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DavidR

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Re: 2019 sea ice area and extent data
« Reply #1550 on: July 10, 2019, 02:14:53 PM »
Would sunlight reflecting off a solid ice pack warm the air more than sunlight being absorbed by the open water between fractured floes?
No. The surface absorbs the majority of sunlight that the Earth absorbs. Air absorbs little sunlight. Any condition where the air above is warmer than the surface mean warmer air has been imported from elsewhere. Why do you ask?
With very  high albedo. corresponding  to fairly solid pack, 90% of the solar radiation is reflected giving it the opportunity to warm the air a second time. With a fragmented pack, as we see now, less radiation is reflected so  the warming of the atmosphere is muted. As a consequence air temperatures with a solid pack may be warmer than with a fragmented pack.
This could explain why summers back in the 40's and 50s were seen as nearly as warm as now in the NOAA-ESRL record.
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1551 on: July 10, 2019, 02:40:24 PM »
NSIDC Total Area as at 9 July 2019 (5 day trailing average) 5,995,583 km2
                        
Total Area         
 5,896,402    km2      
-502,741    km2   <   2010's average.
-425,800    k   <   2018
-1,189,398    k   <   2000's average.
         
Total Area Change   -99    k   loss
Peripheral Seas   -20    k   loss
Central Seas__   -59    k   loss
Other Seas___   -20    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -8    k   loss
Greenland____   -6    k   loss
Barents ______   -5    k   loss
         
CAB Seas         
Beaufort_____    4    k   gain
CAA_________   -9    k   loss
East Siberian__   -26    k   loss
Central Arctic_    3    k   gain
         
Kara_________   -10    k   loss
Laptev_______   -18    k   loss
Chukchi______   -4    k   loss
         
Other Seas         
Okhotsk______   -0    k   loss
St Lawrence___   -0    k   loss
Hudson Bay___   -20    k   loss

- Area loss 99 k, 1 k less than the 2010's average loss of 109 k on this day.
- Total area Lowest, 218 k LESS than 2016, and 146 k less than 2012.

Despite area loss back to average, 2019 is strengthening its position as front runner, but for how long?
 
Other Stuff
Weather
GFS over the next 7 days showing temperature anomalies falling from +1.7 to +0.2 degrees celsius.
- over the Arctic Ocean itself temperatures a bit above average,
- the CAA & Baffin Bay mostly warm,
- Western Canada stays mostly cool.
- Alaska and Eastern Siberian really warm,
- Central Siberia and Western Siberia mostly cool.

The winds described in previous posts seem to have mostly faded away.

A cliff or not a cliff** See below
We are in the period of maximum daily area loss that lasts until late July.
Area losses ticked up a lot in the last 10 days, but for the last 3 days steadily moderating.

It looks like Fram export has stalled, with most area losses in the arc from the ESS along the Russian shore and down to the Greenland Sea. The CAA is showing signs of melt. I think a posting in the Northern Sea Route thread might be interesting.

A steep downward slope, separating 2019 from 2016 and from 2012,  now continuing at average daily area losses..

NSIDC 5 day Area could/would/should/will/will-not continue in pole position for about one week/two weeks/the rest of July/the entire remaining melt season (delete as applicable).
________________________________________________________________________
** While NSIDC daily area loss has slipped back to average levels, daily extent loss (both NSIDC and JAXA) has been spectacularly high in the last few days. This is a reversal of a few days ago when Neven was posting the graphs showing concentration dropping into record lows, reflecting high area losses and low extent losses.

This apparent movement in waves when area and extent losses accelerate or decelerate in opposite directions seems to happen quite often. Yet another reason to be cautious with the hyperbole.
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Alphabet Hotel

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Re: 2019 sea ice area and extent data
« Reply #1552 on: July 10, 2019, 02:44:44 PM »
NSIDC daily extent

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1553 on: July 10, 2019, 03:08:21 PM »
NSIDC Daily Extent graph attached.

