Latest PIOMAS Volume update

[Wipneus]

PIOMAS has updated the gridded thickness data to the 15th of this month. Volume calculated from this was 8.77 [1000km³]. That is the lowest for the day, with quite a margin.

Here is the animation.

Neven, web-master: I can't seem to modify the top post anymore to change the subject of this thread to the latest update.

[Wipneus]

Updated volume and volume-anomaly graphs.

[Wipneus]

Daily Fram volume export graph. Little export as expected in July.

[Wipneus]

Some people have use for the updated regional data files:


daily:
https://sites.google.com/site/arctischepinguin/home/piomas/data/PIOMAS-regional.txt.gz

[Rich]

PIOMAS has updated the gridded thickness data to the 15th of this month. Volume calculated from this was 8.77 [1000km³]. That is the lowest for the day, with quite a margin.

If anyone cares to shares the comparable figure from 2012, it would be much appreciated. The chart showing the volume anomalies gives the appearance that the gap vs. 2012 widened during the first half of July.

[gerontocrat]

Some people have use for the updated regional data files:

Indeed, some of us do.
A feast that needs consuming slowly.

[Stephan]

Daily Fram volume export graph. Little export as expected in July.

Would you mind to plot the average line a little bit thicker to make it better visible? Thanks!

[gerontocrat]

PIOMAS Volume as at 15th July 2019  8,768  km3

The standard graphs and tables as I use for the JAXA extent data are attached.

In June 2019 volume did not take not so much a tumble as crashed and burned..
In the first 15 days of July volume loss was mostly above average, but less so than in June.

2019 volume continues lowest in the satellite record
- less than 2017 by 279 km3,
- less than 2012 by 430 km3,
- less than 2016 by 1,510 km3,
- less than 2018 by 1,425 km3,

It is data that seems to back up numerous observations in the melting thread regarding the condition of the ice  - e.g.s  highly mobile, fractured, disintegrating, rubble, dispersed.

At average volume loss for the rest of the season, minimum volume would be a bit above 3,300 km3, more than 300 km3 below the current record minimum of 2012, and more than 16500 km3 below the 2010's average minimum of nearly  5,000 km3.
_______________________________________________________________

[subgeometer]

Thankyou Wipneus

Grim news, tho not unexpected.

Thinning in the Linciln Sea is pronounced, if it continures at the rate under the current high... we could see something unprecedented there

[gerontocrat]

A look at some individual seas as I get round to it.

The ice in the Chukchi, being attacked by early Bering melt and high SSTs, does look as if it might be a candidate for another sea going past a tipping point if current trends are maintained.

[uniquorn]

Percentage loss from of maximum according to piomas data, for CAB, 2011-2019.
thanks Phil.

[Phil.]

Percentage loss from maximum according to piomas data, for CAB, 2011-2019.

Isn't that the percentage remaining since the maximum?

[oren]

A few more regional charts.
With the CAB becoming the most important in the late season, a chart of all years since 2000, with 2019 showing a disturbing trend. And another chart of the volume for certain days of the year. Anyone who thinks the CAB has stabilized in recent years, check out the black line for day 196 (mid-July, the most recent data point) that set a new record low for the date.
The Barents volume, where 2019 trails 2012 by a huge margin, shows by proxy the state of the Atlantic side. A lot depends on the developments on that front in the next two months.
And the total for Kara, Laptev, ESS, Chukchi, Beaufort, CAB, CAA and Greenland Sea, the only regions expected to participate in the Sept. minimum. Eyeballing the chart shows there are only two options, new record or 2nd lowest, with the 2012 "Great Leap Forward" (days 217-220, the GAC) making things complicated.

[UCMiami]

Oren - great post. What I find interesting with the specific seas CAB and Barents is the significant cause for the volume variances is different:
In the CAB it would appear the 2019 number is driven by ice thickness since if anything area (and extent) in the CAB in 2019 trail vs. other years and not just 2012.

On the Atlantic side and specifically in the Barents the 2019 number lags primarily because the area (and extent) are much higher than in previous years and not just vs. 2012. The slow Atlantic side area is driving the number not the ice thickness.

[jdallen]

A few more regional charts.
With the CAB becoming the most important in the late season, a chart of all years since 2000, with 2019 showing a disturbing trend.
<snippage>

Judging from some of the earlier charts Wip posted, looking back I think we will find that the seminal transitional year for the ice really was 2007 rather than 2012.  If we broke it down by region, I think it would show that is the year that many seas which previously maintained ice year over year consistently took such a serious hit that they have not been able to recover either the thickness nor quality of ice they needed to be stable year over year.  2012 was just a "blip" on what was the new system regime 2007 put us into, and have been following since.

