Support the Arctic Sea Ice Forum and Blog

Author Topic: 2019 sea ice area and extent data  (Read 759062 times)

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1600 on: July 11, 2019, 07:57:14 PM »
gerontocrat --  any insight on what caused the ESS crash in 1990?  That was a tremendous anomaly esp. for its time (oh no, I'm starting to talk like Trump).  Was there a storm, a heat wave, or did the USSR get rid of leftover nukes over the ESS?
Not the faintest idea. In 1990 I was in the South Pacific - no TV, not a lot of telephones, and internet was something tourists talked about in the bars. And I was having too much fun to worry about global warming.
"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)

oren

  • Young ice
  • Posts: 4534
    • View Profile
  • Liked: 912
  • Likes Given: 1305
Re: 2019 sea ice area and extent data
« Reply #1601 on: July 11, 2019, 08:03:24 PM »
I would bet it had to do with persistent south winds, pushing the thick ice away and preventing a refreeze of the resulting polynya. Just a guess.

Sterks

  • Guest
Re: 2019 sea ice area and extent data
« Reply #1602 on: July 11, 2019, 08:14:38 PM »
This is the NSIDC mean concentration of June 1990. I think Oren explanation makes sense looking at this

ArcticMelt2

  • Frazil ice
  • Posts: 488
    • View Profile
  • Liked: 62
  • Likes Given: 27
Re: 2019 sea ice area and extent data
« Reply #1603 on: July 11, 2019, 08:17:45 PM »
In 1990, one of the most significant collapses of the record of the minimum ice extent in the Arctic according to the NSDIC data was observed:

1) 2007-2005 - 800 thousand square kilometers
2) 2012-2007 - 800 thousand square kilometers
3) 1984-1979 - 500 thousand square kilometers
4) 1990-1984 - 400 thousand square kilometers
5) 1999-1990 - 300 thousand square kilometers
6) 2005-2002 - 300 thousand square kilometers
7) 2002-1999 - 100 thousand square kilometers

It is interesting that 1990 is characterized by one of the longest intervals without a record (6 years). In the first place 1990-1999 years (9 years). The current interval lasts 7 years.

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1604 on: July 12, 2019, 05:47:10 AM »
JAXA ARCTIC EXTENT :-  7,772,912 km2(July 11, 2019)

Ouch - extent loss down with a bump.

- Extent is lowest in the satellite record.
- Extent loss on this day 67 k, 27 k less than the average loss on this day of 94 k.
- Extent loss from maximum 6,498 k, 449 k (7.4%) greater than the average of 6,049 k loss from maximum by this day,
- On average 61.2% of the melting season done, with 64 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.94 million km2, 2nd lowest in the satellite record, and 0.76 million km2 above the 2012 low of 3.18 million km2.

The first 10 days in July now certainly greatly above  average area loss, but on this day well below average

Other Stuff
Weather
GFS  showing temperature anomalies in the range of  +1.4 to zero 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 3 days, Central & Western Siberia heat up and Eastern Siberia cools down.
And a few days later Alaska gets cold, and the CAA cooler.

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?)

What all this means for melt ?
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 so far well above average. Immediate weather outlook suggests a cooler  Arctic but still some +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.

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.
______________________________________________________________
"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

  • Nilas ice
  • Posts: 1530
    • View Profile
  • Liked: 543
  • Likes Given: 515
Re: 2019 sea ice area and extent data
« Reply #1605 on: July 12, 2019, 06:09:17 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 11th, 2019:
     7,772,912 km2, a drop of -66,741 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.

ArcticMelt2

  • Frazil ice
  • Posts: 488
    • View Profile
  • Liked: 62
  • Likes Given: 27
Re: 2019 sea ice area and extent data
« Reply #1606 on: July 12, 2019, 09:50:32 AM »
Ice in the Hudson Bay stubbornly resists melting. Unfortunately, the collapse in the Arctic basin continues.

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1607 on: July 12, 2019, 02:13:27 PM »
NSIDC Total Area as at 11 July 2019 (5 day trailing average) 5,661,909 km2
                        
Total Area         
 5,661,909    km2      
-554,548    km2   <   2010's average.
-560,685    k   <   2018
-1,245,953    k   <   2000's average.
         
Total Area Change   -120    k   loss
Peripheral Seas   -10    k   loss
Central Seas__   -97    k   loss
Other Seas___   -13    k   loss
         
Peripheral Seas         
Bering _______    0    k   gain
Baffin  Bay____   -8    k   loss
Greenland____   -1    k   loss
Barents ______   -1    k   loss
         
CAB Seas         
Beaufort_____    2    k   gain
CAA_________   -17    k   loss
East Siberian__   -45    k   loss
Central Arctic_    8    k   gain
         
Kara_________   -14    k   loss
Laptev_______   -23    k   loss
Chukchi______   -9    k   loss
         
Other Seas         
Okhotsk______    0    k   gain
St Lawrence___   -0    k   loss
Hudson Bay___   -13    k   loss

- Area loss 120 k, 21 k more than the 2010's average loss of 99 k on this day.
- Total area Lowest, 212 k LESS than 2016, and 145 k LESS than 2012.

Area loss back to above average, 2019 is strengthening its position as front runner vis-a-vis 2012, but for how long?
 
