Support the Arctic Sea Ice Forum and Blog

Author Topic: 2018 sea ice area and extent data  (Read 133423 times)

Daniel B.

  • ASIF Middle Class
  • Posts: 632
    • View Profile
  • Liked: 8
  • Likes Given: 28
Re: 2018 sea ice area and extent data
« Reply #750 on: June 13, 2018, 02:42:39 PM »
By comparison, the sea ice area is looking healthier than the extent (based on historical data).  The area is only 5th lowest, compared to extent, which is 2nd lowest (based on NORSEX algorithm).  Although the extent looks like it will become 3rd or 4th lowest rather soon.




gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #751 on: June 13, 2018, 03:38:44 PM »
NSIDC Total Area  as at 12th June (5 day trailing average) =  9,167,062 km2


Analysis of individual seas.

Pacific Side
- The Okhotsk Sea area is 18 k.
- The Bering Sea area is 3k.
- Chukchi Sea +1 k, Beaufort Sea -1 k.
i.e. Pacific side stalled...

Atlantic Side
- Total area loss of the Baffin, Greenland, and Barents Seas 9k.
- The Laptev Sea area loss 29 k again  .
- The Kara Sea area loss 7 k.

CAB
- The Central Arctic Sea loss 8k.
- The Canadian Archipelago loss 13k.
- East Siberian Sea 5k

Other seas
- St Lawrence area is <3k,
- Hudson Bay area loss 18k, but still well behind 2010's average area.

But of note is -
- that area loss far exceeds extent loss in the Central Seas (see above posting), while the opposite sometimes happens in the peripheral seas. In total, area loss is still consistently ahead of extent loss. .

- the Laptev Sea Ice is disappearing really fast.
[/quote]
"Para a Causa do Povo a Luta Continua!"

Lord M Vader

  • ASIF Upper Class
  • Posts: 1182
    • View Profile
  • Liked: 6
  • Likes Given: 3
Re: 2018 sea ice area and extent data
« Reply #752 on: June 13, 2018, 05:09:41 PM »
Daily NSIDC Extent reveals an UPTICK of +17K. How unusual is this during the months June-July when the melting is at its largest pace?

miki

  • ASIF Lurker
  • Posts: 55
    • View Profile
  • Liked: 4
  • Likes Given: 31
Re: 2018 sea ice area and extent data
« Reply #753 on: June 13, 2018, 05:24:22 PM »
Daily NSIDC Extent reveals an UPTICK of +17K. How unusual is this during the months June-July when the melting is at its largest pace?

Maybe it's just spreading a bit ?

jdallen

  • ASIF Governor
  • Posts: 2646
    • View Profile
  • Liked: 22
  • Likes Given: 50
Re: 2018 sea ice area and extent data
« Reply #754 on: June 13, 2018, 06:20:12 PM »
[quote author3=Lord M Vader link=topic=2223.msg158597#msg158597 date=1528902581]
Daily NSIDC Extent reveals an UPTICK of +17K. How unusual is this during the months June-July when the melting is at its largest pace?
[/quote]
Dispersal could do this, especially considering how fragmented the ice is.
This space for Rent.

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #755 on: June 13, 2018, 07:03:28 PM »
[quote author3=Lord M Vader link=topic=2223.msg158597#msg158597 date=1528902581]
Daily NSIDC Extent reveals an UPTICK of +17K. How unusual is this during the months June-July when the melting is at its largest pace?
Dispersal could do this, especially considering how fragmented the ice is.
[/quote]
Add to this quite a fierce warming event on the Russian side - even more melting & dispersion. Presumably if that warmth continues it will start to appear in extent data in the next few days.

if not - I will stop making comment entirely and just post the data.
"Para a Causa do Povo a Luta Continua!"

oren

  • ASIF Upper Class
  • Posts: 2154
    • View Profile
  • Liked: 80
  • Likes Given: 171
Re: 2018 sea ice area and extent data
« Reply #756 on: June 13, 2018, 07:51:01 PM »
Daily NSIDC Extent reveals an UPTICK of +17K. How unusual is this during the months June-July when the melting is at its largest pace?
Finally an easy question about arctic sea ice...
According to NSIDC extent data, this happens about 2 times per month in June, and another 1.3 times in July, so nothing to worry about. The typical maximal upward tick is around 40k in June and 25k in July. Even 2012 saw 2 upticks during its spectacular June (but it also saw 13 century breaks).

magnamentis

  • ASIF Upper Class
  • Posts: 1433
    • View Profile
    • Philosophy Ethics Numerology Mikrocirkulation Vaskular Therapie Gesundheit Blut Gesundheit Schmerzen Multiple Sklerose Diabetes Immunsystem Fibromyalgia Modular Mobile Computing iOS Software OSX Android Custom Rom Rooted
  • Liked: 17
  • Likes Given: 41
Re: 2018 sea ice area and extent data
« Reply #757 on: June 13, 2018, 09:23:17 PM »
Daily NSIDC Extent reveals an UPTICK of +17K. How unusual is this during the months June-July when the melting is at its largest pace?
Finally an easy question about arctic sea ice...
According to NSIDC extent data, this happens about 2 times per month in June, and another 1.3 times in July, so nothing to worry about. The typical maximal upward tick is around 40k in June and 25k in July. Even 2012 saw 2 upticks during its spectacular June (but it also saw 13 century breaks).

not sure if the uptick as such is the issue, my point has always been that certain physical conditions must be met for ice to grow or stay equal over all while there is definitely huge melting going on in some places.

the conclusion from this is that the models are not reliable and unfortunately not only that, but at times very very far of.

if dispersion would be the problem, at temps around or above zero, there is no refreeze between fragments, hence area should go down somehow in relation to extent and to me it does not look like it, just show me where i overlook something if that is the case.

