Latest PIOMAS Volume update

[Blizzard92]

My PIOMAS graphics have been updated for September 2021, including thickness-spatial fields: https://sites.uci.edu/zlabe/arctic-sea-ice-volumethickness/

[Juan C. García]

My PIOMAS graphics have been updated for September 2021, including thickness-spatial fields: https://sites.uci.edu/zlabe/arctic-sea-ice-volumethickness/

Great graphics, zlabe!
It's very good to have you here. 
I hope Wipneus will join us soon...

[gerontocrat]

Great graphics, zlabe!
It's very good to have you here. 
I hope Wipneus will join us soon...

Certainly are great graphics.

When (I hope soon) Wipneus finally succeeds in restablishing his database free from the tentacles of Google, I hope to resume a look at the regional seas.

Meanwhile, the PIOMAS data from the Polar Science Center does allow me to producethe summary data. So here goes, with a first look at the freezing season.

PIOMAS  Volume as at 30 Sep 2021  4,987 KM3

- Volume gain from minimum on this date is 343 km3, 17 km3 (5%) less than the 10 year average of 360 km3.

- Volume is at position #6 in the satellite record

- Volume is  1,020 km3 MORE than 2012
- Volume is  37 km3 LESS than 2017
- Volume is  718 km3 MORE than 2020
- Volume is  247 km3 LESS than 2010's average

Projections.

Average remaining volume gain (of the last 10 years) would produce a maximum volume in April 2022 of 22,649 km3, 1,867 km3 above the 2017 record low maximum volume of 20,782 km3.
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N.B. Click on image  for full-size

[gerontocrat]

A bit of commentary on September PIOMAS data

The September volume monthly average (graph attached) at 4.76 thousand km3 is 8th lowest in the satellite record, 600 km3 above the Sep '20 average, and 719 km3 above the long-term linear trend  for the month of Sep 21.

The 365 day trailing average volume continues to rise as the daily 365 volume average remains well above that of the year before. At September 30th the 365-day average of 13.43 thousand km3 is 863km3 above the record low on 31/08/2017 and 598km3 above the long-term linear trend.

However, it is 45% below the 31/12/79 365-day value of 25.39 thousand km3. This is less than the % loss at minimum as loss in winter is less than in summer.

click images to enlarge

[Glen Koehler]

   Thanks Gero.  This may be an off-target nitpick, but it looks to me like the bars for deviation from trend in the Sept Volume graph are showing the difference between the observed Volume and the linear trend Volume of the previous year, not the difference from the linear trend value of the same year as the observation.

[Brigantine]

Is PIOMAS also affected by the NSIDC outage? Or just the Google update?

[gerontocrat]

Is PIOMAS also affected by the NSIDC outage? Or just the Google update?

A major input into the PIOMAS model is NSIDC sea ice area.

The Polar Science Center (did) send data to Wipneus twice a month that Wipneus then processed and placed on the ASIF.

 With Google having stuffed up Wipneus's database I guess the only PIOMAS data we will get is the summary data published by the Polar Science Center once a month - i.e. no regional data,

This assumes NSIDC can get things sorted. NSIDC has produced data to 26 October today, but it still looks a bit odd to me.

[gerontocrat]

Wipneus is away hopefully restoring his databases after being shafted by Google. However, the Polar Science Center ias still producing it's monthly updates, which includes daily total volume data.

So here is an analysis of data to Dec 31 2021 in the format I use for JAXA data.

PIOMAS  Volume as at 31 Dec 2021  15,320 KM3

- Volume gain from minimum on this date is 10,674 km3, 647 km3, (6%),  more than the 10 year average of 10,027 km3.

- Volume is at position #9 in the satellite record

- Volume is  1,399 km3 MORE than 2012
- Volume is  902 km3 MORE than 2017
- Volume is  1,419 km3 MORE than 2020
- Volume is  430 km3 MORE than 2010's average

Projections.

