Support the Arctic Sea Ice Forum and Blog

Author Topic: The 2020/2021 freezing season  (Read 210333 times)

uniquorn

  • Young ice
  • Posts: 3086
    • View Profile
  • Liked: 1381
  • Likes Given: 287
Re: The 2020/2021 freezing season
« Reply #1200 on: February 23, 2021, 10:27:46 AM »
SIMB3 443910 is paired with whoi itp120 in the beaufort.
Ice+snow appear to have thickened during the freezing season by 64cm to 1.716m

SIMB3 344910 is paired with whoi itp121 in the beaufort.
Ice+snow appear to have thickened by 65cm to 2.753m



More details on the buoy thread


<>Meanwhile JAXA extent is flatlining<>
Just a touch of refreeze in Okhotsk so far. amsr2-uhh, feb1-22

edit: added Wipneus UH_AMSR2_3.125km extent, Okhotsk
« Last Edit: February 23, 2021, 08:34:45 PM by uniquorn »

uniquorn

  • Young ice
  • Posts: 3086
    • View Profile
  • Liked: 1381
  • Likes Given: 287
Re: The 2020/2021 freezing season
« Reply #1201 on: February 23, 2021, 02:03:47 PM »
NERSC CMEMS ice concentration forecast, atlantic side, feb22-mar2
« Last Edit: February 23, 2021, 03:52:24 PM by uniquorn »

passenger66

  • New ice
  • Posts: 10
    • View Profile
  • Liked: 2
  • Likes Given: 2
Re: The 2020/2021 freezing season
« Reply #1202 on: February 24, 2021, 01:13:37 AM »
https://news.yahoo.com/russian-tanker-cuts-previously-impossible-153300350.html
"The deepest ice encountered by the ships was about 5 feet thick. The vessels encountered no multi-year buildup of old ice on the route, however, and meteorologist and journalist Eric Holthaus called that a clear indicator of "a climate emergency.""
Will they update the models with ice thickness data from commercial shipping in the future.

Jim Hunt

  • Young ice
  • Posts: 4922
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 540
  • Likes Given: 52
Re: The 2020/2021 freezing season
« Reply #1203 on: February 24, 2021, 01:14:32 AM »
The NSIDC extent metric seems to be back in business:

https://GreatWhiteCon.info/2021/02/the-2021-maximum-arctic-sea-ice-extent/#Feb-23

No new data on Charctic just yet though.
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Cook

  • New ice
  • Posts: 40
    • View Profile
  • Liked: 10
  • Likes Given: 14
Re: The 2020/2021 freezing season
« Reply #1204 on: February 24, 2021, 03:22:07 AM »
So, has the melting season started?

Thomas Barlow

  • Frazil ice
  • Posts: 219
    • View Profile
  • Liked: 50
  • Likes Given: 28
Re: The 2020/2021 freezing season
« Reply #1205 on: February 24, 2021, 03:33:44 AM »
So, has the melting season started?
Unlikely, but not impossible.
My YouTube channel - https://www.youtube.com/channel/UCfk66dfLTAsZIVYbh7bqcoA/videos - talks about climate-change, environmental destruction, BLM, lockdown-hysteria, vampire-capitalism.

oren

  • Moderator
  • First-year ice
  • Posts: 6835
    • View Profile
  • Liked: 2507
  • Likes Given: 2265
Re: The 2020/2021 freezing season
« Reply #1206 on: February 24, 2021, 05:05:18 AM »
Likelihood is increasing daily but the jury is still out. Stephan's stats are a great help in determining probability.

Stephan

  • Nilas ice
  • Posts: 1575
    • View Profile
  • Liked: 556
  • Likes Given: 263
Re: The 2020/2021 freezing season
« Reply #1207 on: February 24, 2021, 07:06:29 AM »
I evaluated the JAXA data of all freezing seasons from Feb 19 to the individual maximum to find out how often an increase of 0.23 M km² has happened after Feb 19. This is the value needed to be higher than the actual maximum from Feb 16 (13.98 M km²). I grouped these evaluations into the different decades. The evaluation has three outcomes:
A - an increase higher than 0.24 M km² has happened in x years (Pass), which means the maximum has not been reached
B - an increase of 0.23 ± 0.01 M km² has happened in y years (Intermediate), which means the maximum may have been reached, but maybe not
C - an increase of less than 0.22 M km² has happened in z years (Fail), which means the maximum has already been reached and we can start the melting season thread.