Also High Arctic Area graph and AWP graph from Tealight.
Area losses in the 7 central seas sufficient to maintain record cumulative AWP.
« Last Edit: July 10, 2019, 05:46:25 PM by gerontocrat »
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Metamemesis

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Re: 2019 sea ice area and extent data
« Reply #1554 on: July 10, 2019, 04:15:59 PM »
According to my spreadsheet, that's the third highest daily drop for July in the 2005-2019 period. 2012 and 2018 had a double century break, both on 24 July.

I do wonder when it starts to level off...

Neven, the daily extent drops show two consecutive double-century drops. Is the latest one a record? (Graph from Alphabet Hotel above)

Sterks

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Re: 2019 sea ice area and extent data
« Reply #1555 on: July 10, 2019, 04:26:31 PM »
NSIDC daily extent
Almost 800k in four days. If tomorrow goes similar, we might have a double century in the 5-day average, or 1 mill loss in 5 days!
Attached two-frame comparison of 1-week Jul 9 vs Jul 2 UH AMSR2, see the continuing Chukchi/ESS drop

Neven

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Re: 2019 sea ice area and extent data
« Reply #1556 on: July 10, 2019, 04:27:28 PM »
Neven, the daily extent drops show two consecutive double-century drops. Is the latest one a record? (Graph from Alphabet Hotel above)

I don't know. Unlike my JAXA spreadsheet, I didn't set up my NSIDC compactness spreadsheet to contain that information.
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BornFromTheVoid

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Re: 2019 sea ice area and extent data
« Reply #1557 on: July 10, 2019, 05:15:43 PM »
Neven, the daily extent drops show two consecutive double-century drops. Is the latest one a record? (Graph from Alphabet Hotel above)

Consecutive double centuries happen every now and then. The most recent was July 27th to 29th last year, with with drops of 211k and 253k.
2014 had one too, between the 27th and 29th of June, with 228k and 275k

Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #1558 on: July 10, 2019, 05:23:48 PM »
NSIDC daily extent
Almost 800k in four days. If tomorrow goes similar, we might have a double century in the 5-day average, or 1 mill loss in 5 days!
Attached two-frame comparison of 1-week Jul 9 vs Jul 2 UH AMSR2, see the continuing Chukchi/ESS drop

Mostly melt in that animation with the possible exception of the CAB near Beaufort which shows some compacting.

Ossifrage

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Re: 2019 sea ice area and extent data
« Reply #1559 on: July 10, 2019, 05:59:40 PM »
Mostly melt in that animation with the possible exception of the CAB near Beaufort which shows some compacting.

I'm not sure how much faith I have in that compaction. The area near the Beaufort/CAB/CAA boundary has been under increasingly heavy cloud for the past several days. It's especially evident on Worldview if you look west and northwest of Prince Patrick Island. However, what's visible through holes and breaks in that cloud isn't inspiring.

A cloud-free window at 150°W 80°N shows rubble with quite a bit of open water, and several visibly identifiable floes near Borden Island have broken apart over the last few days (in addition to displaying nontrivial westward movement).

That's not to say that there isn't some extent loss due to compaction and the way that extent is determined. But I certainly don't think there's good news for the ice in the northeast Beaufort.

Alphabet Hotel

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Re: 2019 sea ice area and extent data
« Reply #1560 on: July 10, 2019, 06:18:22 PM »
Here's a CSV file with the full NSIDC daily data and the calculated 1-day and 5-day extent changes.

be cause

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Re: 2019 sea ice area and extent data
« Reply #1561 on: July 10, 2019, 07:07:52 PM »
 ..that's approx 120 million football pitches in 4 days .. now that the Women's world cup has left everyone capable of visualising the measure .. or 10% of the remaining extent . Such falls would not need to become routine . I'm missing weatherdude telling me the weather is getting better for ice preservation . I'll have to try and convince myself .. b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 ...

magnamentis

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Re: 2019 sea ice area and extent data
« Reply #1562 on: July 10, 2019, 07:18:10 PM »
- Extent loss on this day 182 k, 92 k more than the average loss on this day of 92 k.

