Support the Arctic Sea Ice Forum and Blog

Author Topic: Latest PIOMAS update (December 2019 )  (Read 1080919 times)

oren

  • Young ice
  • Posts: 4537
    • View Profile
  • Liked: 916
  • Likes Given: 1307
Re: Latest PIOMAS update (November 2019 mid-monthly update)
« 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.
« Last Edit: November 20, 2019, 05:42:21 PM by oren »

oren

  • Young ice
  • Posts: 4537
    • View Profile
  • Liked: 916
  • Likes Given: 1307
Re: Latest PIOMAS update (November 2019 mid-monthly update)
« Reply #3151 on: November 20, 2019, 05:37:38 PM »
Laptev, Beaufort, CAA, Baffin Bay.
« Last Edit: November 20, 2019, 05:54:53 PM by oren »

Wipneus

  • Citizen scientist
  • Young ice
  • Posts: 4009
    • View Profile
    • Arctische Pinguin
  • Liked: 644
  • Likes Given: 0
Re: Latest PIOMAS update (December 2019 )
« 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

  • Citizen scientist
  • Young ice
  • Posts: 4009
    • View Profile
    • Arctische Pinguin
  • Liked: 644
  • Likes Given: 0
Re: Latest PIOMAS update (December 2019 )
« Reply #3153 on: December 04, 2019, 11:39:10 AM »
Updated volume and volume-anomaly graphs. Click for the better picture.

Wipneus

  • Citizen scientist
  • Young ice
  • Posts: 4009
    • View Profile
    • Arctische Pinguin
  • Liked: 644
  • Likes Given: 0
Re: Latest PIOMAS update (December 2019 )
« 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

  • Citizen scientist
  • Young ice
  • Posts: 4009
    • View Profile
    • Arctische Pinguin
  • Liked: 644
  • Likes Given: 0

gerontocrat

  • First-year ice
  • Posts: 6832
    • View Profile
  • Liked: 1732
  • Likes Given: 22
Re: Latest PIOMAS update (June 2019)
« 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.
"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)

Wipneus

  • Citizen scientist
  • Young ice
  • Posts: 4009
    • View Profile
    • Arctische Pinguin
  • Liked: 644
  • Likes Given: 0
Re: Latest PIOMAS update (December 2019 )
« Reply #3157 on: December 04, 2019, 01:09:52 PM »
Thickness map compared with previous years and their diff's. Click to size.

gerontocrat

  • First-year ice
  • Posts: 6832
    • View Profile
  • Liked: 1732
  • Likes Given: 22
Re: Latest PIOMAS update (December 2019 )
« 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.
"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)

El Cid

  • Grease ice
  • Posts: 622
    • View Profile
  • Liked: 195
  • Likes Given: 48
Re: Latest PIOMAS update (December 2019 )
« 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

  • Nilas ice
  • Posts: 1096
    • View Profile
  • Liked: 282
  • Likes Given: 76
Re: Latest PIOMAS update (December 2019 )
« Reply #3160 on: December 04, 2019, 01:40:06 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?
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

gerontocrat

  • First-year ice
  • Posts: 6832
    • View Profile
  • Liked: 1732
  • Likes Given: 22
Re: Latest PIOMAS update (December 2019 )
« Reply #3161 on: December 04, 2019, 04:08:04 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.
"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)

El Cid

  • Grease ice
  • Posts: 622
    • View Profile
  • Liked: 195
  • Likes Given: 48
Re: Latest PIOMAS update (December 2019 )
« 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

  • Nilas ice
  • Posts: 1110
  • 0Kg CO2, 35 KWh/wk,130L H2O/wk, No heating
    • View Profile
  • Liked: 165
  • Likes Given: 7207
Re: Latest PIOMAS update (December 2019 )
« 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.
"It is preoccupation with possessions, more than anything else, that prevents us from living freely and nobly" - Bertrand Russell
   Simple: minimize your possessions and be free and kind    It's just a mindset.       Refugees welcome