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oren

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Re: 2019 sea ice area and extent data
« Reply #1000 on: June 06, 2019, 03:55:11 PM »
The St Lawrence. This little sea ignores AGW, variations in weather, ocean currents, et al and after dithering around since the middle of April, finally gives up the last of its sea ice (as near as dammit) on the same day every year - or is it NSIDC changing the mask?
A quick look at the "real" situation in St. Lawrence, as measured by UH AMSR2, shows no ice since early April. NSIDC have big problems with coastal and spurious ice, and change their mask every 1st of the month to get rid of some of the problematic data.

Tor Bejnar

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Re: 2019 sea ice area and extent data
« Reply #1001 on: June 06, 2019, 03:56:03 PM »
I'm certain it's NSIDC changing its mask.  (Or some New Aged fisherfolk go out every May 31 with blow torches.)
Arctic ice is healthy for children and other living things.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1002 on: June 06, 2019, 04:03:41 PM »
The St Lawrence. This little sea ignores AGW, variations in weather, ocean currents, et al and after dithering around since the middle of April, finally gives up the last of its sea ice (as near as dammit) on the same day every year - or is it NSIDC changing the mask?
A quick look at the "real" situation in St. Lawrence, as measured by UH AMSR2, shows no ice since early April. NSIDC have big problems with coastal and spurious ice, and change their mask every 1st of the month to get rid of some of the problematic data.
That is what I thought, but NSIDC do it on one day, the first of the month.
The final drop took place over the first 5 days in June.

So there you are. A little puzzle not quite put to bed.
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Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #1003 on: June 06, 2019, 04:15:49 PM »
The St Lawrence. This little sea ignores AGW, variations in weather, ocean currents, et al and after dithering around since the middle of April, finally gives up the last of its sea ice (as near as dammit) on the same day every year - or is it NSIDC changing the mask?
A quick look at the "real" situation in St. Lawrence, as measured by UH AMSR2, shows no ice since early April. NSIDC have big problems with coastal and spurious ice, and change their mask every 1st of the month to get rid of some of the problematic data.
That is what I thought, but NSIDC do it on one day, the first of the month.
The final drop took place over the first 5 days in June.

So there you are. A little puzzle not quite put to bed.
I guess that is the consequence of the mask and five days average.
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

oren

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Re: 2019 sea ice area and extent data
« Reply #1004 on: June 06, 2019, 04:16:26 PM »
A. It could be due to their 5-day averaging algorithm.
B. Note that the May 1st mask also plays in the graph.
C. I am looking for Wipneus' definition of the St. Lawrence region to make sure it's not different from NSIDC.

Edit: (C) as far as I can tell it's the same region definition.
« Last Edit: June 06, 2019, 04:23:17 PM by oren »

Stephan

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Re: 2019 sea ice area and extent data
« Reply #1005 on: June 06, 2019, 06:41:08 PM »
Very intersting. I remember geronocrat's posting about this fact almost exactly one year ago.
As St. Lawrence is not located at the end of the world (as e.g. is Amundsen Sea close to WAIS) someone should go there and look whether the ice really disappears at this date or whether it already has disappeared weeks ago...

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1006 on: June 06, 2019, 07:42:18 PM »
A. It could be due to their 5-day averaging algorithm.
B. Note that the May 1st mask also plays in the graph.
C. I am looking for Wipneus' definition of the St. Lawrence region to make sure it's not different from NSIDC.

Edit: (C) as far as I can tell it's the same region definition.
University of Bremen image date 5 June sees teeny weeny bits of ice
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petm

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Re: 2019 sea ice area and extent data
« Reply #1007 on: June 06, 2019, 09:04:59 PM »
University of Bremen image date 5 June sees teeny weeny bits of ice

Those are artifacts. Most of the ice was gone by the beginning of April and all of it a month ago.

magnamentis

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Re: 2019 sea ice area and extent data
« Reply #1008 on: June 06, 2019, 09:11:02 PM »
all of st. lawrence ice is fake ice for several weeks now. this seems to be obvious and i'm surprised that anyone believed that there was even a tiny bit left.

