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Author Topic: Latest PIOMAS update (Oktober, mid-monthly update)  (Read 1271669 times)

Wipneus

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Re: Latest PIOMAS update (September, mid-monthly update)
« Reply #3450 on: September 18, 2020, 06:34:57 PM »
PIOMAS has updated the gridded thickness data up to day 259 (15/16th September). Calculated volume on day 259 was 4.06 [1000 km3], which is second lowest for the day. It is also the preliminary minimum for 2020 but that may change of course.

Here is the animation for September so far.

Wipneus

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Re: Latest PIOMAS update (September, mid-monthly update)
« Reply #3451 on: September 18, 2020, 06:37:34 PM »
Updated volume and volume-anomaly graphs.

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Re: Latest PIOMAS update (September, mid-monthly update)
« Reply #3452 on: September 18, 2020, 06:45:22 PM »
The update Fram volume export graph.

Wipneus

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Re: Latest PIOMAS update (September, mid-monthly update)
« Reply #3453 on: September 18, 2020, 06:46:23 PM »
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

gerontocrat

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Re: Latest PIOMAS update (September, mid-monthly update)
« Reply #3454 on: September 18, 2020, 10:35:12 PM »
Thanks Wipneus..

PIOMAS @ 16 September analysed in my standard format

Volume loss did finish on 11th September, but,, started again on the 14th September to a new minimum volume for the year of 4.059 thousand km3, just 9 km3 above the 2019 minimum, and more or less at trend.

The scale of the volume losses in the last 3 days must be linked to the extent and area losses in the Central Arctic Sea. Would the PIOMAS model assume that to be loss of thick ice?

So it does not look as if volume loss has finished. So no definitive outcome until the month end data appears.

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oren

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Re: Latest PIOMAS update (September, mid-monthly update)
« Reply #3455 on: September 19, 2020, 09:42:14 AM »
This year's mid-Sep update brings with it a measure of confusion - is the minimum in or not. One can see a clear correlation between volume and single-day NSIDC area. It really does not help that NSIDC area for the 16th came in as identical to the data from the 15th - 2,583,432 km2. Has this been updated? Does anyone know what really happened on the 16th?

Assuming the 15th as the day of the minimum, here are some regional charts as well as analysis of expectations vs. outcome.

Time for the prediction of volume for the September minimum. Please zoom the regional charts above to follow the analysis.
Of the seas traditionally participating in the minimum, the Laptev is nearly zero now. The ESS is record low. The Kara is very low. The Barents is on the low side. Chukchi is rather low as well. All are assumed to be zero in September - for some of these seas that is a very common achievement, for some a rather rare one.

We remain with the four unknowns:
* Greenland Sea - has been running high since spring. I expect it to crash at some point due to melting and lack of imports, especially now that most of the thick ice at the export region has disappeared. My bet is somewhere above 2019 but far below 2012. 125 km3.
* CAA - had a very slow start, but a fast decline. Temps have been running very high for a month. I expect a result above 2012/2011 but probably below 2019. 100 km3.
* Beaufort - the most anomalous. Has been running high and getting higher, due to extra imports and lower exports. I can't see it heading towards near-zero, and foresee a high volume, probably somewhere below 2013's 200 km3, but above 2018's 80 km3. 125 km3.
* CAB - naturally the most variable in magnitude. has been running high in winter and spring, only to crash in the last month back into the fold. From where we are now it is quite common to reach 4000-4200 km3. Following the high losses of 2007, 2012, 2016, we might get to 3600 km3, still above 2012's minimum of 3400 km3. And who knows? We might break loss records, and perhaps even reach a CAB record in September.

