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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #900 on: June 01, 2019, 08:50:45 AM »
JAXA ARCTIC EXTENT :- 10,768,933 km2(May 31, 2019)

- Extent is 2nd lowest in the satellite record, 342 k > 2016, 122 k < 2018.
- Extent loss on this day 64  k, 4 k less than the average loss of 60 k on this day.
- Extent loss from maximum 3,502 k, 412 k (13%) greater than the average of 3,090k loss from maximum by this day,
- On average 31.3% of the melting season done, with 105 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.98 million km2, 2nd lowest in the satellite record, and 0.80 million km2 above the 2012 low of 3.18 million km2. Looking at the last 5 years average remaining melt only gives a result of 4.23 million km2, 4th lowest.

On 22nd April, 2016 started its 2 months as the front runner with steep declines in extent.  To become lowest again, 2019 will have to match or exceed the above average extent losses of 2016 from now until at least mid-late June. For that reason I have removed 2018 daily change and replaced it with 2016 data on graph Arc2. Later in the season that will be replaced with 2012 as it becomes the front runner.

Other Stuff

GFS shows temperature anomalies varying from +1.7 to +3.0. At the moment little reason to suppose sea ice extent loss will be at much above average in the immediate future.
_________________________________________________________
ps: This year GFS has not seem to me be be "running hot". On the data I use, temperatures and precipitation, it seems to be pretty good at least to 5 days out. Last year it did seem to me to run hot, especially towards the end of the forecast period of 10 days.
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #901 on: June 01, 2019, 02:39:23 PM »
NSIDC Total Area as at 31 May 2019 (5 day trailing average) 9,725,949 km2
               
Total Area         
 9,725,949    km2      
-344,538    km2   <   2010's average.
-255,837    k   <   2018
-783,288    k   <   2000's average.
         
Total Area Change   -60    k   loss
Peripheral Seas   -24    k   loss
Central Seas__   -25    k   loss
Other Seas___   -11    k   loss
         
Peripheral Seas         
Bering _______   -1    k   loss
Baffin  Bay____   -18    k   loss
Greenland____    1    k   gain
Barents ______   -6    k   loss
         
CAB Seas         
Beaufort_____   -8    k   loss
CAA_________   -3    k   loss
East Siberian__    14    k   gain
Central Arctic_   -12    k   loss
         
Kara_________   -8    k   loss
Laptev_______   -2    k   loss
Chukchi______   -6    k   loss
         
Other Seas         
Okhotsk______   -1    k   loss
St Lawrence___    2    k   gain
Hudson Bay___   -12    k   loss

Area loss 60 k, 3 k less than the 2010's average loss of 63 k on this day.
Total area still 2nd lowest (325 k > 2016)

Temperatures etc
GFS shows temperature anomalies varying from +1.7 to +3.0. At the moment little reason to suppose sea ice extent loss will be at much above average in the immediate future.
But the chances of the North-West passage being open this year seem to improve all the time.

(Volume data for May available in a few days time).
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #902 on: June 01, 2019, 03:08:13 PM »
Little sign of more than average overall sea ice loss in the 7 central seas of the "High Arctic".

Once again predictions of Armageddon on the melting season thread - we will see.

See graphs attached.
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binntho

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Re: 2019 sea ice area and extent data
« Reply #903 on: June 01, 2019, 03:10:29 PM »
Little sign of more than average overall sea ice loss in the 7 central seas of the "High Arctic".

Once again predictions of Armageddon on the melting season thread - we will see.

See graphs attached.

Because it's the day for pedantism: The two graphs show that the current year is running about 10 days ahead of the 2010s average - so there is "some" signs of impending Armageddon!

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #904 on: June 01, 2019, 03:19:58 PM »
But the 4 seas that need to melt to open the NW Passage continue to do the biz.
It is the CAA, however, that holds the key. Early opening up from the Pacific end and the Baffin Bay end should allow warmth from ocean currents in and export of ice out from the CAA.
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be cause

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Re: 2019 sea ice area and extent data
« Reply #905 on: June 01, 2019, 03:52:02 PM »
 The two graphs show that the current year is running about 10 days ahead of the 2010s average - so there is "some" signs of impending Armageddon!
[/quote]



.. and Chukchi is 3 weeks ahead of 2018 and 2016 ; Beaufort 5 weeks ahead of 2018 and likely 3 weeks ahead of 2016 in a few days . Of course there may be a major stall in June this year too .. but the forecasts are not promising .
 I'm always asking for stuff .. any chance , Gerontocrat , of including 2016 in all the regional graphs .. and 2012 .. please .. :) .. b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 ...