Other Stuff
Weather
GFS  showing temperature anomalies in the range of  +1.4 to zero 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 3 days, Central & Western Siberia heat up and Eastern Siberia cools down.
And a few days later Alaska gets cold, and the CAA cooler.

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?)

What all this means for melt ?
This low then dissipates?

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 the last 2 days. Being a five-day trailing average, higher than average area loss will continue for 2-3 days at least.

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 2012, but not widening the gap from 2016.

The ESS is not a slope, or a cliff. It is a yawning abyss.

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).
________________________________________________________________________
"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

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1608 on: July 12, 2019, 02:59:48 PM »
I thought I would put Arctic Sea Ice AREA through the same analysis as I do for JAXA extent, so I did.

The answer is that average remaining area loss would put area at 3rd lowest in the satellite record, above 2012 and, though not by much, 2016.

I think tomorrow I  will have a go at Tealight's High Arctic  (7 central) seas area.
"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)

Alphabet Hotel

  • Frazil ice
  • Posts: 246
    • View Profile
  • Liked: 116
  • Likes Given: 44
Re: 2019 sea ice area and extent data
« Reply #1609 on: July 12, 2019, 03:43:04 PM »
NSIDC daily extent

Rich

  • Guest
Re: 2019 sea ice area and extent data
« Reply #1610 on: July 12, 2019, 04:02:10 PM »

Total Area Change   -120    k   loss
CAA_________   -17    k   loss
East Siberian__   -45    k   loss
Laptev_______   -23    k   loss

3 regions carrying all the momentum.

Thw gifs showing the Laptev / ESS losses from yesterday are going to very impressive when they are shared.

Thank you for sharing these regional data tables. They definitely provide an enhanced understanding of what's going on.

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1611 on: July 12, 2019, 04:28:54 PM »
The CAA is just emerging from the usual hiatus.

Over on the Russian side melt is high to enormous.
"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

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1612 on: July 12, 2019, 04:32:41 PM »
And two seas that seem to have forgotten it's the melting season (for now)
"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)

UCMiami

  • New ice
  • Posts: 76
    • View Profile
  • Liked: 29
  • Likes Given: 39
Re: 2019 sea ice area and extent data
« Reply #1613 on: July 12, 2019, 04:53:00 PM »
Interesting to note that the 'slow' CAA melt that posters seem to lament is actually average 2010s loss and right on the 2012 line as well. 2016 area loss is clearly leading the way but this slow loss of area is actually 'right on schedule' and the next three weeks will tell the true story.

philopek

  • Frazil ice
  • Posts: 461
    • View Profile
  • Liked: 207
  • Likes Given: 40
Re: 2019 sea ice area and extent data
« Reply #1614 on: July 12, 2019, 10:05:06 PM »
Ice in the Hudson Bay stubbornly resists melting. Unfortunately, the collapse in the Arctic basin continues.

Thanks, this is what i was looking for when someone posted that there is no significant melt going on in the central arctic proper. I think that's making things clear for the moment.

b_lumenkraft

  • Guest
Re: 2019 sea ice area and extent data
« Reply #1615 on: July 12, 2019, 10:16:23 PM »
@philopek
@UCMiami

Hi guys :)

This thread is supposed to be for the data, not for the talk about the data. Please take the discussions about the data over to the melting season thread. Thanks.

Juan C. García

  • Nilas ice
  • Posts: 1530
    • View Profile
  • Liked: 543
  • Likes Given: 515
Re: 2019 sea ice area and extent data
« Reply #1616 on: July 13, 2019, 05:42:12 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 12th, 2019:
     7,718,646 km2, a drop of -54,266 km2.
     2019 is now 2nd lowest on record.
     (2012 highlighted).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

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

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1617 on: July 13, 2019, 05:57:30 AM »
JAXA ARCTIC EXTENT :-  7,718,646 km2(July 12, 2019)

Ouch - extent loss down with a bump, twice.

- Extent is 2nd lowest in the satellite record, 26k above 2011.
- Extent loss on this day 67 k, 27 k 54 k, 48 k less than the average loss on this day of 102 k.
- Extent loss from maximum 6,552 k, 401 k (6.5%) greater than the average of 6,161 k loss from maximum by this day,
- On average 62.3% of the melting season done, with 63 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.99 million km2, 2nd lowest in the satellite record (just), and 0.81 million km2 above the 2012 low of 3.18 million km2.

The first 10 days in July were certainly greatly above  average area loss, but on the last 2 days day barely above half the average daily losss

Other Stuff
Weather
GFS  showing temperature anomalies falling from about +1 to zero 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 3 days, Central & Western Siberia heat up and Eastern Siberia cools down.
And a few days later Alaska gets cold, and the CAA cooler.

Over the next 5, or even 10, 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?) Strong winds and rain also from the South up Baffin Bay into the CAA

What all this means for melt is.... ?
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. Immediate weather outlook suggests a cooler  Arctic but still some +ve temperature anomalies.

On every measure (JAXA extent, NSIDC daily and 5 day area and extent, and volume), 2019 was lowest in the satellite record. But just like that extent loss rapidly drops, but area loss is ticking up.

The June volume data persuaded me to drop my minimum guesstimate to below 4 million km2 from exactly 4 million km2. A mistake?
______________________________________________________________
"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

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1618 on: July 13, 2019, 02:19:39 PM »
NSIDC Total Area as at 12 July 2019 (5 day trailing average) 5,550,763 km2
                        
Total Area         
 5,550,763    km2      
-574,949    km2   <   2010's average.
-652,874    k   <   2018
-1,268,298    k   <   2000's average.
         
