Author Topic: Latest PIOMAS Volume update (Read 2007043 times)

oren · « **Reply #3150 on:** November 20, 2019, 05:36:29 PM »

Here are some more regional graphs. Big thanks again to Wipneus for his relentless supply of this precious data.

Some notes:
Nothing in this set of charts puts me at ease, even though 2019 left the record low area and extent spots far behind (for now). Numerically, all of the extra volume compared to 2016 (500 km³) and 2012 (300 km³) is to be found in the Atlantic sector - the sum of Kara, Barents and the Greenland Sea, volume that does not contribute very much to the Arctic's resilience during the melting season, although it's good to have of course. I suspect the higher volume in the CAB is also adjacent to this sector, where the extra area is. The CAB's average thickness is 2nd low, almost record low, as the CAB's area is also higher than 2016 for the date. (2012's Oct-Dec AMSR2 area is unknown). The ESS, another strong position during the melting season, is back at record low despite its recent sharp area growth. These are early days, but for now this does not bode well.

In the next post:
The Laptev, Beaufort and CAA are all on the relatively low side of things. Baffin is at record low.

oren · « **Reply #3151 on:** November 20, 2019, 05:37:38 PM »

Laptev, Beaufort, CAA, Baffin Bay.

Wipneus · « **Reply #3152 on:** December 04, 2019, 11:29:36 AM »

PIOMAS has upgraded the gridded thickness data. Last date, 30th Nov, the calculated volume was 10.35[1000km³]. That is third lowest for the day (behind 2016 and 2012).

Here is the animation for November 2019.

Wipneus · « **Reply #3153 on:** December 04, 2019, 11:39:10 AM »

Updated volume and volume-anomaly graphs. Click for the better picture.

Wipneus · « **Reply #3154 on:** December 04, 2019, 11:45:22 AM »

The Fram-volume export graph. Average export was low, compared with average November export.

Wipneus · « **Reply #3155 on:** December 04, 2019, 11:47:13 AM »

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

gerontocrat · « **Reply #3156 on:** December 04, 2019, 01:03:40 PM »

Yet again, this person does "have use for the updated regional data files" from Wipneus:

PIOMAS Volume as at 30 November 2019 10.349 km3 '000

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

Volume gain in 1st week of November well above average.
Volume gain in 2nd week of November well below average.
Volume gain in last 2 weeks of November well above average declining to average by end of the month..

2019 volume is still 3rd lowest in the satellite record, by 211 km3 above 2012, and 965 km3 above 2016, and less than 2018 by 1,104 km3.
_______________________________________________________________
The last table is a look at projections to the next maximum. Far too early to take it seriously.

Wipneus · « **Reply #3157 on:** December 04, 2019, 01:09:52 PM »

Thickness map compared with previous years and their diff's. Click to size.

gerontocrat · « **Reply #3158 on:** December 04, 2019, 01:12:30 PM »

The PIOMAS 365-day trailing average volume continues to decline at around 3 km3 per day.

IFF (a big if) volume continues at around 1,000 km3 less than the previous year, late 2020 would see a new record low average.

El Cid · « **Reply #3159 on:** December 04, 2019, 01:33:51 PM »

You always know that a linear fit is not good when the first half of the data are (mostly) above the trendline and the second half is (mostly) below it.
I suggest that there was not much trend on your chart until the beginning of the 90s, then you had a steep downtrend till cca 2010 and now you have a less steep downtrend since then

binntho · « **Reply #3160 on:** December 04, 2019, 01:40:06 PM »

Quote from: El Cid on December 04, 2019, 01:33:51 PM

You always know that a linear fit is not good when the first half of the data are (mostly) above the trendline and the second half is (mostly) below it.
I suggest that there was not much trend on your chart until the beginning of the 90s, then you had a steep downtrend till cca 2010 and now you have a less steep downtrend since then

I thought the old chestnut season was finished?

gerontocrat · « **Reply #3161 on:** December 04, 2019, 04:08:04 PM »

Quote from: El Cid on December 04, 2019, 01:33:51 PM

You always know that a linear fit is not good when the first half of the data are (mostly) above the trendline and the second half is (mostly) below it.
I suggest that there was not much trend on your chart until the beginning of the 90s, then you had a steep downtrend till cca 2010 and now you have a less steep downtrend since then

Don't matter - the only trend is down.

