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dnem

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Re: 2019 vs 2012
« Reply #150 on: August 06, 2019, 07:16:19 PM »
It looks to me like he's using the average 2011-2018 melt to make his prediction.  Extent on August 4, 2019=5.76, Average melt from 2011-2018= 1.87, 5.76-1.87=3.89.

Glen Koehler

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Re: 2019 vs 2012
« Reply #151 on: August 06, 2019, 08:21:34 PM »
Right dnem. 
I used the 2011-2018 average reduction from latest observation date to the value at Sept. minimum Extent/Area/Volume/Thickness for those years and subtracted it from the value 2019 had on latest observation date.

Prior posts discussed idea of extending currently season anomaly above (or below, if that were the case) the 2011-2018 losses until the end of the melt season.  Thus, if 2019 losses were 5% greater than average losses from start of melt season to latest 2019 observation date, then the average 2011-2018 losses until minimum would be multiplied x 105%.

That seemded like a good idea until Klondike Kat showed an analysis that the anomaly above average melt rates in early season was NOT a good predictor of higher melt rates for remainder of season.  So I stuck with the original method.  That makes sense in that just because June was above average warmth/sunshine etc., that does not mean August will be too.  Just because a stock went up Tue. doesn't mean it will keep going up Wed, Thur, Fri.

But as is often discussed in the ASIF, "melting momentum" is a real thing.  Once ice gets preconditioned by strong melting forces, accelerated melt rate can continue for a long time afterward.

I am going to stick with the simple 2011-2018 average remaining losses as the most reliable predictor for remainder of current year (just my guess), and it is simple to understand.  But I can add a second 2019 estimated Sept. minimum value for Extent/Area/Volume/Thickness that pays heed to melting momentum.  I can do that by dividing the year to date 2019 losses for each measure by the 2011-2018 average for those dates to get the anomaly percentage for 2019 Ext/Ar/Vol/Thick losses up to current date.  Then use those anomaly percentages to multiply x the 2011-2018 average losses for remainder of year to create another estimate for 2019 that assumes continued ice loss anomaly.  I can add them to table without an ordinal number so as not to mess up the rankings by having two ordinal ranks for a single year.  But it's location in the table would show all that anybody wants to know -- how does 2019 compare to 2012 and other years.

Can't do it now, out of time.  But after August 14 which marked the end of GAC in 2012, another update comparing 2019 to 2012 and other years would be interesting and I can show estimates for 2019 minimums using both methods.

Sorry that the 2012 vs 2019 NSIDC conc. map posted so large.  First time I saved it, the size was normal, as is the 1980 vs 2012 Sept. min. image.  I don't know how to control size of the image when added to forum post.

philopek

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Re: 2019 vs 2012
« Reply #152 on: August 06, 2019, 09:05:35 PM »
Right dnem. 
I used the 2011-2018 average reduction from latest observation date to the value at Sept. minimum Extent/Area/Volume/Thickness for those years and subtracted it from the value 2019 had on latest observation date.


That is closing the gap significantly and only volume remains kind of to tight to tell then.

Thanks for elaboration ;)

Good job either way as mentioned ;)

Killian

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Re: 2019 vs 2012
« Reply #153 on: August 07, 2019, 07:11:18 AM »
I used the 2011-2018 average reduction from latest observation date to the value at Sept. minimum Extent/Area/Volume/Thickness for those years and subtracted it from the value 2019 had on latest observation date.

You've probably addressed the issue of why those years, but I don't have time to read back through all your posts, sorry. I see 2011's level as a result of the momentum from the phase change and conditioning of 2005~2010. Weather in 2007 and 2010 (less so) was highly anomalous, but I think the preconditioning of the time period partly made 2011 possible.

2012 is a true statistical anomaly in the truest scientific sense. Had it been a normal part of anything we'd have approached those numbers again at some point in the last 7 years. That is, have you considered simply dismissing 2012 and/or assigning it an average?

There is a very important, never-discussed issue that is a pet of mine. Both 2012 and 2016 were strong El Nino years. The scientific literature in 2012 said EN's do not affect ASI. They're wrong, IMO. As you can see here...

Quote
I went further back, eyeballing from an extent graph through 2010 or so with poor detail (what I could find) and a list of ENSO years and intensities. This is the rough. If anyone has more detailed resources and can nail this down better, please do.

Here is what I found going all the way back to the beginning of ASIE decline @ 1953-ish.

EN ’51 – ’54 = inception of ASI Extent decline.
EN ’57 – ’59 = Near New Low/New Low
EN ’65 – ’66 = Near New Low/New Low
EN ’68 – ’70 = New Low
EN ’72 – ’73 = possible correlation, some delay
EN ’76 – ’78 = New Low
EN ’79 – ’80 = New Low
EN ’82 – ’83 = New Low
EN ’86 – ’88 = New Low (’89,’90)
EN ’94 – ’95 = New Low
EN ’97 – ’98 = Drop from Previous (?)
EN ’04 – ’05 = Near New Low/New Low
EN ’04 – ’05/’06 – ’07 = New Low
EN ’09 – ’10 = New Low (’10, ’12)
EN ’15 – ’16 = New Low ’16,’17?
http://www.realclimate.org/index.php/archives/2015/08/unforced-variations-aug-2015/comment-page-5/#comment-635199

...I predicted the near new low (2nd in the record) of 2016 a full year ahead, in August 2015. How? An EN was brewing and was expected to be strong. I looked back through the data all the way back to the 1950's and noticed a correlation between ENs and ASI changes. However, as we know, it takes time for energy to propogate through a system, particularly the oceans. It was when I used a two-year post-EN window that the correlation jumps out. The year of the EN it is occurring during the melt season, but in the Pacific, not the Arctic. It takes time for that energy to propagate and takes time for ice to react. Bottom melt, as we all know, dominates.