Summing everything, we get 350 km3 outside the CAB. With a reasonable/aggressive scenario of 3600 km3 in the CAB, we get a total of 3950 km3, a respectable 2nd, lower than 2019's 4050 km3, but still much higher than 2012's 3670 km3.
However, my money is still on a record low volume. I am betting the impact of the GAAC was partially missed by the model, and will be incorporated later when ice area crashes. In addition, early open water on the Siberian side might eat deeper into the CAB than usual. If a CAB record can be achieved, total volume will probably also reach a record low.
Examining my mid-July prediction, things appear to be roughly on track, but "my money" is going down the drain.

* Greenland Sea - I now expect a 100 km3 finish, compared to prediction of 125 km3.
* CAA - I now expect a 150 km3 finish, compared to prediction of 100 km3.
* Beaufort - I now expect a 140 km3 finish, compared to prediction of 125 km3.
* CAB - I now expect a 3550-3600 km3 finish, compared to main scenario prediction of 3600 km3.
* Total - I now expect a 3950-4000 km3 finish, compared to main scenario prediction of 3950 km3.

My hunch that PIOMAS will somehow catch up to the GAAC effects proved false (for now, for now).

The minimum should be with us in the next PIOMAS update - stay tuned. With the non-stop winds over the basin, predicted major storm, and lots of uncertainty about timing of the refreeze, it's not going to be boring.
Examining my end-Aug updated expectations, things have not been going just as predicted. The following assumes day of minimum is 259.
* Greenland Sea - a 120 km3 finish, compared to late prediction of 100 km3 and early prediction of 125 km3. Regional minimum was 105 km3 on day 242.
* CAA - a 186 km3 finish, compared to late prediction of 150 km3 and early prediction of 100 km3. Regional minimum was 162 km3 on day 252.
* Beaufort - a 135 km3 finish, compared to late prediction of 140 km3 and early prediction of 125 km3. Min on last day.
* CAB - a 3585 km3 finish, compared to late prediction of 3550-3600 km3 and early prediction of 3600 km3 (reasonable/aggressive scenario). Min on last day.
* Total - a 4059 km3 finish, compared to late prediction of 3950-4000 km3. Min on last day.

Interestingly, compared to July predictions it was almost spot on, except a big miss in the CAA which is what prevented a clear 2nd place and a <4000 km3 result. However compared to my stubborn though irrational expectation of a new record, very poor performance. In my defense, I believe volume north of Greenland is highly exaggerated by the model. Oh well.

If the min was indeed day 259, finish is 3rd place, a meager 7 km3 behind 2019's 4052 km3 (on day 257). For this we will have to wait until the next update.

gerontocrat

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Re: Latest PIOMAS update (September, mid-monthly update)
« Reply #3456 on: September 19, 2020, 10:17:22 AM »
This year's mid-Sep update brings with it a measure of confusion - is the minimum in or not. One can see a clear correlation between volume and single-day NSIDC area. It really does not help that NSIDC area for the 16th came in as identical to the data from the 15th - 2,583,432 km2. Has this been updated? Does anyone know what really happened on the 16th?
Nope- but on the 17th the one day area was 2,656,684 km2 (https://cryospherecomputing.tk/).
NSIDC data for today might put the seal on the 15th as the day on which NSIDC daily area reached minimum.

The same date for the minimum of JAXA extent, NSIDC extent and Area & PIOMAS volume would be a minor miracle.
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gerontocrat

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Re: Latest PIOMAS update (September, mid-monthly update)
« Reply #3457 on: September 19, 2020, 03:35:08 PM »
As the melting season is over, here are some NSIDC Area, & PIOMAS Volume & Thickness graphs

High Arctic
The PIOMAS volume data does not show volume losses to the extent of the NSIDC area data.
Arithmetic therefore ensures that ice thickness appears much closer to the 2010's average than area.
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gerontocrat

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Re: Latest PIOMAS update (September, mid-monthly update)
« Reply #3458 on: September 19, 2020, 03:46:54 PM »
As the melting season is over, here are some NSIDC Area, & PIOMAS Volume & Thickness graphs

The Peripheral Seas
PIOMAS Volume is well above the 2010's average for most of the melting season.
NSIDC Area is well below the 2010's average for most of the melting season.
As a result thickness looks high.