2019 may represent the point at which we transition down the next step in the cascade, or it may be "just another"  2012.

That said, I think both are/will be less causes than effects, and the real story is how they reflect the on-going changes in heat content, atmospheric heat exchange, and water column in the Arctic ocean.

[gerrit]

Wipneus, gerontocrat, oren: great stats and graphs, thanks!
To me the stand-out stat is the rate at which ice is melting out this year (and by eye-balling it, looks like a consistent upwards trend).
CAB has lost about 3.8 (1000 km3) in the last 61 days, vs. 3.5 in 2012, 2.5 in 2007, 1.7 in 2001!
As ice volume change is, in my mind, the best proxy for heat flux, it would mean that summer heat import into the high arctic has almost doubled in the last 20 years?! But I'll leave the analysis to the clever people 

[AmbiValent]

Gerrit,
I think the increasing fragmentation of Arctic sea ice, even in the CAB, is playing a major role as well, as it increases the surface open to melting.

[Shared Humanity]

Wipneus, gerontocrat, oren: great stats and graphs, thanks!
To me the stand-out stat is the rate at which ice is melting out this year (and by eye-balling it, looks like a consistent upwards trend).
CAB has lost about 3.8 (1000 km3) in the last 61 days, vs. 3.5 in 2012, 2.5 in 2007, 1.7 in 2001!
As ice volume change is, in my mind, the best proxy for heat flux, it would mean that summer heat import into the high arctic has almost doubled in the last 20 years?! But I'll leave the analysis to the clever people 

The CAB is no longer large rafts of thick MYI but consists more of smaller floes of MYI stitched together with thin FYI. The rapid melt of this FYI results in larger drops in volume as compared to years past. What is truly interesting to me is how this fragmented, mobile CAB ice responds to the melt season.

[uniquorn]

Wipneus, a gentle reminder about fram export data

[be cause]

Hi Uniquorn .. reply 2952 has the fram update .. it has been quite quiet . b.c.

[charles_oil]

Oren - Barents sea volume graph seems to end at day 180 - is there a further data point ??


PS - Thanks for the great graphs !

[oren]

Oren - Barents sea volume graph seems to end at day 180 - is there a further data point ??


PS - Thanks for the great graphs !

Oh dear 
I have now edited the original post with the extended chart, and lopped off some heads in the Quality Assurance department.

[oren]

Wipneus, a question popped up and i realized I did not know the definitive answer. For the regional PIOMAS volume data, do you use the NSIDC map as I had always assumed, or the CT map that you use for the AMSR2 data?

[UCMiami]

Wipneus, a question popped up and i realized I did not know the definitive answer. For the regional PIOMAS volume data, do you use the NSIDC map as I had always assumed, or the CT map that you use for the AMSR2 data?

Thanks - just came here to ask the same question!

[Steven]

Wipneus, a question popped up and i realized I did not know the definitive answer. For the regional PIOMAS volume data, do you use the NSIDC map as I had always assumed, or the CT map that you use for the AMSR2 data?

He's using the CT regions (which were also used by Chris Reynolds before) for the regional PIOMAS data.  See e.g.

https://forum.arctic-sea-ice.net/index.php/topic,119.msg117013.html#msg117013
https://forum.arctic-sea-ice.net/index.php/topic,119.msg117598.html#msg117598

[Neven]

Neven, web-master: I can't seem to modify the top post anymore to change the subject of this thread to the latest update.

Wip, I'm back again. What would you like to have it changed to?

[gerontocrat]

Wipneus, a question popped up and i realized I did not know the definitive answer. For the regional PIOMAS volume data, do you use the NSIDC map as I had always assumed, or the CT map that you use for the AMSR2 data?

He's using the CT regions (which were also used by Chris Reynolds before) for the regional PIOMAS data.  See e.g.

https://forum.arctic-sea-ice.net/index.php/topic,119.msg117013.html#msg117013
https://forum.arctic-sea-ice.net/index.php/topic,119.msg117598.html#msg117598

If Wipneus is using modified CT Arctic Sea boundaries and not NSIDC definitions for regional PIOMAS volume data, I'm going to have ask Neven for a dispensation to let me go back to change a lot of postings because many are WRONG often where it really matters. (and a lot of stuff is headed for the bin).

Ho hum.

[oren]

Neven, web-master: I can't seem to modify the top post anymore to change the subject of this thread to the latest update.

Wip, I'm back again. What would you like to have it changed to?