Since 2012, and since my theory was posited 4 years ago, two studies have found that Pacific heat and moisture affect ASI. The tie is not as equivocal as my theory, but nobody is looking at my theory because the conventional wisdom EN's don't affect ASI is set. But they do, imo. The combination of the EN, the GAC and the high export gave us 2012. It's not normal. As any good scientist is taught, sometimes you have to throw out the outlier. It does not serve as a good model for a year with no GAC, no EN (though June's and July's high heat might be considered proxies for the EN), and higher but not exceptional export.

That is, I wonder if your method might consider using the clear phase change that came after the EN of 2015/2016 given the clustering of patterns since that time.

FYI, FYC (for your consideration).

Cheers

binntho

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Re: 2019 vs 2012
« Reply #154 on: August 07, 2019, 07:22:14 AM »
<snip>
There is a very important, never-discussed issue that is a pet of mine. Both 2012 and 2016 were strong El Nino years.
</snip>
Well, 2012 certainly wasn't a "strong El Nino year", in fact the beginning of 2010 to the end of 2014 saw two back-to-back La Ninas followed by a child-free period of almost 3 years.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

binntho

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Re: 2019 vs 2012
« Reply #155 on: August 07, 2019, 07:39:33 AM »
<snip>
Quote
I went further back, eyeballing from an extent graph through 2010 or so with poor detail (what I could find) and a list of ENSO years and intensities. This is the rough. If anyone has more detailed resources and can nail this down better, please do.

Here is what I found going all the way back to the beginning of ASIE decline @ 1953-ish.

EN ’51 – ’54 = inception of ASI Extent decline.
EN ’57 – ’59 = Near New Low/New Low
EN ’65 – ’66 = Near New Low/New Low
EN ’68 – ’70 = New Low
EN ’72 – ’73 = possible correlation, some delay
EN ’76 – ’78 = New Low
EN ’79 – ’80 = New Low
EN ’82 – ’83 = New Low
EN ’86 – ’88 = New Low (’89,’90)
EN ’94 – ’95 = New Low
EN ’97 – ’98 = Drop from Previous (?)
EN ’04 – ’05 = Near New Low/New Low
EN ’04 – ’05/’06 – ’07 = New Low
EN ’09 – ’10 = New Low (’10, ’12)
EN ’15 – ’16 = New Low ’16,’17?
http://www.realclimate.org/index.php/archives/2015/08/unforced-variations-aug-2015/comment-page-5/#comment-635199
This list seems strangely incomplete, right from the start there is an error in counting the two ENs of 1951 and 1953 as one and the 1963 EN is not mentioned. The EN events are also vastly different, 76-78 saw two small ENs, 79/80 an almost non-EN while the 1982/3 was a decent sized one and 88-86 a real humdinger.

A good overview of the appearances of the two siblings can be found here https://origin.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_v5.php

As for the claims on lows extent wise (going by the following graph from https://sites.google.com/site/arcticseaicegraphs/longterm), 82 or 83 certainly did not see any new lows, nor did 86, 87 or 88.

The first claim that I find that could be said to be in the ballpark is that 1995 seems to have matched the previous record from 90 (which by the way is not included in the claims above).

Eyeballing graphs with bad resolution is not a good method, and I for one am not convinced that there is a causal link between El Ninos and low sea ice minimums, but I'm open to the possibility.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

binntho

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Re: 2019 vs 2012
« Reply #156 on: August 07, 2019, 08:15:59 AM »
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

SimonF92

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Re: 2019 vs 2012
« Reply #157 on: August 07, 2019, 12:34:53 PM »
very lazy superimposition of both data sets

[sorry the jpeg of that was horrible quality]

[edit, theyre both awful  8) ]

DrTskoul

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Re: 2019 vs 2012
« Reply #158 on: August 07, 2019, 12:36:34 PM »
I don’t really see any correlation...

SimonF92

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Re: 2019 vs 2012
« Reply #159 on: August 07, 2019, 12:41:02 PM »
I don’t really see any correlation...

One may argue that a la nina precedes a recovery, I may plot this properly in R

binntho

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Re: 2019 vs 2012
« Reply #160 on: August 07, 2019, 12:45:06 PM »
I don’t really see any correlation...

One may argue that a la nina precedes a recovery, I may plot this properly in R
Let's take this out of here and over here https://forum.arctic-sea-ice.net/index.php/topic,2274.msg219815.html#msg219815
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

Archimid

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Re: 2019 vs 2012
« Reply #161 on: August 07, 2019, 01:05:04 PM »
When considering the influence of teleconnections it is important to consider that the Arctic is not the same system in the 2010's than it was in the 20th century.

When the ice was thick, extent large and the jetstream strong and stable and when ENSO was not being fed by decades of AGW  the correlation was different than it is now.
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

Killian

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Re: 2019 vs 2012
« Reply #162 on: August 07, 2019, 02:40:58 PM »
<snip>
There is a very important, never-discussed issue that is a pet of mine. Both 2012 and 2016 were strong El Nino years.
</snip>
Well, 2012 certainly wasn't a "strong El Nino year", in fact the beginning of 2010 to the end of 2014 saw two back-to-back La Ninas followed by a child-free period of almost 3 years.

