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Espen

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Re: IJIS/JAXA
« Reply #950 on: February 19, 2015, 06:20:58 AM »
IJIS:

13,774,725 km2(February 18, 2015)another lowest measured for this date.
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Espen

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Re: IJIS/JAXA
« Reply #951 on: February 28, 2015, 10:44:29 AM »
IJIS:

13,835,558 km2(February 27, 2015)another lowest measured for this date.

That is 780,000 km2 below the 2000s average.
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viddaloo

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Re: IJIS/JAXA
« Reply #952 on: February 28, 2015, 11:19:15 AM »
2015 also has an impressive 811 thousand km² slower refreeze than 2012 for Jan–Feb, pending, of course, the last day of February. No IJIS year has a lower Jan–Feb refreeze.
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Espen

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Re: IJIS/JAXA
« Reply #953 on: March 01, 2015, 09:21:05 AM »
IJIS

13,818,317 km2(February 28, 2015)another record low measured for this date.

That is 820,000 km2 below 2000s average
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viddaloo

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Re: IJIS/JAXA
« Reply #954 on: March 01, 2015, 09:50:04 AM »
If my scripts didn't just go crazy, this year has a 35% lower refreeze to date than record year 2012.

35%.
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Espen

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Re: IJIS/JAXA
« Reply #955 on: March 01, 2015, 10:11:47 AM »
If my scripts didn't just go crazy, this year has a 35% lower refreeze to date than record year 2012.

35%.

And we may not reach the 14 million mark for the first time in recent history!
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Espen

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Re: IJIS/JAXA
« Reply #956 on: March 02, 2015, 05:45:38 AM »
IJIS:

13,827,443 km2(March 1, 2015)another record low measured for this date.

And still 820,000 km2 below 2000s average
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Espen

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Re: IJIS/JAXA
« Reply #957 on: March 03, 2015, 05:24:00 AM »
IJIS:

13,798,149 km2(March 2, 2015)a drop of 29,294 km2 from previous and another record low for the date.

and now 860,000 km2 below 2000s average
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Re: IJIS/JAXA
« Reply #958 on: March 03, 2015, 09:20:03 AM »
Oh.

Espen

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Re: IJIS/JAXA
« Reply #959 on: March 04, 2015, 06:10:24 AM »
IJIS:

13,738,251 km2(March 3, 2015)down amazing 59,898 km2 from previous and a new lowest record for the date.

and 930,000 km2 below the 2000s average.

We may soon call it a max?
« Last Edit: March 04, 2015, 06:25:58 AM by Espen »
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viddaloo

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Re: IJIS/JAXA
« Reply #960 on: March 04, 2015, 06:20:07 AM »
Definitely, Espen.

Current Arctic sea ice extent is now an amazing one MILLION square kilometers lower than all–time low year 2012.

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Re: IJIS/JAXA
« Reply #961 on: March 04, 2015, 07:02:31 AM »
Oh, oh.

There should be an increase in March, but that doesn't really matter considering the whole picture.  :(

jdallen

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Re: IJIS/JAXA
« Reply #962 on: March 04, 2015, 08:13:59 AM »
IJIS:

13,738,251 km2(March 3, 2015)down amazing 59,898 km2 from previous and a new lowest record for the date.

and 930,000 km2 below the 2000s average.

We may soon call it a max?

A few more days like this, and I may start thinking my SWAG for the melt season was too conservative. 

We are only half way through the burst of heat predicted to roll across the basin from the Barents.
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Re: IJIS/JAXA
« Reply #963 on: March 04, 2015, 08:56:42 AM »

A few more days like this, and I may start thinking my SWAG for the melt season was too conservative. 

We are only half way through the burst of heat predicted to roll across the basin from the Barents.

There is however a cool spell shown in the Bering Sea at the same time, so there is plenty  of scope there for an increase in extent/area. They  may balance each other out.
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Re: IJIS/JAXA
« Reply #964 on: March 04, 2015, 10:08:32 AM »
We are only half way through the burst of heat predicted to roll across the basin from the Barents.