As area reduces to well under 250k km2, and volume under 250km3, small variations in the volume and /or area data cause wild swings in the thickness measurement. I think these should be discounted, more likely representing limitations in the NSIDC sensors and / or the PIOMAS model rather than real changes in thickness.
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Aluminium

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Re: Latest PIOMAS update (September 2020)
« Reply #3459 on: September 20, 2020, 12:16:15 PM »
Changes from August 31.

Chukchi ... -100%
Beaufort ... -32%
CAB ... -6%
CAA ... +14%
Greenland ... +12%
Baffin ... +43%

gandul

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Re: Latest PIOMAS update (September, mid-monthly update)
« Reply #3460 on: September 20, 2020, 01:15:05 PM »
As the melting season is over, here are some NSIDC Area, & PIOMAS Volume & Thickness graphs

High Arctic
The PIOMAS volume data does not show volume losses to the extent of the NSIDC area data.
Arithmetic therefore ensures that ice thickness appears much closer to the 2010's average than area.
This is a really good result and there may be reasons behind this arithmetic result. Despite the large 2020 melt, the western CAB ends with a significant mass of older and compacted, thicker ice. Maps do not show 2- 3- and 4+ year ice has < 0.5 m as the imagination of some posters depict. On the contrary, this is > 1.5m thick, older ice mostly.
Thank you for separating the Arctic proper from the outer seas in these plots, Gero. It makes all sense.

Edit. We’ll have to wait 1 month to CRYOSAT2+SMOS to validate these thicknesses.
« Last Edit: September 20, 2020, 01:35:51 PM by gandul »

oren

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Re: Latest PIOMAS update (September, mid-monthly update)
« Reply #3461 on: September 20, 2020, 01:19:23 PM »
Wipneus, if you manage to get a GICE file from PIOMAS, it would be interesting to see the end-season distribution chart.

Wipneus

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Re: Latest PIOMAS update (Oktober)
« Reply #3462 on: October 05, 2020, 11:24:01 AM »
PIOMAS has upgraded the gridded thickness data upto day 274 (30th Sep/1st Okt as you like). Calculated volume on that day wa 4.3 [1000lm3], which is the second lowest value for day 274.

Minimum volume was reached on day 261: 4.03 [1000lm3], second lowest.

Here is the September animation.
« Last Edit: October 05, 2020, 11:42:02 AM by Wipneus »

Wipneus

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Re: Latest PIOMAS update (Oktober)
« Reply #3463 on: October 05, 2020, 11:43:04 AM »
The updated volume and volume anomaly graphs.

Wipneus

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Re: Latest PIOMAS update (Oktober)
« Reply #3464 on: October 05, 2020, 11:46:44 AM »
The updated fram volume export shows "normal" September export.

Wipneus

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Wipneus

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Re: Latest PIOMAS update (Oktober)
« Reply #3466 on: October 05, 2020, 12:15:46 PM »
Thickness map, compared with previous years and their differences around the annual minimum.

Wipneus

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Re: Latest PIOMAS update (Oktober)
« Reply #3467 on: October 05, 2020, 12:49:56 PM »
Normally I would present the graphs based on the annual minimum now, including extrapolations of the exponential declining sea ice mass.

But as discussed in last years presentation:
https://forum.arctic-sea-ice.net/index.php/topic,119.msg232081.html#msg232081

there seems little point in doing so. With a new year added, all but the most basic linear fit have shifted the time of "zero" ice one year in the future.

The exception is the linear fit and extrapolation over the full PIOMAS dataset (1979+). Here the extrapolated year of zero ice is 2032, same as "predicted" last year and not different from previous years.

I will attach this years graph with the same one made in 2015. Extrapolated zero is 2032, with a slightly "improved" confidence interval (upper limit no later than 2039).

