2016 sea ice area and extent data

[TerryM]

"You certainly have a way with acronyms"


"Acronyms work initially"
My sweeties boss told this to a room full of cops at a planning session. None even smiled - and he didn't realise what he'd said!


"Police intelligence", an oxymoron


Terry

[budmantis]

That's a good one Terry!

Bud

[Rob Dekker]

Big big drops of extent fellows.
These must be accurate! They adhere well to the established theories around.

I am afraid that that 158 k drop is just the beginning of the big extent drops this week...

[BornFromTheVoid]

Update for the week to August 27th

The current 5 day trailing average is on 4,800,000km2 while the 1 day extent is at 4,537,000km2.

(All the following data is based on a trailing 5 day average)
The daily anomaly (compared to 81-10) is at -1,930,000km2, an increase from -1,855,000km2 last week. The anomaly compared to the 07, 11 and 12 average is at +247,000km2, an increase from +212,000km2 last week. We're currently 2nd lowest on record, up from 3rd lowest last week.



The average daily change over the last 7 days was -55.1k/day, compared to the long term average of -44.4k/day, and the 07, 11 and 12 average of -60.1k/day.
The average long term change over the next week is -38.9k/day, with the 07, 11, and 12 average being -45.2k/day.



The extent loss so far this August is the 5th largest on record. To achieve the largest monthly loss, a drop of at least 176.3k/day is required (requiring ~221.0k/day with with single day values), while the smallest loss requires an increase of at least 207.0k/day (+545.3k/day with single day values) and an average loss requires an increase of 73.7k/day (increase of 278.8k/day with single day values).

[BornFromTheVoid]

Using the single day values, the NSIDC extent is now below every previous minima except 2007, 2011, 2012 and 2015, with gaps of 390k, 204k, 1197k and 196k respectively.

With the 5 day trailing average we're below all previous minima except 2007, 2008, 2010, 2011, 2012 and 2015.



...Diff..... ...No of Years   Percentage
Below 0..... ....31..... .....83.8%
0-100k....... ....0..... ......0.0%
100-250k..... ...2..... ......5.4%
250-500k..... ...2..... ......5.4%
500-1000k..... .1..... ......2.7%
>1000k..... .....1..... ......2.7%

[Wipneus]

Here is the shadow CT-area report based on calibrated F18 NSIDC sea ice concentration data:

day  CT-date       NH               SH                Global
Sat 2016.6493 -170.0  2.918565  +56.9 14.809784  -113.1 17.728349
Sun 2016.6521 -109.9  2.808624  -40.2 14.769591  -150.1 17.578215
Mon 2016.6548  -52.5  2.756159  +81.7 14.851282   +29.2 17.607441
Tue 2016.6575  -57.9  2.698250  +53.4 14.904697    -4.5 17.602947

Single handed done by the CAB: -64k.

Shadow NSIDC extent is now 4.5373 dropping -172.4k. Done by the CAB (-132k), Chukchi (-29k) and ESS (-24k).

The left Wrangle arm is in flames in the attached delta image.

[Wipneus]

NSIDC area (*) is becoming a neck and neck race with only 132k behind 2012.

Date      "NSIDC area"
2015-08-27 3.384752
2010-08-27 3.365565
2008-08-27 3.290108
2011-08-27 3.128499
2007-08-27 3.117733
2016-08-27 2.649995
2012-08-27 2.517081
 
(*) Read my post about when Area is not CT-Area: http://forum.arctic-sea-ice.net/index.php/topic,1457.msg87761.html#msg87761

[nuwanudaraalwis]

Wipneus 2016-08-27 2.649995 vs 2.698250 difference ?

[Buddy]

NSIDC area (*) is becoming a neck and neck race with only 132k behind 2012.

Date      "NSIDC area"
2015-08-27 3.384752
2010-08-27 3.365565
2008-08-27 3.290108
2011-08-27 3.128499
2007-08-27 3.117733
2016-08-27 2.649995
2012-08-27 2.517081

Yea....pretty interesting indeed.  And almost 22% below last year....

And there is more "slushy" that is primed and ready to go.

