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Author Topic: Latest PIOMAS update (September, mid-monthly update)  (Read 1255545 times)

Wipneus

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Re: Latest PIOMAS update (February 2020, mid-monthly update)
« Reply #3200 on: February 19, 2020, 02:25:56 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

Sorry to say Wipneus but the .txt file is dated 4/2/2020 with data to 31 Jan.

My apologies! It should be corrected now.

Wipneus

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Re: Latest PIOMAS update (February 2020, mid-monthly update)
« Reply #3201 on: February 19, 2020, 02:32:05 PM »

Wipneus - thanks for all the efforts - how about a double thickness line for the current year - or a dashed version?

Good suggestion, I will go for the thicker current year (like in some area/extent graphs).


Quote
Equally maybe the ones say before 2010 could be finer / dotted lines so that even if they are  roughly same colour its easy to spot that they in a different category?

Yes, like all suggestions to use different line styles (like dotted or dashed) it takes some experimenting and may not be usable in all my graphs. Eventually as the number of years in the graphs grow it will be necessary at some time.

gerontocrat

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Re: Latest PIOMAS update (February 2020, mid-monthly update)
« Reply #3202 on: February 19, 2020, 05:24:55 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
Sorry to say Wipneus but the .txt file is dated 4/2/2020 with data to 31 Jan.
My apologies! It should be corrected now.
Thanks
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gerontocrat

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Re: Latest PIOMAS update (mid Feb 2020)
« Reply #3203 on: February 19, 2020, 07:20:01 PM »
This person always does "have use for the updated regional data files" from Wipneus:

PIOMAS Volume as at 15 February 2020  19,669 km3

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

Volume gain in 1st week of Feb well above average, 2nd week well below.

2019 volume stays at 5th lowest in the satellite record,
- 2,289 km3 above 2017,
-  1,022 km3 above 2018,
-      18 km3 above the 2010's average,
and less than 2019 by a reduced 255 km3.

Not really a surprise that volume gain in Feb to date was so mixed, given the similar story for both area and extent.
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Re: Latest PIOMAS update (February 2020, mid-monthly update)
« Reply #3204 on: February 19, 2020, 07:39:25 PM »
PIOMAS Volume & Thickness as at 15 February 2020

I attach graphs of volume & thickness for
- total arctic seas,
- the High Arctic Seas -i.e. the 7 seas of the main Arctic Ocean (excludes Barents & Greenland)

You can see average thickness will continue to climb even when volume has maxed - area declining on the fringes that have mainly thin ice.
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Wipneus

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Re: Latest PIOMAS update (March 2020)
« Reply #3205 on: March 04, 2020, 06:29:58 PM »
PIOMAS has updated. Last date was actually day 60 of 2020. Now that would be entirely consistent with 29th of February, except that the PIOMAS year has only 365 days every year. So it could be tagged as 1st March in PIOMAS time scale. For now, I stick to 29th of February. That may change silently later this year.

Anyway here is the animation.

Wipneus

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Re: Latest PIOMAS update (March 2020)
« Reply #3206 on: March 04, 2020, 06:41:40 PM »
Volume and volume-anomaly graphs. Click for larger and clearer images.

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Re: Latest PIOMAS update (March 2020)
« Reply #3207 on: March 04, 2020, 06:58:37 PM »
Fram volume export was above average this month.

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Re: Latest PIOMAS update (March 2020)
« Reply #3208 on: March 04, 2020, 07:06:43 PM »
Thickness map, compared with previous years and their diffs.
That is on the 29th of Feb, admittingly looks a bit silly for the other years.

Images to click for size.

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gerontocrat

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Re: Latest PIOMAS update (mid Feb 2020)
« Reply #3210 on: March 08, 2020, 01:45:31 PM »
PIOMAS Volume as at 28 February 2020   20.787  km3

Note:
PIOMAS has a 365 day year that in Leap Year finishes on 30 December.
I have a 365 day year that turns 29th Feb into 1 March
Makes a small difference.
Ho hum.


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

Daily Volume gain in Feb more above average than below.

