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Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #350 on: March 26, 2018, 06:25:14 AM »
JAXA March 25th, 2018: 13,645,538 km2, a drop of 22,577 km2.
I still think that 2018 can become the lowest on record by the end on March.  8)
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.

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #351 on: March 26, 2018, 06:41:11 AM »
In fact, I am concerned about the end of March forecast. (+3.5°C ?)  :(

Edit 1:
Sorry, I saw Antarctic. Arctic +2.0°C. Still, it looks strong to me.

Edit 2:
I was sure that I saw the 3.5°C on the Arctic.
It is until April 1st. Hope it change to a lower anomaly.
[See 2nd image]
« Last Edit: March 26, 2018, 06:55:47 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.

litesong

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Re: 2018 sea ice area and extent data
« Reply #352 on: March 26, 2018, 03:25:18 PM »
In fact, I am concerned about the end of March forecast. (+3.5°C ?)  :(
Edit 2:
I was sure that I saw the 3.5°C on the Arctic.
It is until April 1st. Hope it change to a lower anomaly.
[See 2nd image]
Right now the entire High Arctic temperature has rebounded from a temporary sub-average temperature to its present 4degC above average. A relative small eastern Siberian region of heat is feeding into the High Arctic. However, a vast line of excess AGW heat from northern Africa to China may also be supporting the eastern Siberian heat flow to the High Arctic. It is this present Africa to China heat(which was positioned further north) that supported the continuous 215 days of High Arctic temperatures of the past winter, the Present High Arctic Berserker(2) or FAB 8)(2).
Of course, the sun has moved ~ 25arcdegs to the north since the beginning of winter & direct solar TSI heat is beginning to raise High Arctic heat. At some point direct solar TSI heat will overcome AGW heat to provide the most heat to the High Arctic. The import of this distinction is that present AGW heat is higher than past AGW heat, while direct solar TSI heat has been low for 11+ years(including a 3+ year period setting a 100 year record low). The low direct solar TSI appears to be affecting High Arctic summer temperatures & driving such temperatures to a sub-average High Arctic level..... as opposed to excess present AGW winter (darkness) heat in the High Arctic that supports winter (& longer) continuous over-temperatures. If the coming summer High Arctic temperatures(driven by low direct solar TSI) do dip below average temperatures, those temperatures do NOT off-set the ever increasing High Arctic winter continuous over-temperature anomalies, confirmed by FAB 8)(2),  FAB 8)(1) & other CONTINUOUSLY increasing days of CONTINUOUS High Arctic over-temperatures.   
« Last Edit: March 26, 2018, 04:02:07 PM by litesong »

oren

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Re: 2018 sea ice area and extent data
« Reply #353 on: March 26, 2018, 06:07:06 PM »
Litesong sorry but this belongs in a different thread (not sure which). This one is for area and extent data.

gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #354 on: March 26, 2018, 09:41:38 PM »
NSIDC Daily Extent at 25 March =  14,192,000 km2, down a mere 8k.

Extent at 25 March is 119k MORE than 2017 on that date (downa trifle from 127k).  But the March 2018 simple average to date is still 95 k less than the 2017 simple March average to 25 March. It is therefore still very probable that NSIDC will record March 2018 as the lowest extent in the satellite record by about 75 to 100k, especially given that in 2017 there was an extent GAIN from 24 to 31 March of 99 k. Just 20+k loss from now to 31 March will make 2018 lowest again. 25 March, 2018 was again 2nd lowest, once gain lower than 2006 - by just 20k.

If NSIDC posts a +75-100k record low March average, this would be (I think) a small acceleration in annual winter sea loss, and in my opinion, more significant than the daily extent max coming in at second lowest. CAVEAT : Not sure how NSIDC is calculating average now.

NSIDC Peripheral Seas Extent as at 25 March - 5 day trailing average

The ups and down of daily extent gains and losses are continuing to feed into the five-day average extent losses in the peripheral seas. Total Peripheral Seas extent losses were just 5k . By far the greatest loss again  (-24k) was in the Bering Sea.

I attach the NSIDC image of NSIDC concentration. It shows where the ice is vulnerable - just about everywhere in the periphery, the south of Chukchi and the western edge of Hudson Bay.
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Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #355 on: March 27, 2018, 06:18:45 AM »
JAXA March 26: 13,663,549 km2. An increase of 18,011 km2.  :o

I guess that it is an increase in extent, not necessary on area.
But I am just guessing!  ;)
« Last Edit: March 27, 2018, 06:28:54 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.