Sorry. It was the "moderate" '09-'10 EN. As I said, a 2-year window. Ended in 2010, low in 2010 and 2012, fitting the theory.

Thanks for the correction, but full context is important.

Killian

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Re: 2019 vs 2012
« Reply #163 on: August 07, 2019, 02:43:37 PM »
I went further back, eyeballing from an extent graph through 2010 or so with poor detail (what I could find) and a list of ENSO years and intensities. This is the rough.

This list seems strangely incomplete, right from the start there is an error in counting the two ENs of 1951 and 1953 as one

Sorry, not the case. Note the start date of the Mauna Loa data...

Quote
and the 1963 EN is not mentioned.

Look at the list. Why wouldn't it have been? The issue is not how EN's *don't* affect the ASI....

Etc.

Your feedback is in error. Could you check your comment then repost? Or, when I have more time and have had less beer, I will address them. Do note the post is from four years ago, so I am unlikely to remember every decision made then, and errors are certainly likely.

Cheers
« Last Edit: August 07, 2019, 02:55:09 PM by Killian »

Killian

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Re: 2019 vs 2012
« Reply #164 on: August 07, 2019, 02:56:50 PM »
When considering the influence of teleconnections it is important to consider that the Arctic is not the same system in the 2010's than it was in the 20th century.

When the ice was thick, extent large and the jetstream strong and stable and when ENSO was not being fed by decades of AGW  the correlation was different than it is now.

Yup. And I called 2016, anyway. EN is a global phenomenon which I think makes it a meta, not macro, input to the system.

binntho

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Re: 2019 vs 2012
« Reply #165 on: August 07, 2019, 02:57:26 PM »
<snip>
Quote
I went further back, eyeballing from an extent graph through 2010 or so with poor detail (what I could find) and a list of ENSO years and intensities. This is the rough.

This list seems strangely incomplete, right from the start there is an error in counting the two ENs of 1951 and 1953 as one

Sorry, not the case. Note the start date of the Mauna Loa data...

Quote
and the 1963 EN is not mentioned.

Look at the list. Why wouldn't it have been? The issue is not how EN's *don't* affect the ASI....

Etc.

Your feedback is in error. Could you check your comment then repost? Or, when I have more time and have had less beer, I will address them. Do note the post is from four years ago, so I am unlikely to remember every decision made then, and errors are certainly likely.

Cheers
Ciao Killian, in a few hours it's gonna be the beers on this side of the globe. Don't worry too much, it's not an important issue - but I did check against the actual numbers to which I've included links. Other than that, I think we should move this discussion, which is off topic for this thread, to here: https://forum.arctic-sea-ice.net/index.php/topic,2274.msg219815.html#msg219815
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

Killian

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Re: 2019 vs 2012
« Reply #166 on: August 07, 2019, 02:58:44 PM »
I don’t really see any correlation...

One may argue that a la nina precedes a recovery, I may plot this properly in R
Let's take this out of here and over here https://forum.arctic-sea-ice.net/index.php/topic,2274.msg219815.html#msg219815

No. For obvious reasons.

Killian

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Re: 2019 vs 2012
« Reply #167 on: August 07, 2019, 03:00:13 PM »
I don’t really see any correlation...

One may argue that a la nina precedes a recovery, I may plot this properly in R

Interesting. I only considered them as related to lows and there was zero correlation. Literally in the 50/50 range.

binntho

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Re: 2019 vs 2012
« Reply #168 on: August 07, 2019, 03:01:15 PM »
I don’t really see any correlation...

One may argue that a la nina precedes a recovery, I may plot this properly in R
Let's take this out of here and over here https://forum.arctic-sea-ice.net/index.php/topic,2274.msg219815.html#msg219815

No. For obvious reasons.
Well, this has nothing to do with 2012 vs. 2019 and it's just one of those silly bickerings about minor points of interest. So let's do the bickering where the bickering belongs.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

Killian

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Re: 2019 vs 2012
« Reply #169 on: August 07, 2019, 03:08:02 PM »
Quote from: binntho link=topic=2792.msg219860#msg219860 date=1565182646is
Ciao Killian, in a few hours it's gonna be the beers on this side of the globe.

It *is* the beers where I am, so consider that WRT my post quality.

Quote
it's not an important issue

Unless it is...

Quote
...which is off topic for this thread

Well.... the idea is not to prove or disprove my theory, but to give someone else the chance to improve their model. That is, the main point is helping Glen constrain which years to include in his modeling/analysis. I suppose we should let him chime in?
« Last Edit: August 07, 2019, 03:27:25 PM by Killian »

Glen Koehler

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Re: 2019 vs 2012
« Reply #170 on: August 07, 2019, 04:11:21 PM »
No analysis.  I simply used 2011-2018 because 8 years is enough to get a reasonably defined average.  And those are the most recent years, so the best we have to reflect any functional changes in the system.  I wanted 2012 in the mix because it happened once so it can, and likely will, happen again.  But by being mixed in with 7 other years, 2012 is only a partial influence.

Killian

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Re: 2019 vs 2012
« Reply #171 on: August 07, 2019, 04:48:43 PM »
Correct analysis, wrong number.

History repeats. I said...

Quote
Call it -75k +/-10k km sq.

but it came in 16k lower than my lowest possible at 5.51M, for the reasons stated, so far as I can tell. I also said...

Quote
And, that, Dear Readers, would be the end of 2019's record run, likely for the rest of the melt season.

...and damned if the two didn't cross, though at a little lower level. (The lesson I would share here is patterns, while not everything, are something, and having what we in permaculture call "pattern literacy" is vital to analysis. Not a hard call, right? However, I did first make a little while back.)

