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Michael Hauber

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Re: The 2020 melting season
« Reply #3350 on: July 22, 2020, 07:32:42 AM »
Short term predictions of extent changes are tricky, and I suspect variations in the impact of cloudiness on sensor detection play a big part.  However I suspsect that today was the last big drop in sea ice extent, and that the rate will now plummet.

The strong high has now lost its grip, the last 48 hours a low from the Atlantic front has moved in and pushed the weakening high pressure towards the Siberian sector.  This has resulted in very warm air in the ESS/Laptev, and a southerly flow between these two systems pushing on the ice front in the Laptev sector.  The last two days have seen the tongue of weak ice in the ESS region that hard been partially separated out from the main ice pack all but disappear according to ADS monitor.  So I suspect this has been a significant contributor to the still strong extent losses over the last two days.  This is likely now over, and with current patterns the Laptev front will stop its rapid advance, and the other fronts have not been doing much or show any reasons to suddenly start doing much.  The one area of potential strong ice losses is the weak area in the Chukchi.  This area has been around for a while, and more resilient than I had expected.  Who knows when or if it might start giving out suddenly to give extent losses a boost.
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S.Pansa

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Re: The 2020 melting season
« Reply #3351 on: July 22, 2020, 07:39:41 AM »
Lots of interesting posts ....

To add another perspective.

Here is an animation oft the sea ice volume change as depicted from the TOPA4 system between 14/07, today - and the forecast for 30/07 (needs a click to run). Added 2019 for comparison
 
As others have noted: The ice may look compact, but it might be seriously vulnerable, if this model is anything to go by.

The Beaufort could indeed prevent a record or even a second place ... a GAC on the other hand could cut through the remaining ice like a hot knife through butter. ESS and Laptev look terrible.

We shall see soon

Cheers

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Re: The 2020 melting season
« Reply #3352 on: July 22, 2020, 08:09:28 AM »
As you can see on the screenshot from todays Arctic sea ice concentration Bremen map there is plenty of melt also in the CAB.

romett1

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Re: The 2020 melting season
« Reply #3353 on: July 22, 2020, 09:15:27 AM »
In this sector open water area today roughly about 55,000 km² (yesterday 50,000 km²).

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Re: The 2020 melting season
« Reply #3354 on: July 22, 2020, 10:42:38 AM »
We are a month from the solstice. I am not sure about the exact timing but I believe we are near to the time when cloud cover is worse for the ice than clear sky.

Tom

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Re: The 2020 melting season
« Reply #3355 on: July 22, 2020, 10:53:13 AM »
I have discovered that HYCOM ice thickness model produce a 30-day animated gif which is really nice to look at, and not that big (they do a 12-month one as well which I highly recommend - see https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/arctic.html)

The below 30-day image includes a forecast for the 20th-28th  (date at the top is the date of ice forecast, date on the map is the date the image was produced, so you will see it's a now-cast up to the 20th, then a forecast)

To my eyes it shows an expectation that area/extent losses will slow, but that thinning will still be occurring

Jim Hunt

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Re: The 2020 melting season
« Reply #3356 on: July 22, 2020, 11:40:37 AM »
Apart from a nice clear view of lots of shattered ice, Worldview reckons there is a fire blazing in the centre of northern Ellesmere.

Meanwhile on the other side of the Arctic lots of fires are most certainly burning.
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IceConcerned

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Re: The 2020 melting season
« Reply #3357 on: July 22, 2020, 11:45:39 AM »
Is it my imagination or is it a signal that 3yr ice is disappearing this year?

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Re: The 2020 melting season
« Reply #3358 on: July 22, 2020, 11:45:46 AM »
What could possibly burn there? :o

Pagophilus

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Re: The 2020 melting season
« Reply #3359 on: July 22, 2020, 11:52:59 AM »
Michael,
<snip>
 We can argue about how much surface melting has occurred this year vs. 2012 because of the compaction.......  <snip>

What compaction? I don't see any compaction to be worth mentioning. I am using a large screen high def laptop. I don't see it. Can those that keep bringing up compaction show some images or other proof? Please.