                     A       B      C
1979-1989:    5       2      4
1990-1999:    1       0      9
2000-2009:    5       1      4
2010-2020:    8       0      3
sum:             19      3     20

Summary: If we assume that the current situation of the ice and its distribution is more like the 2010-2020 years than e.g. the 1990s then it is more likely than not that the maximum of 2021 has not been reached yet.

Update for Feb. 22, 2020. Threshold back to 0.23 M km², "in between" 0.22-0.24 M km²

                     A       B       C
1979-1989:    2       1       8
1990-1999:    1       0       9
2000-2009:    3       0       7
2010-2020:    6       0       5
sum:            12       1     29

The probability that 2021's maximum has already passed, increases slightly.

Update for Feb 23, 2021. Same threshold values.

                     A       B       C
1979-1989:    0       2       9
1990-1999:    1       0       9
2000-2009:    3       0       7
2010-2020:    6       1       4
sum:            10       3     29

Are we already in the melting season?
It is too late just to be concerned about Climate Change

BornFromTheVoid

  • Nilas ice
  • Posts: 1306
    • View Profile
  • Liked: 628
  • Likes Given: 243
Re: The 2020/2021 freezing season
« Reply #1208 on: February 24, 2021, 12:43:39 PM »
For the NSIDC extent data to the 22nd, the peripheral seas are now lowest on record.

It's basically just the Barents sea that's preventing the overall sea ice extent from being lowest
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

Jim Hunt

  • Young ice
  • Posts: 4922
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 540
  • Likes Given: 52
Re: The 2020/2021 freezing season
« Reply #1209 on: February 24, 2021, 12:48:04 PM »
Likelihood is increasing daily but the jury is still out.

Another slight decline today. A comparison with some other low max years:
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Iain

  • Frazil ice
  • Posts: 282
    • View Profile
  • Liked: 65
  • Likes Given: 32
Re: The 2020/2021 freezing season
« Reply #1210 on: February 24, 2021, 04:37:31 PM »
Chartic is back, but a different profile from Jaxa. As if they drew a straight line from last known good to present.
"If I have seen further than others, it is by standing upon the shoulders of giants." Isaac Newton

BornFromTheVoid

  • Nilas ice
  • Posts: 1306
    • View Profile
  • Liked: 628
  • Likes Given: 243
Re: The 2020/2021 freezing season
« Reply #1211 on: February 24, 2021, 05:11:07 PM »
The daily data leaves out the 20th and 21st. I assume they'll be added back at some point.
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

Thomas Barlow

  • Frazil ice
  • Posts: 219
    • View Profile
  • Liked: 50
  • Likes Given: 28
Re: The 2020/2021 freezing season
« Reply #1212 on: February 24, 2021, 09:49:01 PM »
Likelihood is increasing daily but the jury is still out.

Another slight decline today. A comparison with some other low max years:

According to this, the earliest turn-around I can see was in the last century, about Feb. 24 (1996) and Feb. 27 (1987 and '98).
Does anyone know why those turned around early on, and yet nowhere near the summer-lows of this current era?

http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/
« Last Edit: February 24, 2021, 09:56:29 PM by Thomas Barlow »
My YouTube channel - https://www.youtube.com/channel/UCfk66dfLTAsZIVYbh7bqcoA/videos - talks about climate-change, environmental destruction, BLM, lockdown-hysteria, vampire-capitalism.

Stephan

  • Nilas ice
  • Posts: 1575
    • View Profile
  • Liked: 556
  • Likes Given: 263
Re: The 2020/2021 freezing season
« Reply #1213 on: February 24, 2021, 10:35:12 PM »
The annual extent maxima moved to later times and lower values in the last 30 years:
                  JAXA                        Charctic
1980s Feb 27, 15.60 M km² | Feb 27, 16.00 M km²
1990s Feb 23, 15.07 M km² | Feb 24, 15.54 M km²
2000s Mar 08, 14.67 M km² | Mar 10, 15.14 M km²
2010s Mar 15, 14.16 M km² | Mar 16, 14.69 M km²
(please note that the covered years are not exactly the same)