BTW sat-images are a good tool to verify in case of doubt, mostly it's sufficient to verify 4-5 artifacts as artifacts and one can save the work to do all of them.

petm

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Re: 2019 sea ice area and extent data
« Reply #1009 on: June 06, 2019, 09:11:23 PM »
There is some still surviving farther north off Labrador.

magnamentis

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Re: 2019 sea ice area and extent data
« Reply #1010 on: June 06, 2019, 09:30:03 PM »
There is some still surviving farther north off Labrador.

what is your point, there is ice surviving in many places but how does this relate to st. lawrence or in other words, what does the ice north of labrador make special / noteworthy ?

i'm asking because sometimes one can miss a point ;)

petm

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Re: 2019 sea ice area and extent data
« Reply #1011 on: June 06, 2019, 10:04:20 PM »
There is some still surviving farther north off Labrador.

what is your point, there is ice surviving in many places but how does this relate to st. lawrence or in other words, what does the ice north of labrador make special / noteworthy ?

i'm asking because sometimes one can miss a point ;)

It's about as close to the St-L that one can find sea ice at this time of year. Some kind of consolation prize I guess...?  :D

Killian

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Re: 2019 sea ice area and extent data
« Reply #1012 on: June 06, 2019, 10:48:36 PM »
Hey all,

Zach Labe posted a graph of CAB sea ice extent that I thought looked great. I know such is already posted here by someone(s), but it's a nice graph. I inquired about updating and access so he added it to his page of graphs, says he will update a couple times a week.

Thought maybe Neven might like to use it on the graphs page...?

https://sites.uci.edu/zlabe/arctic-sea-ice-extentconcentration/

Cheers

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #1013 on: June 07, 2019, 05:43:33 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

June 6th, 2019:
     10,436,997 km2, a drop of -44,176 km2.
     2019 is 2nd lowest on record.
     (2012 highlighted).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1014 on: June 07, 2019, 06:00:59 AM »
The St Lawrence. This little sea ignores AGW, variations in weather, ocean currents, et al and after dithering around since the middle of April, finally gives up the last of its sea ice (as near as dammit) on the same day every year - or is it NSIDC changing the mask?

Truly astounding!  It is as if someone is turning on the faucet on the same day each year.
Someone did - NSIDC.
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1015 on: June 07, 2019, 06:15:25 AM »
JAXA ARCTIC EXTENT :- 10,436,997 km2(June 6, 2019)


- Extent is 2nd lowest in the satellite record, 104 k > 2016, 82 k < 2018, 735 k < 2012.
- Extent loss on this day 44  k, 21 k less than the average loss on this day of 65k.
- Extent loss from maximum 3,834 k, 426 k (12%) greater than the average of 3,408k loss from maximum by this day,
- On average 34.5% of the melting season done, with 99 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.96 million km2, 2nd lowest in the satellite record, and 0.78 million km2 above the 2012 low of 3.18 million km2.
Looking at the last 5 years average remaining melt only gives a result of 4.19 million km2, 4th lowest, 1.01 million km2 above 2012.

Other Stuff

GFS shows temperature anomalies varying from +1.6 to +2.9. Positive anomalies spread over most of the Arctic. with extreme +ve anomalies in Eastern Siberia from Sunday onwards.

So far average remaining melt data still points towards a 2nd lowest minimum well above 2012. However, only 1/3rd of the average melt in the season completed.
"Para a Causa do Povo a Luta Continua!"
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binntho

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Re: 2019 sea ice area and extent data
« Reply #1016 on: June 07, 2019, 06:49:37 AM »
Hey all,

Zach Labe posted a graph of CAB sea ice extent that I thought looked great. I know such is already posted here by someone(s), but it's a nice graph. I inquired about updating and access so he added it to his page of graphs, says he will update a couple times a week.