They don't see it, they simply assume that a long lasting high pressure system must have compacted (compressed) the ice or stacked it up to 10m hights, an opinion that i do not share.

CAB area is quite low not especially high as it would be in case the above mentioned assumptions were right.
I am happy to oblige.  The following gif is from the N Laptev Sea during the recent high, July 12-18, when winds were swirling clockwise about the pole.  Bottom image is for general context, with the area of the gif circled.
 
I have selected a number of distinctive floes/features and put a red dot just to the left of each .  One would expect the floes to follow the wind direction and just rotate, if one does not take into account the Coriolis Effect.  So if just wind is considered the floes should just move laterally here (to the right of the image, to the west).  Instead, every floe veers to the right and moves north towards the pole (approximately).  If you look carefully, you will see that virtually all the surrounding floes do the same.  The ice cap as a whole is not shifting, because it has nowhere to go on the Canadian side (continent in the way).  The ice is compacting.  Indeed, on the Canadian side, ice is also veering right towards the pole helping produce the cracks you see N of Canada and Greenland.

The retreat of the ice edge in the Laptev is in large part due to this compaction/motion towards the pole.  If you look carefully, you will see even the floes at the ice's edge are moving polewards as well as melting away.  In fact, they are moving more towards the north than the interior floes.  To be clear, I am not denying melting (it is considerable), but you are doubting compaction due to the high, and I hope this helps clear that up.

Warning: large gif.
« Last Edit: July 22, 2020, 02:37:40 PM by Pagophilus »
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Tom_Mazanec

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Re: The 2020 melting season
« Reply #3360 on: July 22, 2020, 11:58:50 AM »
Quote
If one were to design a weather pattern that’s most efficient at ridding the Arctic of its increasingly fragile ice cover during the region’s summer melt season, it would look like what occurred earlier in the month — clear skies, above-average air temperatures, a high-pressure system across the Central Arctic, and an ongoing heat wave and wildfires in Siberia.

So, Freegrass, that is this year's equivalent of the 2012 GAC which is causing the freak records?
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oren

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Re: The 2020 melting season
« Reply #3361 on: July 22, 2020, 12:06:44 PM »
I think there is a miscommunication here. The ice is/was "compacting", meaning it was generally moving towards the center of the pack, as an expected result of the high pressure and anti-cyclonic winds. I think all/most posters agree on that.
However, is the ice compact, meaning with no small holes inside the pack? I think many posters are saying no, it is not compact, since area has disappeared while the ice was moving northward, thus there is less ice covering a smaller extent.
Is the ice strong and defensible? I think many posters are saying no.
And have ice floes stacked on top of one another due to the northward movement, as happens with pressure ridges in winter? I think most/all posters now agree that no.

BTW, great animation Pagophilus.

Paul

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Re: The 2020 melting season
« Reply #3362 on: July 22, 2020, 12:16:06 PM »
However, is the ice compact, meaning with no small holes inside the pack? I think many posters are saying no, it is not compact, since area has disappeared while the ice was moving northward, thus there is less ice covering a smaller extent.

Looking at worldview, Im struggling to find any meaningful holes in the ice pack in the CAV, at least when you compare it to years with heavy dispersion like 2016 in particular. The problem we got is has there been too much compaction to prevent the ice going under 4  million, I have a feeling that could be the case but the charts and worldview does suggest the ice compacted. However ass you say, is it thick and resilient enough, that is something I'm skeptical of all so sadly.
« Last Edit: July 22, 2020, 08:10:09 PM by oren »

Alumril

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Re: The 2020 melting season
« Reply #3363 on: July 22, 2020, 12:26:20 PM »
Quote
If one were to design a weather pattern that’s most efficient at ridding the Arctic of its increasingly fragile ice cover during the region’s summer melt season, it would look like what occurred earlier in the month — clear skies, above-average air temperatures, a high-pressure system across the Central Arctic, and an ongoing heat wave and wildfires in Siberia.