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #356 on: March 28, 2018, 05:46:26 AM »
JAXA March 27th: 13,700,128 km2. An increase for second consecutive day. Today it increased 36,579 km28)
« Last Edit: March 28, 2018, 05:56:28 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.

Lord M Vader

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Re: 2018 sea ice area and extent data
« Reply #357 on: March 28, 2018, 02:18:37 PM »
NSIDC also reports an uptick. Somewhat bigger though, up 49K... Might be due to Fram transport and the fact that the melting hasn't really started in Okhotsk. Once Okhotsk starts melting it will go down quickly..

The 5-day average is still moving down and is by a very slim margin still second lowest behind 2017.

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #358 on: March 29, 2018, 05:56:06 AM »
JAXA March 28th: 13,681,496 km2. A drop of -18,632 km2.
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.

romett1

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Re: 2018 sea ice area and extent data
« Reply #359 on: March 29, 2018, 06:43:19 PM »
Small update before storm - Bering Sea ice area (5-day trailing average) has dropped additional 4,000 km² (NSIDC). 2007 - 2017 average reached current level 56 days later on May 23.

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #360 on: March 30, 2018, 06:02:05 AM »
JAXA March 29th: 13,674,556 km2. A drop of -6,940 km2.
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.

Shared Humanity

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Re: 2018 sea ice area and extent data
« Reply #361 on: March 30, 2018, 06:58:23 PM »
Soon to be 4th lowest.

magnamentis

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Re: 2018 sea ice area and extent data
« Reply #362 on: March 30, 2018, 10:09:22 PM »
Soon to be 4th lowest.

and bit later to be lowest again, this is ice drift caused slow down of extent loss IMO, let's see

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #363 on: April 02, 2018, 06:03:48 AM »
2018 started a clear downward trend, losing extent for five consecutive days:

Date                    SIE (km2)       Change
Mar 27, 2018     13,700,128      36,579
Mar 28, 2018     13,681,496     -18,632
Mar 29, 2018     13,674,556       -6,940
Mar 30, 2018     13,652,018     -22,538
Mar 31, 2018     13,625,158     -26,860
Apr 01, 2018     13,586,994      -38,164

2018 is now the third lowest on record:

Year         SIE (km2)      VS 2018
2015      13,638,921      51,927
2006      13,610,775      23,781
2018      13,586,994               0
2017      13,562,063     -24,931
2016      13,461,256   -125,738  (the lowest)

In order to be 2018 the lowest on record by April 15th, it will need to have an average daily drop of a little more than -33,420 km2.
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: 2018 sea ice area and extent data
« Reply #364 on: April 02, 2018, 06:40:22 AM »
Thank you for your early updates, JCG.

gregcharles

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Re: 2018 sea ice area and extent data
« Reply #365 on: April 03, 2018, 12:53:38 AM »
Not much change in the daily records since last month. 2018 picked up a few, and has nearly two thirds of the daily records for Q1. There's a small chance of more records in April, but then 2016 becomes dominant until summer, and hopefully 2018 won't challenge that.

« Last Edit: April 03, 2018, 01:10:17 AM by gregcharles »

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #366 on: April 03, 2018, 06:50:50 AM »
Thank you for your early updates, JCG.

You are welcome, Oren!

I am not sure that I will be able to do it all nights (for me  ;) ), so if someone can try to do it also, that will be good. I will check if someone did it, before I do it.
The important thing is to have it right away!

JAXA April 2nd, 2018: 13,555,616 km2. A drop of -31,378 km2.
2018 is now second 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.

Jim Pettit

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Re: 2018 sea ice area and extent data
« Reply #367 on: April 03, 2018, 12:50:00 PM »
I am not sure that I will be able to do it all nights (for me  ;) ), so if someone can try to do it also, that will be good. I will check if someone did it, before I do it.
The important thing is to have it right away!

FWIW, I maintain a similar graph for both IJIS and NSIDC extent over at my climate graphs site. If you ever need a day or two off, everyone feel free to see my versions:

IJIS (Click for larger image):


NSIDC (Click for larger image):


Images are updated on the server every day around 1200 UTC.

litesong

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Re: 2018 sea ice area and extent data
« Reply #368 on: April 04, 2018, 05:04:55 AM »
I am not sure that I will be able to do it all nights (for me  ;) ), so if someone can try to do it also, that will be good. I will check if someone did it, before I do it.
The important thing is to have it right away!