Daily Change to Exceed 2012 Record Daily Lows

8/07/2012 = 5.38M km sq.
8/06/2019 = Stands at 5.51M. Loss of > 130k km sq. needed to set a daily record for this date.

Analysis: What stands out is how the ice is not responding strongly to the winds, but seems to be driven by the melt momentum almost exclusively bc the winds in no way supported a drop so large, but the melt season and surface temps did.

For 8/07/19? Not a clue. Worldview is all clouds. SST's are only high on the Pacific side... where much of the junk ice is. Winds indicate compaction on the Pacific side and expansion from Greenland to Siberia.

I really don't know where the 110k came from except melt. Seeing the visible movement on the Atlantic side for expansion and the negligible movement on the Pacific side, but keeping in mind momentum... Let's weight it towards little stuff saying their goodbye's and call it...

-90k+/-10k.

On the positive side of things, 2019 did give up the lead to 2012 as predicted, and I hold, shakily, to the contention that that's it for 2019 in terms of a possible new minimum.

-------------------------------

Daily Changes Needed to Exceed 2012 low on Aug. 10.
(Related to effect of GAC and it's import vs. 2019's melt cycle.)

8/10/2012 stood at 4.94M km sq.
2019 needs an average daily drop of > 142.5k km sq. for a record low on this post-GAC date. (4 days.)

This has become absurd. 2019 cannot meet 2012's low on Aug. 10. I'd put every cent I have on that. Four days over 142k? Yeah, right. I'll ride this horse to the end, but... just to follow through.

Daily Changes Needed to Exceed 2012 Record Low on Sept. 15.
(Related to comparison of 2012 vs 2019's melt cycle.)

9/15/2012 stood at 3.18M km sq. on this date.
2019 needs an average daily drop of > 58.24k km sq. for a record Sept. low. (40 days)

Meh... still within the realm of possibility, but must fall by 38k per day by Sept. Don't hold your breath. Good thing I called 2nd behind 2012 back in July, along with many others.

Killian

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Re: 2019 vs 2012
« Reply #172 on: August 07, 2019, 04:51:02 PM »
But by being mixed in with 7 other years, 2012 is only a partial influence.

But if something truly is anomalous, it should not be used to analyze norms, no?

dnem

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Re: 2019 vs 2012
« Reply #173 on: August 07, 2019, 06:32:30 PM »
I tend to think of the weather in each of past eight years (or whatever span) as having been drawn from some distribution of possible weather years.  The conditions that prevailed in 2012 got drawn from the distribution that year, and they'll come up again in the future.  And the odds of a "super melt" year will only increase in the future.  I think it would be foolish to remove 2012 from the average. 

gerontocrat

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Re: 2019 vs 2012
« Reply #174 on: August 07, 2019, 06:59:19 PM »
But by being mixed in with 7 other years, 2012 is only a partial influence.

But if something truly is anomalous, it should not be used to analyze norms, no?
Not good to exclude a piece of data because in your opinion it is an anomaly.
But it is OK to exclude it if it is part of a generally accepted methodology.

e.g. The DMI often exclude the highest and lowest variation from the average from their graphs (e.g. Greenland SMB graphs).

So I tried that (result attached). i.e. sum the last 10 years, subtract  the max and min values and divide the result by eight. Simple projection of JAXA minimum comes in at 50 k km2 higher.
It's the same as just using just the last 5 years
_______________________________________________________
A Cautionary tale ( and I believe not a shaggy dog story) about anomalies.

The scientists using the satellite system measuring ozone levels in the atmosphere way back when decided, that as there was a lot of noise in the data, to get the analysis program to automatically ignore the raw data outside certain parameters.

Later, a scientist with a bee in his bonnet decided to check the raw data, and quickly published a letter ion a scientific journal saying - "There is a big hole in the ozone layer above Antarctica". He was roundly poo-hoohed and generally derided, scoffed at.

Eventually cooler heads prevailed, the data was analysed again, new data collected, and of course he was right. Panic stations.
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Killian

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Re: 2019 vs 2012
« Reply #175 on: August 08, 2019, 09:46:41 AM »

But if something truly is anomalous, it should not be used to analyze norms, no?
Not good to exclude a piece of data because in your opinion it is an anomaly.

Everything about '12 is... IMO.

LOL...

However, if, as many of us expect, 2019 will come in as the new 2nd lowest, then keeping '12 in the stats gets the closest result to a sub-'16 number. If we're wrong and '19 ends up kissin' cousin to '07 and '16, then... keeping '12 is still more accurate. Ergo, I'll shut up now.

  8   4.53                          8   4.53   
  9   5.05                          9   5.05   
14   4.88                        10   4.62   
13   4.81                        11   4.27   
10   4.62                        12   3.18   
17   4.47                        13   4.81   
18   4.45                        14   4.88   
11   4.27                        15   4.26   
15   4.26                        16   4.02   
16   4.02                        17   4.47   
12   3.18                        18   4.45   
                                   -H/L                                    -H/L
5 yr             4.04          4.18        5 yr          4.42      4.39
5 yr – 12      4.29               
4 yr – 12      4.25               

10 yr            4.40        4.47       10 yr           4.40     4.47
  9 yr – 12    4.54                       9 yr – 12   4.54   
10 yr – 12     4.54                    10 yr – 12    4.54   

Killian

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Re: 2019 vs 2012
« Reply #176 on: August 08, 2019, 11:39:46 AM »
Correct analysis, wrong number.

History repeats.