Total Area Change   -111    k   loss
Peripheral Seas   -13    k   loss
Central Seas__   -91    k   loss
Other Seas___   -8    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -8    k   loss
Greenland____   -0    k   loss
Barents ______   -4    k   loss
         
CAB Seas         
Beaufort_____   -1    k   loss
CAA_________   -14    k   loss
East Siberian__   -43    k   loss
Central Arctic_    10    k   gain
         
Kara_________   -13    k   loss
Laptev_______   -18    k   loss
Chukchi______   -12    k   loss
         
Other Seas         
Okhotsk______   -0    k   loss
St Lawrence___   -0    k   loss
Hudson Bay___   -7    k   loss

- Area loss 111 k, 19 k more than the 2010's average loss of 92 k on this day.
- Total area Lowest, 219 k LESS than 2016, and 104 k LESS than 2012.

Area loss staying above average, difference with 2012 narrowing, with 2016 widening.

Other Stuff
Weather
GFS  showing temperature anomalies falling from about +1 to zero 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 3 days, Central & Western Siberia heat up and Eastern Siberia cools down.
And a few days later Alaska gets cold, and the CAA cooler.

Over the next 5, or even 10, 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?) Strong winds and rain also from the South up Baffin Bay into the CAA

What all this means for melt is.... ?
This low then dissipates?

A cliff or not a cliff** See below
We are in the period of maximum daily area loss that lasts until late July.
Overall, Area losses in July to date above average. Being a five-day trailing average, higher than average area loss will continue for 2-3 days at least.

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 Barents. The CAA is showing signs of melt strongly increasing.

It is definitely a steep downward slope

However, the ESS is not a slope, or a cliff. It is a yawning abyss, (while the CAB gains area).

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).
________________________________________________________________________
The next posts will look at area of the sea ice in the "High Arctic" - the 7 central seas of the Arctic Ocean in more detail. Wait small, want me lunch.
« Last Edit: July 13, 2019, 02:27:38 PM by gerontocrat »
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1619 on: July 13, 2019, 03:04:58 PM »
This analysis uses exactly the same method and format as for the JAXA Daily Extent postings.
Theseas used are -Chukchi, ESS, Laptev, Kara, CAA, Beaufort and the CAB

NSIDC HIGH Arctic Sea Ice AREA at 12 Jul 2019 in KM2 4,945,193, position in table = 1


The High Arctic Sea Ice is clearly in pole position.
- 275 K less than 2016, 208k less than 2012,
- Area loss today 91k, 26 k more tha the average for the day of 65k,
- Area loss from maximum 3,718 k, 617 k (19.9%) more than the average loss of 3,100 k.
- If area loss from now to minimum is average (last 10 years) then minimum would be 2.31 million km2, just above 2016 so in 3rd place.

Looking at the first graph attached, it is obvious that from now to minimum area loss in 2012 and 2016 was well above average. The forecast weather for the next few days does not appear to support a surge in melt.

Next posts show the graphs for each sea.
"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)

Rich

  • Guest
Re: 2019 sea ice area and extent data
« Reply #1620 on: July 13, 2019, 03:13:35 PM »
The CAB now represents > 50% of the remaining ice area.

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1621 on: July 13, 2019, 04:01:14 PM »
The CAB now represents > 50% of the remaining ice area.
Indeed it does, I was just getting ready for that.

In the end, it's all about the CAB. . It is surrounded by 8 seas and to the South, Greenland.
6 of the seas are considered here. Greenland and Barents are not, though when comparing this year with  last year, as of today it is mostly about those seas. never mind.

So to start with two images. One from the NSIDC "MASIE" site https://nsidc.org/data/masie/browse_regions) of the CAB area. I have added the sea names around the edge . The other is today's image from Univ of Bremen, slightly rotated to get the alignment the same as MASIE.

The obvious first remark is that as at July 12 the CAB, as far as area and extent is concerned, is pretty much intact and untouched by the sound and fury around it.
« Last Edit: July 13, 2019, 05:25:37 PM by gerontocrat »
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Alphabet Hotel

  • Frazil ice
  • Posts: 246
    • View Profile
  • Liked: 116
  • Likes Given: 44
Re: 2019 sea ice area and extent data
« Reply #1622 on: July 13, 2019, 04:05:42 PM »
NSIDC daily extent

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1623 on: July 13, 2019, 04:38:31 PM »
But, let's start where all the excitement started and is continuing

The Chukchi
- currently lowest for the 90th day this year, and shows no sign of melt slowing (very thin ice to 75 North),
- leaving solid ice for 5 degrees of latitude (circa 500km) to reach 80 North and the CAB. Surely can't get there until August.

The ESS
- after a slow start area loss of 125k in the last 3 days.
- looks to me only likely to reach 80 N if the Latptev bite widens and deepens and / or the Chukchi reaches 80 N early and open water widens into the ESS. Even in 2012 only really melted out by the last week in August.

the Laptev
- has been losing area at a high rate from the word go, and at the moment only 2nd lowest to 2014. The bite is already at over 80 North and can be expected to widen as the days go by, exposing an ever wider area of open water to the CAB.

