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bbr2314

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Re: The 2017 melting season
« Reply #3000 on: July 20, 2017, 09:58:37 PM »
I believe we are going to see some big changes in PIOMAS from 7/15-8/15 that put 2017 far and ahead of all other years in terms of melt.

Comparing the charts between this time last year and today, 2017 has a substantially larger portion of its remaining area/extent that is far thinner than 2016, especially north of 80 degrees.

The main differences between last year and this year so far have been substantially less ice on the Russian/main Pacific front in 2017, slightly more in Beaufort, and substantially more on the Atlantic.

The Atlantic ice is going to melt out hook or crook and the forecasts from HYCOM et al over the next week+ show this is only going to accelerate. In fact, 2017 is going to begin closing rapidly on 2016 in terms of Atlantic area/extent.

As the Pacific/Russian fronts continue falling towards the CAB at an alarming rate (worse than any year before), this is going to setup a continued area/extent/volume cliff that persists through August and well into September, a la 2012 but likely worse.

The interesting point to consider is whether PIOMAS is overestimating current volume along the Atlantic, and what happens when the ice that it thinks is there melts out completely (as is likely to happen by 9/15 in totality, but by 8/15 in earnest). The ice there is certainly present, but is it actually all that anomalously large in thickness? We will soon find out.

If this all melts out as history would indicate it will, the "false" positive perceived by PIOMAS will result in a relative anomalous drop compared to 2012, as that is the only region holding 2017's #s out of the gutter they had previously been relegated within. Accounting for this, an area/extent record also seems much more plausible when you consider that the current state of 2017 vs. 2012 may be overestimated in 2012's favor.

With AMSR2 probably set to drop below 5M KM2 within the next two days, we could easily drop below 2M KM2 by 9/1, setting the stage for a minimum somewhere between 1.5-1.8KM2 (IMO).

bbr2314

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Re: The 2017 melting season
« Reply #3001 on: July 20, 2017, 10:05:01 PM »
Also:

The typhoons are going to inject a huge plume of moisture into the Arctic. The GFS shows a huge area of the Arctic receiving over an inch of liquid precipitation (some falls as snow, but vast majority as rain).

I wonder whether this will act to rapidly melt much of the remaining FYI along the Russian/Pacific/Beaufort fronts -- common logic would say that combining 1" of liquid QPF with winds and waves results in dramatic losses.



The 993MB low near Wrangel is a direct descendant of one of the typhoons and appears on both GFS/CMC. The moisture punch will be very powerful.


greatdying2

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Re: The 2017 melting season
« Reply #3002 on: July 20, 2017, 11:39:20 PM »
NSIDC sea ice concentration should be more sensitive to melt ponds than the JAXA or Uni Hamburg data.  The fact that it is sensitive to melt ponds is actually useful for making predictions.  The NSIDC sea ice area in June (or July) is a good predictor for the September minimum.

Slater's probabilistic method is based on NSIDC sea ice concentration.  People like Chris Reynolds, Rob Dekker and Alek Petty have also been using NSIDC sea ice area (or concentration) to predict the September minimum in one way or another.  I also use it for my own estimates in the polls on this forum.
Yes, I am aware of this. Such heuristics are not capable of predicting a late melt due for example to the ice being thinner than it has ever been.
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.

Hyperion

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Re: The 2017 melting season
« Reply #3003 on: July 21, 2017, 03:01:27 AM »
I also have this feeling that holes could start to show up in the ice pack real fast, once they get going. But for now, this year isn't looking anything like 2016, 2015, or even 2013. Here's a comparison using Uni Hamburg AMSR2 sea ice concentration maps:

Whats been driving me quite bananas over the last few week is how rare it seems to be to get anything but a few tiny gaps in the clouds to see what the ice really looks like. And whats been most teeth nashing of all is that its been so darned unlucky that these few and far between gaps found by any of the Nasa cameras are by some mysterious phenomena of nature almost always only found over spots where these concentration maps show a few nibbles less than 100% concentration.