IMO data are wrong, a bit rude and a bit too simple perhaps but as i said IMO and IMO mean exactly that, not more but also not less ;)

if there were (there were of course) such upticks in earlier years that only tells me they were wrong as well because without freezing conditions ice cannot freeze, hence it can compact and loose extent but gain area through closed gaps, or it can disperse, gain extent but loose area by opining gaps.

something along that line, while if bot numbers grow or stay level at those temps, something can't be rigth.

again i'm gladly looking forward for input that would explain that in a comprehensive manner.
http://magnamentis.com
Knowledge, Understanding & Insight Are Among The Best Sources For Personal Freedom & Vitality !

dosibl

  • ASIF Lurker
  • Posts: 36
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: 2018 sea ice area and extent data
« Reply #758 on: June 13, 2018, 10:03:34 PM »
I believe extent data is measured and not modeled (I wouldn't count any light post-processing of measurements as modeling), so I'm inclined to decently trust these numbers. With dispersion I'd expect to see a moderate loss of area with neutral or rising extent, which would mean lower compaction. Compaction has indeed been going down over the past several days, so dispersion seems like a reasonable conclusion.

https://sites.google.com/site/cryospherecomputing/daily-data

Stephan

  • ASIF Lurker
  • Posts: 30
    • View Profile
  • Liked: 5
  • Likes Given: 0
Re: 2018 sea ice area and extent data
« Reply #759 on: June 13, 2018, 10:15:57 PM »
I think that unusual winds push ice back again into already open waters (Beaufort, Chukchi, NE Barents, Hudson, ..., see e.g. in the animation of Universität Bremen). The loss in Kara and Laptev can't make up for that. This is IMO the reason for the slow-down of extent loss of the last week. As temps are around or slightly above zero in the most areas a refreeze does not happen. I think the ice volume still decreases although the extent is more or less stable.
So if melting goes on and wind directions re-change the extent loss will return to its "roughly as expected" pace in the second half of June. But the run for second lowest extent is probably lost for this year.

oren

  • ASIF Upper Class
  • Posts: 2154
    • View Profile
  • Liked: 80
  • Likes Given: 171
Re: 2018 sea ice area and extent data
« Reply #760 on: June 13, 2018, 10:45:05 PM »
if dispersion would be the problem, at temps around or above zero, there is no refreeze between fragments, hence area should go down somehow in relation to extent and to me it does not look like it, just show me where i overlook something if that is the case.
Gerontocrat posted this chart up-thread showing exactly what you describe, area going down relative to extent. Dispersion.


Juan C. García

  • ASIF Middle Class
  • Posts: 633
    • View Profile
  • Liked: 32
  • Likes Given: 20
Re: 2018 sea ice area and extent data
« Reply #761 on: June 14, 2018, 06:05:04 AM »
[ADS-NIPR-JAXA] ASI Extent.

June 13th, 2018: 10,363,905 km2, a drop of -14,325 km2.
2018 is the fifth lowest on record.

Lowest   Year     Extent          Difference
   1st.   2016     10,100,637    -263,268
  2nd.   2012     10,223,116    -140,789
   3rd.   2017     10,299,545      -64,360
   4th.   2011     10,334,450      -29,455
   6th.   2015     10,402,787        38,882
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

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #762 on: June 14, 2018, 11:40:08 AM »
JAXA Extent 10,363,905 km2(June 13, 2018)

Again,just to add to Juan's post :
- Extent loss for the melting season to date is, at 3.53 million km2, 290k below the average for the last 10 years. That is a significant amount. Consistently slightly slower than or at average daily melt, a very low 36k, 25k, 44k, 23k and 15k, an increase of 3k, and now a drop of 14k.

Extent is now just 67k (0.7%) below the average for 2010-2017.

On average 38% of the melting is done for this season - still a long way to go, on average 96 91 days.

Excluding 2012 from the 10 year average extent loss. The outcome for the minimum then comes in at 4.33 million km2 as opposed to 4.22 million km2. The range of outcomes from the last 10 years remaining melt is 3.3 to 4.6 million km2.

All is confusion ?:- (I am confused, anyway)

On 11th and 12th June NSIDC daily area loss was 90k per day. I expect (ha-ha)something like that again for the 13th.

GFS (from cci-reanalyzer) still shows large areas of the Arctic having had, getting, and will continue to get a dose of real warmth.

Meanwhile extent loss for the last 7 days has been very, very much below average. See the graph Indeed, if one look at this extent data only for a view of the September minimum one would be thinking more like 4.5 million rather than circa 4.0 million km2 a week or two ago.

I continue to recommend readers have a good long read of the melting season thread - melting ponds / surface water confusing the area data? Ice spread out confusing the extent data?

Time will make things clearer but I think my choices for the June poll for the September minimum requires "Mystic Meg's" assistance even more urgently.
« Last Edit: June 14, 2018, 01:38:18 PM by gerontocrat »
"Para a Causa do Povo a Luta Continua!"

Jim Pettit

  • Global Moderator
  • ASIF Upper Class
  • *****
  • Posts: 1151
    • View Profile
  • Liked: 8
  • Likes Given: 1
Re: 2018 sea ice area and extent data
« Reply #763 on: June 14, 2018, 12:39:22 PM »
Over the past nine days, JAXA Arctic extent has dropped by just 286k. That's precisely as much as was lost during the same span in 2015, and 33k more than was lost in 2016. In fact, of the past four seasons (including this one), only 2017 lost more over the span, with a nine-day loss of 696k. (2012 is still the winner for the period by a long shot, dropping a whopping 1.13M km2, or nearly four times as much as this year's loss.)

It will take more time to know for sure, of course, but my guess is that the seeming disappearance of what used to be known as the early June "cliff" is a new (and perhaps temporary) normal, a complex product of lower spring maximums and numerous other factors.

Anyway: JAXA extent is today in 5th place--somewhere it hasn't been since mid-March--and unless it drops by at least 20k tomorrow, 2018 will fall back to 7th place, somewhere it hasn't been this year. 2018 JAXA extent has spent 20 days in 3rd place, 69 days in 2nd, and 66 days in 1st; just nine days have fallen outside the top three.