I posted a load of stuff on "when will the Arctic go Ice-Free" about outliers. Using the standard methodology (sort-of) I isolated the outliers for extent and volume and the linear regression fit much better. First 3 attachments (September volume only).

I also looked at trends in area, volume & thickness for September using unadjusted data. Attachment 4.

The only trend is down.

El Cid · « **Reply #3162 on:** December 04, 2019, 04:35:58 PM »

binntho,

"I thought the old chestnut season was finished?"

It would be if the problem was solved but it ain't. No matter. If you can't see what I see, there's really not much to say.

gerontocrat,

The problem is not with the outliers, but with the autocorrelation of the residuals. Besides I don't think that taking out so-called outliers from an observed, natural process is a good solution.

We can agree though, that the trend is definitely down.

nanning · « **Reply #3163 on:** December 04, 2019, 05:18:00 PM »

Thanks gero, interesting.

"The only trend is down."
Indeed.

I think it's impossible to stop that trend in the next decades.

Wipneus · « **Reply #3164 on:** December 21, 2019, 09:40:57 AM »

PIOMAS gridded thickness data was updated. last day 15th December. Calculated volume on that day was 12.345 [1000km³]. That is still third lowest for that day after 2016 and 2012.

Here is the animation for the first half of December.

Wipneus · « **Reply #3165 on:** December 21, 2019, 10:00:08 AM »

The updated volume and volume-anomaly graphs.

Wipneus · « **Reply #3166 on:** December 21, 2019, 10:02:06 AM »

Updated Fram volume export graph.

Wipneus · « **Reply #3167 on:** December 21, 2019, 10:04:07 AM »

Some people have use for the updated regional data files:

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

gerontocrat · « **Reply #3168 on:** December 23, 2019, 09:43:26 PM »

Yes, once again, this person does "have use for the updated regional data files" from Wipneus:

PIOMAS Volume as at 15 December 2019 12.346 km3 '000

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

Volume gain in 1st half of December well above average.

2019 volume is still 3rd lowest in the satellite record, by 219 km3 above 2012, and 1,172 km3 above 2016, and less than 2018 by 728 km3.
_______________________________________________________________
NOTE: Ignore the large daily change in the 1010's average on 1 January in the 1st graph (Vol-2).
Simply shows the large annual loss in volume From 1 Jan to 31 Dec.

Wipneus · « **Reply #3169 on:** January 04, 2020, 09:31:31 AM »

PIOMAS gridded thickness data was update. On the last day, 31st December, volume is calculated to be 14.52 [1000km³], which is fourth lowest behind 2016, 2012 and 2017.

Here is the December animation.

Wipneus · « **Reply #3170 on:** January 04, 2020, 09:59:48 AM »

Here are the updated volume and volume-anomaly graphs. Click for full size.

Wipneus · « **Reply #3171 on:** January 04, 2020, 10:02:35 AM »

Updated Fram volume export.

Wipneus · « **Reply #3172 on:** January 04, 2020, 10:05:10 AM »

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

Wipneus · « **Reply #3173 on:** January 04, 2020, 10:09:31 AM »

Thickness map on 31st December 2019, compared with recent years and their diffs.
Clicks are needed for full size.

uniquorn · « **Reply #3174 on:** January 04, 2020, 01:37:33 PM »

Thank you Wipneus.
Animation of the diffs, aug-dec. ctr
Thicker on the Atlantic side south of Svalbard/FJL but thinner Beaufort arch and PGAS area. The continuing export into the Barents leaves the CAB north of Svalbard looking weak.

gerontocrat · « **Reply #3175 on:** January 04, 2020, 02:06:26 PM »

Yes, and again, this person does "have use for the updated regional data files" from Wipneus:

PIOMAS Volume as at 31 December 2019 14.519 km3 '000

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

Volume gain in December well above average.

2019 volume is now 4th lowest in the satellite record,
- 598 km3 above 2012,
- 1,441 km3 above 2016,
- 101 km3 above 2017,
and less than 2018 by 502 km3.