Are you aware that the Arctic view has recently been reinstated at CCI-Reanalyzer?

http://GreatWhiteCon.info/resources/arctic-sea-ice-graphs/#CCITemp

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Peter Ellis

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Re: IJIS/JAXA
« Reply #965 on: March 04, 2015, 10:24:08 AM »
Current Arctic sea ice extent is now an amazing one MILLION square kilometers lower than all–time low year 2012.
Indeed.  The closest match to today's value is 2006, which had... er... the second highest summer extent in the last decade.

In other words - maximum extent has very very little relationship to the summer minimum.  It's really not a good idea to start prognosticating yet.

viddaloo

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Re: IJIS/JAXA
« Reply #966 on: March 04, 2015, 10:36:52 AM »

The 2nd lowest year on March 3rd, of course, being 2011, ended up 3rd lowest in September.
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viddaloo

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Re: IJIS/JAXA
« Reply #967 on: March 04, 2015, 10:43:34 AM »
With 4269199 km2 on Sep 10th, 2011 was 2nd lowest at the time, higher only than 2007 at 4065739 km2 on Sep 17th.

After record–low 2012 arrived, 2011 was relegated to 3rd lowest. Which means 2011 kept its lowest position (at the time) from March 3rd to 2nd lowest minimum (at the time) on September 10th.

Edit: If we're looking at 2nd lowest extent maximum, lowest at the time, it's still 2011. And it persisted till September, only beaten by extreme low year 2007.
« Last Edit: March 04, 2015, 11:07:09 AM by viddaloo »
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Peter Ellis

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Re: IJIS/JAXA
« Reply #968 on: March 04, 2015, 12:09:09 PM »
*shrug*  If you think the winter maximum is a good predictor of the course of the melt season, you're welcome to demonstrate the correlation directly - e.g. by showing a strong correlation between (detrended) winter max and (detrended) summer minimum - rather than reading the tealeaves of day-by-day wiggles near the maximum.

Jim Hunt

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Re: IJIS/JAXA
« Reply #969 on: March 04, 2015, 12:19:33 PM »
*shrug*  If you think the winter maximum is a good predictor of the course of the melt season, you're welcome to demonstrate the correlation directly.

What do you make of the 1st year / multi-year metric being discussed elsewhere Peter?
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viddaloo

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Re: IJIS/JAXA
« Reply #970 on: March 04, 2015, 12:44:17 PM »
Suggestions that 2006 was 2nd lowest on March 3rd or 2nd lowest at maximum seem a bit exaggerated and, well, unbalanced and 'wrong'. They may of course stem from a private metric, but in this case, said metric should be disclosed and its time series revealed, IMO.
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Re: IJIS/JAXA
« Reply #971 on: March 04, 2015, 02:30:56 PM »
It is interesting.....that there doesn't appear to be a "direct" correlation between winter maximum, and the following summer minimum.

While CLEARLY.....the Arctic is much more VULNERABLE to a large amount of melting in the summer because of a low maximum.

I think it is only a matter of time before a "low winter maximum" is followed by a SIGNIFICANTLY lower (record shattering) summer minimum.  And I think that time is quickly approaching.

Too much anomalous heat in the oceans....and the basic laws of physics have not been repealed (except on FOX News:).

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viddaloo

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Re: IJIS/JAXA
« Reply #972 on: March 04, 2015, 02:42:18 PM »
I don't think anyone's ever suggested there was a 'direct' correlation, but it sure as hell doesn't hurt to have a one million km2 head–start on the champion.

I don't think anyone here would suggest 2015 stood a better chance of beating the minimum record if it was the other way, and today's extent was at 15.7 million.
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jdallen

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Re: IJIS/JAXA
« Reply #973 on: March 04, 2015, 04:37:47 PM »

A few more days like this, and I may start thinking my SWAG for the melt season was too conservative. 