The Kara
- Average melt this year until late June but area now below average. Quite a bit of open water along the CAB border, that should be completely clear by the end of the month.

Summary
The Russian side is clearing out really early.
« Last Edit: July 13, 2019, 05:27:26 PM by gerontocrat »
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1624 on: July 13, 2019, 05:15:41 PM »
While in North America.....

The Beaufort
- flattered to deceive, reaching 75 N in record time.
- currently in hiatus, though still at a very low area for the time of year,
- and I, for one, am totally clueless as to what happens next. Maybe the part close to the Chukchi will get to 80 N in time to make a difference to the CAB.

[bThe CAA - Canadian Archipelago Area[/b]
- Every year there is a hiatus for two or three weeks in area loss, and even area gain. I can't remember reading an explanation of this that convinces.
- The same this year, but the CAA area loss has overcome the hiatus and is now losing area at a spanking rate.
- I am not sure that this has much impact on the CAB close by next door, though the snow-free islands surely provide a heat source for any southerly winds arriving.

One thing we know for sure is (?), if the CAA melts out and the NW Passage is open the Secretary of the Navy, USofA, will be taking a boat trip. Hoorah! Hoorah! Hoorah!

Not the 7 seas but damn important.

The Barents & Greenland Seas
- Early in the season received a lot of ice from the CAB so area loss was slow and sometimes -ve.
- Area loss is still really slow,
- the border with the CAB is  still mostly ice.
- the Barents Sea will lose its remaining 75k of area, but probably late.
- the Greenland Sea, which never completely melts out, will likely continue with slow melt and end up with more area than average.
- the contrast with 2018 is very great

Not a lot of record breakers on this side of the Arctic
« Last Edit: July 14, 2019, 02:25:37 AM by gerontocrat »
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1625 on: July 13, 2019, 05:24:14 PM »
The CAB - Central Arctic Basin (3.2. million km2)

I attach the NSIDC 5 day average area and extent graphs.

- Area and Extent loss to date below average.
- I don't see vast areas of open water in the surrounding seas allowing the weather to get at the CAB.
- However, I do see a 2nd or 3rd lowest extent and area minimum.

Is there a storm coming (from the melting thread)?
"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)

philopek

  • Frazil ice
  • Posts: 461
    • View Profile
  • Liked: 207
  • Likes Given: 40
Re: 2019 sea ice area and extent data
« Reply #1626 on: July 13, 2019, 06:21:33 PM »
- Every year there is a hiatus for two or three weeks in area loss, and even area gain. I can't remember reading an explanation of this that convinces.

My theory:

In the Arctic Basin, above 70N, the surface melting is less consistent from Mid-July onward, easily can be explained with temperatures droping way lower during the "night=flat sun angle"

In short, surface melt for the ice that still exists in Mid-July is slowing down while bottom melt will kick in in full only once the first heavy storms, bringing mixing with them, kick in and once the open water at lower latitudes was able to gather sunlight and heat up, so to further attack the edges and the bottom oft the ice in August.

If you go an consult the attached graph by yourself and study all the longterm lines carefully, you will find confirmed that between Mid-July and first week of August there is a pattern of slower melt, a dent one could name it.

Source: https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

EDIT: Of course the dent is not limited to where the arrows are pointing, that's the peaks, it starts around mid July average and it's not an obvious thing at first glance, kind of fine-tuning if you like.


« Last Edit: July 13, 2019, 06:26:56 PM by philopek »

oren

  • Young ice
  • Posts: 4534
    • View Profile
  • Liked: 912
  • Likes Given: 1305
Re: 2019 sea ice area and extent data
« Reply #1627 on: July 13, 2019, 07:28:42 PM »
The CAA hiatus is really simple. Area is lost in one of three ways: surface water/meltponds, export, meltout.
In the CAA there are certain stages in quite predictable times:
Export of loosely attached ice, such as the one exported early to Beaufort (is that Amundsen Gulf?)
Melt pond formation on the fast ice in the channels - widespread surface melt onset happens at a certain time of year. You can see this easily in Worldview - the ice becomes bluish.
Then comes the plateau - no more ice is exported, and no floe melts out. Some meltponds drain or otherwise disappear, no new snow is added to be melted into ponds, thus area stalls or even rises.
Then comes major breakage in the channels (starting from the edges), and/or meltout of thin floes by continued top and bottom attacks, and area loss begins again.
I apologize this is in layman terms, but it's no mystery IMHO.
BTW I think the southerly latitude and closeness to land cause the snow melting weather to be more predictable. But haven't run any statistics about the timing of the various stages.

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1628 on: July 13, 2019, 07:35:14 PM »
- Every year there is a hiatus for two or three weeks in area loss, and even area gain. I can't remember reading an explanation of this that convinces.

My theory:

......
If you go an consult the attached graph by yourself and study all the longterm lines carefully, you will find confirmed that between Mid-July and first week of August there is a pattern of slower melt, a dent one could name it.

I am not sure if you understood that I was referring to the Canadian Archipelago only.
And there the hiatus generally starts around the week 14-21 June and finishes sort of the week 10-17 July. As far as the CAA is concerned, the timing does not fit with your theory.