Not really a surprise that volume gain in December was mostly above average, given the similar story for both area and extent.
_______________________________________________________________

gerontocrat · « **Reply #3176 on:** January 04, 2020, 07:40:53 PM »

What with being the end of year data, here is a graph or 2 dragged out from a musty drawer.

PIOMAS 365 day trailing average continues to decline, currently at around 1.5km3 per day, much less than earlier in 2019.

And the 2nd image shows monthly averages of ice thickness, being a simple division of volume by NSIDC area and extent.

pietkuip · « **Reply #3177 on:** January 04, 2020, 09:32:19 PM »

Quote from: gerontocrat on January 04, 2020, 07:40:53 PM

What with being the end of year data, here is a graph or 2 dragged out from a musty drawer.

PIOMAS 365 day trailing average continues to decline, currently at around 1.5km3 per day, much less than earlier in 2019.

So within 40 years of measurements, half of the average volume is gone.

It looks like there is acceleration. An average of zero in 2050

(Not possible of course, because there won't be negative values in the summer.)

Tor Bejnar · « **Reply #3178 on:** January 04, 2020, 11:49:34 PM »

Quote

around 1.5km3 per day

My reading of the graph suggests 1,000 km3 per 3 years ~ 1 km3/day or 3,000 km3 per 10 years ~ 1.2 km/year.

Stephan · « **Reply #3179 on:** January 05, 2020, 09:14:07 PM »

If you plot the annual mean value you get a linear (fits quite well) trend line with a slope of -0,305 kkm³ per year, which is roughly close enough to your estimation.

RikW · « **Reply #3180 on:** January 06, 2020, 04:17:19 PM »

To me, it appears reasonable stable for the last 8/9 years; Curious why that is the case, is it coincidence? A trend? Mechanics we don't understand yet (okay, that one is at least true

)

Richard Rathbone · « **Reply #3181 on:** January 06, 2020, 08:51:56 PM »

Quote from: RikW on January 06, 2020, 04:17:19 PM

To me, it appears reasonable stable for the last 8/9 years; Curious why that is the case, is it coincidence? A trend? Mechanics we don't understand yet (okay, that one is at least true )

2010 was when virtually the last of the MYI went, so there haven't been large chunks of thick ice there to be lost since then.

Iain · « **Reply #3182 on:** February 03, 2020, 07:31:50 PM »

From The PIOMAS Summer trend line, it's 13 years to go to a September BOE, though as there are excursions above and below the trendline, it's more likely to be sooner than 13y

Could be 8 years with an outlier such as in 2012.

http://psc.apl.uw.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAprSepCurrent.png

Wipneus · « **Reply #3183 on:** February 04, 2020, 07:11:15 PM »

PIOMAS has updated. Volume on 31st January was 18.282[1000km³], this is fifth lowest behind 2011,2013,2017 and 2018.

Here is the animation.

Wipneus · « **Reply #3184 on:** February 04, 2020, 07:21:45 PM »

Thickness map on 2020-01-31, compared with recent years and the diff's. Click for full size.

Wipneus · « **Reply #3185 on:** February 04, 2020, 08:19:07 PM »

Here are volume and volume-anomaly graphs.

It is getting harder to find a new color for a new year. I am trying a new color scheme that I found here:
https://sashat.me/2017/01/11/list-of-20-simple-distinct-colors/

Have a look, I am not sure myself yet, comments are welcome.

Wipneus · « **Reply #3186 on:** February 04, 2020, 08:26:37 PM »

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

Jim Hunt · « **Reply #3187 on:** February 04, 2020, 08:35:49 PM »

Thanks Wipneus,

Some of Judy Curry's denizens have been waiting on tenterhooks for that!

On a slightly different note, your AMSR2 area/thickness processing seems to have gone awry on February 1st and 2nd? Back to normal for the 3rd.

gerontocrat · « **Reply #3188 on:** February 04, 2020, 08:42:31 PM »

Quote from: Wipneus on February 04, 2020, 08:19:07 PM

Here are volume and volume-anomaly graphs.

It is getting harder to find a new color for a new year. I am trying a new color scheme that I found here:
https://sashat.me/2017/01/11/list-of-20-simple-distinct-colors/

Have a look, I am not sure myself yet, comments are welcome.

It is a problem.