Again: Called -90k+/-10k. and got -107k to 5.42M. Lower than the previous day, not as low as I expected. Momentum really does seem to be the thing here. But, then, why the low days just a few days ago? That seems to have been mostly winds, so... ASI... argh...

--------------------------------------

Daily Change to Exceed 2012 Record Daily Lows

Quote
8/07/2012 = 5.38M km sq.
8/06/2019 = Stands at 5.51M. Loss of > 130k km sq.... to set record.

So 2012 leads by @ -40k. 24 hours later it'll be more like -140k, then 200k, then... Oh, my.

8/08/2012 = 5.19M km sq. after a huge 190k km sq fall.
8/07/2019 = Stands at 5.42M. Loss of > 230k km sq. needed to set a daily record for this date.

Analysis:
Little point in an analysis given that gap. It simply will not, cannot, happen. But, then, that's not really the point of this, is it? Nope. Let's try to get as close as we can to a correct number for the 8th, shall we?

Everything looks very much like today, just weaker winds and more surface heat further north, so I'll go with...

8/08/2019 = -90k+/-10km sq or 5.33M km sq.

-------------------------------

Daily Changes Needed to Exceed 2012 low on Aug. 10.
(Related to effect of GAC and it's import vs. 2019's melt cycle.)

8/10/2012 stood at 4.94M km sq.
2019 needs an average daily drop of > 160k km sq. for a record low on this post-GAC date. (3 days.)

This really has become absurd. Might be some strong melt in a couple days, but 2012 lost a LOT of ice over the same time period.

Daily Changes Needed to Exceed 2012 Record Low on Sept. 15.
(Related to comparison of 2012 vs 2019's melt cycle.)

9/15/2012 stood at 3.18M km sq. on this date.
2019 needs an average daily drop of > 57.44k km sq. for a record Sept. low. (40 days)

Even if the average keeps dropping at 1k/day, it ends up nowhere near 20k/day by Sept. 1. However, there is some serious warmth coming in over the Laptev Sea, noted by subgeometer on the 2019 melt season thread, that will likely do some damage to the Siberian side of the CAB, maybe deep into the center. The next 3 or 4 days might tell us quite a lot.

SimonF92

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Re: 2019 vs 2012
« Reply #177 on: August 08, 2019, 02:59:21 PM »
There are tests you can perform to detect outliers. Usually I leave them in my datasets because a reviewer may very well shit on you for asserting something is an outlier and basically send you back to the bench.

Any statistician will tell you that they have a strong distaste for outlier tests and I am inclined to agree, especially when that dataset is changing over time anyway- such as is the case for ASI.

dnem

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Re: 2019 vs 2012
« Reply #178 on: August 08, 2019, 03:52:04 PM »
Well sure, Simon. You can't just throw out a data point.  But we're talking about 7 years of weather here.  Hardly a robust data set from which you can make much of a prediction.  Plus, as you say, the baseline is shifting every year.  Obviously we need to consider the big melt years and the slow (rebound?) years as we think about what's to some.  But make a statistically valid prediction based on the weather since 2007, or 2011 or whatever recent year? Nah.

petm

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Re: 2019 vs 2012
« Reply #179 on: August 08, 2019, 03:58:40 PM »
A Cautionary tale ( and I believe not a shaggy dog story) about anomalies.

The scientists using the satellite system measuring ozone levels in the atmosphere way back when decided, that as there was a lot of noise in the data, to get the analysis program to automatically ignore the raw data outside certain parameters.

Later, a scientist with a bee in his bonnet decided to check the raw data, and quickly published a letter ion a scientific journal saying - "There is a big hole in the ozone layer above Antarctica". He was roundly poo-hoohed and generally derided, scoffed at.

Eventually cooler heads prevailed, the data was analysed again, new data collected, and of course he was right. Panic stations.

Indeed. From what I understand, it wasn't until after British Antarctic Survey scientists published a Nature paper about the hole in 1985 that the Americans (NASA) took their satellite data at face value.

SimonF92

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Re: 2019 vs 2012
« Reply #180 on: August 08, 2019, 04:13:48 PM »
Well sure, Simon. You can't just throw out a data point.  But we're talking about 7 years of weather here.  Hardly a robust data set from which you can make much of a prediction.  Plus, as you say, the baseline is shifting every year.  Obviously we need to consider the big melt years and the slow (rebound?) years as we think about what's to some.  But make a statistically valid prediction based on the weather since 2007, or 2011 or whatever recent year? Nah.

Hence why year on year the ASIF members June predictions of the September-minima are invariably negatively skewed!

Its my personal belief that a state-change occurred around 2000 and that fitting any kind of regression from 1979 is not valid any more. Nor is comparing pre-2000s el-ninos with post-2000s el ninos.

Klondike Kat

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Re: 2019 vs 2012
« Reply #181 on: August 08, 2019, 05:14:41 PM »
Well sure, Simon. You can't just throw out a data point.  But we're talking about 7 years of weather here.  Hardly a robust data set from which you can make much of a prediction.  Plus, as you say, the baseline is shifting every year.  Obviously we need to consider the big melt years and the slow (rebound?) years as we think about what's to some.  But make a statistically valid prediction based on the weather since 2007, or 2011 or whatever recent year? Nah.

Hence why year on year the ASIF members June predictions of the September-minima are invariably negatively skewed!

Its my personal belief that a state-change occurred around 2000 and that fitting any kind of regression from 1979 is not valid any more. Nor is comparing pre-2000s el-ninos with post-2000s el ninos.