As far as TOTAL Arctic melt is concerned, my speculation that belongs to me is that melt starts earlier and accelerates in the peripheral and southernmost seas and then tapers off in those seas as area in each sea gets below a certain point ( Gompertz effect - image attached certainly relevant to yours truly). This is before melt really gets going in the big central Arctic Seas, so overall melt loss declines. Then melt accelerates again as melt kicks in.

But I have not tested it, and when I look at the 7 central seas what do I see but on average the maximum daily melt at about the 10 Jul and declining from then on. Speculation kaput?

"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

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1629 on: July 13, 2019, 07:38:38 PM »
I apologize this is in layman terms, but it's no mystery IMHO.

Layman terms is more than acceptable. That'll do nicely, Oren.
______________________________
All the best stuff can be expressed simply - simply as in e = mc2, not as in TweetLand
"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)

philopek

  • Frazil ice
  • Posts: 461
    • View Profile
  • Liked: 207
  • Likes Given: 40
Re: 2019 sea ice area and extent data
« Reply #1630 on: July 13, 2019, 07:41:40 PM »

I am not sure if you understood that I was referring to the Canadian Archipelago only.


No, I did not realize that you refer to the CAA only, I thought about the Arctic Basin Proper.

Sorry, my bad as far a the CAA is concerned.

Gumbercules

  • NewMembers
  • New ice
  • Posts: 53
    • View Profile
  • Liked: 2
  • Likes Given: 5
Re: 2019 sea ice area and extent data
« Reply #1631 on: July 13, 2019, 11:11:34 PM »
Anyone know what's up with the NSIDC having the "NO DATA" images come up on their Arctic Sea Ice News & Analysis page? It has only happened in the last two days and I have been checking the site daily for months now.

See here:

https://nsidc.org/arcticseaicenews/

Edit: It has now been down for 3 full days in a row.
« Last Edit: July 14, 2019, 11:32:09 PM by Gumbercules »

Juan C. García

  • Nilas ice
  • Posts: 1530
    • View Profile
  • Liked: 543
  • Likes Given: 515
Re: 2019 sea ice area and extent data
« Reply #1632 on: July 14, 2019, 05:40:18 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 13th, 2019:
     7,648,540 km2, a drop of -70,106 km2.
     2019 is now 2nd lowest on record.
     (2012 highlighted).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

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

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1633 on: July 14, 2019, 08:47:53 AM »
JAXA ARCTIC EXTENT :- 7,648,540 km2(July 13, 2019)

Ouch - extent loss down with a bump, thrice.

- Extent is 2nd lowest in the satellite record, 78 k above 2011.
- Extent loss on this day 70k, 34k less[/b] than the average loss on this day of 104 k.
- Extent loss from maximum 6,623 k, 367 k (5.9%) greater than the average of 6,255 k loss from maximum by this day,
- On average 63.3% of the melting season done, with 62 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 4.02 million km2, equal 2nd lowest in the satellite record , and 0.84 million km2 above the 2012 low of 3.18 million km2.

The first 10 days in July were certainly greatly above average area loss, but on the last 3 days day greatly below the average daily losss

Other Stuff
Weather
GFS  showing temperature anomalies falling from +1 to 0.1 degrees celsius over the next week.
Intially
- over the Arctic Ocean itself temperatures a bit above average,
- the CAA & Baffin Bay mostly warm,
- Western Canada stays mostly cool.
- Alaska and Western Siberian  warm,
- Central Siberia  cool.
But as the days go by all Siberia and Alaska cools down.

Over the next 5, or even 10, days it looks like a fairly significant low sits over the central Arctic Ocean north of Central / Eastern Siberia and elsewhere a high sits in the North Atlantic and another high over Greenland. The strongish anticlockwise winds matching but opposite to the normal clockwise movement of the Beaufort Gyre are maintained, starting as northerly winds from the CAA and the North Greenland coast. Strong winds and rain also from the South up Baffin Bay into the CAA at least for the first few days.

What all this means for melt is.... ?
Is this weather pattern there for the long-term?

Area Loss Outlook
We are now in the period of maximum daily extent loss that lasts until late July and then very gradually declines. Immediate weather outlook suggests a cooler Arctic.

On every measure (JAXA extent, NSIDC daily and 5 day area and extent, and volume), 2019 was lowest in the satellite record (just). But just like that extent loss rapidly drops, but area loss is ticking up.

The June volume data persuaded me to drop my minimum guesstimate to below 4 million km2 from exactly 4 million km2. A mistake?
______________________________________________________________
« Last Edit: July 14, 2019, 09:38:46 AM by gerontocrat »
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Killian

  • Frazil ice
  • Posts: 250
    • View Profile
  • Liked: 41
  • Likes Given: 8
Re: 2019 sea ice area and extent data
« Reply #1634 on: July 14, 2019, 10:41:32 AM »
7/9/2019 JAXA extent @ 7.95M km sq.

Avg. daily melt required to maintain record extent lows:

7/12 - 7.69M km sq. -260k km sq requiring >   -86.6k km sq avg/day

Well, in my previous post I stated it looked liked winds were going to give us lower extent losses over the next couple days, but I underestimated the change. '19 couldn't hold on to the lead even one more day!

After a decrease of approx. 70k on 7/11, 2019 needed a drop > than a middling 80k to remain in record territory on the 12th, despite the large 170k loss in 2011, but came in with a small loss of 50k to 7.72 vs. 2011's 7.69. 2011's loss of 170k on the 11th marked a string of large losses for 2011, the next two days coming in at -120 and -130, for a 3-day loss of 420k.