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #906 on: June 01, 2019, 05:04:25 PM »
I'm always asking for stuff .. any chance , Gerontocrat , of including 2016 in all the regional graphs .. and 2012 .. please .. :) .. b.c.
Maybe, but it will take some time.
Lot's of work to do on ice-free days and open water calculations.

Too many graphs. The laptop is working at the ragged edge.
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Observer

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Re: 2019 sea ice area and extent data
« Reply #907 on: June 01, 2019, 05:19:38 PM »
The two graphs show that the current year is running about 10 days ahead of the 2010s average - so there is "some" signs of impending Armageddon!



.. and Chukchi is 3 weeks ahead of 2018 and 2016 ; Beaufort 5 weeks ahead of 2018 and likely 3 weeks ahead of 2016 in a few days . Of course there may be a major stall in June this year too .. but the forecasts are not promising .
 I'm always asking for stuff .. any chance , Gerontocrat , of including 2016 in all the regional graphs .. and 2012 .. please .. :) .. b.c.
[/quote]



So . . . two people can look at the same set of graphs and draw (dramatically) different conclusions. When I was studying engineering some years ago a fellow student remarked that he didn't go into the social sciences because he liked the certainty of numbers. The innocence of youth; I miss it.

be cause

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Re: 2019 sea ice area and extent data
« Reply #908 on: June 01, 2019, 05:53:29 PM »
  .. whereas I see two people making quite seperate observations that are entirely accurate. As is yours .. :) .. b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 ...

jdallen

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Re: 2019 sea ice area and extent data
« Reply #909 on: June 01, 2019, 09:13:36 PM »
But the 4 seas that need to melt to open the NW Passage continue to do the biz.
It is the CAA, however, that holds the key. Early opening up from the Pacific end and the Baffin Bay end should allow warmth from ocean currents in and export of ice out from the CAA.
With current weather, I expect Beaufort area to cross over 2016 sometime in the next 3-4 days and continue plummeting.

The Chukchi is already awful.

Regarding "Armageddon" predictions - not from me anyway, but the drop in *these* two seas in particular are very concerning.  Early opening here weakens extent which buttresses the CAB and strong ice that's hard up against the CAA.

Combine that with what ice is getting shoved through the Atlantic-side meat slicer, and significant but-not-unusual increased open water in the Laptev, and in my view it all the pieces add up to our needing a break in the weather, soon.
This space for Rent.

epiphyte

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Re: 2019 sea ice area and extent data
« Reply #910 on: June 01, 2019, 09:45:09 PM »
@jdallen - I quite concur. There's one other thing I find concerning, which is the polar region. I don't think I've ever seen a sustained surface temp above freezing there at anything like this time of year, unless it was being blown in from somewhere.

...and no, that's not a prediction of imminent armageddon; just another observation of bad things going on, that aren't reflected in extent, but which are potentially setting things up for a big crash later.

Minor aside on scientists vs. engineers in the age of information: If you ask someone what the weather is like outside, and (s)he consults her computer before looking out of the window, which are they more likely to be?

Sterks

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Re: 2019 sea ice area and extent data
« Reply #911 on: June 02, 2019, 12:29:36 AM »

Minor aside on scientists vs. engineers in the age of information: If you ask someone what the weather is like outside, and (s)he consults her computer before looking out of the window, which are they more likely to be?
Average urban person with a smartphone (not computer though)?
I do it all the time, I become that lazy...

petm

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Re: 2019 sea ice area and extent data
« Reply #912 on: June 02, 2019, 02:00:25 AM »
I can see out the window from where I sit, yet I still check the weather online. It's not (only) laziness. With the right measurements and models, you can better see what's likely coming.