Average remaining volume gain (of the last 10 years) would produce a maximum volume in April 2022 of 23,315 km3, 2,533 km3 above the 2017 record low maximum volume of 20,782 km3.
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N.B. Click on image  for full-size

[gerontocrat]

Some more PIOMAS Data

all of which confirms that volume is currently following the upward trend osf sea ice extent and area

[oren]

Thanks for the update Gero. I must confess it's as encouraging as I would have liked. While extent is at around 18th lowest and nearer to the 2000s average, volume is at 9th lowest and quite close to the 2010s average. This could actually mean the ice is thinner than usual, though there's quite a lot more of it.

[Brigantine]

Thinking out loud here...

Dec 31, 2021
- Extent is  336 *10^9 m² MORE than the 2010's Average
- Volume is  430 *10^9 m³ MORE than 2010's average
- Thickness(*concentration) = 1.21m average

So the situation is analogous to the [2010's] average ice being average thickness, and the anomalous ice largely in the Bering / Baltic / Barents etc. being 430/336 = 1.28m thickness(*concentration)

2010's vs 2000's averages...
- Extent -459 *10^9 m²
- Volume -3,126 *10^9 m³
- analogous to a region of 6.81m thickness(*concentration) disappearing
Average thickness(*concentration) 1.41m in the 2000's vs 1.21m in the 2010's

So:

• 2021 thickness(*concentration) is the same as 2010's average (actually 1.8mm thicker)
• one would expect the anomalous, peripheral ice to be thinner than the average, and therefore the more central areas anomalously thick (vs 2010's baseline)
• but the thickness drop from 2000's to 2010's is something much bigger than the extent drop. 17% (volume) vs 3.6%. The gaps between those 2 lines on graphs don't give you an equivalent sense of scale
• any peripheral extent recovery towards the 2000's average is not at all equivalent to a recovery of the MYI of that time

[gerontocrat]

I had a look at ice thickness from two sources.

First 2 graphs - PIOMAS volume divided by NSIDC sea ice area.
The first graph shows how close 2021 average thickness is to the 2010's average.
The 2nd graph takes a closer look at October to Year end., and shows 2021 average thickness for most of the time was somewhat below the 2010's average (until December).

- Last Graph - is from the thickness data from the Polar Science Center -which is only to Dec 31 2020 AND excludes ice less than 15 cms thick. The graph shows average thickness of ice 0.3 metres less than the calculation of PIOMAS volume divided by NSIDC sea ice area. The minimum average thickness in early November is now around 1.0 metre.

Perhaps I should ask Steven to produce area and volume numbers from the HYCOM data?

[oren]

Some people have good use for the updated regional data files:

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

As we seem to have lost ArctischePinguin irrevocably, could someone who downloaded the last version of the regional file in Aug or early Sep upload it here? Not sure the gz file can be attached but maybe as unzipped text file.

[gerontocrat]

As we seem to have lost ArctischePinguin irrevocably, could someone who downloaded the last version of the regional file in Aug or early Sep upload it here? Not sure the gz file can be attached but maybe as unzipped text file.

It is not as simple as that.

1. Wipneus used a different mask from NSIDC to produce regional data. This means the boundaries and area of several regions in the High Arctic are significantly different from the NSIDC definition.

see attached image - click to enlarge

2. Daily regional VOLUME data is only available from 1/1/2000, though monthly averages are available from 1979.

see next post

[gerontocrat]

Here are text .csv files extracted by me from Wipneus' files.

They include volume and area data according to regional boundaries used by Wipneus

[oren]

Thanks a lot. The limitations are known, but at least we'll have the regional files for posterity until a new source comes along.

[oren]

Sadly since Wipneus had the ArctischePinguin site trashed by Google, we lost access to an important data source. At least we still got the monthly posting from the Polar Science Center, quoted below.