We are only half way through the burst of heat predicted to roll across the basin from the Barents.

There is however a cool spell shown in the Bering Sea at the same time, so there is plenty  of scope there for an increase in extent/area. They  may balance each other out.
I wish it were so, but the cool spell in the Bering will still be much higher in absolute temperature even than that of the region getting "hot". 

The primary problem is one of ice thickening rather than building new.  A week of heat over several million KM2 of key Arctic pack will be crippling.  It won't melt, but neither will it strengthen, which is key.

Ice built in the Bering is nearly useless, as it will melt out with absolute certainty; nothing can save it.
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jdallen

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Re: IJIS/JAXA
« Reply #974 on: March 04, 2015, 04:46:18 PM »
*shrug*  If you think the winter maximum is a good predictor of the course of the melt season, you're welcome to demonstrate the correlation directly - e.g. by showing a strong correlation between (detrended) winter max and (detrended) summer minimum - rather than reading the tealeaves of day-by-day wiggles near the maximum.

I agree, it is far from perfect.  However, I think you also would agree the quality of the pack now, including volume, is demonstrably different than it was in 2006.  All else being equal, I'd agree with you, but we are no longer comparing apples to apples.

So no, we can't use extent by itself.  But, the assembly of factors lining up - increased system enthalpy, ice quality, lower volume, predicted weather, et al - are very compelling.
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Sourabh

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Re: IJIS/JAXA
« Reply #975 on: March 04, 2015, 05:44:01 PM »
Espen,

Could you please post the link to IJIS/JAXA sea-ice extent graph? Somehow, old link I bookmarked seems to have stopped working.

Thanks,
Sourabh

Espen

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Re: IJIS/JAXA
« Reply #976 on: March 04, 2015, 06:05:45 PM »
Espen,

Could you please post the link to IJIS/JAXA sea-ice extent graph? Somehow, old link I bookmarked seems to have stopped working.

Thanks,
Sourabh

Here it is : https://ads.nipr.ac.jp/vishop/vishop-extent.html?N
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DavidR

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Re: IJIS/JAXA
« Reply #977 on: March 04, 2015, 10:23:23 PM »

A few more days like this, and I may start thinking my SWAG for the melt season was too conservative. 

We are only half way through the burst of heat predicted to roll across the basin from the Barents.

There is however a cool spell shown in the Bering Sea at the same time, so there is plenty  of scope there for an increase in extent/area. They  may balance each other out.
I wish it were so, but the cool spell in the Bering will still be much higher in absolute temperature even than that of the region getting "hot". 

The primary problem is one of ice thickening rather than building new.  A week of heat over several million KM2 of key Arctic pack will be crippling.  It won't melt, but neither will it strengthen, which is key.

Ice built in the Bering is nearly useless, as it will melt out with absolute certainty; nothing can save it.
I couldn't agree more, any rapid extent increase now will rapidly disappear in April. Since 2007; 2010 peaked on 31 March, 200 K km^2 above the next closest year on that date, 2012. By the end of May both were competing for lowest.
Based on this comparison posted on another thread the CAB, already appears to be 20-30cm thinner than last year.   
http://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=1149.0;attach=14394;image
With a month of anomalously warm conditions it  will be in even worse shape.

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Espen

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Re: IJIS/JAXA
« Reply #978 on: March 05, 2015, 06:10:06 AM »
IJIS

13,688,997 km2(March 4, 2015)down another 49,254 km2 from previous and record low for the date.

and 980,000 km2 below 2000s average.

and name Feb. 15 2015 the maximum at 13,942,060 km2.

and the start of remelt Feb. 25 2015.

and for the first time ever the maximum below 14,000,000 km2
« Last Edit: March 05, 2015, 06:32:20 AM by Espen »
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LRC1962

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Re: IJIS/JAXA
« Reply #979 on: March 05, 2015, 09:26:34 AM »
Scary to think that the sun hasn't risen yet. Want to guess where some of that "missing pause heat" is now?
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crandles

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Re: IJIS/JAXA
« Reply #980 on: March 05, 2015, 05:53:49 PM »
*shrug*  If you think the winter maximum is a good predictor of the course of the melt season, you're welcome to demonstrate the correlation directly - e.g. by showing a strong correlation between (detrended) winter max and (detrended) summer minimum - rather than reading the tealeaves of day-by-day wiggles near the maximum.