So, Freegrass, that is this year's equivalent of the 2012 GAC which is causing the freak records?

I don't think this year is much of a freak in terms of the overall trend.
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Jim Hunt

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Re: The 2020 melting season
« Reply #3364 on: July 22, 2020, 12:37:13 PM »
What could possibly burn there?

A good question! On MODIS 7-2-1 there is a tiny patch of green there:

https://go.nasa.gov/3eY2IAN

Quote
Vegetation is very reflective in the near infrared (Band 2), and absorbent in Band 1 and Band 7. Assigning that band to green means even the smallest hint of vegetation will appear bright green in the image.

The "wildfire" wasn't there the previous day. It will be interesting to see if it's still there later today. Or if the pseudo green has turned black!
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Re: The 2020 melting season
« Reply #3365 on: July 22, 2020, 01:12:44 PM »
Is the ice strong and defensible?

I think, yes. The ice is compact and after winter the Arctic had a bit more ice than could be expected. In this melting season we observe incredibly fierce battle between weather and ice. I don't know if the ice is defensible enough to withstand. But the ice is certainly defensible. Otherwise we already could see massive melting north of 80N, not only at edge.

gandul

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Re: The 2020 melting season
« Reply #3366 on: July 22, 2020, 01:36:04 PM »




Perhaps you overlooked the word MUST, your chart shows the usual or what often happens but that doesn not mean that it always has to be like that, especially under the current special conditions in many aspects.


So get me right, yes it's usual, i doubt the "inevitable" part for the current conditions.

When compactness is at its lowest everybody pull this chart to show how bad the ice is. So the dude has a point.
I believe compactness helps protect the remaining of the ice, and only moderate and dynamic (not central and persistent) storms would end up with 2020 in 1st position. If compactness remains that high, 2020 will most probably end up over 2007.
By the way, look at those big MYI blocks in Beaufort. We should start to monitor if they get broken by storms or if on the contrary they'll survive. A lot of MYI ice in the Beaufort that has not suffered big heat nor big storms. These things can quench the melting season if August weather come dull.

JamesW

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Re: The 2020 melting season
« Reply #3367 on: July 22, 2020, 01:49:54 PM »




Perhaps you overlooked the word MUST, your chart shows the usual or what often happens but that doesn not mean that it always has to be like that, especially under the current special conditions in many aspects.


So get me right, yes it's usual, i doubt the "inevitable" part for the current conditions.

Compactness = Area / Extent. Various satellite sensors (NSIDC / JAXA) and their respective data, tell us 2020 is among the most compact on record.

There is no debate.

Are some on here questioning JAXA and NSIDC sea ice extent and area data?
If record low area is divided by record low extent, then yes, there is a chance that compactness can be higher than other years.

All you are saying is that a record low ice pack is at a record low. LOL. Compactness here is meaningless.

5% more compactness compared to the lowest years after a high anomolous pressure has been sitting over the whole basin for 2 weeks is no surprise! I think we can all agree on this!

Everything in the arctic basin has been compacted. Using the data to express 5% additional compactness at this point in the melting season is open to debate as the high pressure moves out. The motion of the ice is now important if it takes the ice towards the higher SST's in the peripheral seas and other systems that can disperse it.

We know the ice is more compact but how weak is it? Has it just compacted filling melted gaps and cracks? Above average ice edge melt of the peripheral sea ice? I think its a learning curve and given a strong low or two we could now see big drops in compactness.

I am just watching and learning given all the facts its so complex to try to make assumptions. The ice always surprises us at times and can only be deciphered better after the event.

Pagophilus

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Re: The 2020 melting season
« Reply #3368 on: July 22, 2020, 02:02:46 PM »
I think there is a miscommunication here. The ice is/was "compacting", meaning it was generally moving towards the center of the pack, as an expected result of the high pressure and anti-cyclonic winds. I think all/most posters agree on that.
However, is the ice compact, meaning with no small holes inside the pack? I think many posters are saying no, it is not compact, since area has disappeared while the ice was moving northward, thus there is less ice covering a smaller extent.
Is the ice strong and defensible? I think many posters are saying no.
And have ice floes stacked on top of one another due to the northward movement, as happens with pressure ridges in winter? I think most/all posters now agree that no.