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #764 on: June 14, 2018, 02:17:25 PM »
NSIDC Total Area  as at 13th June (5 day trailing average) =   9,109,264 km2

Total Area loss 58k, Central Seas 35k Periphery 6k, Other (Hudson) 17k.   

Analysis of individual seas.

Pacific Side
- The Okhotsk Sea area is 17 k.
- The Bering Sea area is 3k.
- Chukchi Sea +1 k, Beaufort Sea -6 k (Canadian (western) end?).
i.e. Pacific side slow...

Atlantic Side
- Total area loss of the Baffin, Greenland, and Barents Seas just 6 k.
- The Laptev Sea area loss 23 k again  .
- The Kara Sea area loss 7 k.

CAB
- The Central Arctic Sea gained 22k.
- The Canadian Archipelago loss 13k.
- East Siberian Sea loss 13k

Other seas
- St Lawrence area is <3k,
- Hudson Bay area loss 17k, but total area still well behind 2010's average area.
"Para a Causa do Povo a Luta Continua!"

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #765 on: June 14, 2018, 02:54:16 PM »
Just a note to say that this year the melting season has seen a couple of noteworthy events, even if in overall terms things are looking average to slow.

Over half of the sea ice in the Bering Sea was never there, and the remainder disappeared in April and May,

Just one week ago the Laptev Sea started to lose ice at an extraordinary rate and at the moment it is hard to see that not continuing.
"Para a Causa do Povo a Luta Continua!"

Pagophilus

  • ASIF Lurker
  • Posts: 96
    • View Profile
  • Liked: 41
  • Likes Given: 59
Re: 2018 sea ice area and extent data
« Reply #766 on: June 14, 2018, 11:19:57 PM »
I like that you take the last nine days of data and interpret from that, rather than the last couple of days or so.  In my opinion (derived from observations on Worldview and the arguments of others) much of the declining loss (and even small gain) of extent comes from the floes streaming out of the north/east Kara Sea and into the Barents, where they contribute to extent but are rapidly melting out (see image below, fine ribbons of ice at right (S of FJL) that probably still count as extent).

I am a little surprised (no doubt there is a reason) that the Charctic Interactive graph is not mentioned more often here.  I know it has a 5 day trailing average, but that is not dissimilar to your taking the last nine days as a guide to events.  On Charctic, 2018 is still just in second place, although the rate of decline of extent has slowed.  Still, it provides some perspective on what some seem to regard as a baffling or even poor melting year.  Personally, I am rooting for even slower rates of decline, but I think I will be disappointed.  Charctic image attached.  Insight on this would be most welcome.

Over the past nine days, JAXA Arctic extent has dropped by just 286k. That's precisely as much as was lost during the same span in 2015, and 33k more than was lost in 2016. In fact, of the past four seasons (including this one), only 2017 lost more over the span, with a nine-day loss of 696k. (2012 is still the winner for the period by a long shot, dropping a whopping 1.13M km2, or nearly four times as much as this year's loss.)

It will take more time to know for sure, of course, but my guess is that the seeming disappearance of what used to be known as the early June "cliff" is a new (and perhaps temporary) normal, a complex product of lower spring maximums and numerous other factors.

Anyway: JAXA extent is today in 5th place--somewhere it hasn't been since mid-March--and unless it drops by at least 20k tomorrow, 2018 will fall back to 7th place, somewhere it hasn't been this year. 2018 JAXA extent has spent 20 days in 3rd place, 69 days in 2nd, and 66 days in 1st; just nine days have fallen outside the top three.

Juan C. García

  • ASIF Middle Class
  • Posts: 633
    • View Profile
  • Liked: 32
  • Likes Given: 20
Re: 2018 sea ice area and extent data
« Reply #767 on: June 15, 2018, 05:52:57 AM »
[ADS-NIPR-JAXA] ASI Extent.

June 14th, 2018: 10,317,955 km2, a drop of -45,950 km2.
2018 is the fifth lowest on record.

« Last Edit: June 15, 2018, 05:59:22 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.

Wipneus

  • ASIF Governor
  • Posts: 3741
    • View Profile
    • Arctische Pinguin
  • Liked: 69
  • Likes Given: 0
Re: 2018 sea ice area and extent data
« Reply #768 on: June 15, 2018, 08:57:59 AM »
Over the past nine days, JAXA Arctic extent has dropped by just 286k. That's precisely as much as was lost during the same span in 2015, and 33k more than was lost in 2016. In fact, of the past four seasons (including this one), only 2017 lost more over the span, with a nine-day loss of 696k. (2012 is still the winner for the period by a long shot, dropping a whopping 1.13M km2, or nearly four times as much as this year's loss.)

It will take more time to know for sure, of course, but my guess is that the seeming disappearance of what used to be known as the early June "cliff" is a new (and perhaps temporary) normal, a complex product of lower spring maximums and numerous other factors.


About 230k of the slow decline in the begin of June can be explained by a particular "quirk" in the algorithm that Jaxa is using to calculate sea ice concentration with a "smooth" in the calculation to prevent an ugly bump in extent.

The adapted Bootstrap Algorithm that Jaxa uses switches on the first of June from dry ice surface to melting. The switch back to dry ice is set at 15th October. Some may remember old versions of the Jaxa extent graphs (at the time produced by a cooperation of IARC and Jaxa , known as IJIS), that did show visible "bumps" on these dates. A refinement in the calculation did a way with those, presumably by gradually smoothing the results.

The changeover can be observed in some of my graphics, showing extent calculated from Uni Hamburg and from Jaxa Sea Ice concentration. During the freezing season they mostly track each other quite well, but in June-September Jaxa extent is persistently higher.

Attached is a close-up what happens in the beginning of June. Plotted is the average extent in 6 years 2013-2018 from 25th May to 13th June.


gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #769 on: June 15, 2018, 10:29:03 AM »
JAXA Extent 10,317,955 km2(June 14, 2018)

Again,just to add to Juan's post :
- Extent loss for the melting season to date is, at 3.57 million km2, 320k below the average for the last 10 years. That is a significant amount. See the graph on how consistently slower than or average daily melt has been over the last week.