 

gerontocrat

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Re: Latest PIOMAS update (Oktober)
« Reply #3468 on: October 05, 2020, 01:47:30 PM »
In September, the daily reduction in volume up to minimum was mostly well above average, and after the minimum was mostly below the average daily gain.

The minimum was marginally below 2019 at minmum (just by 21 km3), but by the end of the month was a substantial 309 km3 below 2019.

The September monthly average was pretty much on the linear trend.
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BornFromTheVoid

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Re: Latest PIOMAS update (Oktober)
« Reply #3469 on: October 05, 2020, 01:49:55 PM »
Two images. Big thanks to Wipneus for the data provided.

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

Général de GuerreLasse

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Re: Latest PIOMAS update (Oktober)
« Reply #3470 on: October 05, 2020, 02:04:21 PM »
Normally I would present the graphs based on the annual minimum now, including extrapolations of the exponential declining sea ice mass.

But as discussed in last years presentation:
https://forum.arctic-sea-ice.net/index.php/topic,119.msg232081.html#msg232081

there seems little point in doing so. With a new year added, all but the most basic linear fit have shifted the time of "zero" ice one year in the future.

The exception is the linear fit and extrapolation over the full PIOMAS dataset (1979+). Here the extrapolated year of zero ice is 2032, same as "predicted" last year and not different from previous years.

I will attach this years graph with the same one made in 2015. Extrapolated zero is 2032, with a slightly "improved" confidence interval (upper limit no later than 2039).

 

Hi Wipneus, thanks for these interesting numbers and graphs, but what does the "residuals" insert mean?
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oren

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Re: Latest PIOMAS update (Oktober)
« Reply #3471 on: October 05, 2020, 03:01:44 PM »
what does the "residuals" insert mean?
This would be the difference of each data point from the calculated trend.

gerontocrat

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Re: Latest PIOMAS update (Oktober)
« Reply #3472 on: October 05, 2020, 04:34:13 PM »
Volume, Area & Thickness

The High Arctic


It is possible that both NSIDC area and PIOMAS violume will be at a record daily low after a few days.
Daily area and volume gain both below average, and thickness stable in the last few days. If normality prevails, area gain will eventually accelerate faster than volume gain and average thickness as a result decline at last until the end of October.
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gerontocrat

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Re: Latest PIOMAS update (Oktober)
« Reply #3473 on: October 05, 2020, 04:43:54 PM »
Volume, Area & Thickness

The Peripheral Arctic Seas


Volume is currently above the 2010's average, area back to the 2010's average. At this time of year most of the area and volume is in the Greenland Sea, subject to the vagaries of Fram export. As a result, plus the effect of low area and volume values, thickness is very variable.


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gerontocrat

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Re: Latest PIOMAS update (Oktober)
« Reply #3474 on: October 05, 2020, 06:39:35 PM »
The Central Arctic Basin (4.4 million km2) not so many years ago looked like the permanent inviolate fortress of the Arctic Sea Ice.

Here is a graph of the monthly average volume going back to 1979. Alas poor fortress, your walls are crumblimg.
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Archimid

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Re: Latest PIOMAS update (Oktober)
« Reply #3475 on: October 05, 2020, 07:04:14 PM »
Maximum vs Loss linear trends, animated.

I did the same for the CAB.
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oren

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Re: Latest PIOMAS update (September, mid-monthly update)
« Reply #3476 on: October 06, 2020, 05:56:47 AM »
This year's mid-Sep update brings with it a measure of confusion - is the minimum in or not. One can see a clear correlation between volume and single-day NSIDC area. It really does not help that NSIDC area for the 16th came in as identical to the data from the 15th - 2,583,432 km2. Has this been updated? Does anyone know what really happened on the 16th?