BTW, great animation Pagophilus.
Thanks, Oren.  And I agree with the distinction you make, although I am not sure all posters are on the same page.  In addition there has been a lot of debate as to whether extent has gone down because of compaction or melting.  Extent has plummeted largely because the floes have been brought closer together, in addition to melting.

A further point: As I wrote in an earlier post, the high brought the floes closer together (compaction in that sense) but melting within the pack has also proceeded at a ferocious pace, so therefore it is possible for concentration to go down at the same time as the ice is gathered by the anticyclone.
« Last Edit: July 22, 2020, 02:43:46 PM by Pagophilus »
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gandul

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Re: The 2020 melting season
« Reply #3369 on: July 22, 2020, 02:07:01 PM »
5% more compactness compared to the lowest years after a high anomolous pressure has been sitting over the whole basin for 2 weeks is no surprise! I think we can all agree on this!

Everything in the arctic basin has been compacted. Using the data to express 5% additional compactness at this point in the melting season is open to debate as the high pressure moves out. The motion of the ice is now important if it takes the ice towards the higher SST's in the peripheral seas and other systems that can disperse it.

We know the ice is more compact but how weak is it? Has it just compacted filling melted gaps and cracks? Above average ice edge melt of the peripheral sea ice? I think its a learning curve and given a strong low or two we could now see big drops in compactness.

I am just watching and learning given all the facts its so complex to try to make assumptions. The ice always surprises us at times and can only be deciphered better after the event.

All you say may be correct, but the compactness plot is comparing apples to apples

What you're saying is that this year may be an orange. Well, I wait for the demonstration of that.

ArcticMelt2

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Re: The 2020 melting season
« Reply #3370 on: July 22, 2020, 02:09:53 PM »
The ice in the Laptev Sea is so strongly compressed that the current image clearly shows the ice off the coast of the New Siberian Islands. Think of it as thick ice in the Central Arctic.

JayW

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Re: The 2020 melting season
« Reply #3371 on: July 22, 2020, 02:26:45 PM »
A lot of MYI ice in the Beaufort that has not suffered big heat nor big storms. These things can quench the melting season if August weather come dull.
They are currently breaking up under a weak cyclone. Same is happening near Banks island.
https://forum.arctic-sea-ice.net/index.php/topic,2649.msg275928.html#msg275928
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Re: The 2020 melting season
« Reply #3372 on: July 22, 2020, 02:55:11 PM »
I doubt this resolves the compaction debate but here is what osisaf(mid date) overlaid on nullschool 1000hPa wind (0900hr) looks like. jul1-17
Complex  (click to run, 2.6MB)

gerontocrat

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Re: The 2020 melting season
« Reply #3373 on: July 22, 2020, 03:04:53 PM »
I think the patterns are vital. There is too much focus on data points here - and everywhere, frankly. I'm a permaculturist, so looking at things "from patterns to details" is default. Both sides tell you something, but the patterns give the details their overall shape and form.

By their nature, the details will engender more conversation, but I'd like to see more noticing of the patterns. Those two huge drops in 2012, e.g. One we know, but what about the first? Nobody seems interested, but that could be a vital clue into potential early season melt risks. Without that first one, 12's drop isn't nearly as astonishing.
Patterns - I thought let's look at daily change throughout the melting season. First attempt looked at one day changes - too noisy.

I ended up with 7 day trailing average daily change to smooth the data a bit. Graph attached.
 
Note 3 periods of high melt in 2012.  2020 also in 3rd period of above average extent losses.
« Last Edit: July 22, 2020, 05:21:15 PM by gerontocrat »
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Re: The 2020 melting season
« Reply #3374 on: July 22, 2020, 03:12:05 PM »
5% more compactness compared to the lowest years after a high anomolous pressure has been sitting over the whole basin for 2 weeks is no surprise! I think we can all agree on this!