Sheesh! <-- Official scientific term equaling, "Well, that was quite a sudden change."

Quote
7/13 - 7.57M km sq. -380k km sq requiring >   -95k km sq avg/day

Now 30k high of 2011, '19 would need a loss of to keep up with '11's loss of 120 on the 13th. No such bad luck. A rather middling 70k was all '19 could muster, ending up 80k higher than 2011.

Quote
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

2011 had a loss of 130k to the 14th, leaving 2011 a total of 210 to fall to regain record territory. As much as I thought a couple more -100k days could have 2019 in the lead till 2012 retakes the lead on the 25th, I'm now equally doubtful 2011 will regain the lead before then. 2011 does slow a bit coming into the intersection with 2012, so if '19 gets back into the -100k's consistently, it might happen, but 210k is a lot to make up.

Anywho... re the 14th: No way in hell 2019 overtakes 2011. I don't care if God himself comes down a breathes fire on the ice, ain't happening. There's the knee-jerk, now let me go look at some data!

[Searching...]

Well, 2016 had a 160k drop on the 14th, 2017 fell 130k, 2018 fell 160k, so there's precedent for 100+ losses. Winds are mixed according to Windy. The winds across the Siberian coast suggest extent increases while the rest of the Arctic looks neutral to good for compaction.

SST's indicate a lot of heat coming in the Pacific side, but not too hot anywhere else, so who winds? Heat or winds? GFS 2M says mid-since digits temps at the edges. Hmmm... Seems like an average-ish day? Yeah, no way we see a 220k drop for the 14th.

But... what do the forums say? HPS anomaly from 13th to 18th has a warm anomaly over the CAA and into the center of the CAB... Everywhere I look, mixed messages. High uncertainty.
 
The 15th slows all the way down to a mere 90k loss in 2011. I suspect that 80k difference on the 13th is going to grow on both the 14th and the 15th giving us something on the order of a 120+/-20k difference between '11 and '19 after the next two days are posted.

Longer term, there's an inflection after the 14th where the slope decreases. Average losses for '11 from the 14th to the 19th avg. 88k/day followed by another inflection on the 20th which has a loss of 50k, after which the daily average drops to 50k to the 25th.

There certainly is a fair chance '19 will retake '11, but we may be waiting a week or so... or maybe never...? Beating 2012 looks like a tough call to make at this point, I do still see '19 coming in second by the time the season is done. At worst, a very close 4th.

Cheers

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1635 on: July 14, 2019, 12:30:53 PM »
Yesterday I did a lot of posts that perhaps concentrated too much on the protection given to the Central Arctic Basin (CAB) by the surrounding Seas.

The CAB has been losing volume and thickness. Graphs attached - 2019 as at 30 June. (Thickness is PIOMAS Volume divided by NSIDC area).

I make no prediction on what happens next.




"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

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1636 on: July 14, 2019, 02:09:29 PM »
NSIDC Total Area as at 13 July 2019 (5 day trailing average) 5,426,278 km2
                        
Total Area         
 5,426,278    km2      
-602,252    km2   <   2010's average.
-732,729    k   <   2018
-1,303,736    k   <   2000's average.
         
Total Area Change   -124    k   loss
Peripheral Seas   -4    k   loss
Central Seas__   -105    k   loss
Other Seas___   -15    k   loss
         
Peripheral Seas         
Bering _______    0    k   gain
Baffin  Bay____   -5    k   loss
Greenland____    2    k   gain
Barents ______   -2    k   loss
         
CAB Seas         
Beaufort_____   -1    k   loss
CAA_________   -12    k   loss
East Siberian__   -40    k   loss
Central Arctic_   -10    k   loss
         
Kara_________   -10    k   loss
Laptev_______   -19    k   loss
Chukchi______   -12    k   loss
         
Other Seas         
Okhotsk______    0    k   gain
St Lawrence___   -0    k   loss
Hudson Bay___   -15    k   loss

- Area loss 124 k, 33 k more than the 2010's average loss of 91 k on this day.
- Total area Lowest, 233 k LESS than 2016, and 72 k LESS than 2012.

Area loss staying above average, difference with 2012 narrowing, with 2016 widening.

Other Stuff
Weather
GFS  showing temperature anomalies falling from +1 to 0.1 degrees celsius over the next week.
Intially
- over the Arctic Ocean itself temperatures a bit above average,
- the CAA & Baffin Bay mostly warm,
- Western Canada stays mostly cool.
- Alaska and Western Siberian  warm,
- Central Siberia  cool.
But as the days go by all Siberia and Alaska cools down.

Over the next 5, or even 10, days it looks like a fairly significant low sits over the central Arctic Ocean north of Central / Eastern Siberia and elsewhere a high sits in the North Atlantic and another high over Greenland. The strongish anticlockwise winds matching but opposite to the normal clockwise movement of the Beaufort Gyre are maintained, starting as northerly winds from the CAA and the North Greenland coast. Strong winds and rain also from the South up Baffin Bay into the CAA at least for the first few days.

What all this means for melt is.... ?
Is this weather pattern there for the long-term?

A cliff or not a cliff** See below
We are in the period of maximum daily area loss that lasts until late July.
Overall, Area losses in July to date above average. Being a five-day trailing average, higher than average area loss will continue for 2-3 days at least.