I guess for some reason the sky are always cloudy over good secure well packed Floe Fields.  ::)
So anyway, best I can find is comparisons between 19 july 2016, 19 August 2016, and 19 July 2017. In the area polewards of Severnaya Zemlya.
But then I realised to my great Joy that I had an app available that in less than 5min could almost completely overcome NASAs inability to see through clouds! ;D YAY! descent into madness averted! ;)
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Tigertown

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Re: The 2017 melting season
« Reply #3004 on: July 21, 2017, 04:46:50 AM »
@Hyperion
You might spot an area or two on here(20th) where both the concentration has dropped and the ice has thinned.

liefde

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Re: The 2017 melting season
« Reply #3005 on: July 21, 2017, 10:26:49 AM »
If this all melts out as history would indicate it will, the "false" positive perceived by PIOMAS will result in a relative anomalous drop compared to 2012, as that is the only region holding 2017's #s out of the gutter they had previously been relegated within. Accounting for this, an area/extent record also seems much more plausible when you consider that the current state of 2017 vs. 2012 may be overestimated in 2012's favor.
Indeed, I would advise to note the differences in global (and in particular polar edges of) oceanic temperature anomalies between 2016 and 2017:


Note how on the Antarctic side the large refrigerators have pretty much been dissolved in warmer waters. It's quite clear that, not only is there not much of a La Niña to speak of, the heat is much more evenly spread globally now, compared to 2016. We can assume this also applies for depth, as is usually proven by coral reefs, for which troubles move North, and from that we should expect heat from below this year. Ocean currents aren't helping to keep it cool, heat is penetrating towards the poles.

The fact that heat is much more evenly spread out makes me say we've seen Peak Ice, globally (~July 9th 2017). I'm not expecting sudden cooling spikes, as we've had sometimes in previous years, at least not coming from heat-exchange with the oceans. We can't count on a solar minimum, like many crazies presume. The minimum ahead is not very low, 'peaks' around 2019-2020, besides, it's estimated that another solar minimum equivalent to the Dalton and Maunder minima would cause 0.09°C and 0.26°C cooling, respectively, so that's not gonna work against the forcing of GHGs and feedbacks.

nukefix

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Re: The 2017 melting season
« Reply #3006 on: July 21, 2017, 12:23:14 PM »
Whats been driving me quite bananas over the last few week is how rare it seems to be to get anything but a few tiny gaps in the clouds to see what the ice really looks like.
Luckily we'll always have radar ;)

http://www.polarview.aq/arctic



Thawing Thunder

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Re: The 2017 melting season
« Reply #3007 on: July 21, 2017, 12:52:19 PM »
But for now, this year isn't looking anything like 2016, 2015, or even 2013. Here's a comparison using Uni Hamburg AMSR2 sea ice concentration maps:

I agree with 2015 and 2016, not so much with 2013, at least not on the base of a single image. The atlantic side this year already started to show polynya - and is therefore at the brink of open holes.

But what strikes me most, and IMO isn't considered as much as it deserves, is the size of the central ice pack. Despite of its coherent appearance, that means still without holes, the overall size (let's call it extent at eyesight) is much smaller than in the previous years. I would guess and advantage of about one week to ten days. And I also beliefe that big areas of that ice are thinning away at an unprecedented pace and will surprise us soon.

A couple of comments above Tigertown posted today's image of the Arctic from Uni Hamburg which shows the ice is developing into the state and direction I am expecting for the next weeks, a trend that started a couple of days ago.
« Last Edit: July 21, 2017, 01:05:45 PM by Thawing Thunder »

Jim Hunt

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Re: The 2017 melting season
« Reply #3008 on: July 21, 2017, 03:54:23 PM »
I agree with 2015 and 2016, not so much with 2013, at least not on the base of a single image.

Here's a second image, showing some open holes on July 6th 2013:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2013-images/#CAB
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jdallen

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Re: The 2017 melting season
« Reply #3009 on: July 21, 2017, 05:05:55 PM »
I agree with 2015 and 2016, not so much with 2013, at least not on the base of a single image.

Here's a second image, showing some open holes on July 6th 2013:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2013-images/#CAB
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Neven

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Re: The 2017 melting season
« Reply #3010 on: July 21, 2017, 05:22:24 PM »
2013 was very cold, relatively speaking, both air and sea surface temperature. When it comes to sea level pressure, 2017 is somewhat similar, though I'd venture to say that 2013 was more cyclonic (I'd have to look it up to be sure). But temperature is the big difference between the two.
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A-Team

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Re: The 2017 melting season
« Reply #3011 on: July 21, 2017, 05:25:20 PM »
While no algorithm can remove thick clouds from images to reveal the ice below, it is possible to stack scenes closely spaced in time (such as Aqua, Suomi, Terra at WorldView) and simply take the darkest pixel. That is, clouds can move quickly whereas ice moves slowly.