92+92=182?

consider how many numbers (data) the man is turning over each day for our all benefit,
such hints can be made a bit more friendly in my opinion.

kassy

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Re: 2019 sea ice area and extent data
« Reply #1563 on: July 10, 2019, 07:47:28 PM »
It´s in data itself which is a friendly format.
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Sterks

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Re: 2019 sea ice area and extent data
« Reply #1564 on: July 10, 2019, 08:13:08 PM »
Applied the filter, these are all 5-day avg double century drops in NSIDC, so we'll see tomorrow

Sterks

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Re: 2019 sea ice area and extent data
« Reply #1565 on: July 10, 2019, 08:17:01 PM »
Here's a CSV file with the full NSIDC daily data and the calculated 1-day and 5-day extent changes.
Thanks

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1566 on: July 10, 2019, 08:37:08 PM »
It´s in data itself which is a friendly format.
Data is not friendly
Data is not unfriendly
Data is
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u300673

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Re: 2019 sea ice area and extent data
« Reply #1567 on: July 10, 2019, 09:18:19 PM »
Applied the filter, these are all 5-day avg double century drops in NSIDC, so we'll see tomorrow
Careful with the data before 1987, as there is only data reported every two days. So the "five day average loss" is really a "ten day average two day loss".

-u300673

Frivolousz21

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Re: 2019 sea ice area and extent data
« Reply #1568 on: July 10, 2019, 09:25:57 PM »
Applied the filter, these are all 5-day avg double century drops in NSIDC, so we'll see tomorrow

Looks like the ice we lose now in May and early June would last so late in the 80s they would see cliffs just with the basin so much more ice filled.
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BornFromTheVoid

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Re: 2019 sea ice area and extent data
« Reply #1569 on: July 10, 2019, 09:41:11 PM »
Applied the filter, these are all 5-day avg double century drops in NSIDC, so we'll see tomorrow

Perhaps I've got something wrong, but I'm not getting those results. Are you sure the fact extent was collected every 2 days generally between 1979 and 1987 isn't messing up your stats?

Sourabh

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Re: 2019 sea ice area and extent data
« Reply #1570 on: July 10, 2019, 09:53:51 PM »
Neven, the daily extent drops show two consecutive double-century drops. Is the latest one a record? (Graph from Alphabet Hotel above)

Consecutive double centuries happen every now and then. The most recent was July 27th to 29th last year, with with drops of 211k and 253k.
2014 had one too, between the 27th and 29th of June, with 228k and 275k

Welcome back BFV. I missed your special updates you used to provide earlier related to severity of melting seasons.

Killian

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Re: 2019 sea ice area and extent data
« Reply #1571 on: July 10, 2019, 10:15:19 PM »
It´s in data itself which is a friendly format.
Data is not friendly
Data is not unfriendly
Data is

Exactly why I see Magnamentis' response as the problem, not Nikita's: Text is only 30~40% of meaning, so policing style is a no-win game which I strongly suggest not be played here. Less an actual insult to someone, why assume ill intent?

I hope we'll leave PC-speak to the Facebooks and Twitters of the world and deal with real shtuff here.

Anywho...

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1572 on: July 10, 2019, 10:19:32 PM »
It´s in data itself which is a friendly format.
Data is not friendly
Data is not unfriendly
Data is

Exactly why I see Magnamentis' response as the problem, not Nikita's: Text is only 30~40% of meaning, so policing style is a no-win game which I strongly suggest not be played here. Less an actual insult to someone, why assume ill intent?

I hope we'll leave PC-speak to the Facebooks and Twitters of the world and deal with real shtuff here.

Anywho...
The result of insomnia is early JAXA update postings + typos and other simple errors.
I would rather be sleeping late without the errors.
"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)

Sterks

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Re: 2019 sea ice area and extent data
« Reply #1573 on: July 10, 2019, 10:27:20 PM »
Applied the filter, these are all 5-day avg double century drops in NSIDC, so we'll see tomorrow

Perhaps I've got something wrong, but I'm not getting those results. Are you sure the fact extent was collected every 2 days generally between 1979 and 1987 isn't messing up your stats?
I just applied a filter <-199 to the column named "5-day avg" and that's what popped up.
I am interested on those days cause they mean 1 mill Km2 loss in 5 days which is quite extreme... as the filter shows it happened very few times. The 80's and a couple of days 12 years ago.