Extent is now just 46k (0.4%) below the average for 2010-2017.

On average 39% of the melting is done for this season - still a long way to go, on average 90 days.

Excluding 2012 from the 10 year average extent loss. The outcome for the minimum then comes in at 4.34 million km2 as opposed to 4.24 million km2. The range of outcomes from the last 10 years remaining melt is 3.3 to 4.6 million km2.

I continue to recommend readers have a good long read of the melting season thread - melting ponds / surface water confusing the area data? Ice spread out confusing the extent data?

Also read the Wipneus post above, suggesting that JAXA changing its algorithm on 1st June is at least partly responsible for the recorded low daily extent losses. Yet another reason for lpw confidence in any prediction of outcomes this early in the season.

Time will make things clearer but I think my choice later today for the June poll for the JAXA September daily minimum requires "Mystic Meg's" assistance even more urgently.
"Para a Causa do Povo a Luta Continua!"

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #770 on: June 15, 2018, 02:52:53 PM »
NSIDC Total Area  as at 14th June (5 day trailing average) =    9,021,998 km2

Total Area loss 87k, Central Seas 62k Periphery 8k, Other Seas 18k.   

Analysis of individual seas.

Pacific Side
- The Okhotsk Sea area is 16 k.
- The Bering Sea area is 2 k.
- Chukchi Sea +6 k, Beaufort Sea -11 k (Canadian (western) end?).
i.e. Pacific side slow...

Atlantic Side
- Total area loss of the Baffin, Greenland, and Barents Seas just 8 k.
- The Laptev Sea area loss 19 k .
- The Kara Sea area loss 10 k.

CAB
- The Central Arctic Sea gained 12k.
- The Canadian Archipelago loss 21k.
- East Siberian Sea loss 19k

Other seas
- St Lawrence area is 2 k,
- Hudson Bay area loss 16k, but total area still well behind 2010's average area.


PS:- NSIDC ONE DAY DAILY EXTENT DROPPED BY 110 K
"Para a Causa do Povo a Luta Continua!"

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #771 on: June 15, 2018, 04:20:53 PM »
NSIDC Area - Leaders and Laggards of ice loss by each regional sea

I last did this at the end of May. As I am in a dither about what bin to choose for the JAXA June poll, I thought I would give it another whirl.

Explanatory Note:
I developed these graphs to look at the current year in comparison with  10 year averages from the 80s, 90s 00s, and the 2010's to date (2010 to 2017). This tells me if the current year is likely (or not) to drag down the 2010's average area and also give an idea of trends in ice-free days (5%, 15% and 50%).
-------------
1) Pacific End

Bering - leader
Chukchi - laggard (was leader)
Beaufort - laggard
East Siberian Sea - laggard

c.fwd to next post    Leaders 1, Laggards 3
"Para a Causa do Povo a Luta Continua!"

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #772 on: June 15, 2018, 04:28:27 PM »
NSIDC Area - Leaders and Laggards of ice loss by each regional sea (continued)

I last did this at the end of May. As I am in a dither about what bin to choose for the JAXA June poll, I thought I would give it another whirl.

Explanatory Note:
I developed these graphs to look at the current year in comparison with  10 year averages from the 80s, 90s 00s, and the 2010's to date (2010 to 2017). This tells me if the current year is likely (or not) to drag down the 2010's average area and also give an idea of trends in ice-free days (5%, 15% and 50%).
-------------
2) Atlantic End

b.fwd from previous post    Leaders 1, Laggards 3

Baffin - laggard
Greenland Sea -  leader (still)
Barents - neutral
Kara Sea - laggard
Laptev Sea - leader (by a country mile)

c.fwd to next post    Leaders 3, Laggards 5, Neutral 1
"Para a Causa do Povo a Luta Continua!"

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #773 on: June 15, 2018, 04:37:28 PM »
NSIDC Area - Leaders and Laggards of ice loss by each regional sea (continued)

I last did this at the end of May. As I am in a dither about what bin to choose for the JAXA June poll, I thought I would give it another whirl.

Explanatory Note:
I developed these graphs to look at the current year in comparison with  10 year averages from the 80s, 90s 00s, and the 2010's to date (2010 to 2017). This tells me if the current year is likely (or not) to drag down the 2010's average area and also give an idea of trends in ice-free days (5%, 15% and 50%).
-------------
3) CENTRAL ARCTIC

b.fwd from previous post    Leaders 3, Laggards 5, Neutral 1

Canadian Archipelago - Neutral
Central Arctic Sea - Leader (but could become laggard very soon)

4) Other Seas

Hudson - Laggard,
Okhotsk - Leader,
St Lawrence - Neutral

Totals    Leaders 5, Laggards 6, Neutral 4

CONCLUSION - Somewhat of a average year or a bit slow. No help at all.
"Para a Causa do Povo a Luta Continua!"

jdallen

  • ASIF Governor
  • Posts: 2646
    • View Profile
  • Liked: 22
  • Likes Given: 50
Re: 2018 sea ice area and extent data
« Reply #774 on: June 15, 2018, 06:30:14 PM »
Apples->Apples question... while 2018 has 320k +/- less than average melt did wasn't the difference between average max and 2018 much higher than that?
This space for Rent.

magnamentis

  • ASIF Upper Class
  • Posts: 1433
    • View Profile
    • Philosophy Ethics Numerology Mikrocirkulation Vaskular Therapie Gesundheit Blut Gesundheit Schmerzen Multiple Sklerose Diabetes Immunsystem Fibromyalgia Modular Mobile Computing iOS Software OSX Android Custom Rom Rooted
  • Liked: 17
  • Likes Given: 41
Re: 2018 sea ice area and extent data
« Reply #775 on: June 15, 2018, 09:45:26 PM »

About 230k of the slow decline in the begin of June can be explained by a particular "quirk" in the algorithm that Jaxa is using to calculate sea ice concentration with a "smooth" in the calculation to prevent an ugly bump in extent.