The second frame below pulls out the very thickest whitest clouds (pink). These over-exposed regions lack sufficient contrast (color space volume) to retain significant information about darkening from ice leads or polynyas below.

Like many images posted here, the first frame makes very limited use of available contrast (see histogram of boxed region). While literally representative of what the satellite pipeline produced, we are usually looking for something different, something optimized for the very excellent grayscale discrimination capabilities of the monitor and eye.

This can be done by global readjustment of contrast/brightness but that improves some areas as it damages others. Thus it is usual better to use adjustments locally adapted to intrinsic feature scale, here say 32x32 pixels, to draw out ice features.
« Last Edit: July 21, 2017, 05:39:09 PM by A-Team »

Tigertown

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Re: The 2017 melting season
« Reply #3012 on: July 21, 2017, 05:30:49 PM »
Thawing Thunder
And I also beliefe that big areas of that ice are thinning away at an unprecedented pace and will surprise us soon.
The rain showers are not helping the ice at all.

Thomas Barlow

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Re: The 2017 melting season
« Reply #3013 on: July 21, 2017, 05:42:31 PM »
I have marked the region (red oval) which roughly defines the area that is more integrated (unbroken) than some previous years, from looking at Worldview occasional gaps in the clouds in recent weeks. The area is more robust than several previous years (apart from maybe some sticky land-fast ice stuck to coasts this year).
However, the thickness may be low in the region marked.

Conclusion: Mush most places in the Arctic Ocean, with a nice, very large region of robust ice, could almost walk across for 100s of miles, but which is vulnerable due to thin ice status.

(PS. I know DMI changed their methods over the years, but it is not that big a difference, and I do think they are more accurate than the US navy for example. :)  )
« Last Edit: July 21, 2017, 11:57:00 PM by Thomas Barlow »

seaicesailor

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Re: The 2017 melting season
« Reply #3014 on: July 21, 2017, 06:02:43 PM »
(... and I do think they are more accurate than the US navy for example.Those guys can't steer a boat without running into a lighthouse. :)  )
A helluva reason to opt for the DMI crap.

A-Team

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Re: The 2017 melting season
« Reply #3015 on: July 21, 2017, 06:31:08 PM »
While reality remains elusive, our display and inter-product comparison options are getting better, notably the replacement of sea ice thickness by sea ice concentration whenever the latter is less than 80% (as the former is less reliable then). There is another way of doing this, namely bump the Piomas thickness by UH or UB concentration grayscale. (5th frame below, which I didn't have time to do properly: as a 3D animation over wip's daily thickness.)

Tigertown

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Re: The 2017 melting season
« Reply #3016 on: July 21, 2017, 07:24:32 PM »
NSIDC SIE  x 106 km2

2017,    07,  17,      7.765
2017,    07,  18,      7.640       Down 125k
2017,    07,  19,      7.518       Down 122k
2017,    07,  20,      7.395       Down 123k

 Some have commented that cooler air is on the way for many parts of the Arctic. Still, most surface air will remain above freezing, even if slightly, and insolation will continue either way.
Looks like a little wave activity starting to kick up here and there today and over the next few days. This may redistribute enough warm water to escalate the attack on the sea ice.

Thawing Thunder

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Re: The 2017 melting season
« Reply #3017 on: July 21, 2017, 07:40:14 PM »
2013 was very cold, relatively speaking, both air and sea surface temperature. When it comes to sea level pressure, 2017 is somewhat similar, though I'd venture to say that 2013 was more cyclonic (I'd have to look it up to be sure). But temperature is the big difference between the two.

Yes, I remember now the drama of 2013 which finally ended up as a "rebound" year. Very interesting year. So ist this one.

meddoc

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Re: The 2017 melting season
« Reply #3018 on: July 21, 2017, 08:01:43 PM »

This can be done by global readjustment of contrast/brightness but that improves some areas as it damages others. Thus it is usual better to use adjustments locally adapted to intrinsic feature scale, here say 32x32 pixels, to draw out ice features.