A larger extent in the 80s and 90s must have been further south in the so called peripheral seas as the central basin is almost full of ice by this time of the year. These more southern ice floes are more susceptible to earlier melting or to destructive wave actions in only partly ice-covered seas. Therefore the later maximum in the latest decade seems to be logical as it usually is much too cold for melting events in the inner Arctic basin.
An annual maximum in mid February 2021 would be exceptional, but not impossible.
It is too late just to be concerned about Climate Change

oren

  • Moderator
  • First-year ice
  • Posts: 6835
    • View Profile
  • Liked: 2507
  • Likes Given: 2265
Re: The 2020/2021 freezing season
« Reply #1214 on: February 25, 2021, 05:01:40 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

February 24th, 2021:
     13,701,350 km2, a drop of -47,203 km2.
     2021 is now 2nd lowest on record.
     In the graph are today's 15 lowest years.
     Highlighted 2010's average, 2021 and the 5 years with daily lowest minimum:
          (2012, 2020, 2019, 2016 & 2007)

P.S. 277K km2 lost since Feb 16th.
      Is it time to declare the start of 2021 melting season?  :o
It seems it might be time already, though surprises are possible. Stephan - another update of your historical analysis would be most helpful.

Stephan

  • Nilas ice
  • Posts: 1575
    • View Profile
  • Liked: 556
  • Likes Given: 263
Re: The 2020/2021 freezing season
« Reply #1215 on: February 25, 2021, 07:02:02 AM »
Here it is.
New threshold value 0.28 ± 0.01 M km²

                     A       B       C
1979-1989:    1       1       9
1990-1999:    1       0       9
2000-2009:    3       0       7
2010-2020:    4       0       7
sum:              9       1     32
It is too late just to be concerned about Climate Change

Killian

  • Frazil ice
  • Posts: 299
    • View Profile
  • Liked: 62
  • Likes Given: 8
Re: The 2020/2021 freezing season
« Reply #1216 on: February 25, 2021, 07:32:29 AM »
I used JAXA to do an eyeball analysis and no other year in their record has a pre-peak decline this long or this deep, at least not in the same rough time frame. Several have fairly deep declines, but no more than about 2/3 as deep, but none has a decline this long; they are all around half as long or shorter.

Interesting or just an anomaly?

Regardless, with the AO possibly going positive +3 through mid-March, the chance of a higher peak is still pretty good.

Another slight decline today. A comparison with some other low max years:
« Last Edit: February 25, 2021, 07:39:58 AM by Killian »

Iain

  • Frazil ice
  • Posts: 282
    • View Profile
  • Liked: 65
  • Likes Given: 32
Re: The 2020/2021 freezing season
« Reply #1217 on: February 25, 2021, 09:53:07 AM »
A slight down tick on the Jaxa graph
"If I have seen further than others, it is by standing upon the shoulders of giants." Isaac Newton

oren

  • Moderator
  • First-year ice
  • Posts: 6835
    • View Profile
  • Liked: 2507
  • Likes Given: 2265
Re: The 2020/2021 freezing season
« Reply #1218 on: February 25, 2021, 10:36:22 AM »
Thanks to all. I'll give it at least another day.

BornFromTheVoid

  • Nilas ice
  • Posts: 1306
    • View Profile
  • Liked: 628
  • Likes Given: 243
Re: The 2020/2021 freezing season
« Reply #1219 on: February 25, 2021, 10:39:55 AM »
Big loss coming from Barents Sea, under the influence of southerly winds.
Could continue for another few days too.
(click to play)
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

Jim Hunt

  • Young ice
  • Posts: 4922
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 540
  • Likes Given: 52
Re: The 2020/2021 freezing season
« Reply #1220 on: February 25, 2021, 12:15:44 PM »
Regardless, with the AO possibly going positive +3 through mid-March, the chance of a higher peak is still pretty good.

Would you expect that to affect the low hanging fruit in the Barents?

Data to 23rd:
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Niall Dollard

  • Grease ice
  • Posts: 829
    • View Profile
  • Liked: 324
  • Likes Given: 81
Re: The 2020/2021 freezing season
« Reply #1221 on: February 25, 2021, 12:21:16 PM »
Over on the Pacific side, here is a comparison of extents for the date Feb 24th.

Compared with the 2004-2020 average, the Bering Sea this Feb 24th is at 87%.