The adapted Bootstrap Algorithm that Jaxa uses switches on the first of June from dry ice surface to melting. The switch back to dry ice is set at 15th October. Some may remember old versions of the Jaxa extent graphs (at the time produced by a cooperation of IARC and Jaxa , known as IJIS), that did show visible "bumps" on these dates. A refinement in the calculation did a way with those, presumably by gradually smoothing the results.

that's extremely useful to know, many thanks for this one
http://magnamentis.com
Knowledge, Understanding & Insight Are Among The Best Sources For Personal Freedom & Vitality !

Juan C. García

  • ASIF Middle Class
  • Posts: 633
    • View Profile
  • Liked: 32
  • Likes Given: 20
Re: 2018 sea ice area and extent data
« Reply #776 on: June 16, 2018, 05:51:27 AM »
[ADS-NIPR-JAXA] ASI Extent.

June 15th, 2018: 10,236,731 km2, a drop of -81,224 km2.
2018 is the fifth lowest on record.

« Last Edit: June 16, 2018, 06:09:15 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.

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #777 on: June 16, 2018, 10:32:45 AM »
JAXA Extent 10,236,731 km2(June 15, 2018)

Again,just to add to Juan's post ( I like the table, Juan):
- Extent loss for the melting season to date is, at 3.65 million km2, 300k below the average for the last 10 years. That is a significant amount. See the graph on how consistently slower than or average daily melt has been over the last week.

Extent is now just 66k (0.6%) below the average for 2010-2017.

On average 40% of the melting is done for this season - still a long way to go, on average 89 days.

Excluding 2012 from the 10 year average extent loss. The outcome for the minimum then comes in at 4.33 million km2 as opposed to 4.22 million km2. The range of outcomes from the last 10 years remaining melt is 3.3 to 4.6 million km2, (The average September minimum of the last 10 years is 4.41 million km2)

I continue to recommend readers have a good long read of the melting season thread - melting ponds / surface water confusing the area data? Ice spread out confusing the extent data?

ps: Mystic Meg and The Farmers' Almanac gave me no help for my guess at the September minimum.
« Last Edit: June 16, 2018, 10:38:02 AM by gerontocrat »
"Para a Causa do Povo a Luta Continua!"

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #778 on: June 16, 2018, 02:32:41 PM »
NSIDC ONE DAY DAILY EXTENT DROPPED BY:-

112 k 15th June
110 k 14th June

First double century break of the season? Now the June cliff starts (or not) ?

"Para a Causa do Povo a Luta Continua!"

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #779 on: June 16, 2018, 02:42:29 PM »
NSIDC Total Area  as at 15th June (5 day trailing average) = 8,918,224 km2

Total Area loss 104k, Central Seas 72k Periphery 12k, Other Seas 20k.   

First century area loss of the season?

Analysis of individual seas.

Pacific Side
- The Okhotsk Sea area is 15 k.
- The Bering Sea area is 2 k.
- Chukchi Sea -2 k, Beaufort Sea -7 k (Canadian (western) end?).
i.e. Pacific side slow...

Atlantic Side
- Total area loss of the Baffin, Greenland, and Barents Seas just 12 k.
- The Laptev Sea area loss 12 k .
- The Kara Sea area loss 21 k.

CAB
- The Central Arctic Sea gained 13k. Ice pushed in from CAA and ESS the last three days?
- The Canadian Archipelago loss 16k.
- East Siberian Sea loss 26 k

Other seas
- St Lawrence area is still 2 k,
- Hudson Bay area loss 19k, but total area still well behind 2010's average area.
"Para a Causa do Povo a Luta Continua!"

magnamentis

  • ASIF Upper Class
  • Posts: 1433
    • View Profile
    • Philosophy Ethics Numerology Mikrocirkulation Vaskular Therapie Gesundheit Blut Gesundheit Schmerzen Multiple Sklerose Diabetes Immunsystem Fibromyalgia Modular Mobile Computing iOS Software OSX Android Custom Rom Rooted
  • Liked: 17
  • Likes Given: 41
Re: 2018 sea ice area and extent data
« Reply #780 on: June 16, 2018, 10:33:02 PM »
NSIDC ONE DAY DAILY EXTENT DROPPED BY:-

112 k 15th June
110 k 14th June

First double century break of the season? Now the June cliff starts (or not) ?

this is a correction of the recent glitch in sensor reading and/or algorithms IMO

i mean it, not kidding
http://magnamentis.com
Knowledge, Understanding & Insight Are Among The Best Sources For Personal Freedom & Vitality !

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #781 on: June 16, 2018, 10:47:23 PM »
NSIDC ONE DAY DAILY EXTENT DROPPED BY:-

112 k 15th June
110 k 14th June

First double century break of the season? Now the June cliff starts (or not) ?

this is a correction of the recent glitch in sensor reading and/or algorithms IMO

i mean it, not kidding
What glitch ? - Both NSIDC and JAXA extent loss slowed a lot for the week before two days ago, and JAXA extent loss increased a bit on the 14th and rose above average on the 15th.

Independent data sets, different technology and different algorithms.

NSIDC area loss (5 day average) also accelerated on the 14th and 15th.

The data is consistent across all the measures.

Statements without evidence are not very helpful.

"Para a Causa do Povo a Luta Continua!"

Dharma Rupa

  • ASIF Citizen
  • Posts: 245
    • View Profile
  • Liked: 11
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #782 on: June 16, 2018, 11:42:29 PM »
Independent data sets, different technology and different algorithms.

NSIDC area loss (5 day average) also accelerated on the 14th and 15th.

The data is consistent across all the measures.

The weather has been hot for awhile...do we have any clue why the data just picked up in the last couple of days?

magnamentis

  • ASIF Upper Class
  • Posts: 1433
    • View Profile
    • Philosophy Ethics Numerology Mikrocirkulation Vaskular Therapie Gesundheit Blut Gesundheit Schmerzen Multiple Sklerose Diabetes Immunsystem Fibromyalgia Modular Mobile Computing iOS Software OSX Android Custom Rom Rooted
  • Liked: 17
  • Likes Given: 41
Re: 2018 sea ice area and extent data
« Reply #783 on: June 16, 2018, 11:45:13 PM »
What glitch ? - Both NSIDC and JAXA extent loss slowed a lot for the week before two days ago, and JAXA extent loss increased a bit on the 14th and rose above average on the 15th.