2019 volume at 6th lowest in the satellite record,
- 2,187 km3 above 2017,
-  1,153 km3 above 2018,
-      84 km3 above the 2010's average,
and less than 2019 to a much reduced 98 km3.
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Wipneus

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Re: Latest PIOMAS update (March 2020, mid-monthly update)
« Reply #3211 on: March 19, 2020, 04:03:29 PM »
PIOMAS has updated gridded thickness data to day 75, which would normally be the 15th of March. Because a PIOMAS has no leap years, it ends in some graphs at the 16th.
Any way volume calculated from this thickness was 22.10 [km3], 8th lowest for day 75.
Here is the animation of March sofar.

Wipneus

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Re: Latest PIOMAS update (March 2020, mid-monthly update)
« Reply #3212 on: March 19, 2020, 04:04:57 PM »
Updated volume and volume-anomaly graphs.

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Re: Latest PIOMAS update (March 2020, mid-monthly update)
« Reply #3213 on: March 19, 2020, 04:06:04 PM »
Updated Fram volume graph.

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Re: Latest PIOMAS update (March 2020, mid-monthly update)
« Reply #3214 on: March 19, 2020, 04:08:20 PM »
Some people have 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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gerontocrat

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Re: Latest PIOMAS update (March 2020, mid-monthly update)
« Reply #3215 on: March 19, 2020, 05:57:02 PM »
Updated Fram volume graph.
.....showing its effect on Greenland Sea Area.

Fram export is the dominant influence in any one year ... But the 10 year averages show that in the long-term the only direction of travel of sea ice area is...DOWN.
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Re: Latest PIOMAS update (mid Feb 2020)
« Reply #3216 on: March 20, 2020, 12:46:35 PM »
PIOMAS Volume as at 15 March 2020   22,099  km3

Note:
PIOMAS has a 365 day year that in Leap Year finishes on 30 December.
I have a 365 day year that turns 29th Feb into 1 March
Makes a small difference - you may see a gremlin or two with dates on the graphs.
Ho hum.


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

Daily Volume gain in March to date equally below as above average.

2019 volume at 15 March 7th lowest in the satellite record,
- 2,415 km3 above 2017,
-  1,059 km3 above 2018,
-     293 km3 above the 2010's average,
and more than 2019 by 90 km3.

The daily change and plume graphs shows how volume gain in 2019 was so exceptionally low in recent days and from now to maximum.
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Re: Latest PIOMAS update (April 2020)
« Reply #3217 on: April 04, 2020, 04:14:03 PM »
PIOMAS gridded thickness data was updated. Last day was day 91, about 31st of March, the volume calculated from this thickness was 22.73 [km3. Compared with other years on day 91 (most often the first of April) 2020 is the 7th lowest.

Here is the March animation. Ice is thickening impressively against the Canadian Archipelago and North Greenland.

Wipneus

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Re: Latest PIOMAS update (April 2020)
« Reply #3218 on: April 04, 2020, 04:45:12 PM »
The updated volume and volume-anomaly graphs.

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Re: Latest PIOMAS update (April 2020)
« Reply #3219 on: April 04, 2020, 04:47:44 PM »
Updated Fram volume export graph.

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Re: Latest PIOMAS update (April 2020)
« Reply #3220 on: April 04, 2020, 05:01:18 PM »
Thickness map, compared with previous years and their differences on day 91 (here labeled 31st of March).

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Re: Latest PIOMAS update (April 2020)
« Reply #3222 on: April 04, 2020, 05:18:06 PM »
Thanks so much, Wipneus!

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Re: Latest PIOMAS update (April 2020)
« Reply #3223 on: April 04, 2020, 06:16:03 PM »
2020 extra volume is in the Barents Kara Fram and the adjacent CAB sector, not a very secure location. Continued strong export and early Atlantic-side heat could cause this advantage to be lost in the late spring. Another extra volume region is the Beaufort, hopefully this will serve as a good defense against an early meltout there.

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Re: Latest PIOMAS update (mid Feb 2020)
« Reply #3224 on: April 06, 2020, 01:49:26 PM »
PIOMAS Volume as at 31 March 2020   22,693  km3

Note:
PIOMAS has a 365 day year that in Leap Year finishes on 30 December.
I have a 365 day year that turns 29th Feb into 1 March, and finishes on 31 December.
I will be one day out of sync with te PIOMAS data to the end of the year.
Ho hum.


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

Daily Volume gain in March to date equally below as above average.

2019 volume at 31 March was 6 th lowest in the satellite record,
- 2,309 km3 above 2017,
-    781 km3 above 2018,
-    148 km3 above the 2010's average,
and more than 2019 by 473 km3.