Rich

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Re: 2019 sea ice area and extent data
« Reply #913 on: June 02, 2019, 03:40:46 AM »
It's not helpful to use words like Armageddon to describe the views of people you may not agree with.

It's pretty clear from the decadal trend lines which direction the sea ice is headed. The consequences of lost sea ice are already pretty awful at this stage and they are going to get worse.

The only really question is the timing and the mechanisms which bring it about.

It seems like gerontocrat's daily projection that ice losses will not exceed historical averages belongs in the melting season thread where that point of view can be debated.

This is the bookeeper thread, not the analysis thread.

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #914 on: June 02, 2019, 05:52:43 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

June 1st, 2019:
     10,671,125 km2, close to a century drop: -97,808 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.

Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #915 on: June 02, 2019, 07:09:34 AM »

It seems like gerontocrat's daily projection that ice losses will not exceed historical averages belongs in the melting season thread where that point of view can be debated.

This is the bookeeper thread, not the analysis thread.

Without gerontocrat's contribution to this thread, it wouldn't exist.

oren

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Re: 2019 sea ice area and extent data
« Reply #916 on: June 02, 2019, 07:38:42 AM »
Quote
This is the bookeeper thread, not the analysis thread.
True. And the admirable bookkeeper injects his own bits of analysis - so it has been here since time began.
But feel free to quote from here and respond in the melting season thread - a common practice as well.
My own bit while I'm here: ice melting does not equal extent loss. Armageddon in 3D can seem benign in 2D - for a while.

Rich

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Re: 2019 sea ice area and extent data
« Reply #917 on: June 02, 2019, 08:39:49 AM »
Quote
This is the bookeeper thread, not the analysis thread.
True. And the admirable bookkeeper injects his own bits of analysis - so it has been here since time began.
But feel free to quote from here and respond in the melting season thread - a common practice as well.
My own bit while I'm here: ice melting does not equal extent loss. Armageddon in 3D can seem benign in 2D - for a while.

I totally appreciate the bookeeping. It's excellent.

I don't see any analysis here, I see a daily conclusion that there is no reason to believe that sea ice levels will decline by above average amounts in the near term. The analysis behind that conclusion is opaque.

The reference to users who are predicting higher losses to come as predicting Armageddon comes across as passive aggressive.

There are some new users who might come here and look at the data and think everything is fine, especially when the person delivering the data is reinforcing that message.

I'm with Greta Thunberg. People should have appropriate fear of where we are heading. What happens from day to day is a mystery, but the decadal trend is horrible.

We can walk and chew gum at the same time. We can be grateful for the data and be critical of the accompanying editorial.

binntho

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Re: 2019 sea ice area and extent data
« Reply #918 on: June 02, 2019, 09:19:10 AM »
Don't know much about keeping boos but I am very thankful for Gerantocrats excellet bookkeeping and look forward to his posts every day!

b_lumenkraft

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Re: 2019 sea ice area and extent data
« Reply #919 on: June 02, 2019, 09:19:58 AM »
+1

be cause

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Re: 2019 sea ice area and extent data
« Reply #920 on: June 02, 2019, 09:49:06 AM »
  +1 +Juan. C. :)
Juan's figures show a 70K catch up on the 2016 leader . I reckon this year's lead will be impressive by month's end .. b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 ...

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #921 on: June 02, 2019, 09:59:58 AM »
JAXA ARCTIC EXTENT :- 10,671,125 km2(June 1, 2019)

- Extent is 2nd lowest in the satellite record, 266 k > 2016, 150 k < 2018.
- Extent loss on this day 98  k, 43 k more than the average loss of 55 k on this day.
- Extent loss from maximum 3,600 k, 455 k (14.5%) greater than the average of 3,145k loss from maximum by this day,
- On average 31.8% of the melting season done, with 104 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.

Looking at the last 5 years average remaining melt only gives a result of 4.18 million km2, 4th lowest, and 1.01 million km2 above the record low of 2012.

On 22nd April, 2016 started its 2 months as the front runner with steep declines in extent.  To become lowest again, 2019 will have to match or exceed the above average extent losses of 2016 from now until at least mid-late June. For that reason I have removed 2018 daily change and replaced it with 2016 data on graph Arc2.