February 2022 Monthly Update

Average Arctic sea ice volume in February 2022 was 19,700 km3. This value is the 9th lowest on record for February,  about  2,400 km^3 above the  record set in 2017.   Monthly  ice volume was 35% below the maximum in 1979 and 18% below the mean value for 1979-2021. Average February 2022 ice volume was  1.25 standard deviations above the 1979-2021 trend line.  Ice growth anomalies for February 2022 continued to be at the upper end of the most recent decade (Fig 4) with a mean ice thickness  (above 15 cm thickness) at the middle of  recent values.  The ice thickness anomaly map for February 2022 relative to 2011-2020 (Fig 6) shows positive anomalies in the Beaufort and Chukchi but negative anomalies in the Kara and Laptev Seas from. The negative anomalies that have been present  North of Greenland are weakening and a positive anomaly exists north of Baffin Island. CryoSat 2 ice thickness shows an overall similar pattern of sea ice thickness anomalies though the areas  North of Greenland and Baffin Bay show substantial differences.

 The February time series (Fig 8 ) for both data sets have no apparent trend over the past 11 years. Comparing this with the 43 year 1979-2021 time series highlights the importance of natural variability in relatively short time series such as currently available from CS2. Both records show close match in magnitude and similar temporal variability with PIOMAS volume being slightly larger than CS2 except for 2017.

Attachments (click to enlarge):
Fig 4 Comparison of Daily Sea Ice Volume Anomalies relative to 1979-2021.
Fig 6. PIOMAS Ice Thickness Anomaly for February 2022 relative to 2011-2020.
Fig 7. CryoSat-2 (AWI) multi-sensor Sea  Ice Thickness Anomaly for February of 2022 relative to 2011-2020 (version 2.4 prelim)

[gerontocrat]

And I am able to produce some stuff from the Polar Science Center data

1)  PIOMAS  Volume as at 28 Feb 2022  20,882 KM3

- Volume gain from minimum on this date is 16,239 km3, 449 km3, (3%),  more than the 10 year average of 15,791 km3.

- Volume is at position #9 in the satellite record

- Volume is  175 km3 MORE than 2012
- Volume is  2,282 km3 MORE than 2017
- Volume is  103 km3 MORE than 2020
- Volume is  179 km3 MORE than 2010's average

Projections.

Average remaining volume gain (of the last 10 years) would produce a maximum volume in April 2022 of 23,113 km3, 2,331 km3 above the 2017 record low maximum volume of 20,782 km3.
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N.B. Click on image  for full-size

[gerontocrat]

2) Miscellaneous other graphs

February monthly averages and deviations from trend. February average is just over one thousand km3 above the long-term linear trend.

365 day trailing average of the daily volume - still rising

The Polar Science Center this time has updated average daily thickness of ice greater than 15 cms thickness to February 28th.

I attach two graphs tracing the data from 1980 to the present.

[gerontocrat]

PIOMAS  Volume as at 30 Apr 2022  23,082 KM3

- Volume gain from minimum to maximum was 18,439 km3, 666 km3, (4%),  more than the 10 year average of 17,773 km3.

- Volume at 30th April is at position #10 in the satellite record

- Volume is  17 km3 LESS than 2012
- Volume is  2,402 km3 MORE than 2017
- Volume is  538 km3 MORE than 2020
- Volume is  415 km3 MORE than 2010's average

Maximum 2022.

The maximum volume was on 26 April 2022 at 23,225 km3, is 2,443 km3 above the 2017 record low maximum volume of 20,782 km3, and some 9 days later than the average date of the last 10 years. It was 9th lowest in the 44 year satellite record.
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N.B. Click on image  for full-size
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[gerontocrat]

2022 daily volume maximum.

I attach the graph and table of the 26 April 22 maximum. The graph shows that 2022 maximum is nearly 1.5 thousand km3 above the long-term linear trend.

The April Monthly Average graph also shows that the average is more than 1 thousand km3 above  the long-term linear trend, and 9th lowest in the 44 year satellite record.