The daily change and plume graphs shows how volume gain in 2019 was so exceptionally low in recent days and from now to maximum.
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gerontocrat

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Re: Latest PIOMAS update (April 2020)
« Reply #3225 on: April 06, 2020, 02:13:46 PM »
I am starting to separate the 7 High Arctic Seas from the 7 Peripheral Seas. At the moment just a little fishing expedition.

Here is a first little look at volume. Note that the monthly averages data goes back to 1979, which is a help for later comparisons with NSIDC Area & extent data.
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Wipneus

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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3226 on: April 21, 2020, 06:42:16 PM »
PIOMAS has updated the gridded thickness data up-to day 106 (15 or 16 April, see previous announcements for the explanation). On that day volume was 22.94 [1000 km3], 6th lowest for the day.

Here is the animation for the first half of April.

Wipneus

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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3227 on: April 21, 2020, 07:40:30 PM »
The updated volume and volume-anomaly graphs (which get bigger when clicked upon).

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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3228 on: April 21, 2020, 07:48:37 PM »
The updated Fram volume export graph, shows average export levels not abnormal for April.

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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3229 on: April 21, 2020, 07:53:15 PM »
And of course I updated the regional volume data, for those that have a good use for it.

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

gerontocrat

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Re: Latest PIOMAS update (mid Feb 2020)
« Reply #3230 on: April 22, 2020, 10:44:15 PM »
PIOMAS Volume as at 16 April 2020**    22,943   km3


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

Daily Volume gain in April equally below as above average. Possibly the maximum was reached on the 15th April at 22,960 km3.

2019 volume at 16th April remained at 6th lowest in the satellite record,
- 2,169 km3 above 2017,
-    563 km3 above 2018,
-     58 km3 above the 2010's average,
and more than 2019 by 465 km3.

As 2020 volume is somewhat above that of 2019, the 365 da average continues to inch upwards.

The next update for month end April should give a first look at the melting season.
______________________________________________
**Note:
PIOMAS has a 365 day year that in Leap Year finishes on 30 December.
I have a 365 day year that turns 29th Feb into 1 March, and finishes on 31 December.
I will be one day out of sync with the PIOMAS data to the end of the year.
Ho hum.
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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3231 on: April 23, 2020, 04:50:23 AM »
As the Arctic reaches its peak annual volume, here is a look at what the regional volume charts can tell us. As usual, big thanks to Wipneus for providing the data.

Although 2020 is currently at a nondescript volume total, bunched with many other low years and far above the disastrous 2017, this is hiding interesting situations in the various regions, as hinted by Wipneus' monthly maps of difference from previous years.
The bad news: Chukchi, ESS and Laptev in the Inner Basin are all running at near-record low volumes. This could potentially lead to early open water, increasing the High Arctic albedo-warming potential and making the CAB more vulnerable. In addition, the peripheral Baffin Bay is at record low for the date, which could potentially impact the CAA later in the season.

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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3232 on: April 23, 2020, 05:09:12 AM »
The good news: The CAB is running high and has been growing far above average for the period, making an impressive relative gain of 840 km3 vs. 2019 and a gain of 980 km3 vs. 2012. This could potentially make the CAB much more resistant to melting this year and decrease the probability of catastrophe. The big caveat of this is that the extra volume in the CAB appears to be mostly in the Atlantic sector adjacent to Svalbard and FJL, a vulnerable location where survival is highly dependent on ice movement patterns.
In addition, all Atlantic sector seas are exhibiting high volumes - the inner Kara at a "normal" high, while the export-oriented Barents and Greenland Sea are running at record highs. This is actually quite disturbing, as the extra volume could easily disappear and should robust export continue this could pave the way to a weakening of the CAB.
This data suggests that ice movements and export in this sector should be under close scrutiny in the early part of the melting season.

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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3233 on: April 23, 2020, 05:36:34 AM »
The good news: The CAB is running high and has been growing far above average for the period, making an impressive relative gain of 840 km3 vs. 2019 and a gain of 980 km3 vs. 2012. This could potentially make the CAB much more resistant to melting this year and decrease the probability of catastrophe. The big caveat of this is that the extra volume in the CAB appears to be mostly in the Atlantic sector adjacent to Svalbard and FJL, a vulnerable location where survival is highly dependent on ice movement patterns.
In addition, all Atlantic sector seas are exhibiting high volumes - the inner Kara at a "normal" high, while the export-oriented Barents and Greenland Sea are running at record highs. This is actually quite disturbing, as the extra volume could easily disappear and should robust export continue this could pave the way to a weakening of the CAB.
This data suggests that ice movements and export in this sector should be under close scrutiny in the early part of the melting season.