It is a valid point re reading tealeaves of day by day wiggles, I accept that.

I calculated a correlation for 31 day average peak and 31 day average minimum to be 0.07. So no detrended correlation worth speaking of. But what does this mean?

Does it mean that if 2015 max was particularly low, would you conclude this was completely irrelevant?

I think that would be unwise. The reality is that the maximums show a strong downward trend and the minimums show a strong downward trend. This is unlikely to be co-incidental: the downward trend in the maximums is almost certainly partly responsible for the downward trend in the minimums.

If there is almost certainly a causal relationship, then why isn't it showing up in the detrended correlation?

Detrended numbers are only looking at anomalies not the trend. If the anomalies are fairly random with some autocorrelation which seems likely they can show some persistance for some time periods but for longer than some maximum period the anomalies may tend to revert to the mean.

Looking at


I think that you can see that the wiggles tend to persist for a couple of months perhaps even as long as 6 months on some occasions.

Thus I suggest it is not unreasonable to conclude that if this year max is low because of the trend this may result in lower minimum but if it is low because it is lower than trend then there is a good chance that the anomaly will persist for a short while but dissipate before the minimum.

We can reasonably assume a very low maximum is mainly an anomaly rather than trend, however even then a large anomaly may persist long enough to get the season off to a fast start and that could be important - certainly I have seen musings to that effect. IOW rather than testing detrended max and min for correlation, testing 1 May and minimum for correlation may be more relevant?

Perhaps also use PIOMAS rather than area might help to find correlation?

Espen

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Re: IJIS/JAXA
« Reply #981 on: March 05, 2015, 09:23:20 PM »
*shrug*  If you think the winter maximum is a good predictor of the course of the melt season, you're welcome to demonstrate the correlation directly - e.g. by showing a strong correlation between (detrended) winter max and (detrended) summer minimum - rather than reading the tealeaves of day-by-day wiggles near the maximum.

There is a saying: " A good start is half the battle won"? It may be without relevance, though?

« Last Edit: March 05, 2015, 09:29:34 PM by Espen »
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viddaloo

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Re: IJIS/JAXA
« Reply #982 on: March 05, 2015, 10:06:11 PM »
I don't think anyone's ever suggested there was a 'direct' correlation, but it sure as hell doesn't hurt to have a one million km2 head–start on the champion.

I don't think anyone here would suggest 2015 stood a better chance of beating the minimum record if it was the other way, and today's extent was at 15.7 million.

Add to that today's official calling of El–Niño 2015 and I can better understand why denial has gotten his coat on again.
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Re: IJIS/JAXA
« Reply #983 on: March 06, 2015, 03:56:47 AM »
*shrug*  If you think the winter maximum is a good predictor of the course of the melt season, you're welcome to demonstrate the correlation directly - e.g. by showing a strong correlation between (detrended) winter max and (detrended) summer minimum - rather than reading the tealeaves of day-by-day wiggles near the maximum.

I calculated a correlation for 31 day average peak and 31 day average minimum to be 0.07. So no detrended correlation worth speaking of. But what does this mean?

The predictions I've been posting for the past 9 or 10 months have been effectively based on the detrended correlations. My numbers for the correlations in NSIDC extent basically agree with your number above, so the correlation between the maximum and the minimum is too small to be a reliable predictor.

On the other hand, the correlations year over year are relatively large and negative, meaning that because last year's minimum was higher than predicted, this year's minimum should be lower. Lower, in this context, still means above 5 million sq km. (Again, this is the NSIDC extent. The JAXA extent is somewhat different.)