FWIW, I maintain a similar graph for both IJIS and NSIDC extent over at my climate graphs site. If you ever need a day or two off, everyone feel free to see my versions:

IJIS (Click for larger image):


NSIDC (Click for larger image):


Images are updated on the server every day around 1200 UTC.
  Jim.... your graphs & details are spectacular. Your decade decreases in Arctic sea ice Volumes, even betters your spectaculars, tho.
http://iwantsomeproof.com/extimg/siv_annual_polar_graph.png
 At no point during the Earth's revolutions around the sun since the 1980's, do any of Arctic sea ice Volume decade losses cross other Arctic sea ice decade Volume losses. Its almost..... digital!!!! Even with the solar TSI being languid for half a century AND low for 11+ years (including a 3+ year period setting a 100 year record low), Arctic sea ice Volume losses.....remain losses.  There are zero decades of Arctic sea ice Volume increases, with the Arctic sea ice Volume losses of the "2010's" giving little hint that the "cold" sun will have much of any effect on continuing Arctic sea ice Volume losses.
Ditto for your decade extent losses, also:
http://iwantsomeproof.com/extimg/sie_annual_polar_graph.png
« Last Edit: April 04, 2018, 02:46:03 PM by litesong »

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #369 on: April 04, 2018, 06:26:54 AM »
FWIW, I maintain a similar graph for both IJIS and NSIDC extent over at my climate graphs site. If you ever need a day or two off, everyone feel free to see my versions:
...
Images are updated on the server every day around 1200 UTC.

Hi, Jim,

Your graph is great. Is there a way to update it when JAXA figures are published?
It will be great to put it on this thread, when the new data appears.

JAXA had a century drop today!  :o

April 3rd, 2018: 13,418,227 km2. A drop of -137,389 km2.
2018 is now the lowest on record!  :P
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: 2018 sea ice area and extent data
« Reply #370 on: April 04, 2018, 07:52:55 AM »
April 3rd, 2018: 13,418,227 km2. A drop of -137,389 km2.
2018 is now the lowest on record!  :P
Wow. That came out of the blue.

RikW

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Re: 2018 sea ice area and extent data
« Reply #371 on: April 04, 2018, 09:00:14 AM »
April 3rd, 2018: 13,418,227 km2. A drop of -137,389 km2.
2018 is now the lowest on record!  :P
Wow. That came out of the blue.

some more of these and it will be blue ;)

I'm really curious how soon Bering sea will reach zero/ how much earlier in the season that will happen

Wherestheice

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Re: 2018 sea ice area and extent data
« Reply #372 on: April 04, 2018, 09:40:42 AM »
Yikes!
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Neven

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Re: 2018 sea ice area and extent data
« Reply #373 on: April 04, 2018, 10:00:11 AM »
Like Vyvyan from the Young Ones said: That's all right. It was an accident waiting to happen.

Wow... Curious to see which regions contributed most.
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E. Smith

gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #374 on: April 04, 2018, 02:05:24 PM »
Gerontocrat has been and is a poorly bunny, as is his computer.
Normal service may be resumed next week sometime.
But for an hour or two, Gerontocrat is functioning on a functioning (borrowed) computer. Messy but workable.

JAXA DATA AS AT 3RD APRIL

The recent extent losses means, to me, that once again albedo warming potential is high at the time of year and the latitudes (the periphery) where insolation is already high. See Arctic3 attached below. 1.7 million of open ocean where in the 1980's  there was ice must have some positive feedback (especially as this is year after year). It is even 0.5 million more than the 2010's average.

The recent extent losses also mean that using remaining melt in previous years always produces a minimum extent less than last year, while 10 year average remaining melt results in a minimum of 3.82 million, but that average is distorted by the extraordinary melt of 2012. (See Arctic1).
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Neven

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Re: 2018 sea ice area and extent data
« Reply #375 on: April 04, 2018, 02:15:52 PM »
That drop that was reported today, was the largest March drop in the 2005-2018 period. I wonder if there will be a rebound tomorrow...
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gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #376 on: April 04, 2018, 02:46:52 PM »
NSIDC Regional Sea Ice Extent Data (5 day trailing average)

Table below shows extent losses in Bering, Okhotsk, Baffin and St Lawrence  - and as yet do not show full effect of total Arctic daily extent losses of -27,000 (1 April) -68,000 (2 April) and
-138,000 (3 April).
"Para a Causa do Povo a Luta Continua!"
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oren

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Re: 2018 sea ice area and extent data
« Reply #377 on: April 04, 2018, 02:51:22 PM »
That drop that was reported today, was the largest March drop in the 2005-2018 period. I wonder if there will be a rebound tomorrow...
Intetesting that NSIDC reports a similar daily drop.