Everything in the arctic basin has been compacted. Using the data to express 5% additional compactness at this point in the melting season is open to debate as the high pressure moves out. The motion of the ice is now important if it takes the ice towards the higher SST's in the peripheral seas and other systems that can disperse it.

We know the ice is more compact but how weak is it? Has it just compacted filling melted gaps and cracks? Above average ice edge melt of the peripheral sea ice? I think its a learning curve and given a strong low or two we could now see big drops in compactness.

I am just watching and learning given all the facts its so complex to try to make assumptions. The ice always surprises us at times and can only be deciphered better after the event.

All you say may be correct, but the compactness plot is comparing apples to apples

What you're saying is that this year may be an orange. Well, I wait for the demonstration of that.

With record compactness in the charts at this point in the season we already have an orange!

I also stated to express the 5% is open to debate. Its what unfolds from this point is the interesting part. I was not forming an argument rather a wait and see approach as in new territory.

uniquorn

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Re: The 2020 melting season
« Reply #3375 on: July 22, 2020, 03:13:45 PM »
amsr2-uhh, Beaufort, jul20-21 and difference
click to run
JayW rammb here
« Last Edit: July 22, 2020, 03:46:32 PM by uniquorn »

El Cid

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Re: The 2020 melting season
« Reply #3376 on: July 22, 2020, 03:30:05 PM »
I took the 07/28 HYCOM sea ice thickness forecast and filled in green most everywhere where it is more than 50-70 cm thick (supposing that August will likely be able to melt 50 cm but not 1 M). This is what should remain by Sep 1. I don't know how much in million sq km the green area is:

BornFromTheVoid

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Re: The 2020 melting season
« Reply #3377 on: July 22, 2020, 03:56:03 PM »
8 of the last 20 melt seasons will produce a minimum below 2012 now, and the 10 year average gets us down to 3.52 million km2. Slowest melt, 2001, will produce the 6th lowest minimum, at 4.347 million km2.

I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

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Re: The 2020 melting season
« Reply #3378 on: July 22, 2020, 04:05:53 PM »
I took the 07/28 HYCOM sea ice thickness forecast and filled in green most everywhere where it is more than 50-70 cm thick (supposing that August will likely be able to melt 50 cm but not 1 M). This is what should remain by Sep 1. I don't know how much in million sq km the green area is:

Somewhere between 2 and 2.5 million, I'd say.  It's roughly a right triangle, the top edge runs from 80N across the pole and back to 80N on the other side, that's about 2200 km.  The other leg is a bit shorter, but there's some that's outside.   If it were 2200 on each leg, you'd get an area of 2.42x10^6.  Another handy number for eyeballing area in the Arctic is that the entire area N. of 80 is just under 4x10^6 km^2.
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Re: The 2020 melting season
« Reply #3379 on: July 22, 2020, 04:16:59 PM »
Quote
If one were to design a weather pattern that’s most efficient at ridding the Arctic of its increasingly fragile ice cover during the region’s summer melt season, it would look like what occurred earlier in the month — clear skies, above-average air temperatures, a high-pressure system across the Central Arctic, and an ongoing heat wave and wildfires in Siberia.

So, Freegrass, that is this year's equivalent of the 2012 GAC which is causing the freak records?
I'm not sure why you're asking me. I didn't write that. But if you ask my opinion about this years melting season, I predicted a record minimum below 3M km2 at the start of the season due to clean air which would cause record Eurasian heat waves that would be devastating for the ice. And that did happen, which caused early strong melt.

I also said that all that extra heat would bring bigger storms. That didn't happen (yet). Instead we had the GAAC after JAC Daniels opened up the ice a little.

The real consequences of the GAAC will only be visible in a few weeks from now IMHO, because we don't know how much energy went into the ice and the ocean. According to the data, we're already in record territory by far. The question now is how much bottom melt we will have with all the heat that went into the ocean.