[andy_t_roo]

Here is the shadow CT-area report based on calibrated F18 NSIDC sea ice concentration data:

day  CT-date       NH               SH                Global
Sat 2016.6493 -170.0  2.918565  +56.9 14.809784  -113.1 17.728349
Sun 2016.6521 -109.9  2.808624  -40.2 14.769591  -150.1 17.578215
Mon 2016.6548  -52.5  2.756159  +81.7 14.851282   +29.2 17.607441
Tue 2016.6575  -57.9  2.698250  +53.4 14.904697    -4.5 17.602947

Single handed done by the CAB: -64k.

Shadow NSIDC extent is now 4.5373 dropping -172.4k. Done by the CAB (-132k), Chukchi (-29k) and ESS (-24k).

The left Wrangle arm is in flames in the attached delta image.

If this is a compaction event, does anyone know why there is a lack of light blue concentration increases internal to the pack in recent days?  We are even seeing blocs of concentration drops (light red)?

[Tigertown]

NSIDC area (*) is becoming a neck and neck race with only 132k behind 2012.

Date      "NSIDC area"
2015-08-27 3.384752
2010-08-27 3.365565
2008-08-27 3.290108
2011-08-27 3.128499
2007-08-27 3.117733
2016-08-27 2.649995
2012-08-27 2.517081
 
(*) Read my post about when Area is not CT-Area: http://forum.arctic-sea-ice.net/index.php/topic,1457.msg87761.html#msg87761

Yes, indeed. This year doesn't just look bad; it actually is bad.

[magnamentis]

Here is the shadow CT-area report based on calibrated F18 NSIDC sea ice concentration data:

day  CT-date       NH               SH                Global
Sat 2016.6493 -170.0  2.918565  +56.9 14.809784  -113.1 17.728349
Sun 2016.6521 -109.9  2.808624  -40.2 14.769591  -150.1 17.578215
Mon 2016.6548  -52.5  2.756159  +81.7 14.851282   +29.2 17.607441
Tue 2016.6575  -57.9  2.698250  +53.4 14.904697    -4.5 17.602947

Single handed done by the CAB: -64k.

Shadow NSIDC extent is now 4.5373 dropping -172.4k. Done by the CAB (-132k), Chukchi (-29k) and ESS (-24k).

The left Wrangle arm is in flames in the attached delta image.

If this is a compaction event, does anyone know why there is a lack of light blue concentration increases internal to the pack in recent days?  We are even seeing blocs of concentration drops (light red)?

this is not compaction, this is melt out, the term compaction is not accurate IMO to describe current events.

[Michael Hauber]

NSIDC area (*) is becoming a neck and neck race with only 132k behind 2012.

Date      "NSIDC area"
2015-08-27 3.384752
2010-08-27 3.365565
2008-08-27 3.290108
2011-08-27 3.128499
2007-08-27 3.117733
2016-08-27 2.649995
2012-08-27 2.517081
 
(*) Read my post about when Area is not CT-Area: http://forum.arctic-sea-ice.net/index.php/topic,1457.msg87761.html#msg87761

Is that NSIDC area?  Or Wipneus area calculated on NSIDC data?  All extent figures and the only available area figure on Neven's sea ice page show ice much closer to 2007 and well short of 2012.  However the only available area figure is the Arctic Roos which has been a favourite of deniers in the past, and seems to be prone to odd fluctuations.

What is happening with area data?  Cryosphere today is broken.  I'm sure IUP used to publish area, but it no longer seems to exist.  Does anyone else publish area other than the Wipneus home brew? 

[Wipneus]

Wipneus 2016-08-27 2.649995 vs 2.698250 difference ?

That is my "NSIDC area" vs CT-area. Some of the reasons why they differ:
- CT-area includes "Lake ice", about 100k a.t.m.
- CT-area underestimates area within the Arctic Basin (latitude > 70^o)
- CT-area includes ice in grid cells that have ice concentration less than 15%

Some of these differences actually compensate each other, so the diff is quite small now. Comparing with previous years the differences can be much bigger, CT never is never recalculated when NSIDC releases new versions.