So I'm not predicting record breaking ice loss yet. On the other other hand, the behavior of the ice so far in March is far out of line with my current predictions. I'm planning on writing up a description of my prediction model at the end of April, (after I've had a full year of results) and the big weakness of my model is that it doesn't handle shocks very well. If the behavior so far in March is indicative of a shock, it's possible that this year's minimum will be far below my current prediction.

Update: Looking at PIOMAS volume, there is a relatively strong correlation between March and September. However, the most recent data we have is from January, and at that range the volume is basically uncorrelated. We should get the February data soon. We can judge then whether PIOMAS is following the other measures. If so, it may be reasonable to predict a large volume loss this year.
« Last Edit: March 06, 2015, 06:45:23 AM by OSweetMrMath »

epiphyte

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Re: IJIS/JAXA
« Reply #984 on: March 06, 2015, 05:50:11 AM »
*shrug*  If you think the winter maximum is a good predictor of the course of the melt season, you're welcome to demonstrate the correlation directly - e.g. by showing a strong correlation between (detrended) winter max and (detrended) summer minimum - rather than reading the tealeaves of day-by-day wiggles near the maximum.


[... snip...]

We can reasonably assume a very low maximum is mainly an anomaly rather than trend, however even then a large anomaly may persist long enough to get the season off to a fast start and that could be important - certainly I have seen musings to that effect. IOW rather than testing detrended max and min for correlation, testing 1 May and minimum for correlation may be more relevant?

Perhaps also use PIOMAS rather than area might help to find correlation?

Flawed as I believe PIOMAS to be for thin/melting ice, for trends I would have guessed that adding the extra dimension might filter out some of the noise from variations in here-today, gone-tomorrow start/end of season weather conditions. Others have suggested that these effects make area/extent on it's own useless as a predictor of what's going to happen later on in the season - and I'd generally agree.

But eyeballing those PIOMAS monthly trends it seems to me that there's been something very odd going over the past year... either with the model, or with the real world, or both... Viz:

1. The trends for March and May crossed in 2009. Before then, there was consistently more ice in May than in March, since then there has consistently been less ice in May than there was in March - including last year, which was well above the trend for both months.

2. According to PIOMAS there has since 2009 been a consistent 1M km3 volume gain Mar-Apr , and it has always been lost Apr-May, again regardless of trend.

3. Backing up to January , and roughly eyeballing the graph, PIOMAS has never come up with a Jan-Feb volume increase of less than ~2.5 Mkm3, or a Feb-Mar increase less than ~2Mkm3

So if PIOMAS stays true to form, the Feb number will be >= 21M, and under better-than-existing worst case conditions the the March number will be >= 23M and the April number will be >= 24M

In other words, the January number is high enough to guarantee that the April number will be more than a million km3 *higher* than it was in 2014, absent worse than existing worst-case behavior in February and March.

So we just lived through Feb - and to my eyes at least it looked as though it might indeed have have been the worst ever. Assume that PIOMAS cuts it's previous worst-case Feb growth in half (i.e. from ~2.5 to ~1.25m). If it did that the Feb number would be the same as it was last year.

Looking at the actual area today it is essentially the same as it was this time last year - so If PIOMAS does come up with a 50% cut in Feb volume growth over 2014 (which itself was very low),  it might be a plausible number - albeit an unprecedentedly bad February for the arctic -  but only if the avg. thickness is also now the same as this time last year. This seems a stretch given the weak winter and the low thickness estimates. If the ice is actually thinner, then PIOMAS would need essentially zero Feb growth to avoid coming up with an incredible number for Apr/May.

If, OTOH, PIOMAS comes in with the same (already low) Feb & Mar growth that it did in 2014, it can only end with a modeled March-May volume >1m km3 higher than it was last year, which would IMO be astonishing if true, because it would imply faster Feb growth than 2014, on top of thicker ice than 2014, in the presence of higher temperatures than 2014.