I don't care if there are consecutive days or not...

EDIT: oh reading the posts above I think two different statistics were proposed. I was looking at my own thing which is not exactly the same you were looking for.... Apologies for the confusion
« Last Edit: July 10, 2019, 10:37:00 PM by Sterks »

Alphabet Hotel

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Re: 2019 sea ice area and extent data
« Reply #1574 on: July 10, 2019, 10:41:26 PM »
Applied the filter, these are all 5-day avg double century drops in NSIDC, so we'll see tomorrow

Perhaps I've got something wrong, but I'm not getting those results. Are you sure the fact extent was collected every 2 days generally between 1979 and 1987 isn't messing up your stats?

Oh, I didn't even notice that. I'll try to do some kind of workaround tomorrow if nobody else gets to it. The only thing I can think of is to fake values for the missing days by averaging previous and next. I'm not much of a spreadsheet person though.

dnem

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Re: 2019 sea ice area and extent data
« Reply #1575 on: July 10, 2019, 10:44:46 PM »
The 2007 run includes a 320,000 km2 drop logged on July 1st which I think means that it is at least partially a data artifact.

The largest post 2007 5-day running drop is 180,000 around August 9, 2012 and again July 14, 2018.

Killian

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Re: 2019 sea ice area and extent data
« Reply #1576 on: July 11, 2019, 12:01:34 AM »
7/9/2019 JAXA extent @ 7.95M km sq.

Avg. daily melt required to maintain record extent lows:

7/10 - 7.97M km sq.  +20k km sq requiring <  +20k km sq avg/day
7/11 - 7.86M km sq.   -90k km sq requiring >   -45k km sq avg/day
7/12 - 7.69M km sq. -260k km sq requiring >   -86.6k km sq avg/day
7/13 - 7.57M km sq. -380k km sq requiring >   -95k km sq avg/day
7/14 - 7.44M km sq. -510k km sq requiring > -102k km sq avg/day
7/15 - 7.35M km sq. -600k km sq requiring > -100k km sq avg/day
7/16 - 7.24M km sq. -710k km sq requiring > -101.4k km sq avg/day
7/17 - 7.15M km sq. -800k km sq requiring > -100k km sq avg/day
7/18 - 7.06M km sq. -890k km sq requiring >  - 98.9k km sq avg/day
7/19 - 7.00M km sq. -950k km sq requiring >  - 95k km sq avg/day

If JAXA drops a very possible 100k/day through 1/19, it would be 50k below the record. I calculated the average daily extent reductions to minima for the three lowest years to get:

7/19 ~ 9/23/'07: 7,350,000 - 4,070,000 / 58 days = 70,172/day (+17 days over 2016)
7/19 ~ 9/15/'12: 7,220,000 - 3,180,000 / 58 days = 69,655/day (+9 days over 2016)
7/19 ~ 9/06/'16: 7,340,000 - 4,020,000 / 49 days = 67,755/day

The TOTAL differential is a tiny 2,417 km sq/day. That is incredible consistency. While the days to minimum varies significantly, the melt per day is nearly identical. I could never have predicted that; it's very counter-intuitive. Well, then, what would 2019 project out to if still holding the record on 7/19, using the 2012's extent and date for minimum?

7/19 ~ 9/15/19: 7,000,000 km sq - 3,180,000 km sq = 3,820,000 km sq / 58 days = 65,862/day, less than any of the other years, yet still remarkably close to them with a total spread of only 4,310 km sq./day.

Looking at the numbers this way makes a record minimum seem almost certain. If the next 10 days and the rest of the melt season are normal, and in fact, a little calmer and quieter than the other three years given what was posted WRT June heat correlating with Sept. minima, that 4,310 km sq cushion starts to look huge.

The caveat here is I am using only the highest melt years. If we throw in all the years, would it make a significant difference? Too tired to find out.