Finally another thickness update has come through from the Tanana River deep in the interior of Alaska where the annual Nenena Ice Classic takes place.

The late Feb measurement was a quite substantial 43 inches

Compared with late Feb (circa) measurements of more recent years:

2020  31.5
2019  23.5 (very low)
2018  34
2017  31.5

This year is thickest since 2013.

Jim Hunt

  • Young ice
  • Posts: 4922
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 540
  • Likes Given: 52
Re: The 2020/2021 freezing season
« Reply #1222 on: February 25, 2021, 02:56:23 PM »
An interesting forecast from Thomas Lavergne via Twitter:

https://twitter.com/lavergnetho/status/1364929047227211779
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Iain

  • Frazil ice
  • Posts: 282
    • View Profile
  • Liked: 65
  • Likes Given: 32
Re: The 2020/2021 freezing season
« Reply #1223 on: February 25, 2021, 04:56:43 PM »
I don't see any pre-peak downticks of as great a magnitude as 2021 in the last 10 years.
"If I have seen further than others, it is by standing upon the shoulders of giants." Isaac Newton

Shared Humanity

  • Frazil ice
  • Posts: 443
    • View Profile
  • Liked: 193
  • Likes Given: 19
Re: The 2020/2021 freezing season
« Reply #1224 on: February 25, 2021, 08:40:08 PM »
Big loss coming from Barents Sea, under the influence of southerly winds.
Could continue for another few days too.
(click to play)

Not just compaction. There's a whole lot of melt going on.

Thomas Barlow

  • Frazil ice
  • Posts: 219
    • View Profile
  • Liked: 50
  • Likes Given: 28
Re: The 2020/2021 freezing season
« Reply #1225 on: February 26, 2021, 03:40:57 AM »
My YouTube channel - https://www.youtube.com/channel/UCfk66dfLTAsZIVYbh7bqcoA/videos - talks about climate-change, environmental destruction, BLM, lockdown-hysteria, vampire-capitalism.

Killian

  • Frazil ice
  • Posts: 299
    • View Profile
  • Liked: 62
  • Likes Given: 8
Re: The 2020/2021 freezing season
« Reply #1226 on: February 26, 2021, 05:30:12 AM »
I used JAXA to do an eyeball analysis and no other year in their record has a pre-peak decline this long or this deep, at least not in the same rough time frame. Several have fairly deep declines, but no more than about 2/3 as deep, but none has a decline this long; they are all around half as long or shorter.

Interesting or just an anomaly?

Regardless, with the AO possibly going positive +3 through mid-March, the chance of a higher peak is still pretty good.

Another slight decline today. A comparison with some other low max years:

OK, so I just went through comparing 2021 with every other year head-to-head. Turns out there were a couple I underestimated, but the central fact is still true: None equal this year. Significantly, just two years ago there was a 280 sq km pre-peak decline.

We now stand at roughly 310 for JAXA.

I think we are seeing a form of "wobbling" (re chaos) in the climate system.

Killian

  • Frazil ice
  • Posts: 299
    • View Profile
  • Liked: 62
  • Likes Given: 8
Re: The 2020/2021 freezing season
« Reply #1227 on: February 26, 2021, 05:38:28 AM »
Regardless, with the AO possibly going positive +3 through mid-March, the chance of a higher peak is still pretty good.

Would you expect that to affect the low hanging fruit in the Barents?

Data to 23rd:

I have no opinion on that. That sort of narrowly focused question is for the numbers folk, not me, a systems/trends guy.

gerontocrat

  • Multi-year ice
  • Posts: 10910
    • View Profile
  • Liked: 4037
  • Likes Given: 31
Re: The 2020/2021 freezing season
« Reply #1228 on: February 26, 2021, 06:38:27 AM »
It is tempting to declare a 2021 maximum, given extent today at 13.67 million is 0.31 million km2 below the current maximum of 13.98 million km2 on 16th Feb.