Thought maybe Neven might like to use it on the graphs page...?

https://sites.uci.edu/zlabe/arctic-sea-ice-extentconcentration/

Cheers

I really like Zach's graphs, the visuals are astounding. But I'm a bit confused by the topmost graph on the site. It seems to me that the colours are wrong with regard to the green, white and brown lines, at least when comparing them with the Jaxa extent graph showing the same years.

The colours seem about right until the crossovers in july, where it seems that they have been switched: 2012 goes from white to brown, 2016 goes from green to white and 2007 seems to not only switch colours from brown to green, but also to shift years ...

Or am I missing something totally obvious? It wouldn't be the first time!

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1017 on: June 07, 2019, 02:25:21 PM »
NSIDC Total Area as at 6 June 2019 (5 day trailing average) 9,368,713 km2
               
Total Area         
 9,368,713    km2      
-279,192    km2   <   2010's average.
-174,051    k   <   2018
-766,337    k   <   2000's average.
         
Total Area Change   -54    k   loss
Peripheral Seas   -14    k   loss
Central Seas__   -27    k   loss
Other Seas___   -14    k   loss
         
Peripheral Seas         
Bering _______   -1    k   loss
Baffin  Bay____   -11    k   loss
Greenland____    2    k   gain
Barents ______   -3    k   loss
         
CAB Seas         
Beaufort_____   -9    k   loss
CAA_________    1    k   gain
East Siberian__   -1    k   loss
Central Arctic_    10    k   gain
         
Kara_________   -7    k   loss
Laptev_______   -15    k   loss
Chukchi______   -6    k   loss
         
Other Seas         
Okhotsk______   -1    k   loss
St Lawrence___    0    k   gain
Hudson Bay___   -13    k   loss

Area loss 54 k, 24 k LESS than the 2010's average loss of 78 k on this day.
Total area still 2nd lowest (381 k > 2016)

Other Stuff
GFS shows temperature anomalies varying from +1.6 to +2.9. Positive anomalies spread over most of the Arctic. with extreme +ve anomalies in Eastern Siberia from Sunday onwards.

Recent daily area losses consistently lower than average.

Note that daily sea ice area loss is entering the peak season, as must 2019 to stay in contact with 2016 and 2012 (just about to fall over the cliff).

ps: St Lawrence  sea ice might be gone, the artefacts remain.
"Para a Causa do Povo a Luta Continua!"
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Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #1018 on: June 08, 2019, 05:57:16 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

June 7th, 2019:
     10,386,229 km2, a drop of -50,768 km2.
     2019 is 2nd lowest on record.
     (2012 highlighted).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1019 on: June 08, 2019, 07:00:27 AM »
JAXA ARCTIC EXTENT :- 10,386,229 km2(June 7, 2019)

- Extent is 2nd lowest in the satellite record, 88 k > 2016, 97 k < 2018, 641 k < 2012.
- Extent loss on this day 51  k, 1 k less than the average loss on this day of 52 k.
- Extent loss from maximum 3,885 k, 425 k (12%) greater than the average of 3,460k loss from maximum by this day,
- On average 35.0% of the melting season done, with 98 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.97 million km2, 2nd lowest in the satellite record, and 0.79 million km2 above the 2012 low of 3.18 million km2.
Looking at the last 5 years average remaining melt only gives a result of 4.17 million km2, 4th lowest, 0.99 million km2 above 2012.

Other Stuff

GFS shows temperature anomalies varying from +1.9 to +2.7. Positive anomalies spread over most of the Arctic. with extreme +ve anomalies in Eastern Siberia from Sunday onwards for one week, (and high +ve anomalies in the CAA in the last few days of the 10 day forecast period - reliability?).

In the next few days both 2018 and 2016 daily extent loss was very low, so an average 2019 daily loss would make 2019 the lowest extent again for the rest of June at least after this long period of being in 2nd place. From early July..... ? ? ?

So far average remaining melt data still points towards a 2nd lowest minimum well above 2012. However, only just over 1/3rd of the average melt in the season completed.