I'm still thinking we will end below 3 million m2. If we get a GAC or dipole, we'll probably be closer to 2M m2. But that's just the humble opinion from a fat guy behind a computer.  ;)
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Re: The 2020 melting season
« Reply #3380 on: July 22, 2020, 04:27:39 PM »
I think there is a miscommunication here. The ice is/was "compacting", meaning it was generally moving towards the center of the pack, as an expected result of the high pressure and anti-cyclonic winds. I think all/most posters agree on that.
However, is the ice compact, meaning with no small holes inside the pack? I think many posters are saying no, it is not compact, since area has disappeared while the ice was moving northward, thus there is less ice covering a smaller extent.
Is the ice strong and defensible? I think many posters are saying no.
And have ice floes stacked on top of one another due to the northward movement, as happens with pressure ridges in winter? I think most/all posters now agree that no.

BTW, great animation Pagophilus.
Thanks. That was the only reason that I chimed in. I felt like one or two of the earlier posts used the term compact in a way so as to say that a goodly portion of the pack had been toughened up for surviving the season.
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Freegrass

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Re: The 2020 melting season
« Reply #3381 on: July 22, 2020, 04:32:21 PM »
Quote from: oren link=topic=3017.msg276000#msg276000 date=1595412404
However, is the ice [u
compact[/u], meaning with no small holes inside the pack? I think many posters are saying no, it is not compact, since area has disappeared while the ice was moving northward, thus there is less ice covering a smaller extent.

Looking at worldview, Im struggling to find any meaningful holes in the ice pack in the CAV, at least when you compare it to years with heavy dispersion like 2016 in particular. The problem we got is has there been too much compaction to prevent the ice going under 4  million, I have a feeling that could be the case but the charts and worldview does suggest the ice compacted. However ass you say, is it thick and resilient enough, that is something I'm skeptical of all so sadly.

When you look at the thick ice close to the CAAAGC, you can still see many holes. Worldview link
When you look at the ice in the CAB, there are almost no holes to be found anymore.
There used to be many little holes, but they have all disappeared during compaction.

So my theory is that the thinner the ice gets, the easier it is to compact the ice and close the holes. So IMHO I think that less holes means weak and thin ice.

But I have no idea if any of that is true...
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Pagophilus

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Re: The 2020 melting season
« Reply #3382 on: July 22, 2020, 05:10:21 PM »
Evidence of melting ribbons on the Laptev and Atlantic margins wherever one can peek through the clouds on Worldview.  Including these rather attractive tendrils N of Svalbard. Tendril length varies from 10-30km.  This Atlantic margin may not budge much, but it is being constantly supplied with ice, which duly melts as it meet warm Atlantic waters.
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KenB

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Re: The 2020 melting season
« Reply #3383 on: July 22, 2020, 05:23:17 PM »
Evidence of melting ribbons on the Laptev and Atlantic margins wherever one can peek through the clouds on Worldview.  Including these rather attractive tendrils N of Svalbard. Tendril length varies from 10-30km.  This Atlantic margin may not budge much, but it is being constantly supplied with ice, which duly melts as it meet warm Atlantic waters.

Nice pic.  Just west of there, a number of floes can be seen moving S. at what looks to me like 8-10 km/day.
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El Cid

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Re: The 2020 melting season
« Reply #3384 on: July 22, 2020, 05:50:22 PM »
I took the 07/28 HYCOM sea ice thickness forecast and filled in green most everywhere where it is more than 50-70 cm thick (supposing that August will likely be able to melt 50 cm but not 1 M). This is what should remain by Sep 1. I don't know how much in million sq km the green area is:

Somewhere between 2 and 2.5 million, I'd say... Another handy number for eyeballing area in the Arctic is that the entire area N. of 80 is just under 4x10^6 km^2.

Thanks! That is a pretty low number...

Milwen

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Re: The 2020 melting season
« Reply #3385 on: July 22, 2020, 06:00:16 PM »
This is not looking good. Looks like triple cyclone over Arctic from Nullschool.