 Later this week that will be replaced with 2012 as it becomes the front runner (see next post).

Other Stuff

GFS shows temperature anomalies varying from +1.7 to +2.9. The sheer persistence of above average temperatures across most of the Arctic that has existed for a good while, should reinforce that 2019 will be a continuation of the 2010's decadal decline in sea ice extent and area.

However, at the moment little reason to suppose sea ice extent loss will be at much above average in the immediate future, despite the high extent loss on this day.
_________________________________________________________
ps: This year GFS has not seem to me be be "running hot". On the data I use, temperatures and precipitation, it seems to be pretty good at least to 5 days out. Last year it did seem to me to run hot, especially towards the end of the forecast period of 10 days.

pps: As the June poll is underway, I have promoted the projections table Arc1 to the top of the attachments.
« Last Edit: June 02, 2019, 10:55:58 AM by gerontocrat »
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b_lumenkraft

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Re: 2019 sea ice area and extent data
« Reply #922 on: June 02, 2019, 10:16:50 AM »
Extent loss on this day 98  k, 43 k less than the average loss of 55 k on this day

Extent loss on this day 98  k, 43 k less more than the average loss of 55 k on this day

  ;)

Viggy

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Re: 2019 sea ice area and extent data
« Reply #923 on: June 02, 2019, 10:17:14 AM »

I totally appreciate the bookeeping. It's excellent.

I don't see any analysis here, I see a daily conclusion that there is no reason to believe that sea ice levels will decline by above average amounts in the near term. The analysis behind that conclusion is opaque.

The reference to users who are predicting higher losses to come as predicting Armageddon comes across as passive aggressive.

There are some new users who might come here and look at the data and think everything is fine, especially when the person delivering the data is reinforcing that message.

I'm with Greta Thunberg. People should have appropriate fear of where we are heading. What happens from day to day is a mystery, but the decadal trend is horrible.

We can walk and chew gum at the same time. We can be grateful for the data and be critical of the accompanying editorial.

All that's well and good but there are different, specific threads to discuss them. This is a thread about past and present data and maybe gleaming patterns from it to understand what range of scenarios we may face.

Let's bottle the fake outrage - everyone here understands whats at stake. We don't need people to scare the newbies or give them undue hope. We need a place to objectively observe data and that is what this is.

And the obligatory but fully deserved, thanks Geron!

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #924 on: June 02, 2019, 10:53:32 AM »
A book-keeper's response (Be humble, Gero, be humble)

Someone posted that without my postings, there would be no thread.
NOT TRUE. I've only been around for a couple of years on this forum.
Many have exhausted themselves putting info on this thread before myself and Juan, and many more will do so in the future.

The title of the thread is "2019 sea ice area and extent data", not "When will the Arctic Go Ice-Free".

My guess on the latter is a BOE before 2030 - but mainly based on volume declining much faster than area, leading to a tipping point when average thickness is low enough for a massive area loss. But that discussion belongs on the other threads.

I believe a BOE this year is in the realms of vanishing probabilities. History does give us the limits of melting from now to minimum.
- The maximum is about 23% above (the 10 year) average - in 2012 - but from a starting extent nearly 0.8 million km2 above 2019's extent as of now. Even this would give a minimum of 2.45 million km2, hardly a BOE.
- The next highest melt from now was in 2007, +9.5% above average, giving a minimum of 3.3 million km2, just above the 2012 record low of 3.18 million km2.
- The 5 previous years melt from now were all below average.
- Temperatures, though above average and over the entire Arctic Ocean, are not hugely so.
-And, yesterday Tealight updated his May volume stuff on https://cryospherecomputing.tk/SIT.html Volume about 3rd lowest, average thickness up at 1.8 meters.

So, what is my guess for the immediate future. Melt will continue, at average, or maybe a bit above. One or more seas (e.g. the Chukchi) will accelerate their change from ice deserts (with occasional open water periods) to open water seas (with occasional icy periods).

Armageddon will be postponed for another year, though a second lowest minimum is on the cards.