Neven

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Re: 2018 sea ice area and extent data
« Reply #378 on: April 04, 2018, 05:37:23 PM »
That should be 'largest April drop'.
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E. Smith

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Re: 2018 sea ice area and extent data
« Reply #379 on: April 04, 2018, 07:16:59 PM »
That drop that was reported today, was the largest March drop in the 2005-2018 period. I wonder if there will be a rebound tomorrow...
Intetesting that NSIDC reports a similar daily drop.
That would tend to argue against a rebound tomorrow....if I understand correctly that these are different data.

magnamentis

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Re: 2018 sea ice area and extent data
« Reply #380 on: April 04, 2018, 08:21:16 PM »
April 3rd, 2018: 13,418,227 km2. A drop of -137,389 km2.
2018 is now the lowest on record!  :P
Wow. That came out of the blue.

not really, i had some post in reply to SharedHumanity 7-8 days ago but still there is never a guarantee that things go the way we thought ;) it's just that okhotsk as well as some other regions were quite green and yellowish for quite a few days on the UniBremen maps. and so much south there must be some significant solar impact by now.

A "significant" rebound for above reasons is not probable while small moves are hardly predictable if anything. no cold spell in those regions and the now increased area of open water will certainly catch a fair share of sunlight, albedo is dropping
« Last Edit: April 04, 2018, 08:26:35 PM by magnamentis »

bbr2314

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Re: 2018 sea ice area and extent data
« Reply #381 on: April 04, 2018, 08:24:44 PM »
April 3rd, 2018: 13,418,227 km2. A drop of -137,389 km2.
2018 is now the lowest on record!  :P
Wow. That came out of the blue.

not really, i had some post in reply to SharedHumanity 7-8 days ago but still there is never a guarantee that things go the way we thought ;) it's just that okhotsk as well as some other regions were quite green and yellowish for quite a few days on the UniBremen maps. and so much south there must be some significant solar impact by now.

i rebound for above reasons is not probable, no cold spell in those regions and the now increased area of open water will certainly catch a fair share of sunlight, albedo is dropping
I agree. I think we will see massive continued sustained declines as the fake ice a la 2012 gives out even earlier than that year (with substantially more heat bubbling into Beaufort and Chukchi as we speak).

Wherestheice

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Re: 2018 sea ice area and extent data
« Reply #382 on: April 04, 2018, 08:30:41 PM »
the ice is definitely gonna be interesting this year
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Re: 2018 sea ice area and extent data
« Reply #383 on: April 05, 2018, 10:39:57 AM »
That drop that was reported today, was the largest March drop in the 2005-2018 period. I wonder if there will be a rebound tomorrow...
I have an IJIS  drop of 169382 on Mar 23 2014. Making this the second biggest drop to date.
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Re: 2018 sea ice area and extent data
« Reply #384 on: April 05, 2018, 10:44:11 AM »
That should be 'largest April drop'.
And a drop of 154512 on April 10 2004 makes it the second biggest drop in April. It  does rate as the third biggest drop prior to June 1st.
Toto, I've a feeling we're not in Kansas anymore

oren

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Re: 2018 sea ice area and extent data
« Reply #385 on: April 05, 2018, 12:56:10 PM »
Surprisingly, instead of a correction we have another small drop:
13,387,430, down 30,797 from yesterday's 13,418,227, and still at 1st place slightly below 2016.

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #386 on: April 05, 2018, 02:01:11 PM »
Surprisingly, instead of a correction we have another small drop:
13,387,430, down 30,797 from yesterday's 13,418,227, and still at 1st place slightly below 2016.

Even that 2017 is lower than 2016 on April 13th-16th, afterwards 2016 has a deep drop trend, being the lowest until June 27th.
So, in order to be 2018 the lowest on April 15th, it has to drop a daily average of 26k km2 for 11 days. But the real question is if 2018 will emulate 2016 afterwards and/or which will be its value at the end of June, when several years have similar extent.