It is interesting to note the previous volume high for the Atlantic sector (2009) coincided with a significant disruption to the Gulf Stream later on that melt season. Was it due to the El Nino, or did the abnormally high sea ice in these sectors also play a crucial role? We may find out later on in 2020.

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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3234 on: April 23, 2020, 06:26:43 AM »
Only miracle should happen to protect the Siberian seas from the early melt out. In 2017 there were June snowfalls but this year I rather expect the early meltponding to accelerate disaster

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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3235 on: April 23, 2020, 09:34:52 AM »
Only miracle should happen to protect the Siberian seas from the early melt out. In 2017 there were June snowfalls but this year I rather expect the early meltponding to accelerate disaster
Agree - the state of the ESS, Laptev and Chukchi are very concerning and early melt with them could have a serious cascading effect on the adjacent seas.
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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3236 on: April 24, 2020, 10:50:24 AM »
Herewith a look at Arctic Sea Ice area, volume & thickness.

Firstly the High Arctic, i.e. the 7 central seas.

Sea ice AREA in the high arctic stayed at or around maximum until the 17th April at above the 2010's average.

Sea Ice VOLUME in the high arctic is still increasing. On average the maximum is in early May.
As a result, sea ice thickness in the high arctic is gradually increasing. On average the maximum is in mid-May.
Both volume and thickness are below the 2010's average.

This is in contrast with events in the peripheral seas (see next post)
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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3237 on: April 24, 2020, 11:10:44 AM »
Herewith a look at Arctic Sea Ice area, volume & thickness (continued).

Secondly the the 7 Peripheral Arctic seas.

Sea ice AREA in these peripheral seas arctic peaked in early March at well above the 2010's average. Since then strong area losses have brought area down to well below the 2010's average.

Sea Ice VOLUME in the peripheral seas reached maximum in Mid March at well above the 2010's average. Since then pnly modest volume loss has happened. Volume remains well above the 2010's average.

As a result of these strong sea ice area losses and only marginal volume loss, average sea ice thickness in these peripheral arctic seas has increased dramatically to 2nd highest in the satellite record since 2000. Note that something similar happened in 2019.

This is in contrast with events in the High Arctic seas (see previous post)
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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3238 on: April 24, 2020, 12:44:58 PM »
Wipneus,

Further to our previous conversations re NRT CS2 thickness, do you by any chance possess "regional masks" for the standard OSI-SAF EASE grid?
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3239 on: April 29, 2020, 07:37:22 PM »
Wipneus,

Further to our previous conversations re NRT CS2 thickness, do you by any chance possess "regional masks" for the standard OSI-SAF EASE grid?

I am afraid not, neither do I see an real easy solution to get one.

The PIOMAS regional masks where developed by Chris Reynolds from the Cryosphere Today originals. That would have to be repeated but now with an EASE grid.

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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3240 on: April 29, 2020, 07:57:31 PM »
Wipneus,

Further to our previous conversations re NRT CS2 thickness, do you by any chance possess "regional masks" for the standard OSI-SAF EASE grid?

Do you mean the NSIDC regions?

-> ftp://ftp.awi.de/sea_ice/auxiliary/mask/regions_nsidc/region_mask_nsidc_adapted_v1p0.nc

But these are EASE2 though.

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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3241 on: April 29, 2020, 09:49:41 PM »
Do you mean the NSIDC regions?

-> ftp://ftp.awi.de/sea_ice/auxiliary/mask/regions_nsidc/region_mask_nsidc_adapted_v1p0.nc

But these are EASE2 though.

Thanks Stefan (and Wipneus),

I'll take a look at those when I have a spare 5 minutes in amongst all the UK #CoronavirusShambles
« Last Edit: April 29, 2020, 10:10:11 PM by Jim Hunt »
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gerontocrat

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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3242 on: April 29, 2020, 11:02:26 PM »
Do you mean the NSIDC regions?