2012
2012 did its first collapse in JAXA extent from the 5th to the 13th June. On the 5th I will change graph Arc2 to show the 2012 daily change and dump 2016.
_____________________________________________________
The book-keeper returns to his quill pen and Kalamazoo ledger

And that's all I am going to say about that
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #925 on: June 02, 2019, 10:56:50 AM »
Extent loss on this day 98  k, 43 k less than the average loss of 55 k on this day

Extent loss on this day 98  k, 43 k less more than the average loss of 55 k on this day

  ;)
Thanks, sorted
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Rich

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Re: 2019 sea ice area and extent data
« Reply #926 on: June 02, 2019, 11:36:31 AM »

Let's bottle the fake outrage - everyone here understands whats at stake.

It's neither fake nor outrage. And unless you have some special telepathic powers, you have no way of knowing who gets it or not. It would be interesting to understand how many new people are visiting here.

Agree with you 100% as to the purpose of the various threads. This is area and extent data thread.

Like everyone else, I'm grateful for the data that gerontocrat and Juan are providing. Thank you guys.

That said, everyone has their own reasons for being here. The world at large is vastly uniformed about the nature of the AGW thread and the timing of severe consequences. The situation in the Arctic is a bellwether for potentially catastrophic AGW consequences in the near future.

Like it or not, this community is a leader in the public discussion of the Arctic and it's consequences and a gateway for people to learn and become informed and cultivate the political pressure necessary to reduce GHG levels.

I understand that not everyone here shares the mission  of wanting to fix the AGW problem. Some are content to just watch it peacefully. Some don't think it's that big a problem. Some think the problem is real but that they have no influence on the outcome. They've accepted defeat.

I'm an activist. I am pointing this out because I care about details.

All of the responses here seem to be in alignment. Everyone highly values the data being shared here. Your comment seems to support mine. This isn't the thread to unilaterally cast aspersions and downplay the risks of what is presented in the melting season thread.

If anyone has an opinion on the daily statement that says there's No Reason to think that ice losses will be above average in the near term...please speak to that specifically. That's what I'm criticizing.

This is science. I disagree with that statement. I think there are plenty of good reasons to suspect that ice losses will be above average in June.




Stephan

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Re: 2019 sea ice area and extent data
« Reply #927 on: June 02, 2019, 11:40:21 AM »

2012 did its first collapse in JAXA extent from the 5th to the 13th June. On the 5th I will change graph Arc2 to show the 2012 daily change and dump 2016.


I'd like to know which seas in particular were affected in June 2012 (I didn't know the forum existed at that time and therefore didn't follow the details) and whether this rapid loss in June 2012 influenced further losses in July and August 2012.

Neven

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Re: 2019 sea ice area and extent data
« Reply #928 on: June 02, 2019, 11:52:27 AM »
I'd like to know which seas in particular were affected in June 2012 (I didn't know the forum existed at that time and therefore didn't follow the details) and whether this rapid loss in June 2012 influenced further losses in July and August 2012.

Lots of info on that in the ASIB archives.
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #929 on: June 02, 2019, 11:59:59 AM »
I'd like to know which seas in particular were affected in June 2012 (I didn't know the forum existed at that time and therefore didn't follow the details) and whether this rapid loss in June 2012 influenced further losses in July and August 2012.

Lots of info on that in the ASIB archives.
I've been leant on by - you know who you are - to add 2012 and 2016 lines to the area graphs. It will happen - soonish.

ps: The ASIF spellchecker does not know the word "leant". Huh
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Sterks

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Re: 2019 sea ice area and extent data
« Reply #930 on: June 02, 2019, 12:03:15 PM »
Don't know much about keeping boos but I am very thankful for Gerantocrats excellet bookkeeping and look forward to his posts every day!
Fully agree.
The Armageddon characterization of some of us comments is fairly accurate as well. Who would be coming to this forum if not expecting Apocalypse one of these summers. So I don’t agree with the guy sometimes but that’s ok.
Let’s take some of the heat out of this. Opposite to what’s coming to the Asian side in this week.

Rich

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Re: 2019 sea ice area and extent data
« Reply #931 on: June 02, 2019, 01:41:42 PM »
If we define Armageddon as a BOE, then there are almost no posters on the melting season thread pitching Armageddon for this year.