Wipneus edits the top post, changing the title every time there is a PIOMAS update. Now with the new 48h limit this is no longer possible. The law of unforeseen consequences.

[Neven]

Wipneus edits the top post, changing the title every time there is a PIOMAS update. Now with the new 48h limit this is no longer possible. The law of unforeseen consequences.

Ah yes, that's right. But I believe this is the only topic where that happens. I'll change it and then see if I can change permissions for Wipneus.

[Glen Koehler]

Some people have use for the updated regional data files:
daily:
https://sites.google.com/site/arctischepinguin/home/piomas/data/PIOMAS-regional.txt.gz

Dear Wipneus
Truly and thanks.  I can get the daily PIOMAS volumes by adding up the regional values from the file you post at https://sites.google.com/site/arctischepinguin/home/piomas/data

Can you also share the mid-month update for daily Thickness values?  The latest Thickness I can find on the PIOMAS site are from June 30. 

Or if not, what was the PIOMAS thickness on July 15, 2019?

Thanks much.  I have a detailed summary of 2019 vs. previous years I'd like to post that uses the latest available PIOMAS values.  I have NSIDC Extent and Area (thanks to you) up through July 26, and Volume up to July 15, but Thickness stops at June 30.

(Sorry if I am missing something blatantly obvious, wouldn't be the first time.)

[oren]

Here are some average thickness charts. Starting with CAB thickness (two charts, the difference is just in the scale). The calculation is based on regional PIOMAS volume for the CAB, divided by the University of Hamburg AMSR2 regional area based on 3.125km grid. Both data sets provided by Wipneus, and both are based on the "CT" regional demarcation map. Note 2012 AMSR2 data was only available for a short period.

The full year chart shows how thickness drops sharply at the beginning of the freezing season, when lots of newly-frozen thin ice is added.

I produced similar charts for some of the adjacent seas. The problem is PIOMAS data is quite smooth while UH area data is somewhat noisy. When getting down to low area numbers, below 200k or even 300k, the thickness begins swinging wildly.
In addition as far as I am aware PIOMAS is calibrated with NSIDC area numbers, which often diverge from UH numbers, adding to the noise level.
ESS and Chukchi charts are attached for impression.

I feel the most informative chart is the CAB thickness for the melting season, and will attempt to update it regularly. Just a reminder that the PIOMAS model is based on a distribution of thicknesses in each grid cell, where a significant chunk of the total volume is in very thick ice. Therefore care should be used when looking at the average thickness.

[Renerpho]

Is there an August PIOMAS update already? The chart below includes volume data as of August 2nd. That may not be PIOMAS data?
http://polarportal.dk/fileadmin/polarportal/sea/CICE_curve_thick_LA_EN_20190802.png

[gerontocrat]

Is there an August PIOMAS update already? The chart below includes volume data as of August 2nd. That may not be PIOMAS data?

It is DMI - Danish Met Institute. The clue is the logo. They have their own model.
Some posters will be horrified that an image from THAT! model has appeared on the PIOMAS thread.

[DrTskoul]

The horror....

[gerontocrat]

Here are some average thickness charts. .

I produced similar charts for some of the adjacent seas. The problem is PIOMAS data is quite smooth while UH area data is somewhat noisy. When getting down to low area numbers, below 200k or even 300k, the thickness begins swinging wildly.

Glad you found the same problem as I got with wildly varying daily thickness as smaller seas reach low volume and low area.. Started to think my arithmetic had done wonky. I put in an if statement to make the thickness result blank when area dropped below a certain amount. Better empty spaces on the graph than obvious junk?

A please please to make the colours for 2012 and 2019 much more of a contrast , e.g. a nice blue for one of the years? It's me old eyes are not so good at colour differentiation as they were.

[oren]

A please please to make the colours for 2012 and 2019 much more of a contrast , e.g. a nice blue for one of the years? It's me old eyes are not so good at colour differentiation as they were.

The current year is always black and usually thicker in my charts. I've made 2012 thicker as well but I will change the automatic brown to something more contrasting vs. black.

Edit: I just realized 2017 is also blackish. I will fix the colors in the next edition.

[Klondike Kat]

If I read those plot correctly, 2019 has been tracking alongside 15 and 16 for most of the season.  We shall see what happens in August as they diverged.

[Wipneus]

PIOMAS gridded thickness data was updated. I calculate volume from the thickness data, gives 6.46 [1000km³] on 2019-07-31. Lowest for the day with a small margin with 2012 (6.68 [1000km³]).

Here is the animation.

[Wipneus]

Updated volume and volume-anomaly graphs.

[Wipneus]

Fram volume export is low as expected for July.