As ever, if I've made any math errors - quite likely - do help a brother out.

Killian

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Re: 2019 sea ice area and extent data
« Reply #1577 on: July 11, 2019, 12:10:55 AM »
It´s in data itself which is a friendly format.
Data is not friendly
Data is not unfriendly
Data is

Exactly why I see Magnamentis' response as the problem, not Nikita's: Text is only 30~40% of meaning, so policing style is a no-win game which I strongly suggest not be played here. Less an actual insult to someone, why assume ill intent?

I hope we'll leave PC-speak to the Facebooks and Twitters of the world and deal with real shtuff here.

Anywho...
The result of insomnia is early JAXA update postings + typos and other simple errors.
I would rather be sleeping late without the errors.

Even citizen science benefits from peer review.

 ;)

I don't care about the errors (I just spent a couple hours editing my latest post, including two really obvious math errors, and there are likely still language and math errors within), but here's to better sleep for you.

Cheers

Sterks

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Re: 2019 sea ice area and extent data
« Reply #1578 on: July 11, 2019, 12:29:54 AM »
Applied the filter, these are all 5-day avg double century drops in NSIDC, so we'll see tomorrow

Perhaps I've got something wrong, but I'm not getting those results. Are you sure the fact extent was collected every 2 days generally between 1979 and 1987 isn't messing up your stats?
By the way this would invalidate probably all those 80s hits I was getting, and the one in 2007 may be affected by the beginning of the month effect as indicated above.

So my table is reduced to nil in practical terms, and if tomorrow a extent loss or around 200k happens again making the 5 avg loss > 200k that would be unprecedented .... or morally at least.

Anyway to all involved in this my search thru the numbers of the year, cheers, now clearly I will never try occupy Gero’s place, good night!

Matt

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Re: 2019 sea ice area and extent data
« Reply #1579 on: July 11, 2019, 03:45:28 AM »
Isn't this as simple as Neven was commenting to Jaxa data and Alphabet Hotel's chart is NSIDC data? or do i have this completely wrong  ::)
 
Edit: sorry in reply to post 1553  :)

magnamentis

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Re: 2019 sea ice area and extent data
« Reply #1580 on: July 11, 2019, 04:06:40 AM »
as you like neven, but bear in mind that:

- that what you call blahblah.. is about the stuff that is a few layers lower and is responsible for the human behaviours that cause all that this forum is about. if you see this as blahblah... so be it, i say it's narrow minded and if you prefer the real blahblah.... over attempts to get to the root problems that are in humen behaviour and motivations and driving big cars for bragging rights is only a result of those underlaying causes.

on the other hand i cannot deny that it sometimes goes off hands, hence i'll make another attempt to let people talk and smile, if that helps the cause i doubt but it's your house, hence your rules.

cheers

DavidR

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Re: 2019 sea ice area and extent data
« Reply #1581 on: July 11, 2019, 05:08:11 AM »
According to my spreadsheet, that's the third highest daily drop for July in the 2005-2019 period. 2012 and 2018 had a double century break, both on 24 July.

I do wonder when it starts to level off...
There were however two larger breaks in August  and one in June.

2008-08-06  -183782

2012-08-08 -183330

There are few century  breaks after 8 August.

Toto, I've a feeling we're not in Kansas anymore

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #1582 on: July 11, 2019, 05:44:54 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 10th, 2019:
     7,839,653 km2, a century drop of -113,644 km2.
     2019 is the 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.

Killian

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Re: 2019 sea ice area and extent data
« Reply #1583 on: July 11, 2019, 07:53:23 AM »
7/9/2019 JAXA extent @ 7.95M km sq.

Avg. daily melt required to maintain record extent lows:

7/10 - 7.97M km sq.  +20k km sq requiring <  +20k km sq avg/day
7/11 - 7.86M km sq.   -90k km sq requiring >   -45k km sq avg/day
7/12 - 7.69M km sq. -260k km sq requiring >   -86.6k km sq avg/day

Update:

7/10/2019 JAXA extent @ 7.84M km sq.