The 365 day trailing average graph also shows a strong upward trend - volume being well above the previous year

[The Walrus]

Perhaps it is finally time to abandon the linear curve for the trendline.

[oren]

With the last 7 years all in the bottom 9 lowest maxima, the trend is still there for the time being.

[binntho]

Purely for fun, the graph shows annual melt (i.e. the difference between max and min) every year in the satellite record.

According to the linear trendline, on average 56 km3 are added to the melt each year. By far the least melt happened in 1996, a tad under 14,000 km3, while the joint winners are 2010 and 2012 with 19,693 and 19,692 km3 respectively. Last year came in at a fraction below long-term trend in spite of being a major dud when it came to extent.

Given the linear trend, the minimum of between 4000 and 5000 km3 that we have seen for the last 6 years would disappear in 70-90 years.

EDIT: When looking at the twin peaks of 2010 and 2012, a similar peak within the next few years would leave us with only some 2000 km3 of ice at minimum. I wonder what that would look like!

[binntho]

And the obverse of the coin - the annual refreeze, i.e. the difference between the minimum one year and the maximum the next. The first 25 years seem to be flatlining. But in 2008, things really took off with the first ever >18.000 km3 refreeze. Since then, things have remained high but it is unclear whether there is an upward trend since 2008. Perhaps what we are seeing are two different flatlines, pre and post 2008.

[The Walrus]

With the last 7 years all in the bottom 9 lowest maxima, the trend is still there for the time being.

That would be the case with any downward trend.  But with 15 out of 16 consecutive years falling below the trendline, that is cause to rethink a linear fit.  The residuals are just not there to defend such a curve!

[binntho]

With the last 7 years all in the bottom 9 lowest maxima, the trend is still there for the time being.

That would be the case with any downward trend.  But with 15 out of 16 consecutive years falling below the trendline, that is cause to rethink a linear fit.  The residuals are just not there to defend such a curve!

It seems strange to me to use the word "curve" for a linear trend. How about "line"? The third order polynomial curve seems to fit better than the linear line, with more random distribution of deviations and there is a small difference in R squared, with the third order polynomial doing better than the linear trend.

However, this is not sufficient to say anything about the actual physical reality behind the data. A truly linear trend is unlikely but probably the best approximation we have. A third order polynomial belongs to science fiction, not to the reality of the competing physical processes that are battling the ice.

The real question is of course whether the trend is slowing down. Perhaps it is, but we need to add a few more years before we can say anything definite.

[El Cid]

We've discussed these trendlines on many threads. They are obviously wrong. The question is: do we have any better and is there a reason for them being wrong?

I think there are 3 phases here: The first phase was normal ice loss as the seas heated up. Then (as more and more heat arrived and accumulated) came the loss of MYI (cc. mid2000s to 2012) which speeded up things a lot. Since then we are back to the original regime of "slow" ice loss. The data and the explanation fit each other and there will be no change in it until WINTER extent and volume drops significantly signalling the loss of permanent ice cover in some seas and yet again fundamentally changing melt processes. This has not yet happened.

[The Walrus]

Agreed.  The heating up melted the sea ice that was most vulnerable and extent dropped precipitously.  With less ice and more open water, heat is lost more readily and less heat is available to melt the ice.  Increased melt may have led to the observed increased summer cloud cover, which could be a contributing factor. 

Some, like Tamino, have argued for a three-phase linear trend, as opposite to a polynomial curve.  That would correspond better to the 3-phases of ice loss.  Whatever the depiction, it is obvious from the data that the current trend is different from the losses previously.  How long this "slow" ice loss will continue depends on the underlying reason(s) for the slowdown. 

[The Walrus]

With the last 7 years all in the bottom 9 lowest maxima, the trend is still there for the time being.

That would be the case with any downward trend.  But with 15 out of 16 consecutive years falling below the trendline, that is cause to rethink a linear fit.  The residuals are just not there to defend such a curve!