« Last Edit: June 08, 2019, 07:05:42 AM by gerontocrat »
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1020 on: June 08, 2019, 02:18:12 PM »
NSIDC Total Area as at 7 June 2019 (5 day trailing average) 9,332,503 km2
               
Total Area         
 9,332,503    km2      
-241,213    km2   <   2010's average.
-142,783    k   <   2018
-735,930    k   <   2000's average.
         
Total Area Change   -36    k   loss
Peripheral Seas   -17    k   loss
Central Seas__   -6    k   loss
Other Seas___   -14    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -15    k   loss
Greenland____    2    k   gain
Barents ______   -3    k   loss
         
CAB Seas         
Beaufort_____   -12    k   loss
CAA_________    1    k   gain
East Siberian__   -1    k   loss
Central Arctic_    20    k   gain
         
Kara_________   -3    k   loss
Laptev_______   -4    k   loss
Chukchi______   -7    k   loss
         
Other Seas         
Okhotsk______   -0    k   loss
St Lawrence___    0    k   gain
Hudson Bay___   -14    k   loss

Area loss 36 k, 41 k LESS than the 2010's average loss of 77 k on this day.
Total area still 2nd lowest (407 k > 2016)

Other Stuff
GFS shows temperature anomalies varying from +1.9 to +2.7. Positive anomalies spread over most of the Arctic. with extreme +ve anomalies in Eastern Siberia from Sunday onwards for one week, (and high +ve anomalies in the CAA in the last few days of the 10 day forecast period - reliability?).

Recent daily area losses consistently lower than average, today's less than half the 2010's average area loss on this day. The NSIDC "5 day trailing average area" story is somewhat different from the JAXA daily extent story.

Note that daily sea ice area loss is entering the peak season, as must 2019 to stay in contact with 2016 and 2012 (just about to fall over the cliff).
____________________________________________________________
ps: St Lawrence  sea ice might be gone, the artefacts remain.
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FishOutofWater

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Re: 2019 sea ice area and extent data
« Reply #1021 on: June 08, 2019, 02:36:55 PM »
I really like Zach's graphs, the visuals are astounding. But I'm a bit confused by the topmost graph on the site.

You're confused because that graph shows 2018 not 2016.

binntho

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Re: 2019 sea ice area and extent data
« Reply #1022 on: June 08, 2019, 03:36:55 PM »
I really like Zach's graphs, the visuals are astounding. But I'm a bit confused by the topmost graph on the site.

You're confused because that graph shows 2018 not 2016.
This makes me even more confused. Perhaps the graph does show 2018 in stead of 2016, it's very hard to tell. But that does not explain the problems I had with understanding the graph.

But going back to Zach's site I see that the graph has "corrected" itself. The same years are shown in the two graphs below, but look at the lines and colors around minimum. Totally different in the two versions, with the lower looking a lot more like it "should".


gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1023 on: June 08, 2019, 03:40:12 PM »
The Beaufort and The Chukchi Seas

Are the "meth'd up Germans marching + Panzer-ing through the Ardennes" (pace bbr2314 - 1 June) ?

The Chukchi is declining in area muchly, 80 days at lowest area this year.
The Beaufort is also declining in area muchly, and area is again less than the extraordinary 2016 year, and now 15 days at lowest area this year.

The 7 Central Seas (as in the table in the post above), Tealight's High Arctic.

But is this blitzkreig stretching across the whole of the Central Arctic Ocean?

Yes, if you look at EXTENT,
No, if you look at AREA.

I look at the Area graphs from NSIDC as they are a leading indicator of sea ice loss (or gain).
i.e. as the ice melts it shows up on the area measure before it does on extent (and vice-versa). The 15% rule ensures this.

Area loss has slowed, extent loss has increased. Arithmetic says the answer must be that average concentration has increased The next post shows this.

Does this mean the ice is less or more prone to melt from now?
As the man from Vichy said "je ne sais pas".
________________________________________________
ps:
Solstice 2019 will be at 16:54 on
Friday, 21 June
All times are in United Kingdom Time.