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 Barents. The CAA is showing signs of melt strongly increasing.

It is definitely a steep downward slope

However, the ESS is not a slope, or a cliff. It is a yawning abyss,

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).
________________________________________________________________________
ps: Meanwhile, Extent loss continues to be well below average
"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)

oren

  • Young ice
  • Posts: 4534
    • View Profile
  • Liked: 912
  • Likes Given: 1305
Re: 2019 sea ice area and extent data
« Reply #1637 on: July 14, 2019, 02:12:04 PM »
With large area losses and small extent drops, this can only mean bad news for the ice. Tightly packed ice survives longer than dispersed floes.

Steven

  • Grease ice
  • Posts: 555
    • View Profile
  • Liked: 133
  • Likes Given: 16
Re: 2019 sea ice area and extent data
« Reply #1638 on: July 14, 2019, 02:18:04 PM »
NSIDC daily area is currently the lowest on record for the date:




(Note: data from Wipneus.  He uses leap year corrections for the anomaly data.)

Alphabet Hotel

  • Frazil ice
  • Posts: 246
    • View Profile
  • Liked: 116
  • Likes Given: 44
Re: 2019 sea ice area and extent data
« Reply #1639 on: July 14, 2019, 05:13:03 PM »
NSIDC daily extent

Killian

  • Frazil ice
  • Posts: 250
    • View Profile
  • Liked: 41
  • Likes Given: 8
Re: 2019 sea ice area and extent data
« Reply #1640 on: July 15, 2019, 04:24:40 AM »
NSIDC daily area is currently the lowest on record for the date:




(Note: data from Wipneus.  He uses leap year corrections for the anomaly data.)

I recall some years back - I think after the 2012 Big Melt - saying extent was going to become less indicative of change in the Arctic as the area and volume fell because it would quite simply be much easier for the ice to be spread out by winds and currents the thinner and smaller floes got. (Obvious, I know.)

That ASI Area is taking such a dive in that graph while extent loss has slowed significantly over the last several days illustrates this phenomenon perfectly. Watching the ice flow back toward the AO from the Nares also illustrates this, The wind has no trouble pushing this ice around given the ice north of the Nares looks like popcorn floating in crushed ice - very easy to compact.

I really wish we could do volume as well or better than extent; it would tell a far more accurate story.

Juan C. García

  • Nilas ice
  • Posts: 1530
    • View Profile
  • Liked: 543
  • Likes Given: 515
Re: 2019 sea ice area and extent data
« Reply #1641 on: July 15, 2019, 05:59:29 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 14th, 2019:
     7,571,174 km2, a drop of -77,366 km2.
     2019 is 2nd lowest on record.
     (2012 highlighted).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

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

Killian

  • Frazil ice
  • Posts: 250
    • View Profile
  • Liked: 41
  • Likes Given: 8
Re: 2019 sea ice area and extent data
« Reply #1642 on: July 15, 2019, 06:46:20 AM »
Quote
7/14 - 7.44M km sq. -510k km sq

re the 14th: No way in hell 2019 overtakes 2011. I don't care if God himself comes down a breathes fire on the ice...

Seems like an average-ish day? Yeah, no way we see a 220k drop for the 14th.

And, indeed, about 80k to 7.57, leaving '19 130k higher than 2011:

Quote
I suspect that 80k difference on the 13th is going to grow on both the 14th ... on the order of a 120+/-20k difference between '11 and '19 after the next two days are posted.

Right in there for the 14th. As for the 15th:

Quote
7/15 - 7.35M km sq.

With '11 dropping 90k into the 15th, 2019 may well keep pace to give me a rather precise short-term prediction - which I've a dearth of in recent days.

Cheers

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1643 on: July 15, 2019, 07:23:33 AM »
JAXA ARCTIC EXTENT :- 7,571,174 km2(July 14, 2019)

- Extent is 2nd lowest in the satellite record, 129 k above 2011.
- Extent loss on this day 77k, 26k less[/b] than the average loss on this day of 103 k.
- Extent loss from maximum 6,700 k, 342 k (5.4%) greater than the average of 6,358 k loss from maximum by this day,
- On average 64.3% of the melting season done, with 61 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 4.05 million km2, 3rd lowest in the satellite record , and 0.87 million km2 above the 2012 low of 3.18 million km2.

Other Stuff
Weather
GFS  showing temperature anomalies in the range +0.9 to 0 degrees celsius over the next 10 days.
Intially
- over the Arctic Ocean itself temperatures a bit above average,
- the CAA & Baffin Bay mostly warm,
- Western Canada stays mostly cool.
- Alaska and Western Siberian  warm,
- Central Siberia  cool.
But as the days go by all Siberia and Alaska cools down.

Over the next 5, or even 10, days it looks like a fairly significant low sits over the central Arctic Ocean north of Central / Eastern Siberia and elsewhere a high sits in the North Atlantic and another high over Greenland. The strongish anticlockwise winds matching but opposite to the normal clockwise movement of the Beaufort Gyre are maintained, starting as northerly winds from the CAA and the North Greenland coast. Strong winds and rain also from the South up Baffin Bay into the CAA at least for the first few days.

What all this means for melt is.... ?
Is this weather pattern there for the long-term?