However, the plume showing projection of future extent from previous years' extent change shows 3 out of the previous 10 years produce a new maximum.
« Last Edit: February 26, 2021, 12:43:51 PM by gerontocrat »
"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)

Stephan

  • Nilas ice
  • Posts: 1575
    • View Profile
  • Liked: 556
  • Likes Given: 263
Re: The 2020/2021 freezing season
« Reply #1229 on: February 26, 2021, 06:54:55 AM »
A further loss increased the threshold value to 0.31 ± 0.01 M km².
The evaluation is:

                     A       B       C
1979-1989:    2       1       8
1990-1999:    1       0       9
2000-2009:    1       1       8
2010-2020:    4       0       7       (2010, 2012, 2014, 2020 result in "A")
sum:              8       2     32

From my opinion it is more likely than not that the 2021 maximum has already passed.
It is too late just to be concerned about Climate Change

oren

  • Moderator
  • First-year ice
  • Posts: 6835
    • View Profile
  • Liked: 2507
  • Likes Given: 2265
Re: The 2020/2021 freezing season
« Reply #1230 on: February 26, 2021, 07:11:59 AM »
Unless there is some rebound (or an additional crash), we will change over to a melting season thread on March 1st.

interstitial

  • Nilas ice
  • Posts: 1050
    • View Profile
  • Liked: 297
  • Likes Given: 78
Re: The 2020/2021 freezing season
« Reply #1231 on: February 26, 2021, 10:41:24 AM »
the ice is still thickening and does so for a short time after peak on the other hand it is close to calling it and with some fresh arctic weather headed to washington state this freezing season looks about done.

RikW

  • Frazil ice
  • Posts: 243
    • View Profile
  • Liked: 44
  • Likes Given: 18
Re: The 2020/2021 freezing season
« Reply #1232 on: February 26, 2021, 11:16:12 AM »
So or there is an increase like 2012/2020 - the 2 worst melting seasons we have had, or the start is with such a 'headstart' that a bad melting season won't be unlikely...

Jim Hunt

  • Young ice
  • Posts: 4922
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 540
  • Likes Given: 52
Re: The 2020/2021 freezing season
« Reply #1233 on: February 26, 2021, 12:06:20 PM »
Still no "rebound". Still second lowest.

Plus the GOFS forecast. Click to animate.

Watch the Bering Sea for example. A rebound in prospect?

Reality is merely an illusion, albeit a very persistent one - Albert Einstein

pauldry600

  • Frazil ice
  • Posts: 235
    • View Profile
    • weathergossip
  • Liked: 24
  • Likes Given: 3
Re: The 2020/2021 freezing season
« Reply #1234 on: February 26, 2021, 12:12:44 PM »
Watching with interest

I think it will rebound. It will be close.

Jim Hunt

  • Young ice
  • Posts: 4922
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 540
  • Likes Given: 52
Re: The 2020/2021 freezing season
« Reply #1235 on: February 26, 2021, 01:16:40 PM »
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Jim Hunt

  • Young ice
  • Posts: 4922
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 540
  • Likes Given: 52
Re: The 2020/2021 freezing season
« Reply #1236 on: February 26, 2021, 01:20:47 PM »
I have no opinion on that.

It seems to me that a strong polar vortex for what remains of winter might increase central ice thickness slightly.

It's less clear that it would increase extent on the periphery.
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Freegrass

  • Nilas ice
  • Posts: 1852
  • None but ourselves can free our minds...
    • View Profile
  • Liked: 556
  • Likes Given: 796
Re: The 2020/2021 freezing season
« Reply #1237 on: February 26, 2021, 02:16:25 PM »
Latest Five Day Forecast
Wind + Temp @ Surface
Large GiF!

The weather in the coming days looks very favorable for a Barents and Bering Sea ice increase, and a return of Fram export. A.k.a. normal arctic weather...
« Last Edit: February 26, 2021, 02:28:28 PM by Freegrass »
And so we pray...

When factual science is in conflict with our beliefs, we cuddle up in our own delusional fantasy where everything starts making sense again...