7/11/11: 7.86M km sq.  +20k km sq requiring < +20k km sq
7/12/11: 7.69M km sq. -150k km sq requiring >  -75k km sq avg/day

2019 seems very likely to remain the record low extent through the 12th, though my gut says a significant slowing might happen. E.g., Windy dot come appears to indicate good conditions for dispersal. Still, looks like two more days of records.

Getting past the 12th in the lead just might set 2019 up to stay there until 7/24~27 when 2012 takes a four-day 570k km plunge from 6.94M km to 6.37M km.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1584 on: July 11, 2019, 08:18:57 AM »
JAXA ARCTIC EXTENT :-  7,839,653 km2(July 10, 2019)

5 century breaks in a row is serious melting. If it looks like a cliff, then it is a cliff.
One more daily loss like that and it is  time to reach for the hyperbolic dictionary for a hyperbolic "ooooh!".

- Extent is lowest in the satellite record.
- Extent loss on this day 114 k, 23 k more than the average loss on this day of 91 k.
- Extent loss from maximum 6,431 k, 476 k (8.0%) greater than the average of 5,956 k loss from maximum by this day,
- On average 60.3% of the melting season done, with 65 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.91 million km2, 2nd lowest in the satellite record, and 0.73 million km2 above the 2012 low of 3.18 million km2.

The first 9 days in July now certainly greatly above  average area loss.

Other Stuff
Weather
GFS  showing temperature anomalies in the range of  +1.5 to +0.5 degrees celsius.
Intially
- over the Arctic Ocean itself temperatures a bit above average,
- the CAA & Baffin Bay mostly warm,
- Western Canada stays mostly cool.
- Alaska and Eastern Siberian really warm,
- Central Siberia and Western Siberia mostly cool.
But from around 5 days, Central & Western Siberia heat up and Eastern Siberia cools down.

Over the next 5 days it looks like a fairly significant low sits over the Arctic Ocean sending strongish anticlockwise winds matching but opposite to the normal clockwise movement of the Beaufort Gyre. These low also looks like pushing ice north from the CAA/Beaufort crack (flaw polynya?)

This low then dissipates?

Area Loss Outlook
We are now in the period of maximum daily extent loss that lasts until mid or late July and then very gradually declines. Extent loss this month well above average. Immediate weather outlook suggests a slightly cooler of the Arctic but still moderately overall +ve temperature anomalies.

On every measure (JAXA extent, NSIDC daily and 5 day area and extent, and volume), 2019 is now lowest in the satellite record.

To end the season on a record low, remaining extent loss must be more than 20 % above the previous 10 years' average.
For a BOE,  remaining extent loss must be more than 70 % above the previous 10 years' average.

The June volume data persuaded me to drop my minimum guesstimate to below 4 million km2 from exactly 4 million km2. This assumes remaining extent loss will continue at  average.
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"Para a Causa do Povo a Luta Continua!"
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"Damn, I wanted to see what happened next" (Epitaph)

Richard Rathbone

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Re: 2019 sea ice area and extent data
« Reply #1585 on: July 11, 2019, 09:45:38 AM »
On June 30th JAXA was 121k ahead of the 2010s average, 870k ahead of the 2000s average, and 1563k ahead of the 1990s average. (all numbers based on Juan's postings)

On July 10th JAXA was 389k ahead of the 2010s, 1268k ahead on the 2000s and 2027k ahead of the 1990s.

Thats a pickup of 268k compared to the 2010s, 398k compared to the 2000s and 464k compared to the 1990s.

Chunky, but if I was putting (round) numbers on what makes a cliff, it would be beating the average for the time of year by at least 500k in at most 10 days.


gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1586 on: July 11, 2019, 09:53:36 AM »
Ok, so it was a mini-cliff.  5 century breaks in a row is unusual and shifted the outlook for the minimum from 4th to 2nd place.