Area Loss Outlook
We are now in the period of maximum daily extent loss that lasts until late July and then very gradually declines. Immediate weather outlook suggests a cooler Arctic.

Extent loss in the last few days well below average,, but area loss well above.

The June volume data persuaded me to drop my minimum guesstimate to below 4 million km2 from exactly 4 million km2. A mistake?
______________________________________________________________
"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)

Rich

  • Guest
Re: 2019 sea ice area and extent data
« Reply #1644 on: July 15, 2019, 10:05:04 AM »
Some comments on the NSIDC 5 day area data.

IMO - it's right up there at the top of the useful content on ASIF. It's well organized and provides information on each region every day.  Also consistent and timely. Kudos Gerontocrat.

The data is subdivided into a sub-hierarchy of 3 regions. Central Seas, Periphery and Other. I'm not sure if the NSIDC provides these categories or they are ASIF constructions, but the logic is pretty clear. The distinctions are based upon a clear geographic relationship to the Arctic Ocean.

In the current hierarchy, one could question whether the Kara could be in the Periphery, but not a big deal IMO. Everything is logical and understandable.

My issue with the way the data is presented is that it is somewhat dissonant with the interests of the customer base.

The customers and discussion around the forum are dominated by progression of AGW, potential records in
ice minima and when to expect a BOE. There's some tension in the melting season thread over the potential for a record surrounding the potential to bite into the CAB.

At this moment, the CAB area is behind the 2010's average when it comes to melt. Gerontocrat put out a nice chart on that yesterday. Thank you.

For purposes of being consistent with the way people seem most interested in using the data, I don't think it makes sense to group the CAB with other "Central Seas" that substantially melt out.

If CAB as a separate entity was more highlighted, then the arguments on the melting season thread might be a little different or less. I would argue for harmonizing the data with the way people are using it (according to expected melt) vs. the current geographic organization.

Personally, I can see what I need with the data as presented and adjusting for the understanding of the CAB as fundamentally different from the other seas it is bundled with. I'm not sure that's easy for everyone.

Alison

  • New ice
  • Posts: 40
    • View Profile
  • Liked: 14
  • Likes Given: 97
Re: 2019 sea ice area and extent data
« Reply #1645 on: July 15, 2019, 11:24:28 AM »
Quote
My issue with the way the data is presented is that it is somewhat dissonant with the interests of the customer base.

Not in my case, it isn’t.

Neven

  • Administrator
  • First-year ice
  • *****
  • Posts: 7209
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 732
  • Likes Given: 477
Re: 2019 sea ice area and extent data
« Reply #1646 on: July 15, 2019, 12:07:19 PM »
My issue with the way the data is presented is that it is somewhat dissonant with the interests of the customer base.

I assume you have doen a survey?

The data is freely available. If you believe there's a better way to present it, then do it. Don't pontificate, do something.
Il faut comparer, comparer, comparer, et cultiver notre jardin

gerontocrat

  • First-year ice
  • Posts: 6804
    • View Profile
  • Liked: 1701
  • Likes Given: 22
Re: 2019 sea ice area and extent data
« Reply #1647 on: July 15, 2019, 12:33:22 PM »
My issue with the way the data is presented is that it is somewhat dissonant with the interests of the customer base.

I assume you have done a survey?

The data is freely available. If you believe there's a better way to present it, then do it. Don't pontificate, do something.
heavy sigh...

The data is organised into 3 sections because that is the way it looked to me.
Tealight's High Arctic analyses also use the same 7 seas. That is really useful- being able to match extent, area and volume, to AWP.

I sometimes use other ways of looking at the data, e.g. the Atlantic Front, the Pacific Gateway, the Canadian Seas, the 3 Central Seas when it seems appropriate.

Wipneus's inner basin uses 5 seas. (excludes Kara and CAA?) and he uses AMSR2 high res data, but that only goes back to 2012.

For the sake of consistency it is better to continue as is for my standard daily postings even if it is a sub-optimal solution at different times of the year. And anyway, my clapped out old laptop (and my brain) is already having problems in coping with 60 megabytes of somewhat complex interlinked spreadsheets.

Customer base?
_________________________________________________________
Gosh Neven, better stop while I am still being polite.

Follow this link at your own risk....
https://forum.arctic-sea-ice.net/index.php/topic,1860.msg213578.html#msg213578
« Last Edit: July 15, 2019, 12:47:28 PM by gerontocrat »
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

be cause

  • Grease ice
  • Posts: 891
  • Citizenship .. a Lurker gets asylum
    • View Profile
  • Liked: 261
  • Likes Given: 218
Re: 2019 sea ice area and extent data
« Reply #1648 on: July 15, 2019, 12:45:19 PM »
I didn't realise Rich was paying to be here . I hope his riches enrich us all . b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 ...

Rich

  • Guest
Re: 2019 sea ice area and extent data
« Reply #1649 on: July 15, 2019, 01:01:41 PM »
OK.

So I'll just append a stat to the Area figures.

On the 13th, 5 day average area decline outside the CAB was 114.7k km2 or 4.1% of the non-CAB total. (A hefty %).

Area decline inside the CAB was 9.7k or 0.3% of the total.

Over the last 5 days we're losing non-CAB ice more than 10x faster than CAB ice.

If anyone can point me to the y/e 2012 NSIDC 5 day average figures, I'll take 'em.