Iain

  • Frazil ice
  • Posts: 282
    • View Profile
  • Liked: 65
  • Likes Given: 32
Re: The 2020/2021 freezing season
« Reply #1238 on: February 26, 2021, 06:13:27 PM »
F' What?!
"If I have seen further than others, it is by standing upon the shoulders of giants." Isaac Newton

Iain

  • Frazil ice
  • Posts: 282
    • View Profile
  • Liked: 65
  • Likes Given: 32
Re: The 2020/2021 freezing season
« Reply #1239 on: February 26, 2021, 06:17:09 PM »
So not only do I not see a comparable downtick in the last 10 years, nor do I see a comparable uptick to take 2021 back to 14.542 (Feb 15th)

More likely than not the 2021 peak has passed
"If I have seen further than others, it is by standing upon the shoulders of giants." Isaac Newton

be cause

  • Nilas ice
  • Posts: 1538
    • View Profile
  • Liked: 652
  • Likes Given: 528
Re: The 2020/2021 freezing season
« Reply #1240 on: February 26, 2021, 08:18:03 PM »
I do find it strange that while we all agree that volume is the best measure , we ignore what it says about where we are in the freeze/melt cycle . Peak volume is probably 2 or 3 months away , at which time melt finally exceeds freeze .. Neither melt or freeze are seasonal in that both are always ongoing , unless we have passed the point where that is true , yet twice a year excitement builds . Are the Inuit and the polar bears awaiting the news with bated breath ? AS IF ! :) b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 + 2 = 2021 + 1 =  ' if only we could have seen it coming ' ...

oren

  • Moderator
  • First-year ice
  • Posts: 6835
    • View Profile
  • Liked: 2507
  • Likes Given: 2265
Re: The 2020/2021 freezing season
« Reply #1241 on: February 26, 2021, 08:42:08 PM »
Total volume peaks in early April, and CAB volume can peak in early May. However, the melting season in the peripheral seas begins when extent reaches the annual maximum, and the forum traditionally switches over to the melting season thread at this time.

Freegrass

  • Nilas ice
  • Posts: 1852
  • None but ourselves can free our minds...
    • View Profile
  • Liked: 556
  • Likes Given: 796
Re: The 2020/2021 freezing season
« Reply #1242 on: February 26, 2021, 09:10:06 PM »
I've seen many spaghetti graphs here for the last few days, but none tell the story like this one...

Is this right? Or still data error?
And so we pray...

When factual science is in conflict with our beliefs, we cuddle up in our own delusional fantasy where everything starts making sense again...

gerontocrat

  • Multi-year ice
  • Posts: 10910
    • View Profile
  • Liked: 4037
  • Likes Given: 31
Re: The 2020/2021 freezing season
« Reply #1243 on: February 26, 2021, 09:22:11 PM »
I've seen many spaghetti graphs here for the last few days, but none tell the story like this one...

Is this right? Or still data error?
Data error.

Just looked at the latest data files from NSIDC. Area data now only to 23rd Feb with big differences with previous downloads. So recent previous posts of NSIDC data on the data thread may be junk. Extent data for 25 Feb an outlier with missing data for previous 2 days.

NSIDC have a problem. Still hoping its just a problem down here on the ground and not up there with the satellite(s).
"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)

Freegrass

  • Nilas ice
  • Posts: 1852
  • None but ourselves can free our minds...
    • View Profile
  • Liked: 556
  • Likes Given: 796
Re: The 2020/2021 freezing season
« Reply #1244 on: February 26, 2021, 09:45:12 PM »
I've seen many spaghetti graphs here for the last few days, but none tell the story like this one...

Is this right? Or still data error?
Data error.

Just looked at the latest data files from NSIDC. Area data now only to 23rd Feb with big differences with previous downloads. So recent previous posts of NSIDC data on the data thread may be junk. Extent data for 25 Feb an outlier with missing data for previous 2 days.

NSIDC have a problem. Still hoping its just a problem down here on the ground and not up there with the satellite(s).
Thanks Gerontocrat. That graph was pure horror...

If there's one thing the new Cryosat satellite should be good at, it's finding the ice edge, and calculating extent. So why are Americans still using and posting corrupted old satellite data? What does the new Cryosat have to say about extend? Is there a website like the NSIDC one with similar graphs from the new Cryosat extend data?

It looks like Americans are better with websites, and Europeans better with data...  :-\
And so we pray...

When factual science is in conflict with our beliefs, we cuddle up in our own delusional fantasy where everything starts making sense again...

Jim Hunt

  • Young ice
  • Posts: 4922
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 540
  • Likes Given: 52
Re: The 2020/2021 freezing season
« Reply #1245 on: February 26, 2021, 09:56:10 PM »
So why are Americans still using and posting corrupted old satellite data?

I can't speak to the "posting corrupted" part, but they're "using old satellite data" for long term consistency.