So all in all, I'm wondering if this might be the year when PIOMAS last-meter uncertainties finally cause it to part company with directly observable reality.

Interesting times indeed.

« Last Edit: March 06, 2015, 06:23:08 AM by epiphyte »

Espen

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Re: IJIS/JAXA
« Reply #985 on: March 06, 2015, 06:10:52 AM »
IJIS:

13,664,797 km2(March 5, 2015)down 24,200km2 from previous and
 1,000,000 km2 *)
below 2000s average.

*) The same as the combined area of France, UK, Ireland and Denmark!

or a little less than California and Texas combined!

or 1,400 times the size of Singapore!

or for the Catholics: 2,272,727 times the size of the Vatican!
« Last Edit: March 06, 2015, 09:57:57 PM by Espen »
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Re: IJIS/JAXA
« Reply #986 on: March 06, 2015, 07:47:15 AM »
Now I'm almost in denial...

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Re: IJIS/JAXA
« Reply #987 on: March 06, 2015, 08:23:11 AM »
So all in all, I'm wondering if this might be the year when PIOMAS last-meter uncertainties finally cause it to part company with directly observable reality.

I'd say there are signs it already has waved goodbye. The extreme silence mode after Cryosat figures were mumblingly and deceivingly presented (through the anti–science tabloid press), and the fact PIOMAS uses NSIDC that has presently 0.7 million KM2 ghost ice only on their hard–drives despite better alternatives, tells me pretty loud and clear that PIOMAS is no longer about reality, but 'the art of the possible'.

I'm hoping that a better alternative for ice volume will come up during the spring or summer, and JAXA's new ice monitor looks promising in that sense:

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Re: IJIS/JAXA
« Reply #988 on: March 06, 2015, 08:54:39 AM »
I calculated a correlation for 31 day average peak and 31 day average minimum to be 0.07. So no detrended correlation worth speaking of. But what does this mean?

It means we need to look elsewhere for causes  ;)

<Snippage>
So I'm not predicting record breaking ice loss yet. On the other other hand, the behavior of the ice so far in March is far out of line with my current predictions... the big weakness of my model is that it doesn't handle shocks very well. If the behavior so far in March is indicative of a shock, it's possible that this year's minimum will be far below my current prediction.

<insert wry look>  I do believe the end of February and the start of March qualifies as a "Shock".  It reminds me of when I was programming genetic algorithm models of stock behavior.  Then as now, the behavior is predictable... until it isn't.  I think we're in one of those "Isn't" phases.

Update: Looking at PIOMAS volume, there is a relatively strong correlation between March and September. However, the most recent data we have is from January, and at that range the volume is basically uncorrelated. We should get the February data soon. We can judge then whether PIOMAS is following the other measures. If so, it may be reasonable to predict a large volume loss this year.

I have serious doubts about attempting to find meaningful predictive relationships in extent, area and volume numbers over time.  It really Does strike me as very similar to trying to predict stock price over time based on the movement of price alone (Trust me on this, it doesn't work).

The basic problem is, Ice metrics, like stock price are driven entirely by forces independent of their actual scalar values.  The actual feedback of the metric  is very limited as compared to the other forces involved, and as such, predictive models built on them *will* fail if the underlying forces shift - as some of us believe they have.
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Wipneus

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Re: IJIS/JAXA
« Reply #989 on: March 06, 2015, 11:39:41 AM »
I am always quite capable to ignore high levels of nonsense, but this is just too much.

The extreme silence mode after Cryosat figures were mumblingly and deceivingly presented (through the anti–science tabloid press),

This is the first time I heard that a presentation on the American Geophysical Union’s autumn meeting is being described this way.

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, and the fact PIOMAS uses NSIDC that has presently 0.7 million KM2 ghost ice only on their hard–drives despite better alternatives, tells me pretty loud and clear that PIOMAS is no longer about reality, but 'the art of the possible'.