[Wipneus]

Some people have use for the updated regional data files:

monthly:
https://sites.google.com/site/arctischepinguin/home/piomas/data/PIOMAS-regional-monthly.txt.gz
daily:
https://sites.google.com/site/arctischepinguin/home/piomas/data/PIOMAS-regional.txt.gz

[sja45uk]

PIOMAS gridded thickness data was updated. I calculate volume from the thickness data, gives 6.46 [1000km³] on 2019-07-31. Lowest for the day with a small margin with 2012 (6.68 [1000km³]).

Here is the animation.

Thanks Wipneus, great animation and clearest picture for a newbie of what is happening in the Arctic!

[Wipneus]

2019-0-31 thickness map, a comparison with previous years and their differences (need clicks for the true size).

[gerontocrat]

PIOMAS Volume as at 31 July 2019  6.463  km3

The standard graphs and tables as I use for the JAXA extent data are attached.

In June 2019 volume did not take not so much a tumble as crashed and burned..
In the first 15 days of July volume loss was mostly above average, but less so than in June.
In the second half of July volume was below average on most days.

2019 volume continues lowest in the satellite record, but by less.
- less than 2017 by 250 km3,
- less than 2012 by 213 km3,
- less than 2016 by 1,138 km3,
- less than 2018 by 1,118 km3.

It is data that seems designed to make sure that observers such as me get no further clue as to the final minimum for the year..

At average volume loss for the rest of the season, minimum volume would be a bit above 3,700 km3, a bit more than the current record minimum of 2012. This is quite a change from the June and mid-July projections
_______________________________________________________________

[oren]

2019-0-31 thickness map, a comparison with previous years and their differences (need clicks for the true size).

Thanks a lot for these updates Wipneus. The comparison map against 2012 shows the main differences:
A..2019 leading in the ESS
B. 2012 leading in the Beaufort
C. 2012 leading in the western CAA
D. 2019 has extra volume around FJL and Svalbard
E. 2019 has much lower volume around the CAA CAB crack and north of Greenland.
F. 2019 is generally slightly thicker in the CAB.

Of these, A (ESS) is known to have disappeared in 2012. E (crack) did not appear in 2012, so 2019 has an inherent advantage in the CAB.
I expect B (Beaufort) to disappear despite the seeming strength of the ice exported there.
I also expect D (FJL) to disappear, there is still a month to go and that ice will have a very hard time surviving.
I expect C to hold up until the end of the season.
So bottom line, 2019 is neck and neck with 2012, with the crack balancing the general CAB, and the CAA potentially serving as a tie-breaker for 2012. Caveat:All is weather dependent of course.

[gerontocrat]

As at 31 July over 95% of the remaining ice volume (and nearly 95% of remaining sea ice area) is in the 7 seas of the High Arctic.

High Arctic Volume & average thickness graphs attached. Thickness reduction stalled in the last few days of July.

[meddoc]

If PIOMAS is calculated by what we see on Wip's first Animation-
then the Reality must be much worse:
no sign of the Break- up above CAA & Greenland, no Rubble in the ESS either.

That sloppy Resolution is just a Joke.

[grixm]

If PIOMAS is calculated by what we see on Wip's first Animation-
then the Reality must be much worse:
no sign of the Break- up above CAA & Greenland, no Rubble in the ESS either.

That sloppy Resolution is just a Joke.

The animation is showing thickness only. The area data which is combined with thickness to produce volume, is separate.

[oren]

If PIOMAS is calculated by what we see on Wip's first Animation-
then the Reality must be much worse:
no sign of the Break- up above CAA & Greenland, no Rubble in the ESS either.

That sloppy Resolution is just a Joke.

The difference with 2012 shows both of these phenomena clearly. PIOMAS is low resolution but it usually captures these things.

[Killian]

D. 2019 has extra volume around FJL and Svalbard

If this is so, it will mean there is very little Fram export, and at least two of the three lowest years so far have had high Fram export. While people repeatedly, mistakenly, talk about "resilient" or high levels of ice along Svalbard, et al., or the lack thereof, it's actually ice continually being pushed to that line of islands and melting away. There is no "resileince" at all, there's either ice being pushed through that archipelago to die or not.

So bottom line, 2019 is neck and neck with 2012, with the crack balancing the general CAB, and the CAA potentially serving as a tie-breaker for 2012. Caveat:All is weather dependent of course.

I think the key is always general melt (primarily bottom, as we know) plus export. Other things matter, but these are #1 and #2, so export is the real tie-breaker. Little ice along that archipelago strongly indicates no new record, imo.