See:

https://GreatWhiteCon.info/2016/02/dmi-masie-and-the-sea-ice-index-an-interview-with-walt-meier/

Quote
The Sea Ice Index was designed to use a consistent methodology over a long period of time using a single type of sensor. 100% automatically processed passive microwave data is the “gold standard” when it comes to determining sea ice trends. It is subject to some biases and thus is not necessarily as accurate on a given day as MASIE. However, the biases are consistent over time, so the time series will be consistent over time. This means that year-to-year comparisons and trend estimates will be more accurate in the passive microwave data than in MASIE.
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Freegrass

  • Nilas ice
  • Posts: 1852
  • None but ourselves can free our minds...
    • View Profile
  • Liked: 556
  • Likes Given: 796
Re: The 2020/2021 freezing season
« Reply #1246 on: February 26, 2021, 10:23:51 PM »
The Sea Ice Index was designed to use a consistent methodology over a long period of time.....It is subject to some biases and thus is not necessarily as accurate on a given day as MASIE. However, the biases are consistent over time...
WTF? Our data is wrong, but it's consistently wrong... So don't worry about it... Just don't tell anyone that my penis is actually 3 inches shorter than what we're telling you...  :o

And then people ask me why I call them Americannots?

How hard can it be to find the error, calculate it, and then recalculate and correct historical data?

Edit: It's probably not that easy, but don't they have historical visuals of the ice that computers can recalculate? Or find an average error coefficient, and use that to correct historical data?
« Last Edit: February 26, 2021, 10:37:04 PM by Freegrass »
And so we pray...

When factual science is in conflict with our beliefs, we cuddle up in our own delusional fantasy where everything starts making sense again...

gerontocrat

  • Multi-year ice
  • Posts: 10910
    • View Profile
  • Liked: 4037
  • Likes Given: 31
Re: The 2020/2021 freezing season
« Reply #1247 on: February 26, 2021, 10:46:17 PM »
The Sea Ice Index was designed to use a consistent methodology over a long period of time.....It is subject to some biases and thus is not necessarily as accurate on a given day as MASIE. However, the biases are consistent over time...
WTF? Our data is wrong, but it's consistently wrong... So don't worry about it... Just don't tell anyone that my penis is actually 3 inches shorter than what we're telling you...  :o

And then people ask me why I call them Americannots?

How hard can it be to find the error, calculate it, and then recalculate and correct historical data?
If it was that easy then either they or someone else would have done it.

Even JAXA for their long-term series do not use the full resolution capability of their latest onboard instruments to ensure that current measurements are consistent with the older measurements.

Sooner or later something will have to be done because the satellites in question are years and years beyond their design life, and at the moment there is nothing up there that can replicate the data in a manner consistent with the historical record. At which point I get my redundancy notice.

EDIT
NSIDC posted another update about an hour ago. Still no joy. I will wait until tomorrow and then ask them what goes on. is it the satellites? Is it the ground receiving stations ? If it is the satellites......
"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)

Freegrass

  • Nilas ice
  • Posts: 1852
  • None but ourselves can free our minds...
    • View Profile
  • Liked: 556
  • Likes Given: 796
Re: The 2020/2021 freezing season
« Reply #1248 on: February 26, 2021, 11:05:13 PM »
They always have the option to post the consistently wrong data, and the new corrected one side by side...

Isn't that what HYCOM is doing? Continuously updating their model so it becomes more accurate? I remember something about someone saying that you can't compare historical HYCOM data with the current one, because it differs. I completely understand this now...
And so we pray...

When factual science is in conflict with our beliefs, we cuddle up in our own delusional fantasy where everything starts making sense again...

gerontocrat

  • Multi-year ice
  • Posts: 10910
    • View Profile
  • Liked: 4037
  • Likes Given: 31
Re: The 2020/2021 freezing season
« Reply #1249 on: February 26, 2021, 11:29:54 PM »
They always have the option to post the consistently wrong data, and the new corrected one side by side...

Isn't that what HYCOM is doing? Continuously updating their model so it becomes more accurate? I remember something about someone saying that you can't compare historical HYCOM data with the current one, because it differs. I completely understand this now...

Continuously updating the data processing so it becomes more accurate, and then you can't compare historical HYCOM data with the current one data, because it differs.

So no meaningful comparisons can be made so the analysis actvivity is redundant.
"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)