Sometimes in very crowded graphs I change the line type for the bits I want to highlight - e.g. dotted ........... instead of continuous . I think it often works better than making the data to be highlighted a thicker line.

oren · « **Reply #3189 on:** February 04, 2020, 10:07:36 PM »

I think the new color scheme is quite readable.
My color strategy includes assigning the more distinct colors (black is great) for the more interesting years (2012, 2016 etc.) and giving the less distinct shades to the "filler" years. I also use thicker lines where applicable.

gerontocrat · « **Reply #3190 on:** February 05, 2020, 03:25:12 PM »

This person always does "have use for the updated regional data files" from Wipneus:

PIOMAS Volume as at 31 January 2020 18,283 km3

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

Volume gain in January well above average.

2019 volume is now 5th lowest in the satellite record,
- 2,123 km3 above 2017,
- 715 km3 above 2018,
and less than 2019 by 334 km3.

Not really a surprise that volume gain in January was mostly above average, given the similar story for both area and extent.
_______________________________________________________________

slow wing · « **Reply #3191 on:** February 07, 2020, 05:45:40 AM »

Quote from: Wipneus on February 04, 2020, 08:19:07 PM

Here are volume and volume-anomaly graphs.

It is getting harder to find a new color for a new year. I am trying a new color scheme that I found here:
https://sashat.me/2017/01/11/list-of-20-simple-distinct-colors/

Have a look, I am not sure myself yet, comments are welcome.

Hi Wipneus, you asked the same question a year ago and I replied then with a suggested colour palette.

Did you try those colours and, if so, did they work OK?

mabarnes · « **Reply #3192 on:** February 07, 2020, 06:57:24 AM »

Quote from: gerontocrat on February 05, 2020, 03:25:12 PM

PIOMAS Volume as at 31 January 2020 18,283 km3

First, thanks again G ... appreciate all you do.

OCD Alert (mine lol) - in the comparison table (4th graphic), the cell that reads "2019 More (+) or Less (-) than" ... should say "2020" ...

Wipneus · « **Reply #3193 on:** February 19, 2020, 09:29:59 AM »

PIOMAS has updated the gridded thickness data upto the 15th. Calculated volume at 2020-2-15 was 19.67 [1000km³], This is fifth lowest for the day, exactly the same as the volume on that day in 2016, the "final official" volume data may change that exact match.

Here is the animation for February so far.

Wipneus · « **Reply #3194 on:** February 19, 2020, 09:47:27 AM »

The gridded velocity data was not updated (yet?), so Fram export graph cannot be updated.

Here are the volume and volume and volume-anomaly graphs. Colors have been a bit tweaked, a light grey background added to make the yellows a bit readable, and shared with existing area/extent graphs.

[edit: gave 2020 a thicker line as suggested by charles_oil]

Wipneus · « **Reply #3195 on:** February 19, 2020, 09:51:14 AM »

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

Wipneus · « **Reply #3196 on:** February 19, 2020, 10:14:10 AM »

Quote from: slow wing on February 07, 2020, 05:45:40 AM

Hi Wipneus, you asked the same question a year ago and I replied then with a suggested colour palette.

Did you try those colours and, if so, did they work OK?

[sorry for the late reply]

Hi slow wing.

Yes I have been using that approach: create an ordered set of colors nicely spaced out in RGB space. Unfortunately nice spaced in RGB is not perceived as such by our eyes. So I start tweaking colors, not to my complete satisfaction.

Jim Hunt · « **Reply #3197 on:** February 19, 2020, 11:26:40 AM »

Quote from: Wipneus on February 19, 2020, 09:29:59 AM

PIOMAS has updated the gridded thickness data upto the 15th.

Thanks very much Wipneus.

Now I'm forced to ponder once again why the CryoSat-2/SMOS thickness "measured" numbers seem to be more at variance with PIOMAS than in previous years:

gerontocrat · « **Reply #3198 on:** February 19, 2020, 12:24:50 PM »

Quote from: Wipneus on February 19, 2020, 09:51:14 AM

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.

charles_oil · « **Reply #3199 on:** February 19, 2020, 12:55:28 PM »

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

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?

News:

Author Topic: Latest PIOMAS Volume update (Read 2007043 times)