That's a helluva Mess. One or two GACs in the Remainder & we're Toast until the North Pole.

seaicesailor

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Re: The 2017 melting season
« Reply #3019 on: July 21, 2017, 08:54:55 PM »
<snip: Off-topic, argumentative, and contained too many layers of nested posts. JP>
« Last Edit: July 21, 2017, 10:55:24 PM by Jim Pettit »

jdallen

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Re: The 2017 melting season
« Reply #3020 on: July 21, 2017, 09:20:20 PM »
<snip: Too many nested OT comments. Leaving your relevant notice intact. JP>

Back to topic please.  Discussion of the relative accuracy and merit of various organizations data belong elsewhere on the forums.  Ad hominem attacks belong nowhere in our discussions.
« Last Edit: July 21, 2017, 10:54:31 PM by Jim Pettit »
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seaicesailor

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Re: The 2017 melting season
« Reply #3021 on: July 21, 2017, 09:36:33 PM »
<snip: Off-topic, and too many layers of nested posts. JP>
« Last Edit: July 21, 2017, 10:52:29 PM by Jim Pettit »

Hyperion

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Re: The 2017 melting season
« Reply #3022 on: July 21, 2017, 09:54:09 PM »
Clockwise from the East Siberian sea to the CAA. Filenames are fairly explainatory as to exactly where. No Images on the most packed region off CAA yet but best peeks thru the clouds since 17th.
21st July:
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Hyperion

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Re: The 2017 melting season
« Reply #3023 on: July 21, 2017, 10:02:28 PM »
And the rest. If Piomass or Hycom or whoever are counting lots of volume between Svalbard and the pole then They've blink and missed it. This stuff is auguring. Like the Russian and Pacific front also. The rubble fields between the floes that we there everywhere 3 days ago are largely open sea now. Probable around 0.5 sea the rest floes and rubble in the above and these Svalbard/ frams to pole below.
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jplotinus

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Re: The 2017 melting season
« Reply #3024 on: July 21, 2017, 10:56:04 PM »
Interesting to compare July 21 date for 2017 and 2013 near North Pole, Worldview imagery.
2013 appears to be worse:
« Last Edit: July 21, 2017, 11:02:26 PM by jplotinus »

VeliAlbertKallio

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Re: The 2017 melting season
« Reply #3025 on: July 21, 2017, 11:04:31 PM »
2017 image is showing low-level clouds, not sea ice. For comparison, I would say two quartiles is necessary, one quartile isn't enough adjascent to the pole. I recall 2013 having one quartile broken, three solids, since then two broken, two solid has been the rule. (Quartiles from 80N to the pole.)
Interesting to compare 2017 with 2013 near North Pole Worldview imagery. 2013 appears to be worse:

CalamityCountdown

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Re: The 2017 melting season
« Reply #3026 on: July 21, 2017, 11:54:26 PM »
The drop in extent over the last 10 days is the largest in the NSIDC record for the July 11-July 20 period. The 1.2 million km2 decrease (daily average of 119.6 km2) has come as 7 of the 10 days had century plus declines.

Other years with seven figures declines for this 10 day period include 1989 - 1.0, 1990 - 1.0, 1994 - 1.0, 2002 - 1.1, 2003 - 1.0, 2007 - 1.1, 2008 - 1.0, 2011 - 1.1, 2013 - 1.0, 2015 - 1.17. While the 2017 result was only a +2% drop versus 2015, it still shows that significant melting momentum has been building over the past week and a half.

subgeometer

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Re: The 2017 melting season
« Reply #3027 on: July 22, 2017, 12:35:16 AM »
NSIDC SIE  x 106 km2

2017,    07,  17,      7.765
2017,    07,  18,      7.640       Down 125k
2017,    07,  19,      7.518       Down 122k
2017,    07,  20,      7.395       Down 123k

 Some have commented that cooler air is on the way for many parts of the Arctic. Still, most surface air will remain above freezing, even if slightly, and insolation will continue either way.
Looks like a little wave activity starting to kick up here and there today and over the next few days. This may redistribute enough warm water to escalate the attack on the sea ice.

The coldest temps are on the Siberian/Pacific side where the ice is thin and SSTs will melt much or all of it out, whereas warm winds are blowing north of Greenland and Ellesmere Island most of the week according to ECMWF/Windy, as well as along the Atlantic fringe. For ice retention it would be better if the core of the cold were between the Pole and Greenland/CAA.

The NH tropical cyclone season is cranking up, so we'll likely soon see one tracking into the Polar region with attendant warmth and moisture.