Examining my end-Aug updated expectations, things have not been going just as predicted. The following assumes day of minimum is 259.
* Greenland Sea - a 120 km3 finish, compared to late prediction of 100 km3 and early prediction of 125 km3. Regional minimum was 105 km3 on day 242.
* CAA - a 186 km3 finish, compared to late prediction of 150 km3 and early prediction of 100 km3. Regional minimum was 162 km3 on day 252.
* Beaufort - a 135 km3 finish, compared to late prediction of 140 km3 and early prediction of 125 km3. Min on last day.
* CAB - a 3585 km3 finish, compared to late prediction of 3550-3600 km3 and early prediction of 3600 km3 (reasonable/aggressive scenario). Min on last day.
* Total - a 4059 km3 finish, compared to late prediction of 3950-4000 km3. Min on last day.

Interestingly, compared to July predictions it was almost spot on, except a big miss in the CAA which is what prevented a clear 2nd place and a <4000 km3 result. However compared to my stubborn though irrational expectation of a new record, very poor performance. In my defense, I believe volume north of Greenland is highly exaggerated by the model. Oh well.

If the min was indeed day 259, finish is 3rd place, a meager 7 km3 behind 2019's 4052 km3 (on day 257). For this we will have to wait until the next update.
Turns out the minimum was on day 261 despite the beginning of area growth. The CAB dipped for a few days and carried the minimum below 2019, though remaining above the 4000 km3 threshold.
Summing the components of the minimum one final time, we have:
* Baffin Bay - a high 35 km3 finish. Regional minimum was 18 km3 as late as day 238.
* Greenland Sea - a 125 km3 finish. Regional minimum was 105 km3 on day 242.
* CAA - a 188 km3 finish. Regional minimum was 162 km3 on day 252.
* Beaufort - a 133 km3 finish. Regional late minimum was 108 km3 on day 269.
* CAB - a 3548 km3 finish, aligning regional minimum on day 261 with the total minimum.
* Total - a 4029 km3 finish.

The CAB charted an interesting course in September, see next post.

oren

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Re: Latest PIOMAS update (Oktober)
« Reply #3477 on: October 06, 2020, 06:04:44 AM »
Looking at the CAB, it appears to have "pulled off an 2018" in September, despite having much lower volume to begin with. 2020 is only 33 km3 away from 2012's CAB volume on the last day, and seems to be headed for the no. 1 spot very soon.
In general, 2020 broke all kinds of records in the CAB (smacking poor Phoenix's pet theories in the process), as shown in the little table - highest late summer and total summer volume losses, passing even the dreaded 2012 by 600 km3 of extra loss. If not for the very high winter growth, the results could have been even more impressive, following the low base inherited from 2019.

Glen Koehler

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Re: Latest PIOMAS update (Oktober)
« Reply #3478 on: October 06, 2020, 07:50:45 AM »
    I really like the day 266 to 266 Min to Min accounting vs. calendar year.  It shows how the impact of winter 2006-2007 created a fundamental reset in the ASI that persists to this day.  It also gives deserved "credit" to the 2015-2016 winter, when the 2M temperature anomaly maps on Climate Reanalyzer were blood red for weeks on end.  And it shows why 2020 felt like such a wild ride of a melt season (-7.4 vs. -6.8 for 2012). 
« Last Edit: October 06, 2020, 07:58:19 AM by Glen Koehler »

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Re: Latest PIOMAS update (Oktober)
« Reply #3479 on: October 06, 2020, 08:37:59 AM »
Does anybody now, if and when the next CryoSat-2/SMOS volume numbers will be released?

I still think, the PIOMAS model is far away from this year’s actual volume. The most evident indication is the route of the Polarstern to the north pole, which was no way through ice with an average thickness of 2 meters, but also other areas do not really fit to what was viable through world view.