Edit:
If 2018 follows 2016 on May, it will be a heart attack year for some of us, that follow-up the ASIE daily...
« Last Edit: April 05, 2018, 02:40:16 PM 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

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Re: 2018 sea ice area and extent data
« Reply #387 on: April 05, 2018, 03:01:54 PM »
JAXA Data as at 4th April 2018

Nothing to add to Juan's comments except to say

- that since 2016 CO2 is up by over 4 ppm,
- CO2 emissions rose in 2017 and are expected to rise again in 2018,
- global ocean heat content is up substantially (record increase in 2017) and should rise strongly in 2018 while La Nina or ENSO neutral conditions prevail,
- global warming potential in the peripheral seas is already high due to current low sea ice extent,
- I understand ocean temperature anomalies (especially in the N. Pacific?) are very high,

so conditions favour melting and it would require a really lousy Arctic summer as in last year to prevent strong extent loss at least at the moment.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #388 on: April 06, 2018, 06:11:04 AM »
JAXA April 5th, 2018: 13,371,769 km2. A drop of -15,661 km2.
2018 continues to be the lowest on record.
« Last Edit: April 07, 2018, 08:20:38 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

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Re: 2018 sea ice area and extent data
« Reply #389 on: April 06, 2018, 04:37:45 PM »
To add to Juan's analysis,

NSIDC Regional Extent Data ( 5 day trailing average) as at 5th April 2018

The strongest extent loss by far is in the Okhotsk Sea another 26 k on top of 21k and 14k the two days before. On the one hand this is irrelevant to what happens in the CAB, but on the other hand its another 60k of open water at around 60 o North so high insolation.

Regional sea ice extent loss in total was 46k, with no extent losses in the CAB (but Area?)

NSIDC Daily extent loss for the Arctic was 47k after a small gain of 12k the day before.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #390 on: April 07, 2018, 07:54:45 AM »
JAXA April 6th, 2018: 13,376,062 km2. A slight increase of 4,293 km2.
Now, 2018 is second lowest on record, above 2016 by 23,970 km2.
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.

Jim Pettit

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Re: 2018 sea ice area and extent data
« Reply #391 on: April 07, 2018, 02:21:55 PM »
In the meantime, NSIDC is firmly in first place after a solid 93k drop:

CLICK FOR LARGER AND MOST-RECENT IMAGE]



Tor Bejnar

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Re: 2018 sea ice area and extent data
« Reply #392 on: April 07, 2018, 02:54:21 PM »
Jim wrote "CLICK FOR LARGER AND MOST-RECENT IMAGE]".  When I don't click on the image, I definitely see an old image.
Arctic ice is healthy for children and other living things because "we cannot negotiate with the melting point of ice"

Alexander555

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Re: 2018 sea ice area and extent data
« Reply #393 on: April 07, 2018, 03:47:33 PM »
How do you get that big difference in the the average 1980 and 1990 data ? Is it because they exclude/include some area's in the periferhy ?

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #394 on: April 07, 2018, 06:09:07 PM »
How do you get that big difference in the the average 1980 and 1990 data ? Is it because they exclude/include some area's in the periferhy ?

There is not an important difference between NSIDC 1980's and 1990's average...
Or are you talking on JAXA figures? I don't know how they calculated...
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.

charles_oil

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Re: 2018 sea ice area and extent data
« Reply #395 on: April 07, 2018, 06:58:51 PM »

Alex - Maybe you meant between 1990s and 2000s.  Best to go to NSIDC chartic (easy via ASI graphs) and you can see all the different lines & add / remove them as required as well as the std deviations etc. 


The 2010's line will be a step down again (probably...).


Jim Pettit

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Re: 2018 sea ice area and extent data
« Reply #396 on: April 07, 2018, 08:54:56 PM »
Jim wrote "CLICK FOR LARGER AND MOST-RECENT IMAGE]".  When I don't click on the image, I definitely see an old image.

I imagine you're looking at a locally cached version of that image; I promise it links to the current one. :)

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #397 on: April 08, 2018, 06:12:40 AM »
JAXA April 7th,2018: 13,358,472 km2. A drop of -17,590 km2.
2018 is second lowest on record, above 2016 by 49,216 km2.

How do you get that big difference in the the average 1980 and 1990 data ? Is it because they exclude/include some area's in the periferhy ?

JAXA April 7th:
    80’s Average: 15,070,144 km2.
    90’s Average: 14,590,636 km2.
    Difference 80’s – 90’s: 479,508 km2.

I agree that the JAXA difference seems big.  :o
Maybe someone else on this Forum can give us an answer, because I don't know why...

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.
« Last Edit: April 08, 2018, 06:55:19 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.

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #398 on: April 08, 2018, 07:19:03 AM »
How do you get that big difference in the the average 1980 and 1990 data ? Is it because they exclude/include some area's in the periferhy ?

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:
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.

Alexander555

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Re: 2018 sea ice area and extent data
« Reply #399 on: April 08, 2018, 07:50:44 AM »
My question was about the diffrence between the JAXA end the NSIDC. But i explained myself pretty bad. With the JAXA you see a clear trend , the 1990 average is half a million below the 1980 average. And if you look at the NSIDC , at some days the 1990 average is above the 1980 average.