It seems strange to me to use the word "curve" for a linear trend. How about "line"? The third order polynomial curve seems to fit better than the linear line, with more random distribution of deviations and there is a small difference in R squared, with the third order polynomial doing better than the linear trend.

However, this is not sufficient to say anything about the actual physical reality behind the data. A truly linear trend is unlikely but probably the best approximation we have. A third order polynomial belongs to science fiction, not to the reality of the competing physical processes that are battling the ice.

The real question is of course whether the trend is slowing down. Perhaps it is, but we need to add a few more years before we can say anything definite.

You have been arguing for a liner trend for quite some time now.  With each new (yearly) data point, you just change the slope of the line.  Here is how the that slope has changed over the past decade, with corresponding values for 2022 and an ice-free Arctic, based on the given slope:

Year       Slope      2022     Ice-Free

2012     -0.090      3.74      2052
2013     -0.088      3.90      2055
2014     -0.086      3.83      2055
2015     -0.086      3.99      2057
2016     -0.087      3.79      2054
2017     -0.086      3.97      2057
2018     -0.084      4.00      2057
2019     -0.085      3.97      2057
2020     -0.086      3.95      2056
2021     -0.083      3.96      2058

The negative slope has been decreasing for a decade.  This follows 14 years of an increasing slope.  The point at which the curve switches from an increasing to decreasing slope is called an inflection point.

Not only has the slope changed over that time, but over the past ten years, the calculation for an ice-free Arctic year has increase by six years. 

[binntho]

You have been arguing for a liner trend for quite some time now. 

Simply because there physics of the situation does not support anything other than a trend that is as close to linear as makes no difference over the medium-to-long run. This goes back 70 years as I show in my post over on the Basic questions and discussion about melting and freezing physics thread. The third-order polynomial that is shown above and on Gero's graphs does not fit the data before 1979, so is obviously not correct.

[The Walrus]

You have been arguing for a liner trend for quite some time now. 

Simply because there physics of the situation does not support anything other than a trend that is as close to linear as makes no difference over the medium-to-long run. This goes back 70 years as I show in my post over on the Basic questions and discussion about melting and freezing physics thread. The third-order polynomial that is shown above and on Gero's graphs does not fit the data before 1979, so is obviously not correct.

Neither does a linear fit the data pre-1979.  So it is obviously not correct either.  In reality, nature does not adhere to mathematical curve fitting very well.  Your best explaining on the other thread concerns the weather, with which I agree completely.  Weather dictates both winter ice growth and summer ice loss.  Hence, the colder weather in mid-century led to increased sea ice.  No mathematical equation can fit the sea ice data for the past century.  A linear trendline fit the data well for about 20 years, during the period of greatest decline, but falls apart both before and afterwards.  This can be seen in the attached graph and also in the graph you presented on the other thread from the History of sea ice in the Arctic.

https://journals.ametsoc.org/view/journals/clim/32/15/jcli-d-19-0008.1.xml

The underlying physics related to weather explains the annual growth and decline of the sea ice quite well.  The long-term global warming trend explained the decline quite well, when the summer sea ice extended throughout the Arctic basin.  The basics physics extends largely to melting from solar insolation and warm waters beneath,  As the ice retreats, other factors come into play.  The ice is grounded on the North America side.  This is a larger fraction of the ice now, that it was thirty years ago.  Additionally, open water leads to greater evaporation and increased cloudiness.  This has been documented in the following study, which states, "this study found that cloud coverage in ice-free regions in the Arctic linearly increased with the area of ice-free water during the melt seasons."  The effects of increased cloud cover cannot be ignored, and the study further concludes, "the high cloud coverage over the melted water dominates the albedo change in the albedo feedback process. On average, the extra cloud cover stimulated by sea ice loss is of second-order contribution."