Also new HYCOM +7day forecast change.


gerontocrat

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Re: The 2020 melting season
« Reply #3386 on: July 22, 2020, 06:22:20 PM »
I took the 07/28 HYCOM sea ice thickness forecast and filled in green most everywhere where it is more than 50-70 cm thick (supposing that August will likely be able to melt 50 cm but not 1 M). This is what should remain by Sep 1. I don't know how much in million sq km the green area is:

Somewhere between 2 and 2.5 million, I'd say... Another handy number for eyeballing area in the Arctic is that the entire area N. of 80 is just under 4x10^6 km^2.

Thanks! That is a pretty low number...
Quote
just under 4x10^6 km^2
= 3.875 million km2.

But for the sea area North of 80 you have to exclude the largish lump of land which is the North of Greenland & about half of Ellesmere Island.
The area of the Central Arctic Sea as defined by NSIDC is 3.224 million km2, which follows closely but not exactly 80 North.
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gandul

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Re: The 2020 melting season
« Reply #3387 on: July 22, 2020, 06:26:39 PM »
A lot of MYI ice in the Beaufort that has not suffered big heat nor big storms. These things can quench the melting season if August weather come dull.
They are currently breaking up under a weak cyclone. Same is happening near Banks island.
https://forum.arctic-sea-ice.net/index.php/topic,2649.msg275928.html#msg275928
Yes I saw your animation, thanks. Still very big guys down there. The fact that big blocks resist this time of the season is a sign that Beaufort started with plenty of thick ice and not much shaking nor straight heat has hit this year over there. These guys won't go unless they are really pulverized storm after storm.

gandul

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Re: The 2020 melting season
« Reply #3388 on: July 22, 2020, 06:32:17 PM »
All you say may be correct, but the compactness plot is comparing apples to apples

What you're saying is that this year may be an orange. Well, I wait for the demonstration of that.

With record compactness in the charts at this point in the season we already have an orange!

I also stated to express the 5% is open to debate. Its what unfolds from this point is the interesting part. I was not forming an argument rather a wait and see approach as in new territory.
I was not trying to create an argument. What I mean by ''I'll wait for the demonstration of that' is that I wait for the season evolution to tell me this was an 'orange' or not. Given the level of insolation so far my feeling is that the CAB  must be in a very fragile state, but if the ice simply stays there, it is difficult that it melts out as it sits over a cool deep ocean far from warm currents. You can have 40 cm thick ice that simply won't go unless it receives a good shake and some more heat.


F.Tnioli

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Re: The 2020 melting season
« Reply #3389 on: July 22, 2020, 06:32:40 PM »
Note to Neven / Oren

<Original post moved to posting style thread. O>
« Last Edit: July 22, 2020, 08:16:10 PM by oren »
To everyone: before posting in a melting season topic, please be sure to know contents of this moderator's post: https://forum.arctic-sea-ice.net/index.php/topic,3017.msg261893.html#msg261893 . Thanks!

gandul

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Re: The 2020 melting season
« Reply #3390 on: July 22, 2020, 06:35:49 PM »
Wasting your time

<He wasn't. O>
« Last Edit: July 22, 2020, 08:16:35 PM by oren »

JamesW

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Re: The 2020 melting season
« Reply #3391 on: July 22, 2020, 06:54:52 PM »
All you say may be correct, but the compactness plot is comparing apples to apples

What you're saying is that this year may be an orange. Well, I wait for the demonstration of that.

With record compactness in the charts at this point in the season we already have an orange!

I also stated to express the 5% is open to debate. Its what unfolds from this point is the interesting part. I was not forming an argument rather a wait and see approach as in new territory.
I was not trying to create an argument. What I mean by ''I'll wait for the demonstration of that' is that I wait for the season evolution to tell me this was an 'orange' or not. Given the level of insolation my feeling is that the CAB  must be in a very fragile state, but if the ice simply stays there, it is difficult that it melts out as it sits over a cool deep ocean far from warm currents. You can have 40 cm thick ice that simply won't go unless it receives a good shake and some more heat.