I appreciate Gero's laying out his rationale for his 2019 outlook and would just point out that the analysis is rooted in prior results. The assumptions of what can happen in 2019  are constrained by what happened in past years.

It's not a bad starting point for a wild ass guess about a system that is probably too complicated for anyone to really home in on with predictive accuracy. When ice loss minimums made major declines in 2007 and 2012, there was no obvious advance warning.

Every year presents us with a new opportunity to make the leap forward to a new record and 2019 is still in the hunt.

I also appreciate the message about being humble which includes acknowledging I have no idea what the final 2019 result will look like.

 All that said, I am absolutely grateful for the volunteer labor that goes into providing the sea ice data free of charge. It is an essential service to the community. Many thanks to Gero for the detailed accounting and historical comparisons.

PS - It's perhaps an interesting exercise to debate when to characterize an outcome. Some might argue that a BOE that we can anticipate a decade out is worse than one that catches us by surprise, because we have to
Iive with the awareness of it's inevitability without a guide for how to prepare for it.

Maybe we've already hit the threshold for Armageddon?







Mozi

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Re: 2019 sea ice area and extent data
« Reply #932 on: June 02, 2019, 02:13:59 PM »
Perhaps you would prefer to take this BOE discussion to the "When will the Arctic go Ice Free" thread?

https://forum.arctic-sea-ice.net/index.php/topic,2348.400.html

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #933 on: June 02, 2019, 02:55:41 PM »
NSIDC Total Area as at 1 June 2019 (5 day trailing average) 9,656,832 km2
               
Total Area         
 9,656,832    km2      
-357,094    km2   <   2010's average.
-233,895    k   <   2018
-801,342    k   <   2000's average.
         
Total Area Change   -69    k   loss
Peripheral Seas   -28    k   loss
Central Seas__   -24    k   loss
Other Seas___   -17    k   loss
         
Peripheral Seas         
Bering _______   -1    k   loss
Baffin  Bay____   -19    k   loss
Greenland____   -0    k   loss
Barents ______   -8    k   loss
         
CAB Seas         
Beaufort_____   -11    k   loss
CAA_________    2    k   gain
East Siberian__    13    k   gain
Central Arctic_   -10    k   loss
         
Kara_________   -7    k   loss
Laptev_______   -3    k   loss
Chukchi______   -7    k   loss
         
Other Seas         
Okhotsk______   -1    k   loss
St Lawrence___   -3    k   loss
Hudson Bay___   -13    k   loss

Area loss 69 k, 14 k MORE than the 2010's average loss of 55 k on this day.
Total area still 2nd lowest (325 k > 2016)

Temperatures etc
GFS shows temperature anomalies varying from +1.7 to +2.9. The sheer persistence of above average temperatures across most of the Arctic that has existed for a good while, should reinforce that 2019 will be a continuation of the 2010's decadal decline in sea ice extent and area.

The chances of the North-West passage being open this year seem to improve all the time, in contrast to the Russian side.

(PIUMAS Volume data for May available in a few days time. Tealight has already done his at https://cryospherecomputing.tk/SIT.html ).
« Last Edit: June 02, 2019, 05:06:24 PM by gerontocrat »
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Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #934 on: June 02, 2019, 03:30:35 PM »
This is science. I disagree with that statement. I think there are plenty of good reasons to suspect that ice losses will be above average in June.

Great. Rather than telling gerontocrat to quit providing his analysis based on past ice behavior and current temperatures, provide us with reasons why you expect losses to be greater than average. This discussion would help all of us develop a better understanding of the ice.
« Last Edit: June 02, 2019, 03:38:48 PM by Shared Humanity »

Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #935 on: June 02, 2019, 03:34:29 PM »
Perhaps you would prefer to take this BOE discussion to the "When will the Arctic go Ice Free" thread?

https://forum.arctic-sea-ice.net/index.php/topic,2348.400.html

Good idea. We have a person concerned that the thread should be a bookkeeping thread and then we go off the rails.

Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #936 on: June 02, 2019, 03:39:59 PM »
gerontocrat and Juan

keep doing what you do...it is why I visit this thread daily.

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Re: 2019 sea ice area and extent data
« Reply #937 on: June 02, 2019, 03:42:48 PM »
NSIDC NT sea ice concentration dropped -186k. Most of this (over 110k) is caused by the new monthly ice mask, removing ice from regions that are expected to be ice-free in all years during the month of the year.

From the attached delta image lots of coastal ice is "removed" (the bright red colors) in the St.Lawrence region, the Baltic and various costal areas in the Pacific.

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data
Date: 2019-06-01 12:00  Values in 1000 km^2

Extent (value, one day change, anomaly):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
  4436.2   -0.7   -14.5    935.1   +0.0    +4.7    676.6   -7.7   -43.5
               Kara Sea             Barents Sea           Greenland Sea
   857.9   +2.5   -30.1    316.7  -17.2  -294.0    540.6   -7.6  -125.3
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
   755.2   -2.1  -203.7      1.0  -61.2    -7.1   1184.9   +2.7    -2.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   712.5   +1.3   -22.6    383.6   -4.4  -127.8    401.6  -13.6  -170.6
             Bering Sea          Sea of Okhotsk                   Lakes
    28.1  -13.8  -109.7     64.4  -14.1   -58.0    204.2   +3.5   +60.5
          Other regions       Total (ex. lakes)
     6.1  -49.8    +3.3  11300.6 -185.7 -1201.7

Area (value, one day change, anomaly):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
  4165.3   -0.6   -89.2    888.8  +11.2   +22.8    610.2   -4.6   -31.2
               Kara Sea             Barents Sea           Greenland Sea
   620.2   -9.1  -125.2    181.2   -6.9  -207.9    386.0   -3.6   -59.3
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
   504.8   -6.8  -178.7      0.5  -17.9    -2.4    907.0  -15.0   -38.4
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   660.7  +20.3   -13.1    234.1   -5.5  -216.4    349.8   -6.2  -158.7
             Bering Sea          Sea of Okhotsk                   Lakes
    14.2   -3.7   -38.1     22.4   -4.2   -35.8    111.3   +1.7   +31.4
          Other regions       Total (ex. lakes)
     2.5  -14.8    +1.3   9547.8  -67.5 -1170.4

Rich

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Re: 2019 sea ice area and extent data
« Reply #938 on: June 02, 2019, 04:16:05 PM »
For clarification, the header of the sea ice area chart indicates it's a 5 day moving average.

Since the loss reported for the day is 69k, up from the previous day of 60k, I'm inferring that the latest day total added to the 5 days average is 45k greater loss than the day that dropped out.

69*5 = 345
60*5 = 300

When comparing today's extent loss of 97k to today's area loss of 69k, I'd guess we need to factor in different techniques for measuring as well as a 5 day vs. 1 day measurement period.
« Last Edit: June 02, 2019, 04:37:44 PM by Rich »

b_lumenkraft

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Re: 2019 sea ice area and extent data
« Reply #939 on: June 02, 2019, 04:24:31 PM »
Rich, can you talk about the numbers in this thread, please? Thank you.

Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #940 on: June 02, 2019, 05:00:19 PM »
For clarification, the header of the sea ice area chart indicates it's a 5 day moving average.

Since the loss reported for the day is 69k, up from the previous day of 60k, I'm inferring that the latest day total added to the 5 days average is 45k greater loss than the day that dropped out.

69*5 = 345
60*5 = 300

When comparing today's extent loss of 97k to today's area loss of 69k, I'd guess we need to factor in different techniques for measuring as well as a 5 day vs. 1 day measurement period.

I believe the 5 day moving average is being used because of the volatility of the single day metric as ice blinks on and off.

oren

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Re: 2019 sea ice area and extent data
« Reply #941 on: June 02, 2019, 05:07:35 PM »
Quote
I believe the 5 day moving average is being used because of the volatility of the single day metric as ice blinks on and off.
Yes, that is especially true of NSIDC data. JAXA uses an algorithm that is somewhat like a 2 day average, but only Wipneus can really explain it. I think UH AMSR2 data doesn't use averaging. And the best data (both resolution, reliability and prevention of false ice) is UH filtered by the "Home brew" algorithm by Wipneus, which he once explained in detail.

