).

So...  If the peripheral seas had completely melted out today, we would still see rising anomalies while we waited for the historic average to catch up.  I'm not sure I like using this anomaly approach.  It leads to you saying stuff which sounds like its devastating to certain points of views, but which doesn't mean anything if we take it out of context.  And in order to supply the context, we pretty much ignore the sentence and study the graph for awhile to see how 2015 compares to 2012, 2011, and 2007.

Anomalies beat the crap out of just plain unadjusted metrics

Yes, but...  you said the lines are flat in a tone (yes, I can read tones ;-) ) stating that you thought a flat line indicated slow melting.  But a flat line might be indicative of fast melting at an earlier point in time, followed by a flat line because there ain't nothing left to melt.  The anomaly graphs encourage that sort of sloppy writing.

You can't counter-argue by showing a graph of one year when we were originally talking about a multi-year graph.  That's comparing apples and oranges.  ;-)
If you want to make that argument, show me the graph of the extent of the peripheral seas with a line for each year from 2007 through 2015.  And show me how the anomaly graph is better than that graph.

The anomaly graph of regions still isn't great.  Comparing against the average since 1980 exaggerates the negativeness of the anomaly.  We really want to use the 2007..2014 average.  You can look at that graph and say "July melted fast compared to the historic average".  You can't tell whether or not July melted fast compared to recent hot years that have all been well below the historic average.

People constantly post temperature anomaly graphs on this forum.  While I greatly enjoy Friv's enthusiasm, you can't just look at the anomaly and say:  "Look, it's hotter than normal everything is going to melt."  You have to look at the non-anomaly graph so that you can tell whether or not hotter than normal is above freezing. 

So, sure, use them right, use them carefully.  But don't write in a way that implies that every single occurrence of a flat line on an anomaly graph means the same as every single other occurrence of a flat line on the graph.  The line is flat in winter because there isn't any more extent to freeze.

« Last Edit: August 12, 2015, 04:26:09 AM by cesium62 »

cesium62

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Re: The 2015 melting season
« Reply #3298 on: August 12, 2015, 04:17:33 AM »
With those the unnecessary use of primary colours, fiddly depiction of ice concentration and too fast a framerate change makes parts of my brain switch off.  8)

A frame rate change of 1.5 seconds to 2 seconds per day, ice concentrations using lines with a colour grading of deep blue to white for the sea would show things with more clarity I believe.

Evidently you can't please all of the people all of the time. My initial version was criticised with "You could speed it up slightly"!

http://forum.arctic-sea-ice.net/index.php/topic,1149.msg50163.html#msg50163

The colour scheme is the default supplied by the University of Hamburg. Perhaps we should run a poll of a few alternatives?
Could you make it interactive and let us choose from a palette of pre-defined good color schemes as well as letting us build our own color scheme?  And let us control the speed?

;-)

slow wing

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Re: The 2015 melting season
« Reply #3299 on: August 12, 2015, 04:36:51 AM »
Even more food...
Yep, spectacular prediction!

Still a week away but if it does come to pass that the cyclone leaks into the Arctic Basin and sweeps through it with up to ~40 mph winds then all bets are off as to the amount of ice left at minimum.

Will be following with interest how this forecast develops, at
http://cci-reanalyzer.org/Forecasts/
In drop-down menu choose:
Arctic
Surface wind speed
Then, initially, place the cursor arrow over the final square of "Forecast Index"