[Wipneus]

Is that NSIDC area?  Or Wipneus area calculated on NSIDC data?  All extent figures and the only available area figure on Neven's sea ice page show ice much closer to 2007 and well short of 2012.  However the only available area figure is the Arctic Roos which has been a favourite of deniers in the past, and seems to be prone to odd fluctuations.

What is happening with area data?  Cryosphere today is broken.  I'm sure IUP used to publish area, but it no longer seems to exist.  Does anyone else publish area other than the Wipneus home brew?

It is indeed area calculated by me from NSIDC gridded sea ice concentration data in such a way that is can be compared with the NSIDC extent.

I am not aware of other sources of near-real-time source of area data.

[Jim Pettit]

IJIS (ADS-NIPR) Extent:

4,464,681 km2 (28 August)

Down 9,477,826 km2 (67.98%) from 2016 maximum of 13,942,507 km2 on 29 February.

1,287,226 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 31,793 km2 (-.7%) from previous day.

Down 461,598 km2  (-9.43%) over past seven days (daily average: -65,943 km2).

Down 2,005,222 km2  (-16.39%) for August (daily average: -71,615 km2).

1,336,170 km2 below 2000s average for this date.

256,635 km2 below 2010s average for this date.

93,520 km2 below 2015 value for this date.

846,213 km2 above 2012 value for this date.

Lowest year-to-date (01 January - 28 August) average.

3rd lowest August to-date average.

2nd lowest value for the date.

128 days this year (53.33% year-to-date) have recorded the lowest daily extent.

39 days (16.25%) have recorded the second lowest.

47 days (19.58%) have recorded the third lowest.

214 days in total (89.17%) have been among the lowest three on record.

CT Area:

2,698,250 km2 (28 August [Day 0.6576])

Down 10,223,108 km2 (79.12%) from 2016 maximum of 12,921,358 km2 on 29 March [Day 0.2384].

464,241 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 57,909 km2 (-2.1%) from previous day.

Down 430,690 km2 (-13.67%) over past seven days (daily average: -61,527 km2).

Down 1,582,976 km2 (-14.21%) for August (daily average: -54,585 km2).

1,429,677 km2 below 2000s average for this date.

546,857 km2 below 2010s average for this date.

712,185 km2 below 2015 value for this date.

175,826 km2 above 2012 value for this date.

* - NOTE: due to the prolonged absence of official CT sea ice area data, I've incorporated Wipneus' "shadow" area numbers as calculated from NSIDC data. The official numbers will be inserted if/when available. In the meantime, thanks, Wipneus!

[Wipneus]

Comparisons of extent/area from Arctic Roos with "home brew" UH AMSR2 3.125km for selected years.

[Juan C. García]

Is that NSIDC area?  Or Wipneus area calculated on NSIDC data?  All extent figures and the only available area figure on Neven's sea ice page show ice much closer to 2007 and well short of 2012.  However the only available area figure is the Arctic Roos which has been a favourite of deniers in the past, and seems to be prone to odd fluctuations.

What is happening with area data?  Cryosphere today is broken.  I'm sure IUP used to publish area, but it no longer seems to exist.  Does anyone else publish area other than the Wipneus home brew?

It is indeed area calculated by me from NSIDC gridded sea ice concentration data in such a way that is can be compared with the NSIDC extent.

I am not aware of other sources of near-real-time source of area data.

Hi Wipneus.

I remember that NSIDC used to publish area data, in the same file that they give the daily Arctic extent data. Do you know if they gave any reason to stop publishing total ASI daily area?

[Wipneus]

Hi Wipneus.

I remember that NSIDC used to publish area data, in the same file that they give the daily Arctic extent data. Do you know if they gave any reason to stop publishing total ASI daily area?

No, I cannot remember daily area data. The monthly files have both area and extent. For instance for August:

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/Aug/N_08_area_v2.txt

This "area" differs from mine, not only because it is monthly, but also in not estimating the ice in the pole hole (same as assuming zero ice there). On the other hand extent is calculated assuming greater than 15% ice, 100% extent in the pole hole. These extent and area are in my opinion not compatible.