That'll do, probably history now, unless it isn't.
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"Damn, I wanted to see what happened next" (Epitaph)

be cause

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Re: 2019 sea ice area and extent data
« Reply #1587 on: July 11, 2019, 10:03:28 AM »
I call it a cliff if you could break your leg by stepping off it . If Gerontocrat calls a cliff in melt I am happy to  keep my legs intact . I'll just look over the edge and agree .
  Of course there may be a few ledges on the way down . A dead cat might even bounce . b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 ...

Alphabet Hotel

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Re: 2019 sea ice area and extent data
« Reply #1588 on: July 11, 2019, 01:42:13 PM »
NSIDC daily extent

I've attached a CSV file with the data as well. I solved the every-other-day problem by dropping those rows, so now it only goes back to mid-1987 or so.

Killian

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Re: 2019 sea ice area and extent data
« Reply #1589 on: July 11, 2019, 02:52:53 PM »
According to the Pettite NSIDC graph, the Arctic just blew through 5M km sq of sea ice in just 70 days. Clearly a record, and an avg daily loss of 71,428, which is right in the ballpark of the daily losses needed after July 19, if the ASI is at or below 7M km sq on that date, to reach a new record low.

Holy flippin' moly.

(Does this belong on the Melt Season thread?)

Sterks

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Re: 2019 sea ice area and extent data
« Reply #1590 on: July 11, 2019, 02:56:46 PM »
NSIDC daily extent

I've attached a CSV file with the data as well. I solved the every-other-day problem by dropping those rows, so now it only goes back to mid-1987 or so.
Well, it seems the - 200k loss in the 5-day avg won't happen this time either, but it was seriously close. Huge extent loss in one week. Thanks for the data

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1591 on: July 11, 2019, 03:11:02 PM »
NSIDC Total Area as at 10 July 2019 (5 day trailing average) 5,782,390 km2
                        
Total Area         
 5,782,390    km2      
-519,485    km2   <   2010's average.
-477,162    k   <   2018
-1,215,861    k   <   2000's average.
         
Total Area Change   -114    k   loss
Peripheral Seas   -14    k   loss
Central Seas__   -80    k   loss
Other Seas___   -20    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -9    k   loss
Greenland____   -3    k   loss
Barents ______   -2    k   loss
         
CAB Seas         
Beaufort_____    7    k   gain
CAA_________   -12    k   loss
East Siberian__   -37    k   loss
Central Arctic_   -1    k   loss
         
Kara_________   -12    k   loss
Laptev_______   -20    k   loss
Chukchi______   -5    k   loss
         
Other Seas         
Okhotsk______   -1    k   loss
St Lawrence___   -0    k   loss
Hudson Bay___   -19    k   loss

- Area loss 114 k, 15 k more than the 2010's average loss of 99 k on this day.
- Total area Lowest, 207 k LESS than 2016, and 163 k LESS than 2012.

Area loss back to above average, 2019 is strengthening its position as front runner, but for how long?
 
Other Stuff
Weather
GFS  showing temperature anomalies in the range of  +1.5 to +0.5 degrees celsius.
Intially
- over the Arctic Ocean itself temperatures a bit above average,
- the CAA & Baffin Bay mostly warm,
- Western Canada stays mostly cool.
- Alaska and Eastern Siberian really warm,
- Central Siberia and Western Siberia mostly cool.
But from around 5 days, Central & Western Siberia heat up and Eastern Siberia cools down.

Over the next 5 days it looks like a fairly significant low sits over the Arctic Ocean sending strongish anticlockwise winds matching but opposite to the normal clockwise movement of the Beaufort Gyre. This low also looks like pushing ice north from the CAA/Beaufort crack (flaw polynya?)

A cliff or not a cliff** See below
We are in the period of maximum daily area loss that lasts until late July.
Area losses ticked up a lot in the last 10 days, but for the last 3 days steadily moderating but up again on this day.

It looks like Fram export has stalled, with most area losses in the arc from the ESS along the Russian shore and down to the Greenland Sea. The CAA is showing signs of melt.