-> ftp://ftp.awi.de/sea_ice/auxiliary/mask/regions_nsidc/region_mask_nsidc_adapted_v1p0.nc

But these are EASE2 though.

Thanks Stefan (and Wipneus),

I'll take a look at those when I have a spare 5 minutes in amongst all the UK #CoronavirusShambles
Far too technical for me but....

Or do you mean this mask?

Arctic_region_mask_Meier_AnnGlaciol2007.msk
The Arctic Sea Ice Index regions are defined using the mask file,
Arctic_region_mask_Meier_AnnGlaciol2007.msk, created by Meier et al. (2007). Figure 1 provides a
visual representation of the regions defined by the mask file.
The mask file is a 1 byte, unsigned integer headerless binary file with 304 columns x 448 rows. The
values in the mask are the following:
0 - Lake (which are not considered part of the sea ice-covered region even if they are ice-covered)
1 - Ocean (outside of the defined regions)
2 - Okhotsk
3 - Bering
4 - Hudson
5 - St Lawrence
6 - Baffin
7 - Greenland
8 - Barents
9 - Kara
10 - Laptev
11 - East Siberian
12 - Chukchi
13 - Beaufort
14 - Canadian Archipelago
15 - Central Arctic
20 - Land
21 - Coast
The file can be read using Python with NumPy with the following lines of code:
import numpy as np
regional_mask = np.fromfile(‘./Arctic_region_mask_Meier_AnnGlaciol2007‐
1.msk’,dtype=np.uint8).reshape((448, 304))
Note that this mask file does not contain latitude and longitudes of the regioins, however, the mask file
is based on NSIDC Polar Stereographic projection. Therefor, the lat/lon polygons could be constructed
by using the psn25lats_v3.dat and psn25lons_v3.dat geolocation files available from the Polar
Stereographic Data: Geocoordinate and Pixel-Area Tools page.
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Re: Latest PIOMAS update (April 2020, mid-monthly update)
« Reply #3243 on: April 29, 2020, 11:34:29 PM »
Thanks Gerontocrat,

However after a very brief look it seems as if the AWI file Stefan linked to is probably the one I want. Both the CS2/SMOS thickness data and mask are 25 km EASE 2, but the former is  432x432 whereas the latter is 448x304.

Further investigations will have to wait until tomorrow (UTC)
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Re: Latest PIOMAS update (May 2020)
« Reply #3244 on: May 05, 2020, 10:03:30 AM »
PIOMAS has updated once again. Last date corresponds to day 121 of this year, which in the PIOMAS data is the first of May (ignoring the leap year). Volume (calculated from thickness) was 22.52 [1000km3], the sixth lowest for day 121.
The maximum seems to have been reached on day 105 (15th April) with a volume of 22.96 [1000km3].

Here is the monthly animation.

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Re: Latest PIOMAS update (May 2020)
« Reply #3245 on: May 05, 2020, 10:05:33 AM »
The volume and volume-anomaly graphs. Needs clicks for size and clarity.

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Re: Latest PIOMAS update (May 2020)
« Reply #3246 on: May 05, 2020, 10:08:02 AM »
The Fram volume export got into trouble the second half of the month.

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Re: Latest PIOMAS update (May 2020)
« Reply #3247 on: May 05, 2020, 10:58:00 AM »
Thickness map, compared with previous years and their diff's. All need a click for better view.

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Re: Latest PIOMAS update (mid Feb 2020)
« Reply #3249 on: May 06, 2020, 12:48:39 PM »
Herewith some use being made of Wipneus' files. (Not for me to say if good use or bad use)

PIOMAS Volume as at 1 May 2020**   22,522 km3

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

Volume gain in the first half of April, in the 2nd half of April volume loss. with the maximum reached on the 15th April at 22,960 km3.

2019 volume at 1 May remained at 6th lowest in the satellite record,
- 1,843 km3 above 2017,
-    243 km3 above 2018,
-    103 km3 below the 2010's average,
and more than 2019 by 255 km3.

The attached first graph shows April volume was somewhat above trend.
______________________________________________
**Note:
PIOMAS has a 365 day year that in Leap Year finishes on 30 December.
I have a 365 day year that turns 29th Feb into 1 March, and finishes on 31 December.
I will be one day out of sync with the PIOMAS data to the end of the year.
Ho hum.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)