[Juan C. García]

Hi Wipneus.

I remember that NSIDC used to publish area data, in the same file that they give the daily Arctic extent data. Do you know if they gave any reason to stop publishing total ASI daily area?

No, I cannot remember daily area data. The monthly files have both area and extent. For instance for August:

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/Aug/N_08_area_v2.txt

This "area" differs from mine, not only because it is monthly, but also in not estimating the ice in the pole hole (same as assuming zero ice there). On the other hand extent is calculated assuming greater than 15% ice, 100% extent in the pole hole. These extent and area are in my opinion not compatible.

Thank you Wipneus. You are right that it was only on the monthly data. 

[BornFromTheVoid]

Big uptick in the NSIDC daily extent, +170k. Still 2nd lowest but now 949k off 2012.

[Wipneus]

Here is the shadow CT-area report based on calibrated F18 NSIDC sea ice concentration data:

day  CT-date       NH               SH                Global
Sun 2016.6521 -109.9  2.808624  -40.2 14.769591  -150.1 17.578215
Mon 2016.6548  -52.5  2.756159  +81.7 14.851282   +29.2 17.607441
Tue 2016.6575  -57.5  2.698689  +53.3 14.904628    -4.1 17.603317
Wed 2016.6603  +27.0  2.725728  +42.0 14.946673   +69.1 17.672401

Due to an uptick in the CAB: +33k.

Shadow NSIDC extent is now 4.7067 increasing +169.4k. That is a cooperation of the CAB (+63k), Chukchi (+36k), ESS (+26k) and a helping hand from the Greenland Sea (+24k).

The attached delta map shows the reappearing act of the ice in the so called "Wrangel arm".

[budmantis]

First poof then unpoof. My head is spinning!

[bbr2314]

First poof then unpoof. My head is spinning!

I think that portends additional century drops as the clouds clear again. There is no way those gains are possible given what's ongoing over the Arctic. Until we hit rock bottom we will likely continue seeing dramatic stair-stepping instead of a more consistent decline (in reality we are experiencing the latter, idk why Neven said I only believe the days with drops are legit, untrue, they are still missing the full picture).

Models now showing the polar vortex retreating from the Siberian peripheral seas entirely with lows continually spinning up next to Greenland. I assume this will destroy the lingering fragile ice along the Atlantic front while compacting the shrinking Triangle of Fortitude further. 2M or less is a given and the decrease this September will more than make up for the lack of momentum in June and July.

[lurkalot]

First poof then unpoof. My head is spinning!

I think Neven once referred to it as peek-a-boo ice - is that easier on your head?

[crandles]

I preferred flashback as the term to use.

[A-Team]

Back from vacation at 'Glacier' National Park on the Canadian border. All 148 glaciers seen in 1850 to be gone by 2020. Took a nice selfie of Grinnell 'Glacier' as a grizzly bear crossed the trail (not shown -- would get Neven in dutch with park authorities).

Here are the last four days of the Wrangel arm at UHH AMSR2 3.1k along with various zooms of the area at WorldView. The first WV, the one showing the 200 km scale bar, needed a 105% enlargement to overlay the large version of the AMSR file.

[Shared Humanity]

2M or less is a given and the decrease this September will more than make up for the lack of momentum in June and July.

Of course we need to wait until the end of the melt season but there is no way, IMHO, that we will hit 2M

[Peter Ellis]

I think that portends additional century drops as the clouds clear again. There is no way those gains are possible given what's ongoing over the Arctic.

Why do you leap to saying that the gain is inaccurate, rather than the preceding loss being inaccurate?  Both options are perfectly plausible.

[Archimid]

Of course we need to wait until the end of the melt season but there is no way, IMHO, that we will hit 2M

I shared your opinion until I saw Wipneus 2012 vs 2016 animation over at the home-brew thread, took a good look at Fram export and then checked nullschool https://earth.nullschool.net/#current/wind/surface/level/overlay=mean_sea_level_pressure/orthographic=-58.26,91.45,410

 There is a good chance that Fram export accelerates. if that happens a lot of multiyear ice might be lost because of it. But it has to be something truly spectacular to hit 2M.