That's 13 days from today.
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1024 on: June 08, 2019, 03:47:21 PM »
Here are the "area divided by extent" graphs for the High Arctic seas only and for all seas.
The story is much the same for both graphs.
Note how much more compact the High Arctic seas are than the average for all seas.
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Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #1025 on: June 09, 2019, 05:42:55 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

June 8th, 2019:
     10,361,292 km2, a drop of -24,937 km2.
     2019 is 2nd lowest on record.
     (2012 highlighted).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

Rich

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Re: 2019 sea ice area and extent data
« Reply #1026 on: June 09, 2019, 06:10:32 AM »
Thanks for the update Juan.

On this date, the 8 lowest extent's are all from this decade and the 4 lowest are all from the past 5 years.

Your compact chart is pretty elegant in terms of highlighting the chronic and unrelenting advance of AGW.

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #1027 on: June 09, 2019, 06:34:08 AM »
Thanks for the update Juan.

On this date, the 8 lowest extent's are all from this decade and the 4 lowest are all from the past 5 years.

Your compact chart is pretty elegant in terms of highlighting the chronic and unrelenting advance of AGW.

You are welcome.  :)
It could be the AMSR2 better resolution against older satellites, as I mentioned before:

Edit: Maybe as the satellite gets an equipment with better resolution, the sea ice extent gets a lower value. Kind of implicit when the definition is: "If sea ice on a grid is equal or more than 15%, then it becomes 100%". As the grid gets smaller, the rounding becomes smaller also.

Explaining graphically what I mean:


That is,older satellites can tend to give bigger extent values.
I think that to make comparisons with older years, NSIDC is better. But to follow the last years, ADS-NIPR-VISHOP or Hamburg University will be more accurate.
« Last Edit: June 09, 2019, 07:08:35 AM by Juan C. García »
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

Rich

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Re: 2019 sea ice area and extent data
« Reply #1028 on: June 09, 2019, 06:44:08 AM »
Are there any plans to reduce the grid size?

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #1029 on: June 09, 2019, 06:58:36 AM »
Are there any plans to reduce the grid size?
There are always new satellites with better resolution. The question is if institutions like NSIDC are going to change the algorithm that they use to measure extent and take full advantage of the new instruments.

https://nsidc.org/news/newsroom/first-data-sets-icesat-2-data-now-available
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

Stephan

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Re: 2019 sea ice area and extent data
« Reply #1030 on: June 09, 2019, 08:51:34 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

June 8th, 2019:
     10,361,292 km2, a drop of -24,937 km2.
     2019 is 2nd lowest on record.
   

The "2017 feeling" remains. Area and extent losses below average. No acceleration of extent losses, independent of what is written in the "2019 melt season" thread.
One reason may be that we are already quite low - the ice that has to be melted now, is further north and maybe thicker or harder to melt than in the peripheral seas further south...

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1031 on: June 09, 2019, 10:14:52 AM »
Are there any plans to reduce the grid size?
There are always new satellites with better resolution. The question is if institutions like NSIDC are going to change the algorithm that they use to measure extent and take full advantage of the new instruments.

Nobody can go back in time and adjust the NSIDC data collected by the instrument on the DMSP satelliteS  to the higher resolution data collected by current instruments and maintain consistency in the record. That is why the graphs using higher-resolution data from the new instruments on the new satellites (e.g. from Wipneus) only go back a few years.

The much greater problem is the inevitability of the NSIDC record dating from 1979 ending. The satellite up there is years beyond its design life and the United States Air Force programme DMSP was killed by Mike Rogers in 2017. The last satellite is now in a museum somewhere.

I asked NSIDC a few months ago what the plan is for when this last satellite fails. The answer was along the lines of "under discussion". It will be a real shame if this unique record is cut short.