[edit} And waves... The low tracking from the ESS through the Beaufort will generate large waves right at the ice edge, up to about 4m by the colour of the visual, unfortunately the conditions at location feature doesn't seem to work in the Windy TV 3D view
« Last Edit: July 22, 2017, 12:46:26 AM by subgeometer »

bbr2314

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Re: The 2017 melting season
« Reply #3028 on: July 22, 2017, 12:45:44 AM »
NSIDC SIE  x 106 km2

2017,    07,  17,      7.765
2017,    07,  18,      7.640       Down 125k
2017,    07,  19,      7.518       Down 122k
2017,    07,  20,      7.395       Down 123k

 Some have commented that cooler air is on the way for many parts of the Arctic. Still, most surface air will remain above freezing, even if slightly, and insolation will continue either way.
Looks like a little wave activity starting to kick up here and there today and over the next few days. This may redistribute enough warm water to escalate the attack on the sea ice.

The coldest temps are on the Siberian/Pacific side where the ice is thin and SSTs will melt much or all of it out, whereas warm winds are blowing north of Greenland and Ellesmere Island most of the week according to ECMWF/Windy, as well as along the Atlantic fringe. For ice retention it would be better if the core of the cold were between the Pole and Greenland/CAA.

And the NH tropical cyclone season is cranking up, so we'll likely soon see one tracking into the Polar region with attendant warmth and moisture
The first moisture plume from the epic impending WPAC typhoon is visible here @hr198 of the 18z GFS as it tracks over the Beaufort/CAB. At that time the GFS is also flinging another typhoon north towards the Arctic to join the fray. The event is already beginning in its formation, and as we continue seeing century drops the next few days (or near century drops), we are probably likely to push back into the 100K+++ range for at least a period as the below unfolds.

That is a *serious* amount of tropical moisture and it is going to fall across and impact the Pacific/Beaufort pack, which is in the worst condition ever and is already giving way to the tune of tens/hundreds of K KM2 per day.



Look at all that rain -- and it isn't light, either!




Hyperion

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Re: The 2017 melting season
« Reply #3029 on: July 22, 2017, 02:15:58 AM »
Youch!  I've just been watching on  Nullschool the two westernmost Pac Typhoons merge into a real whopper off Japan on the 25th. We've already been seeing inch per day rain in the last few days Nth of the CAA. And I'm estimating incoming water roughly equally coming in from Atlantic and Pacific ends of around 10 cubic km a day. Thats been releasing enough latent heat to melt 100 cubic km of ice. The reason we haven't been seeing a view of areas with lots of slushy rubble is the fogbanks condensing from all the heat transfer that the slushy state can provide. a lot of the heat warms air and rises of course. And before escaping at altitude it forms ice cloud that is very very bad for ice preservation because it lets most of the solar energy come in but insulates outgoing longwave very well. Simularly with large droplet size in fog and thunderclouds This whole cycle is self reinforcing as the more updraft and high altitude exit, the more low level warm air and moisture comes in. Only when most of the slush disappears from around the more resilient floes, or where there is a decently compressed pack is the capacity for thermal transfer low enough for us to expect to have clear skys. People keep hoping that all the clouds will preserve the ice. Its faster to boil a potato than to bake it. And faster to steam it than boil it. Water vapour at or below boiling point is a very effective heat transfer vehicle to colder objects. The Area receiving insolation at in the arctic ocean is puny compared to what it can draw in heat from with a slushy salt-ice heat sink to attract it.
And the southerly's in Fram are very bad with this over 15 degree gulf stream water surfacing there. That waters submerging about as far south as Spain, directly south of Greenland. It may even be less Saline hence lighter for its temp and easier mixed with the polar surface water than we are used to. Sliding under the nth Atlantic melt pool as it is there is bound to be some mixing and energy exchange.

Check out the Super-Bar claw marks nth of Greenland. About a km apart and 100km long. The Polar bear god getting grumpy?
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Tigertown

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Re: The 2017 melting season
« Reply #3030 on: July 22, 2017, 05:21:02 AM »
Looks like there is melting from both sides, at least for the moment.
CLICK IMAGE

slow wing

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Re: The 2017 melting season
« Reply #3031 on: July 22, 2017, 07:20:24 AM »
People keep hoping that all the clouds will preserve the ice. Its faster to boil a potato than to bake it. And faster to steam it than boil it. Water vapour at or below boiling point is a very effective heat transfer vehicle to colder objects.
  Hyperion, I read your analyses with great interest. Not so sure about your potato-cooking analogy of the bolded bit though.

  Baking a potato relies on thermal convection and conduction through the air in the oven. The Arctic ice melt process that best corresponds to is not to direct insolation but instead to the different heating mechanism of warm winds blowing across the ice.