Edit: I think, I found the answer. Last year, those maps did start for the time span from 15th to 21st of October, so in around two weeks they should be available.  :)

Edit2: FTP-Links seem not to be supported. So you have to add ftp:// in front of the following urls:
ftp.awi.de/sea_ice/product/cryosat2_smos/v202/nh/2019/10/ for last year’s maps.
ftp.awi.de/sea_ice/product/cryosat2_smos/v202/nh/LATEST/ for the most recent maps.
« Last Edit: October 06, 2020, 08:57:22 AM by Sepp »

gandul

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Re: Latest PIOMAS update (Oktober)
« Reply #3480 on: October 06, 2020, 10:59:47 AM »
Maximum vs Loss linear trends, animated.

I did the same for the CAB.

Nice idea!
If you plot both the “inner” and “outer” solutions should asymptotically approach same year (2032??) although it seems CAB solution is “chasing a carrot” since 2012.

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Re: Latest PIOMAS update (Oktober)
« Reply #3481 on: October 06, 2020, 11:36:17 AM »
Does anybody now, if and when the next CryoSat-2/SMOS volume numbers will be released?

I still think, the PIOMAS model is far away from this year’s actual volume. The most evident indication is the route of the Polarstern to the north pole, which was no way through ice with an average thickness of 2 meters, but also other areas do not really fit to what was viable through world view.

Edit: I think, I found the answer. Last year, those maps did start for the time span from 15th to 21st of October, so in around two weeks they should be available.  :)
I agree sepp, the region north of Greenland is probably very wrong in PIOMAS, and it will be quite interesting to see what CryoSat-2/SMOS has to say.

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Re: Latest PIOMAS update (Oktober)
« Reply #3482 on: October 17, 2020, 06:57:40 PM »
Looks like that data is now starting, one was posted a few days ago.

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Re: Latest PIOMAS update (Oktober)
« Reply #3483 on: October 18, 2020, 06:15:48 PM »
Extrapolated zero is 2032


I'm not sure about the usefulness of employing a trend to predict the first ice-free year only a few years out. I suspect the first blue ocean will be an outlier, e.g. 2024 dropping below the trend line by 2012's amount.

Wipneus

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Re: Latest PIOMAS update (Oktober, mid-monthly update)
« Reply #3484 on: October 18, 2020, 06:59:10 PM »
PIOMAS has updated the gridded thickness data upto day 289 (15th or 16th of Oktober). Volume calculated from thickness on that day was 4.91 [1000 km3]. That is the second lowest value for day 289. The difference with the lowest (2012) is very small though.

Here is the animation for Oktober 2020 sofar.

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Re: Latest PIOMAS update (Oktober, mid-monthly update)
« Reply #3485 on: October 18, 2020, 07:02:21 PM »
Here are the volume and volume-anomaly graphs.

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Re: Latest PIOMAS update (Oktober, mid-monthly update)
« Reply #3486 on: October 18, 2020, 07:11:44 PM »
The Fram volume export graph. Looks are a bit different this time  after upgrading the plotting software (matplotlib), probably needs a bit of tweaking.

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Re: Latest PIOMAS update (Oktober, mid-monthly update)
« Reply #3487 on: October 18, 2020, 07:14:14 PM »
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

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Re: Latest PIOMAS update (Oktober, mid-monthly update)
« Reply #3488 on: October 18, 2020, 09:32:48 PM »
Once again, October is the month when records might be broken, as the freeze is delayed.
Volume gain since minimum is 369 (29%) km3 less than the 10 year average.

October 16th volume is 2nd lowest, 319 km3 below 2019, and just 45 km3 above 2012.

The (very early) projected maximum for April 2021 is 21.64 '000 km3, which would be 2nd lowest. But it is far too early to have any confidence in any projection.
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Re: Latest PIOMAS update (Oktober, mid-monthly update)
« Reply #3489 on: October 18, 2020, 10:19:57 PM »
PIOMAS Mid- October - a bit more

I attach the plume of projections to the 2021 maxmimum from the previous 10 years volume gains.
Given the 6 month period, the range is fairly tight and evenly spread.