As Arctic Sea Ice Shows Record Decline, Scientists Prepare to Go Blind
https://www.newsdeeply.com/oceans/articles/2017/05/30/as-arctic-sea-ice-shows-record-decline-scientists-prepare-to-go-blind

Air Force unveils $500M satellite museum piece
https://www.c4isrnet.com/home/2017/12/22/500m-never-flown-air-force-weather-satellite-goes-on-display/
_____________________________________________________________________
And things are not much better at JAXA. JAXA’s GCOM-W1 satellite was launched in 2012 with the Advanced Microwave Scanning Radiometer 2 (AMSR2) on board.

Its design life was 3 to 5 years.
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Jontenoy

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Re: 2019 sea ice area and extent data
« Reply #1032 on: June 09, 2019, 10:25:27 AM »
Looking at AREA ~ EXTENT again, a good explanation was given by Neven in 2010....

"Say, for instance, we have three grid cells. One is covered with 10% ice, the second with 50% ice and the third with 100% ice. The first grid cell has less than 15% ice concentration and so isn't counted, but the other two are. Total extent is thus 1,250 square km (two grid cells of 625 km). For total area we take 10%, 50% and 100% of the surface areas of the grid cells, adding up to 937.5 square km (0 + 312.5 + 625). Total area will practically always be lower than extent."

oren

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Re: 2019 sea ice area and extent data
« Reply #1033 on: June 09, 2019, 10:44:00 AM »
Are all certain of this? I seem to recall that area is only counted in cells where concentration is above 15%.

Edit: that's what Neven's example shows. But the words seem to imply differently.

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Re: 2019 sea ice area and extent data
« Reply #1034 on: June 09, 2019, 10:48:46 AM »
So, if we were to lose the old satellites we would lose the ability to make apples to apples comparisons with past years.....and would then transition to reporting on data from the new satellites?

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1035 on: June 09, 2019, 10:49:54 AM »
JAXA ARCTIC EXTENT :- 10,361,292 km2(June 8, 2019)

EDIT: - Extent is 2nd lowest in the satellite record, 88 83 k > 2016, 97 96 k < 2018, 641 483 k < 2012.
- Extent loss on this day 25  k, 29 k less than the average loss on this day of 54 k.
- Extent loss from maximum 3,910 k, 395 k (11%) greater than the average of 3,515k loss from maximum by this day,
- On average 35.6% of the melting season done, with 97 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 4.00 million km2, 2nd lowest in the satellite record, and 0.82 million km2 above the 2012 low of 3.18 million km2.
Looking at the last 5 years average remaining melt gives a result of 4.17 million km2, 4th lowest, 0.99 million km2 above 2012.

Other Stuff

GFS shows temperature anomalies varying from +1.5 to +2.6. Positive anomalies spread over most of the Arctic.

So far average remaining melt data still points towards a 2nd lowest minimum well above 2012. However, only just over 1/3rd of the average melt in the season completed.
« Last Edit: June 09, 2019, 12:24:36 PM by gerontocrat »
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1036 on: June 09, 2019, 10:55:56 AM »
So, if we were to lose the old satellites we would lose the ability to make apples to apples comparisons with past years.....and would then transition to reporting on data from the new satellites?

Yes - the NSIDC record is unique and to keep consistency must NOT use more accurate data.
If it all goes to pot I guess there will be some sort of fudge with a caveat about using data spanning the years of analysis from different instruments and different algorithms.
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Rich

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Re: 2019 sea ice area and extent data
« Reply #1037 on: June 09, 2019, 11:28:31 AM »
Thank you for the explanation gerontocrat. I agree that it will be a shame to lose the apples to apples comparison, but also look forward to more accurate data.

I think it might be hard to justify a half billion dollars to prolong the life of the older data. We know enough about the direction of the sea ice trend toward zero at this point.

Hopefully, the US and JAXA satellites don't cut out in roughly the same time frame. That would seem to make for a tricky reporting transition here at ASIF.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1038 on: June 09, 2019, 11:42:15 AM »

I think it might be hard to justify a half billion dollars to prolong the life of the older data. We know enough about the direction of the sea ice trend toward zero at this point.