Independent data sets, different technology and different algorithms.

NSIDC area loss (5 day average) also accelerated on the 14th and 15th.

The data is consistent across all the measures.

Statements without evidence are not very helpful.

most theories that were later proven correct lacked evidence initially.

IMO those data were incorrect, it could be seen with naked eyes.

some believe in formulas even though they are based on past conditions that do not apply anymore.

the same is the reason why we have to work so hard to convince people to change their life style, it was working in the past and there is no evidence how exactly future will deal with certain changes, so we can lean back and live in the past until it's too late.

that said i have no problem with different points of view but will certainly keep mine until proven otherwise, thinking out of the box with an open ear for different opinions has often proven to be a good thing.

if i write IMO it means "in my opinion" and opinions are free and only i know my quota of ultimately having had the feel. perhaps it's poor perhaps it's close to 100% LOL.

thanks however for all the great contributions, my full respect and appreciation for sure.  ;)

EDIT: someone, i think it was WIP, even posted one possible explanation for possible flaws in algorithms leading possibly to errors (misinterpretation of readings)

i for one often think (without evidence) that we should perhaps start to pay more attention to water vapor and clouds as possible causes for spikes and throughs in the graphs. just an idea, really dunno and cant' prove anything but here i paste my reasoning, posted earler this week in the melting season thread:

a) almost the entire arctic is(was) around or above zero, (hence no refreeze is possible)

b) parts of the ice cover are/was hit with temps way above melting temps and in places above 30C
.   (and more widely spread between 20 and 25C)

c) ice is thin and mobile and the winter was warm

d) there have been extraordinarily strong winds recently and rain throwing water on the surface, 
.   (lowering albedo significantly)

the logics tell us that there has definitely been significant melt in some places but there has
certainly not been any refreeze because temps were far away from freezing point for see-ice.

the result is that there must have been a reduction in ice over all, melt versus no freeeze.

the charts/numbers were showing more or less the same like the day before and the above considered that's not possible without good explanation that evades me.

in the wake of this i believe that the numbers were wrong, without knowing how much, but if they were wrong they can as well be significantly wrong and sooner or later, once the reason for the glitch has gone aways, there would be a correction, this is what apparently is happening now.

no, this is not a proof, but it's also not totally of, not enough off to say it's useless to think about it and consider the possibility for errors of the kind WIP mentioned and/or others.
« Last Edit: June 17, 2018, 03:14:53 AM by magnamentis »
http://magnamentis.com
Knowledge, Understanding & Insight Are Among The Best Sources For Personal Freedom & Vitality !

magnamentis

  • ASIF Upper Class
  • Posts: 1433
    • View Profile
    • Philosophy Ethics Numerology Mikrocirkulation Vaskular Therapie Gesundheit Blut Gesundheit Schmerzen Multiple Sklerose Diabetes Immunsystem Fibromyalgia Modular Mobile Computing iOS Software OSX Android Custom Rom Rooted
  • Liked: 17
  • Likes Given: 41
Re: 2018 sea ice area and extent data
« Reply #784 on: June 17, 2018, 03:26:11 AM »
Independent data sets, different technology and different algorithms.

NSIDC area loss (5 day average) also accelerated on the 14th and 15th.

The data is consistent across all the measures.

The weather has been hot for awhile...do we have any clue why the data just picked up in the last couple of days?

that's exactly the question that made me think further and Wipneus posted somewhere a possible explanation.

again it's interesting how we have to loose ourselves in more or less personal (useless post) arguments, even though, at least i for my part, am so much in agreement with what is said here
and the general line of thinking is so often so similar. it's basically a waste somehow because if i remember correctly the same people themselves were very surprised as well and had difficulties to believe the numbers, while they obviously, other then myself, came to the decisions to believe the numbers more or less blindly while if i see a contradiction between condition and numbers someone would have to proof they're right and not only the other way around.

i believe that the algorithms are based on conditions decades ago when things were easier to calculate, high freeboards, stable ice cover with less fissures where the water can drain instead of ponding etc. etc. who can tell for sure that those calculations have the same accuracy and reliability nowadays like they had 10-15 years ago.

i don't insist that they don't but i suspect that they don't always and simply throw that into the round. gladly listing to proper explanation why my suspicion is wrong. after all i was thinking this is a place to discuss and not one to believe. if we were believers and not seekers for the truth, we could still believe that the earth is a disk. the guy who dared to suspect otherwise has almost been killed and history is full of such examples.

and no, galileo did not have proof in form of an image from space, he just made a logical assumption based on observations. other who did the same were wrong, he was right, so who knows exactly what we shall find out soon what the truth is.
http://magnamentis.com
Knowledge, Understanding & Insight Are Among The Best Sources For Personal Freedom & Vitality !

DavidR

  • ASIF Middle Class
  • Posts: 643
    • View Profile
  • Liked: 6
  • Likes Given: 1
Re: 2018 sea ice area and extent data
« Reply #785 on: June 17, 2018, 04:04:45 AM »

if i write IMO it means "in my opinion" and opinions are free and only i know my quota of ultimately having had the feel. perhaps it's poor perhaps it's close to 100% LOL.

a) almost the entire arctic is(was) around or above zero, (hence no refreeze is possible)

b) parts of the ice cover are/was hit with temps way above melting temps and in places above 30C
.   (and more widely spread between 20 and 25C)

c) ice is thin and mobile and the winter was warm

d) there have been extraordinarily strong winds recently and rain throwing water on the surface, 
.   (lowering albedo significantly)

the logics tell us that there has definitely been significant melt in some places but there has
certainly not been any refreeze because temps were far away from freezing point for see-ice.

the result is that there must have been a reduction in ice over all, melt versus no freeeze.

the charts/numbers were showing more or less the same like the day before and the above considered that's not possible without good explanation that evades me.

no, this is not a proof, but it's also not totally of, not enough off to say it's useless to think about it and consider the possibility for errors of the kind WIP mentioned and/or others.