I also attach the October monthly averages graph, the 2020 average using averge extent gains for the 2nd half of October. No surprise, pretty much on trend.
"Para a Causa do Povo a Luta Continua!"
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Re: Latest PIOMAS update (Oktober, mid-monthly update)
« Reply #3490 on: October 19, 2020, 03:40:16 AM »
Thanks again Wipneus for providing the data.

The total volume is nearly at record low, thanks to:
* Very poor growth in the CAB, which shifted to lowest on record and is leading by nearly 200 km3.
* A wobble in the Beaufort, which lost a lot of its seasonal advantage by letting the remaining "Tail" go on melting for too long. A sub-100 km3 minimum was reached on day 279 before sharp growth began.
* A rather average showing in the CAA and the Greenland Sea.

However the main story is shifting to the Siberian side, where volume has been record low for an astounding 189-day period, ever since day 111. So far this autumn it's been bearable as a few other years remained quite low as well, but the 2nd half of October is a period of sharp growth in Siberian volume. Every day this growth is delayed for 2020 will make the situation worse.

2020 was a latecomer in producing low volume numbers, thanks to the cold winter. However despite getting into the game only on day 171, the year has managed to garner a respectable number of 4th, 3rd and 2nd daily awards, though it's still far from the performance of leader 2017 as well as several other years. I have no doubt the next reporting period will finally bring a number of the coveted daily record low awards.

Click to enlarge charts.
« Last Edit: October 19, 2020, 03:50:50 AM by oren »

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Re: Latest PIOMAS update (Oktober)
« Reply #3491 on: October 20, 2020, 09:17:54 AM »
Looks like that data is now starting, one was posted a few days ago.

Thanks. I suspect, this is still work in progress, since, they only released one image, while they usually release one per day.

They also have an folder v203 now, so they probably adjusting something there.

By the way: Is there already some pixel-count tool available to get the actual volume according to CryoSat-SMOS? Or is this already provided by the AWI somewhere else?

Edith says: My apologies for the unnessary question, I just found it here. Will test it soon. (:

Edith also says: The script only works on .nc-files, which were not provided so far for this October. Interestingly, the only png was removed from the server just within the last minutes. So I suppose I have to wait a bit more for the new numbers.
« Last Edit: October 20, 2020, 09:39:13 AM by Sepp »

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Re: Latest PIOMAS update (Oktober, mid-monthly update)
« Reply #3492 on: October 20, 2020, 09:40:10 AM »
This should best be discussed in the Cryosat SMOS thread, or in PIOMAS vs. Cryosat thread.

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Re: Latest PIOMAS update (Oktober, mid-monthly update)
« Reply #3493 on: October 21, 2020, 09:21:46 AM »
The siberian sea graph is shocking to see; When, if ever, will it go up to more normal numbers?

Don't know what else to say about it, just shocking

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Re: Latest PIOMAS update (Oktober, mid-monthly update)
« Reply #3494 on: October 21, 2020, 11:27:56 AM »
The siberian sea graph is shocking to see; When, if ever, will it go up to more normal numbers?

Don't know what else to say about it, just shocking

It had 6-8 days of extra sunshine going into the water. That energy has to come back out before it freezes. Once the water is back to to freezing, the ice will form at the same sort of rates, but it'll be a few days later than in the past because there's more heat to lose before getting to freezing this year. Energy tends to come out of open water faster in the autumn than it goes in during late summer, so the "U" shape will probably be a bit closer to the pack on the way up than it was on the way down.


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Re: Latest PIOMAS update (Oktober, mid-monthly update)
« Reply #3495 on: October 21, 2020, 01:23:38 PM »
Once the water is back to to freezing, the ice will form at the same sort of rates, but it'll be a few days later than in the past...

I'd say it will be a faster refreeze as the surrounding air and the continents will be much colder by then than during previous refreezes. Late but fast refreeze. We shall see