Satellites are NOT single use. The satellites used by NSIDC were part of the USAF system for combat readiness (as well as sea ice, weather data and other stuff (classified))  . USAF is now looking at satellites from friendly countries to maintain its combat readiness data. Friends may not be friends forever.

The sum required to put the last one up was 50 million USD, while it cost USD 500 million to build. To scrap it was an act of monumental stupidity.
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1039 on: June 09, 2019, 02:15:12 PM »
NSIDC Total Area as at 8 June 2019 (5 day trailing average) 9,303,316 km2
               
Total Area         
 9,303,316    km2      
-189,470    km2   <   2010's average.
-109,077    k   <   2018
-702,888    k   <   2000's average.
         
Total Area Change   -29    k   loss
Peripheral Seas   -19    k   loss
Central Seas__   -2    k   loss
Other Seas___   -8    k   loss
         
Peripheral Seas         
Bering _______   -1    k   loss
Baffin  Bay____   -15    k   loss
Greenland____    0    k   gain
Barents ______   -4    k   loss
         
CAB Seas         
Beaufort_____   -13    k   loss
CAA_________    0    k   gain
East Siberian__    1    k   gain
Central Arctic_    24    k   gain
         
Kara_________   -2    k   loss
Laptev_______   -4    k   loss
Chukchi______   -8    k   loss
         
Other Seas         
Okhotsk______    1    k   gain
St Lawrence___   -0    k   loss
Hudson Bay___   -9    k   loss

Area loss 29 k, 45 k LESS than the 2010's average loss of 74 k on this day.
Total area still 2nd lowest (448 k > 2016)

Other Stuff
GFS shows temperature anomalies varying from +1.5 to +2.6. Positive anomalies spread over most of the Arctic. with extreme +ve anomalies in Eastern Siberia from Today onwards for one week, and high +ve anomalies in Baffin Bay and the CAA developing.

Recent daily area losses consistently lower than average, the last 2 days at  less than half the 2010's average area loss on those days.

Note that daily sea ice area loss is entering the peak season, as must 2019 to stay in contact with 2016 and 2012 (just about to fall over the cliff).
____________________________________________________________
bbr2314's Panzer divisions ran out of gas?
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1040 on: June 09, 2019, 02:28:06 PM »
 It's been a long time since I gave the graphs an airing. So here are the area graphs

The Peripheral Seas.

The Bering Sea - all over bar the shouting. The second year where winter has seen the sea as an open water sea, not an icy sea.

the Baffin Sea - area now at a record low (3 days on the trot).

The Greenland Sea - area stalled or growing - Fram export?

The Barents Sea - area loss very slow - clockwise rotation of the entire icepack ?
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1041 on: June 09, 2019, 02:34:46 PM »
To continue

Seas with little or no connection to the Arctic Ocean

Hudson Sea - pretty much average,
Okhotsk - almost finished,
St Lawrence - I am told the area data ain't real - artifacts.
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1042 on: June 09, 2019, 02:45:53 PM »
The 7 seas of the High Arctic - area graphs again
Because these seas determine the final outcome.

The High Arctic Graph shows area loss has slowed and then stalled. This is in great contrast to two of the High Arctic Seas....

The Chukchi has been lowest in the satellite record for 81 days this year and continues to quickly melt out
The Beaufort has been lowest in the satellite record for 15 days this year and continues to quickly melt out.

but elsewhere.....

 
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1043 on: June 09, 2019, 02:50:46 PM »
......
The Central Arctic Sea (the big beast)
The Canadian Archipelago
The East Siberian Sea

all went into reverse at the end of May...

and...
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1044 on: June 09, 2019, 02:54:05 PM »
....
The Kara and Laptev seas are declining at around average.
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Killian

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Re: 2019 sea ice area and extent data
« Reply #1045 on: June 09, 2019, 02:58:41 PM »
I see that the graph has "corrected" itself. The same years are shown in the two graphs below, but look at the lines and colors around minimum. Totally different in the two versions, with the lower looking a lot more like it "should".