It may have been a state change, or it may just be that the peripheral ice has all melted, and the core remains.  The core will be more difficult to melt, hence the slowdown.  Then again, maybe there was some systematic change in the oceans.  Whatever the reason, there has been a change.

Killian

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Re: 2019 vs 2012
« Reply #182 on: August 09, 2019, 04:40:02 AM »
But we're talking about 7 years of weather here.  Hardly a robust data set from which you can make much of a prediction.

You mean 7 years of data isn't enough to predict weather? That would b a wild assertion given the short-term nature of weather forecasting. I'm assuming you mean seven years of weather is not enough to forecast climate?

Either way, this would be incorrect. First, in any given year, the majore forcing for the ASI minima is weather, but overall the climatic changes are setting the context. I would suggest that climate forcing is changing so fast and at such magnitude, it is having noticeable yearly effects. Still, most of the year-to-year differences will be weather. Climate is found in the trends.

Killian

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Re: 2019 vs 2012
« Reply #183 on: August 09, 2019, 05:19:26 AM »
Well sure, Simon. You can't just throw out a data point.  But we're talking about 7 years of weather here.  Hardly a robust data set from which you can make much of a prediction.  Plus, as you say, the baseline is shifting every year.  Obviously we need to consider the big melt years and the slow (rebound?) years as we think about what's to some.  But make a statistically valid prediction based on the weather since 2007, or 2011 or whatever recent year? Nah.

Hence why year on year the ASIF members June predictions of the September-minima are invariably negatively skewed!

Its my personal belief that a state-change occurred around 2000 and that fitting any kind of regression from 1979 is not valid any more. Nor is comparing pre-2000s el-ninos with post-2000s el ninos.

It may have been a state change, or it may just be that the peripheral ice has all melted, and the core remains.  The core will be more difficult to melt, hence the slowdown.  Then again, maybe there was some systematic change in the oceans.  Whatever the reason, there has been a change.

Simon can dismiss what he likes, but I suggest he's making logical errors in doing so. Claiming 1. there was a phase change in 2000 and 2. ignoring the biggest EN happened in '98 is not a tenable position. The EN's bring water energy to the surface. It does not suck it back in the way it rapidly ejects it. It's essentially a tide raiser for climate change.

It is no accident the lows of '05, '07, '10, '11 '12 and '16 are all associated with EN's. Not only do the EN's pump energy into the atmosphere in general, affecting *global* weather, but they must send energy into the Arctic, also. The ENs are a Pacific phenomenon and it is Pacific waters flowing into Chukchi and feeding the Transpolar current across Siberia. Is it any accident the Siberian coast has the least ice when it is fed by the Pacific inflow? The Beaufort is also clearly effected by this as the gyre sucks water around into the Beaufort.

Note, also, there were a lot of ENs in the 2000's and the range of minima was huge, 3M km, while the 2010's range has fewer ENs and a range of 1.8M or so. Take out 2012 and it's less than 1M. Let's go back to the potential outlier. I had forgotten 2010 *and* 2011 were record years. No wonder we thought 2012 was the end of the ice! We'd seen a mild (in retrospect) new low in 2005, a bigger one in 2007, then '10 and '11 came along, and the differential was quite large: @ 350k km sq between '10 and '11.

In this context, we must see the preceding lows as preconditioning for 2012 which made the very unusual weather patterns for 2012 particularly impactful. All those EN's pumped a lot of energy into the global system.

Also, there is absolutely nothing that says ENs function differently pre- and post-2000, so no rationale for treating them differently.

Michael Hauber

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Re: 2019 vs 2012
« Reply #184 on: August 09, 2019, 05:58:48 AM »

It is no accident the lows of '05, '07, '10, '11 '12 and '16 are all associated with EN's.

Nino 3.4 index for September for the above years:

2005 -0.08
2007 -1.04
2010 -1.56
2011 -0.76
2012 +0.44
2016 -0.46

Warmest nino 3.4 index for 12 months prior to September for the above years:

2005 +0.71
2007 +1.1
2010 +1.81
2011 -0.23
2012 +0.44
2016 +2.57

None of those minimums occurred during el nino events.  Four of those six minimums occurred within 12 months after an el nino event, which is only one more than half.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

Killian

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Re: 2019 vs 2012
« Reply #185 on: August 09, 2019, 06:05:08 AM »
Daily Change to Exceed 2012 Record Daily Lows
8/08/2012 = 5.19M km sq. after a huge 190k km sq fall.
8/07/2019 = Stands at 5.42M. Loss of > 230k km sq. needed to set a daily record for this date.

8/08/2019 = -90k+/-10km sq or 5.33M km sq.

On the nose. Good. Whew...

8/09/2012 = 5.04M km sq. after a large 150k km sq fall.
8/08/2019 = Stands at 5.33M. Loss of > 290k km sq. needed to set a daily record for this date.

Winds shift more to favorable for compaction except along the Svalbard, et al., archipelago, where export should be stronger, but similar to the previous day. That should be balanced by more heat energy flowing in from the Beaufort around to the Laptev and more favorable winds for compaction there, generally, too. I'm tempted to call 90k again bc of the export/expansion, but the winds and heat should eat up some of that remaining whispy stuff. Losing ice in the CAA, too.

Call it 105k+/-10k.

-------------------------------

Daily Changes Needed to Exceed 2012 low on Aug. 10.
(Related to effect of GAC and it's import vs. 2019's melt cycle.)

8/10/2012 stood at 4.94M km sq.
2019 needs an average daily drop of > 160k km sq. for a record low on this post-GAC date. (2 days.)