Rich

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Re: 2019 sea ice area and extent data
« Reply #942 on: June 02, 2019, 05:35:46 PM »
Rich, can you talk about the numbers in this thread, please? Thank you.

With all due respect, I'm only commenting on the topics that gerontocrat is bringing to the thread.

I'm learning my way around here. My understanding is that Neven is the moderator. If he says that he wants gerontocrat to make and question predictions about the 2019 melting season in this thread and doesn't want anyone else to question his / her assumptions....I'm cool with that. I would have to be, no?

I'm 100% with you on this thread being about the data.

Peace.

Neven

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Re: 2019 sea ice area and extent data
« Reply #943 on: June 02, 2019, 05:45:56 PM »
There's one thing that has been really tiresome to me lately, and that's meta-discussions, ie a discussion about the discussion. Gerontocrat can do what he likes here, as long as he posts the data. If there's anything anyone wants to take up with him, I'd like to ask them to copy the quote in question, paste it in another thread and comment on it there.
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Rich

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Re: 2019 sea ice area and extent data
« Reply #944 on: June 02, 2019, 06:52:14 PM »
There's one thing that has been really tiresome to me lately, and that's meta-discussions, ie a discussion about the discussion. Gerontocrat can do what he likes here, as long as he posts the data. If there's anything anyone wants to take up with him, I'd like to ask them to copy the quote in question, paste it in another thread and comment on it there.

Thank you for the clarification. It's very helpful to understand the forum rules and exceptions.

Which thread would you suggest is most appropriate for continuing the discussion The melting season thread or another one?

Neven

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Re: 2019 sea ice area and extent data
« Reply #945 on: June 02, 2019, 06:55:10 PM »
If you want to discuss whether this melting season will be Armageddon or whatever, you can do it in the melting season thread, but not endlessly. If you want to discuss Arctic sea ice Armageddon in general, there are various threads for that, like the BOE thread.

But whatever you do, do not start discussions about the discussions.  ;)
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Tim

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Re: 2019 sea ice area and extent data
« Reply #946 on: June 02, 2019, 07:08:21 PM »
But Neven, didn't you just have a meta discussion yourself?  ;D

Neven

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Re: 2019 sea ice area and extent data
« Reply #947 on: June 02, 2019, 07:18:24 PM »
Well, to be exact, it was a discussion about meta-discussions. Which is probably why I have a headache now.  ;D
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Rich

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Re: 2019 sea ice area and extent data
« Reply #948 on: June 02, 2019, 10:08:04 PM »
If you want to discuss whether this melting season will be Armageddon or whatever, you can do it in the melting season thread, but not endlessly. If you want to discuss Arctic sea ice Armageddon in general, there are various threads for that, like the BOE thread.

But whatever you do, do not start discussions about the discussions.  ;)

I feel less like I'm stuck in an Abbott and Costello routine.

I don't want to claim that this melt season is going to be Armageddon. I don't have any such conviction.

I simply disagree with the daily mantra that there is little or no reason to believe that ice loss will be much above average in the near future.

Frankly, there:is an appeal to your just putting it out there that certain people don't have to follow the same rules as everyone else.

It's a good metaphor for the state of privilege that ails the world. 

I just engaged in a simple act of protest against privilege and every single person who weighed in on the discussion defended that privilege.

That's what we're up against in the fight against AGW.

The only hope to slow down AGW is massive protest. We should all learn to embrace protest behavior and the struggle for equity.

I don't have a serious disagreement with Gerontocrat. We basically agree on the big picture that the sea ice version of Armageddon (BOE) is coming in the not too distant future.

I'm just a protester with an habitual reaction to the privilege you described.

Sorry to interrupt everyone. You can all go back to the peaceful and orderly process of watching civilization come to an end without a fight.




Neven

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Re: 2019 sea ice area and extent data
« Reply #949 on: June 02, 2019, 10:16:03 PM »
Good, that settles it. On-topic now, please.

Compactness going up a bit again, due to big extent drop, not matched by area:
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