Thank you Gandul for taking the time to explain more in depth. I am in agreement that the remaining ice will require motion to warmer SST's, or low pressure systems and more insolation if it stays in situ to make matters so much worse than they already are. So yes along with us all we watch with glaring eyes, as this season evolves as you mention 'the demonstration of what unfolds'. I obviously misconstrude some of your text/comment in my previous reply so apologies for that.

werther

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Re: The 2020 melting season
« Reply #3392 on: July 22, 2020, 06:57:48 PM »
El Cid - on your graph in green: through my effort on CAD yesterday I suppose you rounded the pack ice up to 2,4 Mkm2. I had a Greenland Sea Tongue and some bigger CAA channels more, about 2,9 Mkm2...

ArcticMelt2

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Re: The 2020 melting season
« Reply #3393 on: July 22, 2020, 07:03:19 PM »
Somewhere between 2 and 2.5 million, I'd say... Another handy number for eyeballing area in the Arctic is that the entire area N. of 80 is just under 4x10^6 km^2.

Thanks! That is a pretty low number...
Quote
just under 4x10^6 km^2
= 3.875 million km2.

But for the sea area North of 80 you have to exclude the largish lump of land which is the North of Greenland & about half of Ellesmere Island.
The area of the Central Arctic Sea as defined by NSIDC is 3.224 million km2, which follows closely but not exactly 80 North.

It is important to note there that each degree latitude in the Сentral Аrctic is a large area. Look at the minimum extent of 2019 and 2012. It seems the difference between them is minimal - one degree latitude, but in extent it is almost a million square kilometers.

ArcticMelt2

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Re: The 2020 melting season
« Reply #3394 on: July 22, 2020, 07:10:35 PM »
But it is important to note that in 2019 the ice was still poorly melting in the Canadian archipalagus. Therefore, in reality, the difference in the Central Arctic between 2012 and 2019 is even smaller. Almost twins years with the difference that in 2019 there was no strong storm.
« Last Edit: July 22, 2020, 07:35:05 PM by ArcticMelt2 »

tybeedave

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Re: The 2020 melting season
« Reply #3395 on: July 22, 2020, 07:17:29 PM »
insolation continues in the Arctic Ocean in large areas including the

Beaufort Sea which is looks to be in poor shape on worldview (7/21).....

https://worldview.earthdata.nasa.gov/?v=-1675181.427966618,39647.102817245235,-1116077.427966618,301791.10281724524&p=arctic&t=2020-07-20-T16%3A46%3A52Z

td


« Last Edit: July 22, 2020, 07:32:42 PM by tybeedave »
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igs

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Re: The 2020 melting season
« Reply #3396 on: July 22, 2020, 07:33:36 PM »

tybeedave

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Re: The 2020 melting season
« Reply #3397 on: July 22, 2020, 07:36:39 PM »
We are a month from the solstice. I am not sure about the exact timing but I believe we are near to the time when cloud cover is worse for the ice than clear sky.
i agree except it is 2 months to solstice
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ArcticMelt2

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Re: The 2020 melting season
« Reply #3398 on: July 22, 2020, 07:55:43 PM »
The 2019 extent area in the Central Arctic was close to the 2012 boundary. Probably PIOMAS actually overestimates the volume of ice, and in fact it is much smaller. If so, then even a weak cyclone in the Central Arctic should break a lot of ice and get a lot of open water. As it was in 2013. We need to watch Bremen map the next day. Today, just a weak cyclone is in the Central Arctic.

igs

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Re: The 2020 melting season
« Reply #3399 on: July 22, 2020, 08:04:38 PM »
We are a month from the solstice. I am not sure about the exact timing but I believe we are near to the time when cloud cover is worse for the ice than clear sky.
i agree except it is 2 months to solstice

Calculate again LOL

22nd of July is one mont after 22nd of June so the one month from solstice was correct.

Could be that there is a language barrier somewhere ?  from, to,  or skipping explanatory parts of the sentence, however, we are 1 month from solstice EXACTLY to the day.