Let the absurdity roll: -190k/day with 2 days to go.

Daily Changes Needed to Exceed 2012 Record Low on Sept. 15.
(Related to comparison of 2012 vs 2019's melt cycle.)

9/15/2012 stood at 3.18M km sq. on this date.
2019 needs an average daily drop of > 56.38k km sq. for a record Sept. low. (38 days)

Steady drops, bad weather maybe on the way according to the folks who keep tabs on the long-range forecasts. The ice looks like poop. Lots of ice going bye-bye in the CAA. Still at record low PIOMAS volume.

Could still be interesting.

Killian

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Re: 2019 vs 2012
« Reply #186 on: August 09, 2019, 06:06:54 AM »

It is no accident the lows of '05, '07, '10, '11 '12 and '16 are all associated with EN's.

Nino 3.4 index for September for the above years:

2005 -0.08
2007 -1.04
2010 -1.56
2011 -0.76
2012 +0.44
2016 -0.46

Warmest nino 3.4 index for 12 months prior to September for the above years:

2005 +0.71
2007 +1.1
2010 +1.81
2011 -0.23
2012 +0.44
2016 +2.57

None of those minimums occurred during el nino events.  Four of those six minimums occurred within 12 months after an el nino event, which is only one more than half.

Why are you commenting if you don't understand the theory?

Michael Hauber

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Re: 2019 vs 2012
« Reply #187 on: August 09, 2019, 06:11:34 AM »


Why are you commenting if you don't understand the theory?

I know enough about ENSO to correctly identify which years were el nino influenced and which were not.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

binntho

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Re: 2019 vs 2012
« Reply #188 on: August 09, 2019, 07:58:29 AM »


Why are you commenting if you don't understand the theory?

I know enough about ENSO to correctly identify which years were el nino influenced and which were not.
Yes, it's a bit weird continuing to claim things that do not verify. If you have a theory that you are working from, how about some explanations and then we can see if the theory holds by comparing it to actual data.

<snip>
It is no accident the lows of '05, '07, '10, '11 '12 and '16 are all associated with EN's
</snip>

Associated how?

'05 was preceded by three years with positive ENSO index, including two minor EN
'07 preceded by five years positive ENSO index,  three minor EN and one minor LN
'10 was not a low - one year positive ENSO, 2 years negative. Since '07 two LN and one EN
'11 was not a low - preceded by one year negative, 1 positive, 2 negative, three LN and one EN
'12 preceded by 2 negative, 1 positive, 2 negative.
'16 in the middle of a massive EN, including previous year, preceded by a decade of negative ENSO index (with the exception of 2009)

I'm not seeing any rythm here.

Quote
Not only do the EN's pump energy into the atmosphere in general, affecting *global* weather, but they must send energy into the Arctic, also.
Must they? Well, yes, of course, as a part of their general contribution to global warming. But not as a discernible direct causal effect. Or are we missing something? What?
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

SimonF92

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Re: 2019 vs 2012
« Reply #189 on: August 09, 2019, 11:06:28 AM »
Killian, if you feel so strongly about it and so readily rebut other's opinions  (which is fair enough), why not collate your data and submit it as a paper? Cryology is clearly lacking a cohesive and strong argument either way- why not contribute?

Submit it for a peer review and see what comes back.

oren

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Re: 2019 vs 2012
« Reply #190 on: August 09, 2019, 12:16:30 PM »
Killian - I believe you are making a wrong statement about the relationship of EN and sea ice minima, not supported by the data, as so many above have already rebutted. However, as you are intent on your claim, and assuming submitting a peer-reviewed paper is not your thing, why not at least start a new thread (or dig up an existing one) dealing specifically with the effect of ENSO on sea ice? This thread here was started by Neven specifically to compare 2012 and 2019, and should not be derailed by a side scientific discussion, as interesting as it might be.

Archimid

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Re: 2019 vs 2012
« Reply #191 on: August 09, 2019, 12:41:27 PM »
My reply To ENSO/ASI discussion here:

https://forum.arctic-sea-ice.net/index.php/topic,405.0.html

I invite you to continue this, IMHO, highly relevant discussion there. If you have a better thread let me know.
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

Killian

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Re: 2019 vs 2012
« Reply #192 on: August 09, 2019, 02:25:03 PM »
Killian, if you feel so strongly about it and so readily rebut other's opinions  (which is fair enough), why not collate your data and submit it as a paper? Cryology is clearly lacking a cohesive and strong argument either way- why not contribute?

Submit it for a peer review and see what comes back.

Not my job. Not a scientist. I bring things to people's attention. Let them that do that sort of thing do so. Not being flippant; I do not have the chops to do a scientific paper on this. I'm a systems, patterns, meta thinker, not a data, fine details sort. One half of a great team, maybe, but not both halves on my own.

Others,

The issue WRT EN has evolved re it's relevance here. My theory, in specific, need not be gone over any further on this thread. I would ask that people who this interests pay attention to the *seeming* correlation of ENs, their "goosing" of the global system (and the more disturbed a systm becomes the more sensitive to changes, so maybe that's why we've seen a potential change in impacts post-2000 (1998 in my book)?) and longer-term effects on sea ice.

BTW, it's not about directly melting ice, per se, so much as it's about energy broadly distributed and preconditioning.

I'll try to find the two papers on Pacific heat and moisture affecting sea ice that would seem to lend peripheral support to this concept.

What still most interests me re 2012 vs 2019 is the anomalous aspects of 2012 and the fact 2019 has had none like 2012, but has 1 or two of it's own.