[magnamentis]

I think that portends additional century drops as the clouds clear again. There is no way those gains are possible given what's ongoing over the Arctic.

Why do you leap to saying that the gain is inaccurate, rather than the preceding loss being inaccurate?  Both options are perfectly plausible.

what he is saying that it's too warm for refreezing except melt ponds of which are few and that the gains are fake as well as the huge drops are not real because the in parts correct for the fake-gains. he explicitly mentioned that he does NOT say/mean what you imply, hence why ask. some should jump over their shadow and start proper reading and then proper pondering before shooting away repeatedly.

that said i as well don't believe in 2M but as you can see, i just utter my opinion without obvious or hidden offend.
i just say that i dont believe in 2M but in second place while leaving room for a surprise (longer and stormy melting season for example)

[budmantis]

First poof then unpoof. My head is spinning!

I think Neven once referred to it as peek-a-boo ice - is that easier on your head?

I think a cervical collar might work better, but thanks for the suggestion. I'd inset a smiley, but I don't know how!

[budmantis]

I think that portends additional century drops as the clouds clear again. There is no way those gains are possible given what's ongoing over the Arctic.

Why do you leap to saying that the gain is inaccurate, rather than the preceding loss being inaccurate?  Both options are perfectly plausible.

what he is saying that it's too warm for refreezing except melt ponds of which are few and that the gains are fake as well as the huge drops are not real because the in parts correct for the fake-gains. he explicitly mentioned that he does NOT say/mean what you imply, hence why ask. some should jump over their shadow and start proper reading and then proper pondering before shooting away repeatedly.

that said i as well don't believe in 2M but as you can see, i just utter my opinion without obvious or hidden offend.
i just say that i dont believe in 2M but in second place while leaving room for a surprise (longer and stormy melting season for example)

I think Peter's is a fair question. As far as reaching 2M, it would take an unprecedented amount of melt for that to occur, which would require weather conditions considerably worse than we are currently observing. I'd say 2M has less than a 1% chance of happening.

[Tigertown]

First poof then unpoof. My head is spinning!

I think Neven once referred to it as peek-a-boo ice - is that easier on your head?

I think a cervical collar might work better, but thanks for the suggestion. I'd inset a smiley, but I don't know how!

Just click on the smiley and it will appear at the last place you leave the cursor while typing...

[bbr2314]

I think that portends additional century drops as the clouds clear again. There is no way those gains are possible given what's ongoing over the Arctic.

Why do you leap to saying that the gain is inaccurate, rather than the preceding loss being inaccurate?  Both options are perfectly plausible.

what he is saying that it's too warm for refreezing except melt ponds of which are few and that the gains are fake as well as the huge drops are not real because the in parts correct for the fake-gains. he explicitly mentioned that he does NOT say/mean what you imply, hence why ask. some should jump over their shadow and start proper reading and then proper pondering before shooting away repeatedly.

that said i as well don't believe in 2M but as you can see, i just utter my opinion without obvious or hidden offend.
i just say that i dont believe in 2M but in second place while leaving room for a surprise (longer and stormy melting season for example)

I think Peter's is a fair question. As far as reaching 2M, it would take an unprecedented amount of melt for that to occur, which would require weather conditions considerably worse than we are currently observing. I'd say 2M has less than a 1% chance of happening.

The current weather *is* among the worst patterns (if not the worst ever pattern) the Arctic has ever seen. By D4 it goes from "horrific" to "merely very bad" but I don't think it gets any worse than this.

[Tigertown]

Huge amount of ice headed into the Fram. I don't know how far south it needs to go before its no longer counted in extent or area or does it need to melt out completely first, which it is doomed to do.
 Until then it is the same as inflating extent, I would think.

[Shared Humanity]

Rather than using undefined or ill defined qualifiers like "worst" or "best", why not just describe the current and/or forecast weather and its likely impacts? Your "worst" weather, for example, looks like it will continue to rake the Wrangel arm with high winds while further compacting ice against the CAA. It seems less inclined to drive Fram export but certainly looks as if it could make for a choppy Barents. Effect on season end???