<Note this study has data only until 2015, and looks at cloudiness only between August and October, hardly peak insolation period, so its conclusions are not very relevant to the discussion. O>

https://www.nature.com/articles/s41598-019-44155-w

These factors help explain the continued decline in winter sea ice extent and the stabilizing of the sea ice in summer.  The winter sea ice decline cannot continue indefinitely either, as dictated by physics.  The lack of sunlight and cold temperatures will cause the water to freeze.  I suspect we will eventually see a slow down in this loss also. 

The ice will continue to decline as long as temperature continues to increase.  That is basic physics.  Whether the summer decline follows a linear trends towards ice-free conditions thirty years from now or continues slowing down and forestalls such a condition until next century is uncertain.  Only time will tell.

[Steven]

Since Wipneus hasn't posted anything on the forum in the past 8 months and it's unclear if and when he will be back, I looked at the gridded PIOMAS data:

http://psc.apl.uw.edu/research/projects/arctic-sea-ice-volume-anomaly/data/model_grid

and using the documentation there, I wrote a script to calculate the total sea ice volume from the gridded data.  My calculations match exactly with the official PIOMAS volume values.

Next, I made an approximation of Wipneus' regional mask and used it to calculate regional volume. 

Attached are csv-files with my calculated regional volume numbers, monthly and daily, from January 1979 up to April 2022. 

Note the regional volume numbers differ slightly from Wipneus' numbers, due to some minor differences in the definitions of the region boundaries, but the differences are small (almost always less than 10 km3).

[Steven]

Here is a plot of the April monthly average regional PIOMAS volume values for the last 10 years.  The data for 2022 are shown with red bars, while the other colors show the other years (2012 to 2021).  The different regions are shown on the vertical axis.

[oren]

Steven, you deserve a medal for this. THANKS x 10. We have been flying blind for way too long.
If you have time available to update this on a regular basis during the melting season, we will finally be able to actually know what's going on, generate charts etc.

[Steven]

If you have time available to update this on a regular basis during the melting season

I'll keep the files updated until Wipneus returns (if and when he does).  Here are the links:

https://www.dropbox.com/s/2d9a8b9az8gsj91/piomas_regional_volume_monthly.csv

https://www.dropbox.com/s/1k95c8eg1n2b6gw/piomas_regional_volume_daily.csv

The gridded data on the PIOMAS website used to be updated around the 4th or 5th day of the month, and with a mid-monthly update around the 18th or 19th day of the month.  If that is still the case, the csv-files will be updated on those dates.

[oren]

Amazing. Thanks again, Steven. Much appreciated.

[uniquorn]

Cab volume, 2016-22
Thanks Steven

added the difference between Steven and Wipneus data from 2020-21 for ref.

[uniquorn]

A comparison of CAB volume (left scale) and total volume (right hand scale) with 365day moving averages
maybe the thread title needs an update

[oren]

Interesting how a failure to grow total volume enough in winter 2007 led to a significant new total low that summer, and in 2009 a failure to grow winter CAB volume led to a significant new CAB low. In both cases the effect lasted a long time, probably due to a demise of MYI which caused downstream effects on further years.
It would appear a precursor to (at least some) bad melting seasons is a bad freezing season.
Luckily 2017's winter did not lead to a new summer low, as Neven said back then "the Arctic dodged a cannonball".

[P-maker]

Could it be that before 2007/2012, it was the MYI in the CAB, which helped to 'dodge the bullets'?

Since then, it has been the peripheral winter ice, which helped to avert the disaster. Just a thought.

[The Walrus]

Could it be that before 2007/2012, it was the MYI in the CAB, which helped to 'dodge the bullets'?

Since then, it has been the peripheral winter ice, which helped to avert the disaster. Just a thought.

It is entirely possible.  If enough ice grows in the winter, a new summer low may will be averted.  How long will this last?