Specifically, the two periods of very high, short-term extent loss from June 6th to the 13th or so and the period of the GAC in 2012. The latter has been beaten pretty wellm though I think a somewhat more nuanced discussion might be had there tha would bring everyone to agreement. The June event needs some discussion.

I finally, after wallowing around trying to figure out how to get info on the conditions for that second week in June (because literally not one person ever responded about it in any way, shape, or form), just went to Worldview and looked. Et viola! VERY sunny skies just during that period. We all learned only recently about a strong correlation between June insolation and Sept. minima. Well, there's your smoking gun. While June 2019 blew the doors off, there was a solid 8 days in early June 2012 with almost all sun... and a 930k km sq, iirc, drop.

If you use JAXA's interactive ASIE graph and pull up only 2019 and 2012... or 2012 and any other years, you can see those two weeks very clearly.

Cheers

binntho

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Re: 2019 vs 2012
« Reply #193 on: August 09, 2019, 02:36:08 PM »
The issue WRT EN has evolved re it's relevance here. My theory, in specific, need not be gone over any further on this thread. I would ask that people who this interests pay attention to the *seeming* correlation of ENs, their "goosing" of the global system (and the more disturbed a systm becomes the more sensitive to changes, so maybe that's why we've seen a potential change in impacts post-2000 (1998 in my book)?) and longer-term effects on sea ice.

Well I think this was OT from the start, EN has no bearing on any comparison between 2012 and 2019 given how radically different the ENSO index has been in the lead up to those two years, e.g.  2008-2012 (0.1) and 2015-2019 (0.9)

So a bit more OT: Your theory, "in specific", has not been gone over at all on this thread. There is no "seeming" correlation of ENs, and what in earth does "goosing" have to do with this? Will we be "gandering" soon as well?
because a thing is eloquently expressed it should not be taken to be as necessarily true
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AndyW

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Re: 2019 vs 2012
« Reply #194 on: August 09, 2019, 03:23:51 PM »

We can dumb down the 2019 v 2012 argument simply to Occams razer, and that is that so far there in 2019 there has not been any severe  weather so far that could create enough of a change either way, up or down, to provide an outlier as 2007 and 2012 had.

2007 had an anomalously large number of sunny days coupled with a warm southerly wind from the Russian side,  2012 had warm conditions plus cyclonic wind that provided dispersion and melting.

It would be best to actually ignore these two outliers completely and instead concentrate on the other years in the last 15 years to compare 2019 to.


Andy

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Re: 2019 vs 2012
« Reply #195 on: August 09, 2019, 04:16:41 PM »
It becomes more and more interesting.

Killian

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Re: 2019 vs 2012
« Reply #196 on: August 09, 2019, 06:01:24 PM »
The issue WRT EN has evolved re it's relevance here. My theory, in specific, need not be gone over any further on this thread. I would ask that people who this interests pay attention to the *seeming* correlation of ENs, their "goosing" of the global system (and the more disturbed a systm becomes the more sensitive to changes, so maybe that's why we've seen a potential change in impacts post-2000 (1998 in my book)?) and longer-term effects on sea ice.

Well I think this was OT from the start, EN has no bearing on any comparison between 2012 and 2019 given how radically different the ENSO index has been in the lead up to those two years, e.g.  2008-2012 (0.1) and 2015-2019 (0.9)

So a bit more OT: Your theory, "in specific", has not been gone over at all on this thread. There is no "seeming" correlation of ENs, and what in earth does "goosing" have to do with this? Will we be "gandering" soon as well?

I'm not going to go over the entire history of it all to deal with your lack of insight or awareness. You don't see, so it doesn't exist. Got it. God, thank you.

Now, not-God, Since I had clearly stated I wasn't going to discuss it anymore, your post is a perfect example of trolling/blowing on the embers. It was let lie, but you could not.

Get you ego and your arrogance out of the equation, please, and pay attention to what people say. I said I was happy to let it go. Suggest you do, too, particularly when you have exactly zero to add to the conversation other than, "Uh-uh!"

Criminy....

binntho

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Re: 2019 vs 2012
« Reply #197 on: August 09, 2019, 06:24:13 PM »
Temper, Killian. I wasn't the one filling the thread with OT unsupported claims that were simply wrong as has been repeatedly shown.

I did suggest several times to move this over into another thread, but no, you apparently felt your claims were too important. Yet somehow very difficult to substantiate.

Anyway, I'm happy to leave this subject, since it's clearly been battered out of existence by lack of evidence.
because a thing is eloquently expressed it should not be taken to be as necessarily true
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Killian

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Re: 2019 vs 2012
« Reply #198 on: August 09, 2019, 07:07:13 PM »
Temper, Killian. I wasn't the one filling the thread with OT unsupported claims that were simply wrong as has been repeatedly shown.

I did suggest several times to move this over into another thread, but no, you apparently felt your claims were too important. Yet somehow very difficult to substantiate.

Anyway, I'm happy to leave this subject, since it's clearly been battered out of existence by lack of evidence.

Seriously, get over yourself. Stop posting comments that serve nothing but your ego.

Someone said there is a way to mute people... I don't like jerks.

Killian

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Re: 2019 vs 2012
« Reply #199 on: August 09, 2019, 07:10:52 PM »


Why are you commenting if you don't understand the theory?

I know enough about ENSO to correctly identify which years were el nino influenced and which were not.

It is not your theory, thus you are completely incorrect. I stated clearly you must look at a two-year period, you responded discussing only a one-year period making your response irrelevant.

And your statement is an opinion which you state as fact, so doubly incorrect.