[Shared Humanity]

Huge amount of ice headed into the Fram. I don't know how far south it needs to go before its no longer counted in extent or area or does it need to melt out completely first, which it is doomed to do.
 Until then it is the same as inflating extent, I would think.

Has to melt out as the Greenland Sea ice is included in the metrics. I think the thicker, rhomboid shaped MYI floes will not melt out before the minimum.

[bbr2314]

Rather than using undefined or ill defined qualifiers like "worst" or "best", why not just describe the current and/or forecast weather and its likely impacts? Your "worst" weather, for example, looks like it will continue to rake the Wrangel arm with high winds while further compacting ice against the CAA. It seems less inclined to drive Fram export but certainly looks as if it could make for a choppy Barents. Effect on season end???

Here's a description -- the GEFS anomalies at 384. I think the outline surrounded by higher anomalies is what will survive, everything else (including what the anomalies cover) will melt, perhaps with the exception of some remnants N of Siberia of not more than 250K KM2.

[Shared Humanity]

I guess my point is that, after coming here for many years, weather in the Arctic is simply weather. Are vicious lows worse than cloudless highs. I find it enlightening when someone explains how cloudless skies driven by high pressure in June and July lead to melting momentum due to melt ponds and reductions in albedo, a description of the weather and impacts.

Simply saying something is the "worst" does nothing to help me understand.

[budmantis]

We'll know soon enough how it all turns out BBR. I admire your passion, but I'm skeptical of your assertions. If you turn out to be on target, I'll be one of the first to congratulate you.

[BornFromTheVoid]

Here's a description -- the GEFS anomalies at 384. I think the outline surrounded by higher anomalies is what will survive, everything else (including what the anomalies cover) will melt, perhaps with the exception of some remnants N of Siberia of not more than 250K KM2.

The anomalies from t+384 tell you next to nothing as models will vary drastically from one run to the next. Anomalies spike in Autumn as temperatures dip well below 0C and heat gets released from the ocean, allowing anomalies to jump across the Arctic. This is in contrast to the summer, where anomalies are kept small due to being held close to the melting point of the ice. You see the same almost every Autumn in recent years. Those positive anomalies will often cover the entire Arctic, especially when averaged out over several days. They are not a very useful guide to where the ice is located.

2007-2015 September Surface Air Temp Anomaly


Anyway, what is being asked is that you give some substance to "worst ever" other such hyperbolic claims, preferably over in the melt season thread.

If folk wouldn't mind taking the weather conversation to the melt season, or indeed, the refreeze thread for longer range discussion, that would be great

[Neven]

I've made this animation of Uni Bremen SIC maps for an ASIB update later today, and it clearly shows the flashing-unflashing going on in the Wrangel Arm:

[Sterks]

Here is the shadow CT-area report based on calibrated F18 NSIDC sea ice concentration data:

day  CT-date       NH               SH                Global
Sat 2016.6493 -170.0  2.918565  +56.9 14.809784  -113.1 17.728349
Sun 2016.6521 -109.9  2.808624  -40.2 14.769591  -150.1 17.578215
Mon 2016.6548  -52.5  2.756159  +81.7 14.851282   +29.2 17.607441
Tue 2016.6575  -57.9  2.698250  +53.4 14.904697    -4.5 17.602947

Single handed done by the CAB: -64k.

Shadow NSIDC extent is now 4.5373 dropping -172.4k. Done by the CAB (-132k), Chukchi (-29k) and ESS (-24k).

The left Wrangle arm is in flames in the attached delta image.

If this is a compaction event, does anyone know why there is a lack of light blue concentration increases internal to the pack in recent days?  We are even seeing blocs of concentration drops (light red)?

this is not compaction, this is melt out, the term compaction is not accurate IMO to describe current events.

Cannot both? More experienced commenters than us newbies show maps with ice crashed against the shores of North America. That pack is joined closely together. This is the definition of compaction. However, it is more difficult. However, two-dimensional maps aren't able to demonstrate actual melting because meting is a three-dimensional process. Concur?