The issue here is that extent is only a loose proxy for melt.  Because of the 15% threshhold for extent it is possible to go from 100% cover to 50 % cover without a drop in extent. In fact  it  is possible to  spread that 50% over double the area and double the extent. 

In my view that  is what we are seeing over the past few years. Extent within the central area starts June at very close to 100%. The ice is no longer cohesive so is easily spread by the prevailing winds so the extent decline in June is actually decreasing even though the melt is not.  Because the ice is loose right through the pack there is a brownian motion effect on the ice so that it is spread out into the space available. This was less common when the individual ice sheets were larger. This could even be affecting the PIOMAS modelling. 

Looking at 2015 we see a very low extent loss in June.  But the total volume loss from June 1 was nearly as high as 2012.  2017 on the other hand had a very high extent loss in June but ended with a low volume loss.  The prevailing winds appear to be much more important to the extent values in June than they were even a few years ago.
Toto, I've a feeling we're not in Kansas anymore

Pagophilus

  • ASIF Lurker
  • Posts: 96
    • View Profile
  • Liked: 41
  • Likes Given: 59
Re: 2018 sea ice area and extent data
« Reply #786 on: June 17, 2018, 05:28:48 AM »
Magnamentis, thanks for your thoughts.  I think it necessary to comment on a couple of your statements in the interests of accuracy.  First, sea ice extent is just sea ice extent.   There seems to be nothing wrong with the AMSR 2 measurements  -- they simply are what they are, and nothing more.  Processing the measurements through two different  algorithms and getting similar results for extent is pretty persuasive evidence that all is well. 

To challenge these measurements just because we think there has been a lot of melting of the ice is rather like challenging an accurate measurement of a person's height just because we think they have lost some weight.  One is not directly linked to the other.   

Second, Galileo was not persecuted for suggesting the Earth was a sphere and not a disk.  He was supporting Copernicus' idea, aided by evidence he, Galileo, had gathered, that the Earth orbited the Sun.  This was theologically perilous because it meant the Earth was not the center of the Universe. 

BTW, there was ample evidence that the Earth was a sphere by Galileo's time, and it had been gathered and mathematically analyzed.  An ancient Greek, Eratosthenes, had made a pretty good calculation of the size of the Earth.  And about a hundred years before Galileo was put on trial, Columbus had set sail to the west to get to the East Indies, a journey that would be irrational, if not suicidal, on a flat Earth.   

Independent data sets, different technology and different algorithms.

NSIDC area loss (5 day average) also accelerated on the 14th and 15th.

The data is consistent across all the measures.

The weather has been hot for awhile...do we have any clue why the data just picked up in the last couple of days?

that's exactly the question that made me think further and Wipneus posted somewhere a possible explanation.

i believe that the algorithms are based on conditions decades ago when things were easier to calculate, high freeboards, stable ice cover with less fissures where the water can drain instead of ponding etc. etc. who can tell for sure that those calculations have the same accuracy and reliability nowadays like they had 10-15 years ago.

i don't insist that they don't but i suspect that they don't always and simply throw that into the round. gladly listing to proper explanation why my suspicion is wrong. after all i was thinking this is a place to discuss and not one to believe. if we were believers and not seekers for the truth, we could still believe that the earth is a disk. the guy who dared to suspect otherwise has almost been killed and history is full of such examples.

and no, galileo did not have proof in form of an image from space, he just made a logical assumption based on observations. other who did the same were wrong, he was right, so who knows exactly what we shall find out soon what the truth is.
« Last Edit: June 17, 2018, 06:03:57 AM by Pagophilus »

Juan C. García

  • ASIF Middle Class
  • Posts: 633
    • View Profile
  • Liked: 32
  • Likes Given: 20
Re: 2018 sea ice area and extent data
« Reply #787 on: June 17, 2018, 05:53:41 AM »
JAXA Extent 10,236,731 km2(June 15, 2018)

Again,just to add to Juan's post ( I like the table, Juan):
Thanks, gerontocrat  :)
___________________________________
[ADS-NIPR-JAXA] ASI Extent.

June 16th, 2018: 10,169,264 km2, a drop of -67,467 km2.
2018 is the fifth lowest on record.
« Last Edit: June 17, 2018, 05:59:53 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.

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #788 on: June 17, 2018, 10:35:24 AM »
JAXA Extent 10,169,264 km2(June 16, 2018)

Again,just to add to Juan's post ( I like the table, Juan):
- Extent loss for the melting season to date is, at 3.72 million km2, 300k below the average for the last 10 years. That is a significant amount. See the graph on how consistently slower than or average daily melt was been over the week before the last two days.

Extent is now just 62k (0.6%) below the average for 2010-2017.

On average 40% of the melting is done for this season - still a long way to go, on average 88 days.

Excluding 2012 from the 10 year average extent loss. The outcome for the minimum then comes in at 4.33 million km2 as opposed to 4.22 million km2. The range of outcomes from the last 10 years remaining melt is 3.3 to 4.6 million km2, (The average September minimum of the last 10 years was 4.41 million km2)

I continue to recommend readers have a good long read of the melting season thread - melting ponds / surface water confusing the area data? Ice spread out confusing the extent data?

ps: Mystic Meg and The Farmers' Almanac gave me no help for my guess at the September minimum.
[/quote]
"Para a Causa do Povo a Luta Continua!"

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #789 on: June 17, 2018, 10:48:19 AM »
Independent data sets, different technology and different algorithms.

NSIDC area loss (5 day average) also accelerated on the 14th and 15th.

The data is consistent across all the measures.

The weather has been hot for awhile...do we have any clue why the data just picked up in the last couple of days?

that's exactly the question that made me think further and Wipneus posted somewhere a possible explanation.