[Tor Bejnar]

My first visual take-away is that the annual-average CAB used to hold a larger portion of total ice volume, but my calculation shows it is a tiny increase with time (from 12.8/25.2s to 7.5/14ths OR 0.51 to 0.54). I presume the left (black) scale is for the blue line and the right (red) scale is for the red line.

[Steven]

No update yet of the gridded PIOMAS data.  I don't know if they're still doing mid-month updates.

Meanwhile, here's a plot of the PIOMAS thickness anomaly for 30 April 2022 relative to the average of the last 10 years (30 April 2012 to 2021).  Green color shows ice that is thicker than in previous years, blue shows thinner ice.

[gerontocrat]

Quote from Steven..

No update yet of the gridded PIOMAS data.  I don't know if they're still doing mid-month updates.

The Polar Science Center used to send mid-month PIOMAS data to Wipneus as a special favour. I think he was in regular contact with a Dr. Zhang?

Thickness
Wipneus also used to post a link to NSIDC daily regional data every day analysed using his mask that he also used to analyse PIOMAS data. From that thickness data & graphs for every sea could be generated. Using NSIDC data files works for Total Arctic, the High Arctic and Periphery totals, every region in the periphery, and in the High Arctic is OK for the Canadian Archipelago and (more or less OK) for the Kara. But the differences between the Wipneus and NSIDC area definitions for the CAB, the Laptev, the ESS, the Chukchi and the Beaufort are too great. (see last image)

I haven't got to doing the thickness stuff yet.

I attach volume graphs for the High Arctic, the peripheral regions and the CAB. This year volume loss so far in the periphery is well below average.
 

[oren]

The Polar Science Center used to send mid-month PIOMAS data to Wipneus as a special favour. I think he was in regular contact with a Dr. Zhang?

Correction, the PSC uploads a mid-month update of several files on a general basis, following an email nobody me sent to Dr. Zhang back in 2017 (the "dodging a cannonball" year) requesting to increase the frequency. I was quite surprised that he agreed immediately and was very nice.
I will write him again if the mid-month doesn't show up. I think it should have by now.

[gerontocrat]

The Polar Science Center used to send mid-month PIOMAS data to Wipneus as a special favour. I think he was in regular contact with a Dr. Zhang?

Correction, the PSC uploads a mid-month update of several files on a general basis, following an email nobody me sent to Dr. Zhang back in 2017 (the "dodging a cannonball" year) requesting to increase the frequency. I was quite surprised that he agreed immediately and was very nice.
I will write him again if the mid-month doesn't show up. I think it should have by now.

So it was U wot dunnit, Oren.

[Steven]

The Polar Science Center used to send mid-month PIOMAS data to Wipneus as a special favour. I think he was in regular contact with a Dr. Zhang?

Correction, the PSC uploads a mid-month update of several files on a general basis, following an email nobody me sent to Dr. Zhang back in 2017 (the "dodging a cannonball" year) requesting to increase the frequency. I was quite surprised that he agreed immediately and was very nice.
I will write him again if the mid-month doesn't show up. I think it should have by now.

For reference, the daily gridded thickness data on the piomas website are here:

https://pscfiles.apl.washington.edu/zhang/PIOMAS/data/v2.1/hiday/?C=M;O=D

Currently the 2022 file in that folder has "Last modified 2022-05-03 00:32".

[Steven]

The PIOMAS gridded data have been updated up to the end of May.  The daily sea ice volume on 31 May 2022 is 20.233 k km3.

I have updated the regional csv files:

Monthly:
https://www.dropbox.com/s/2d9a8b9az8gsj91/piomas_regional_volume_monthly.csv

Daily:
https://www.dropbox.com/s/1k95c8eg1n2b6gw/piomas_regional_volume_daily.csv

[Steven]

Some images:

PIOMAS sea ice thickness on 31 May 2022:


PIOMAS thickness on 30 April 2022:
https://i.imgur.com/oOnC1VS.png

PIOMAS thickness anomaly on 31 May 2022 (relative to the 2012-2021 average):