  About the fastest way to cook a potato is to microwave it and that might provide the best analogy for direct solar insolation into the ice.

  With direct insolation, the sun's energy (which of course is ultimately responsible for the other heating processes you discuss as well) is deposited directly into the interior of the ice (or melt-pond water) - which is how microwave ovens work as well, just using a different part of the electromagnetic spectrum.

  So my gut feeling is that this heat transfer by vapour condensation must need a lot of vapour (as you point out, this is the situation at the moment) and be reasonably efficient in order to be comparably effective to direct solar insolation.

  I'm skeptical because to the extent that it's falling as rain at a few degrees C then that part of the 10 cubic kilometres per day of incoming total atmospheric water that you mention is only going to melt a fraction of one cubic kilometre of ice per day (compare water's 334 J/g heat of fusion with a few times 4.2 J/g-degrees C). The only really efficient mechanism will be direct contact of the water vapour with the ice.

  That also accords with experience from observing the melt season in past years: generally the best atmospheric conditions for melting ice near mid-Summer appears to have been clear skies.

  I do appreciate your point that there is an anomalously large amount of incoming water at the moment so it will anyway be interesting to see how much melt there has been on the Pacific side when the clouds clear.
« Last Edit: July 22, 2017, 07:30:22 AM by slow wing »

Bruce Steele

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Re: The 2017 melting season
« Reply #3032 on: July 22, 2017, 07:42:32 AM »
The Barrow ice cam shows a 51F air temperature and a wet roof on the camera building.
 Red Dog Dock water temp. Is ~ 55 and the Nome water temp. is ~ 60.  Those are water temperatures similar to Calif . water temperatures.

anthropocene

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Re: The 2017 melting season
« Reply #3033 on: July 22, 2017, 09:03:24 AM »


That is a *serious* amount of tropical moisture and it is going to fall across and impact the Pacific/Beaufort pack, which is in the worst condition ever and is already giving way to the tune of tens/hundreds of K KM2 per day.

From Wipneus'  "Home brew AMSR2 extent and area calculation" taking combined Beaufort and Chukchi combined as "Pacific/Beaufort pack" area loss over the last few days (K km2) :


20/07:    -3.8
19/07:    -11.8
18/07:    -28.2
17/07:    +9
16/07:    +27.6
15/07:     -56.9
14/07:    +2.6

Total loss over 7 days:  -61.5k km2

meddoc

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Re: The 2017 melting season
« Reply #3034 on: July 22, 2017, 09:32:31 AM »
And as of today, HYCOM is: 404

Prepare for something BIG going off.

Neven

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Re: The 2017 melting season
« Reply #3035 on: July 22, 2017, 09:50:39 AM »
And as of today, HYCOM is: 404

Prepare for something BIG going off.

In what sense?
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Quantum

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Re: The 2017 melting season
« Reply #3036 on: July 22, 2017, 10:25:34 AM »
Do we actually know its raining or are we just going on GFS reanalysis? I would not trust the GFS to get the precipitation type right.

JayW

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Re: The 2017 melting season
« Reply #3037 on: July 22, 2017, 12:58:02 PM »
Do we actually know its raining or are we just going on GFS reanalysis? I would not trust the GFS to get the precipitation type right.

First attachment: AMSR2 thickness indicating a lot of wet surfaces.  I think one could interpret some of this as rain.

https://ads.nipr.ac.jp/vishop/#/monitor


Second attachment: ~40 hour AVHRR loop, well defined cyclone moving north of Wrangel.  I suspect there will be a stripe of snow laid down north of the track, rain to the south.  Looks like a potent little storm, but a quick mover.

http://weather.gc.ca/satellite/satellite_anim_e.html?sat=hrpt&area=dfo&type=nir
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Re: The 2017 melting season
« Reply #3038 on: July 22, 2017, 12:59:00 PM »
I compared these two images 2012 same date with 2017 same date next thing you know navy. mil site is down?  why is that? https://scontent-dft4-3.xx.fbcdn.net/v/t31.0-8/20157158_10210148246970711_2836757399888286108_o.jpg?oh=b7693a4967f6b990da608618deb576c8&oe=59F6DBCA

Jim Pettit

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Re: The 2017 melting season
« Reply #3039 on: July 22, 2017, 03:29:41 PM »
Both NSIDC and IJIS extent have moved into 2nd place. And the graphic below indicates that at least NSIDC may/will even take 1st place from 2011 (which started to flatten out the last week of July), and stay there until the first week in August, when the GAC took 2012 on its major downward excursion.