I believe that the algorithms are based on conditions decades ago when things were easier to calculate, high freeboards, stable ice cover with less fissures where the water can drain instead of ponding etc. etc. who can tell for sure that those calculations have the same accuracy and reliability nowadays like they had 10-15 years ago.


Hullo magnamentis,

In your original post when you said "glitch" I thought you meant a temporary problem with the hardware or software used by NSIDC. If that was so, they would tell us ( hope). Hence my demand for evidence.

But when you say "based on conditions decades ago when things were easier to calculate" I think you may very well have a point, especially when looking at just one, two or three days observations.

Let's see what the NSIDC and JAXA data show us for the second half of June, because by the looks of it, Arctic temperatures (especially in Central Siberia) are looking warm to hot for the rest of the month.
"Para a Causa do Povo a Luta Continua!"

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #790 on: June 17, 2018, 02:48:39 PM »
NSIDC Total Area  as at 16th June (5 day trailing average) = 8,823,778 km2

Total Area loss 94k, Central Seas 64k Periphery 17k, Other Seas 13k.   

Another big loss.

Analysis of individual seas.

Pacific Side
- The Okhotsk Sea area is 15 k.
- The Bering Sea area is 2 k.
- Chukchi Sea -2 k, Beaufort Sea -7 k (Canadian (western) end?).
i.e. Pacific side slow...

Atlantic Side
- Total area loss of the Baffin, Greenland, and Barents Seas just 17 k, of which the Baffin was 15k
- The Laptev Sea area loss just 5 k .
- The Kara Sea area loss 21 k.

CAB
- The Central Arctic Sea gained 19k. Ice pushed in from CAA and ESS the last fourdays?
- The Canadian Archipelago loss 24k.
- East Siberian Sea loss 23 k

Other seas
- St Lawrence area is still 2 k,
- Hudson Bay area loss 13k, but total area still well behind 2010's average area.
"Para a Causa do Povo a Luta Continua!"

gerontocrat

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #791 on: June 17, 2018, 02:52:24 PM »
NSIDC ONE DAY DAILY EXTENT DROPPED BY:-

  96 k 16th June
112 k 15th June
110 k 14th June


Now looking increasingly at odds with JAXA extent loss data. Time will tell.
"Para a Causa do Povo a Luta Continua!"

Neven

  • Administrator
  • ASIF Royalty
  • *****
  • Posts: 5183
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 51
  • Likes Given: 53
Re: 2018 sea ice area and extent data
« Reply #792 on: June 17, 2018, 03:39:07 PM »
NSIDC area has been dropping as well, but not that much faster than extent, and so compactness is still relatively high (at last year's level now):
Il faut cultiver notre jardin

ArcticMelt1

  • ASIF Lurker
  • Posts: 33
    • View Profile
  • Liked: 12
  • Likes Given: 0
Re: 2018 sea ice area and extent data
« Reply #793 on: June 17, 2018, 06:20:54 PM »
In the Central Arctic is still a record.

ArcticMelt1

  • ASIF Lurker
  • Posts: 33
    • View Profile
  • Liked: 12
  • Likes Given: 0
Re: 2018 sea ice area and extent data
« Reply #794 on: June 17, 2018, 06:37:03 PM »
Now there is less ice around Svalbard than usually in September.  :'(

Juan C. García

  • ASIF Middle Class
  • Posts: 633
    • View Profile
  • Liked: 32
  • Likes Given: 20
Re: 2018 sea ice area and extent data
« Reply #795 on: June 18, 2018, 05:57:05 AM »
[ADS-NIPR-JAXA] ASI Extent.

June 17th, 2018: 10,126,025 km2, a drop of -43,239 km2.
2018 is the fifth lowest on record.
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

  • ASIF Upper Class
  • Posts: 2177
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: 2018 sea ice area and extent data
« Reply #796 on: June 18, 2018, 12:09:39 PM »
JAXA Extent 10,126,025 km2(June 17, 2018)

Again,just to add to Juan's post :
Extent loss for the melting season to date is, at 3.77 million km2, 310k below the average for the last 10 years. That is a significant amount. See the graph on how consistently slower than or average daily melt has been for some time.

Extent is now just 45k (0.4%) below the average for 2010-2017.

On average 41% of the melting is done for this season - still a long way to go, on average 87 days.

Excluding 2012 from the 10 year average remaining extent loss. The outcome for the minimum then comes in at 4.35 million km2 as opposed to 4.24 million km2. The range of outcomes from the last 10 years remaining melt is 3.3 to 4.6 million km2, (The average September minimum of the last 10 years was 4.41 million km2).

There is a contrast developing with NSIDC data, which has recently showed strong extent and area losses.
« Last Edit: June 18, 2018, 03:38:36 PM by gerontocrat »
"Para a Causa do Povo a Luta Continua!"

Aluminium

  • ASIF Lurker
  • Posts: 30
    • View Profile
  • Liked: 21
  • Likes Given: 18
Re: 2018 sea ice area and extent data
« Reply #797 on: June 18, 2018, 12:34:55 PM »
JAXA Extent 110,126,025 km2(June 17, 2018)
Wow. :)

Pmt111500

  • ASIF Upper Class
  • Posts: 1323
    • View Profile
  • Liked: 4
  • Likes Given: 2
Re: 2018 sea ice area and extent data
« Reply #798 on: June 18, 2018, 12:57:00 PM »
JAXA Extent 110,126,025 km2(June 17, 2018)
Wow. :)
I had to check if 11 or 10 was the correct one. I've been doing this for too long 8) 8).
A quantity relates to a quantum like camel's back relates to camel's _______ ? (back, vertebra, vertebral tendon, spinal disc, paralysis)

FishOutofWater

  • ASIF Citizen
  • Posts: 434
    • View Profile
  • Liked: 38
  • Likes Given: 17
Re: 2018 sea ice area and extent data
« Reply #799 on: June 18, 2018, 01:11:21 PM »
Yes, Pmt1111500.