It is definitely a very steep downward slope, separating 2019 from 2016 and from 2012

The ESS is not a slope, or a cliff. It is a yawning abyss. CAVEAT - see next post for a cautionary graph

NSIDC 5 day Area could/would/should/will/will-not continue in pole position for about one week/two weeks/the rest of July/the entire remaining melt season (delete as applicable).
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"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)

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1592 on: July 11, 2019, 03:22:28 PM »
A cautionary tale

There is great excitement over the area losses in the ESS, which are very large indeed.

So I had a look to see if ESS area was lowest in the satellite record. It is not.
So I had a look to see in which year on this day was area lowest.

The answer?1990, 29 years ago.

So I added 1990 to the graph (see below). If you were a looking at it in 1990 at this , time you might say - "Well that's the end of Arctic Sea Ice".

But it took at least another 15 years for an average minimum to catch up with 1990, and as at 10th July 2019 1990 remains the lowest area for that date and for many days before and for a few days after.
"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)

AmbiValent

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Re: 2019 sea ice area and extent data
« Reply #1593 on: July 11, 2019, 03:42:23 PM »
As the CAA has seemed to be holding well so far, is the current area loss in the data real, or is it an illusion caused by melt ponding?
Bright ice, how can you crack and fail? How can the ice that seemed so mighty suddenly seem so frail?

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1594 on: July 11, 2019, 03:50:57 PM »
As the CAA has seemed to be holding well so far, is the current area loss in the data real, or is it an illusion caused by melt ponding?

Don't know.
It has been warmish in the CAA.
But what do I know?

Here's the map.
"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)

Sterks

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Re: 2019 sea ice area and extent data
« Reply #1595 on: July 11, 2019, 03:57:03 PM »
Quote from: gerontocrat

... cautionary tale...
If anything, what your graph shows is that the Arctic was a completely different ocean in 1990

Alphabet Hotel

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Re: 2019 sea ice area and extent data
« Reply #1596 on: July 11, 2019, 05:04:24 PM »
Well, it seems the - 200k loss in the 5-day avg won't happen this time either, but it was seriously close. Huge extent loss in one week. Thanks for the data

Yeah, it would have taken one more 200k or greater loss to make that average reach 200k.

Rich

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Re: 2019 sea ice area and extent data
« Reply #1597 on: July 11, 2019, 05:19:49 PM »
3.4M km2 area decline in 30 days. Pretty impressive.

When was the last time we had a day with a zero or negative temperature anomaly? 2018?

FishOutofWater

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Re: 2019 sea ice area and extent data
« Reply #1598 on: July 11, 2019, 05:25:59 PM »
Thanks for digging into the history Gcrat. Who would have guessed 1990 was in the lead in the ESS?

We should never forget how quirky the weather and the environment can be, especially in places like the Arctic. As for the CAA, there was lots of heat early when the ice was very thick. Expect surprises.

The mid range (5 to 10 day) GFS and ECMWF output show storminess over the Arctic ocean that is pulling heat in from well south. No, the moisture from the hurricane in the Gulf of Mexico won't reach the pole, but moisture from the Labrador sea might. The Labrador sea is quickly turning into a heat and moisture source for the Arctic as the sea ice in Baffin bay approaches zero extent.

Will an Arctic dipole develop? Maybe but it is too soon to predict with confidence. We need to show a little humility here about our ability to predict September conditions in the Arctic, but we know where things stand today.

In my examination of the Arctic oscillation, I have not seen any year that has had so much stratospheric impact on sea ice area, volume and extent as this one. It's stunning and disturbing. And now it appears that lower pressure and geopotential heights over the polar region will continue to pump warm air into the Arctic. We'll see.

Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #1599 on: July 11, 2019, 05:29:58 PM »

Average remaining melt would give a minimum of 3.91 million km2, 2nd lowest in the satellite record, and 0.73 million km2 above the 2012 low of 3.18 million km2.


So the real question is whether we believe the melt season up to this point has set the CAB up for average melt for the remainder of the season. It would seem to me that we can expect something more than average melt.

A solid 2nd place is in the cards IMHO unless, of course, it isn't.
« Last Edit: July 11, 2019, 05:36:47 PM by Shared Humanity »