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Re: The 2017 melting season
« Reply #3040 on: July 22, 2017, 03:46:47 PM »
Both NSIDC and IJIS extent have moved into 2nd place. And the graphic below indicates that at least NSIDC may/will even take 1st place from 2011 (which started to flatten out the last week of July), and stay there until the first week in August, when the GAC took 2012 on its major downward excursion
But something can happen in August 2017, as it still have lower volume in the central basin than 2012

JayW

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Re: The 2017 melting season
« Reply #3041 on: July 22, 2017, 04:10:40 PM »
The 22.0z ECMWF ensemble mean MSLP at hour 144 now has a bit of high pressure showing up in the Beaufort region.  Have to see if the holds run to run, could evolve into a bit of a dipole.  Especially if a -NAO/Greenland high develops.  Lots can change 6 days out.

https://www.tropicaltidbits.com/analysis/models/?model=ecmwf-ens&region=nhem&pkg=mslpa&runtime=2017072200&fh=144&xpos=0&ypos=133

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meddoc

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Re: The 2017 melting season
« Reply #3042 on: July 22, 2017, 05:37:31 PM »
Now, HYCOM is back online, again :D

It still looks terrifying.
Without Nuclear Winter- that Ice could be Toast by September.

And all Forests in the NH, also.

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Re: The 2017 melting season
« Reply #3043 on: July 22, 2017, 06:13:08 PM »
A view of the waves currently breaking on the shore at Utqiaġvik (Barrow as was):

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NeilT

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Re: The 2017 melting season
« Reply #3044 on: July 22, 2017, 06:16:53 PM »
A view of the waves currently breaking on the shore at Utqiaġvik (Barrow as was):

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Retron

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Re: The 2017 melting season
« Reply #3045 on: July 22, 2017, 06:31:29 PM »
A view of the waves currently breaking on the shore at Utqiaġvik (Barrow as was):
And with a strong westerly breeze with a fetch of hundreds of miles, the waves are set to increase for the next few hours, peaking at more than double their current height! If that forecast comes off the view will be a bit different this time tomorrow...

http://www.tides4fishing.com/us/far-north-alaska/point-barrow

I doubt the swell will be doing the ice much good as it heads eastwards.

http://polar.ncep.noaa.gov/waves/viewer.shtml?-multi_1-latest-hs-alaska-


Albatross

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Re: The 2017 melting season
« Reply #3046 on: July 22, 2017, 06:32:20 PM »
Gah, you just beat me to posting about the swells at Barrow NeilT :) Not good for coastal erosion...

greatdying2

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Re: The 2017 melting season
« Reply #3047 on: July 22, 2017, 07:08:45 PM »
Total loss over 7 days:  -61.5k km2
Perhaps you have overlooked the Beaufort gyre? If the net area loss is near zero, then I guess the total area melted in that zone is, very roughly speaking, equal to the amount imported by the gyre. How much is that?
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.

magnamentis

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Re: The 2017 melting season
« Reply #3048 on: July 22, 2017, 07:36:11 PM »
@slow wing

you point would be correct between around 21st of may and 21st of july while in may albedo spoils that mechanism quite a bit.

for the rest of the melting season which i think @hyperion is exactly right because insolation from now on, in places where there still is significant ice, plays an ever smaller role and this very rapidly and almost on a daily basis.

last but not least, it's common knowledge that clouds keep the heat below them once it's there and due to  a lot of energy in the ocean and through open waters the heat IS there by now therefore it can be assumed that less of that heat will escape as long as the skies are cloud covered, at least from now on this effect should overrule insolation IMO.
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liefde

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Re: The 2017 melting season
« Reply #3049 on: July 22, 2017, 09:02:03 PM »
Both NSIDC and IJIS extent have moved into 2nd place. And the graphic below indicates that at least NSIDC may/will even take 1st place from 2011 (which started to flatten out the last week of July), and stay there until the first week in August, when the GAC took 2012 on its major downward excursion.
What good is extent if thickness is incomparable to 2012?
http://sites.uci.edu/zlabe/files/2017/07/sit_PIOMAS_mask_June17.gif
What's left over is very thin. 95% of 2 meter ice is gone now, 99% of the 3, 4 and 5 meter thick ice too.