I'd guess the error was in coloration of the graph w/ him just messing it up on the earlier one, perhaps using a "paint" function and it going awry. Then, either he caught it or... maybe he read your comment here.

;-)

He's at @ZLabe on twitter if you want to query.

meddoc

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Re: 2019 sea ice area and extent data
« Reply #1046 on: June 09, 2019, 03:58:59 PM »
....
The Central Arctic Sea (the big beast)
The Canadian Archipelago
The East Siberian Sea
all went into reverse at the end of May...

The Kara and Laptev seas are declining at around average.

That's all just wind- driven Dispersion.

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #1047 on: June 10, 2019, 05:43:21 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

June 9th, 2019:
     10,318,541 km2, a drop of -42,751 km2.
     2019 is 2nd lowest on record.
     (2012 highlighted).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1048 on: June 10, 2019, 05:47:16 AM »
JAXA ARCTIC EXTENT :- 10,318,541 km2(June 9, 2019)

- Extent is 2nd lowest in the satellite record, 81  k > 2016, 94 k < 2018, 641 483 374k < 2012.
- Extent loss on this day 43  k, 9 k less than the average loss on this day of 52 k.
- Extent loss from maximum 3,953 k, 386 k (11%) greater than the average of 3,566k loss from maximum by this day,
- On average 36.1% of the melting season done, with 96 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 4.00 million km2, 2nd lowest in the satellite record, and 0.82 million km2 above the 2012 low of 3.18 million km2.
Looking at the last 5 years average remaining melt gives a result of 4.17 million km2, 4th lowest, 0.99 million km2 above 2012.

Other Stuff

GFS shows temperature anomalies varying from +1.8 to +3.2. Positive anomalies spread over most of the Arctic, with high +ve anomalies at various times along the coastal fringes of Eastern and Central Siberia and the entire coastal fringe of Alaska, Canada and Greenland.

So far average remaining melt data still points towards a 2nd lowest minimum well above 2012. However, only just over 1/3rd of the average melt in the season completed.
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1049 on: June 10, 2019, 02:34:13 PM »
NSIDC Total Area as at 9 June 2019 (5 day trailing average) 9,266,422 km2
               
Total Area         
 9,266,422    km2      
-139,571    km2   <   2010's average.
-80,093    k   <   2018
-681,204    k   <   2000's average.
         
Total Area Change   -37    k   loss
Peripheral Seas   -11    k   loss
Central Seas__   -9    k   loss
Other Seas___   -17    k   loss
         
Peripheral Seas         
Bering _______   -1    k   loss
Baffin  Bay____   -9    k   loss
Greenland____    1    k   gain
Barents ______   -2    k   loss
         
CAB Seas         
Beaufort_____   -12    k   loss
CAA_________   -4    k   loss
East Siberian__   -4    k   loss
Central Arctic_    17    k   gain
         
Kara_________    2    k   gain
Laptev_______   -2    k   loss
Chukchi______   -6    k   loss
         
Other Seas         
Okhotsk______    1    k   gain
St Lawrence___   -1    k   loss
Hudson Bay___   -17    k   loss

Area loss 37 k, 44 k LESS than the 2010's average loss of 81 k on this day.
Total area still 2nd lowest (498 k greater than 2016, and only 23 K less than 2012)

Other Stuff
GFS forecasts show temperature anomalies varying from +1.8 to +3.2. Positive anomalies spread over most of the Arctic, with high +ve anomalies at various times along the coastal fringes of Eastern and Central Siberia and the entire coastal fringe of Alaska, Canada and Greenland.

Recent daily area losses consistently lower than average, the last 3 days at  less than half the 2010's average area loss on those days.

Note that daily sea ice area loss is entering the peak season, as must 2019 to stay in contact with 2016 and 2012 (now falling over the cliff).
____________________________________________________________
AREA to be half a million km2 GREATER THAN 2016 says to me that perhaps the undoubtedly extraordinary area losses in the Chukchi and the Beaufort are not the whole story.
"Para a Causa do Povo a Luta Continua!"
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