[abbottisgone]

Here is the shadow CT-area report based on calibrated F18 NSIDC sea ice concentration data:

day  CT-date       NH               SH                Global
Sat 2016.6493 -170.0  2.918565  +56.9 14.809784  -113.1 17.728349
Sun 2016.6521 -109.9  2.808624  -40.2 14.769591  -150.1 17.578215
Mon 2016.6548  -52.5  2.756159  +81.7 14.851282   +29.2 17.607441
Tue 2016.6575  -57.9  2.698250  +53.4 14.904697    -4.5 17.602947

Single handed done by the CAB: -64k.

Shadow NSIDC extent is now 4.5373 dropping -172.4k. Done by the CAB (-132k), Chukchi (-29k) and ESS (-24k).

The left Wrangle arm is in flames in the attached delta image.

If this is a compaction event, does anyone know why there is a lack of light blue concentration increases internal to the pack in recent days?  We are even seeing blocs of concentration drops (light red)?

this is not compaction, this is melt out, the term compaction is not accurate IMO to describe current events.

Cannot both? More experienced commenters than us newbies show maps with ice crashed against the shores of North America. That pack is joined closely together. This is the definition of compaction. However, it is more difficult. However, two-dimensional maps aren't able to demonstrate actual melting because meting is a three-dimensional process. Concur?

Did anyone miss the 'if'

[Michael Hauber]

Rather than using undefined or ill defined qualifiers like "worst" or "best", why not just describe the current and/or forecast weather and its likely impacts? Your "worst" weather, for example, looks like it will continue to rake the Wrangel arm with high winds while further compacting ice against the CAA. It seems less inclined to drive Fram export but certainly looks as if it could make for a choppy Barents. Effect on season end???

Andrew Slater's 925hp temps suggest that the recent spell was almost but not quite the warmest ever for the date.  The forecast spell looks pretty similar in heat.  With quite high winds its a pretty good contender for worst ever weather for this time of year.  However biggest heatwaves in July are 3-4 degrees warmer averaged over the entire Arctic, and with high solar radiation on top of the heat I think those would qualify as worse melting weather conditions by a significant margin.  However those events were earlier in the season so presumably acting on thicker ice.

[Sterks]

If this is a compaction event, does anyone know why there is a lack of light blue concentration increases internal to the pack in recent days?  We are even seeing blocs of concentration drops (light red)?

this is not compaction, this is melt out, the term compaction is not accurate IMO to describe current events.

Cannot both? More experienced commenters than us newbies show maps with ice crashed against the shores of North America. That pack is joined closely together. This is the definition of compaction. However, it is more difficult. However, two-dimensional maps aren't able to demonstrate actual melting because meting is a three-dimensional process. Concur?

Did anyone miss the 'if'

I don't understand your point. Is that essentieal? I am answering to magnamentis and I can ignore the "if" because I am purporting a "yes"

[Neven]

Did anyone miss the 'if'

Of course we'll miss the 'if' if you are too lazy to delete all the quoted text that isn't pertinent to your comment.

[BornFromTheVoid]

Blink and you miss it/flash and un-flash melt continues with the NSIDC daily extent.

The last 3 days of change:

27th: -173k
28th: +170k
29th: -160k

While it's a short term pause overall for the daily values, the 5 day trailing average continues with steady losses, down now to just 85k and 55k off the 2008 and 2010 minima respectively.

[Sterks]

Did anyone miss the 'if'

Of course we'll miss the 'if' if you are too lazy to delete all the quoted text that isn't pertinent to your comment.

@ Neven, I will try to do so
@ Abbotisgone, I am cool, apologies didn't mean to sound like aggresive

On topic, recently, there's increasing interest towards the values of extent than simply area, among the more juvenile responders that disregarded extent in the past weeks. It is maybe the time of year when extent is switched from being less relevant to most relevant. Beat me if there was a real explanation behind, or only because it will keep falling and it is more suitable to make a goal. In reality, there are more accuracy of area now that there are no melt ponds. Extent is always as good except when more and more is closer to 15% in concentration hence the disgusting flash-unflash effects. In summary, if any there is a greater precision, if not acuracy, of area these days. However it does not feel certain goals. Lurker long-time question.