No, NSIDC has no "0.7 million KM2 ghost ice". The index is called "EXTENT" not ice. If you are purely interested in ice you MUST use "AREA". The NSIDC area (one calculation is Cryosphere Today's area) is still at fourth place or so and LOWER than other "alternatives".

PIOMAS has no uses for EXTENT, it uses in some ways (assimilates) CONCENTRATION, again if they use this source it is LOWER than from alternatives.

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I'm hoping that a better alternative for ice volume will come up during the spring or summer, and JAXA's new ice monitor looks promising in that sense:

Spring yes, Summer no.

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This product is an essentially experimental and research product. This product has the effectiveness in the relative dry freezing seasons such as autumn, winter and spring (September – May), but cannot provide the accurate sea ice thickness in melting wet season (June - August) because the sea ice surface is covered by melt ponds.
This product is opened to the public for the usages of research and validation of algorithms. The Arctic Data archive System (ADS) is not liable for any loss or damage resulting from the use of this data.

viddaloo

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Re: IJIS/JAXA
« Reply #990 on: March 06, 2015, 12:16:39 PM »
I am always quite capable to ignore high levels of nonsense, but this is just too much.

The extreme silence mode after Cryosat figures were mumblingly and deceivingly presented (through the anti–science tabloid press),

This is the first time I heard that a presentation on the American Geophysical Union’s autumn meeting is being described this way.

Wipneus, I'm not suggesting they said nothing during that hour of presentation at the AGU, which I've studied extensively, only that they said nothing about the discrepancy between Cryosat and PIOMAS for autumn and winter 2014. Saying absolutely nothing about a very interesting subject may be considered being in 'extreme silence mode'. That's why I chose those words.

To this day there is no official explanation for the discrepancy, only 'best guesses' from amateurs like us.

I'm still curious about those discrepancies, but at the same time I have a feeling they will never be explained by the people responsible. You're mistaking curiosity for nonsense ....  ;D

PS: In my opinion, the American Geophysical Union meeting is not a tabloid newspaper. I'm primarily talking about Cryosat's findings being presented through tabloid newspapers by bad journalists twice a year. And I also find Cryosat researchers to hold their cards really close to their chest, and they never use the fabulous medium 'World Wide Web' to just disclose their sea ice volume estimates day by day.
« Last Edit: March 06, 2015, 12:43:42 PM by viddaloo »
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crandles

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Re: IJIS/JAXA
« Reply #991 on: March 06, 2015, 12:27:52 PM »
only that they said nothing about the discrepancy between Cryosat and PIOMAS for autumn and winter 2014. Saying absolutely nothing about a very interesting subject may be considered being in 'extreme silence mode'. That's why I chose those words.

Not saying anything about a subject you find interesting may be disappointing for you. However does it really justify "mumblingly and deceivingly presented"? "Deceivingly" suggests intent to misinform; can you really justify that ?????

Espen

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Re: IJIS/JAXA
« Reply #992 on: March 06, 2015, 10:09:12 PM »
IJIS:

13,664,797 km2(March 5, 2015)down 24,200km2 from previous and
 1,000,000 km2 *)
below 2000s average.

*) The same as the combined area of France, UK, Ireland and Denmark!

or a little less than California and Texas combined!

or 1,400 times the size of Singapore!

or for the Catholics: 2,272,727 times the size of the Vatican!

Or a little less than half the size of Greenland (2,166,086 km2) just to make it local? ;)
« Last Edit: March 06, 2015, 10:31:42 PM by Espen »
Have a ice day!

OSweetMrMath

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Re: IJIS/JAXA
« Reply #993 on: March 06, 2015, 11:27:18 PM »
<insert wry look>  I do believe the end of February and the start of March qualifies as a "Shock".  It reminds me of when I was programming genetic algorithm models of stock behavior.  Then as now, the behavior is predictable... until it isn't.  I think we're in one of those "Isn't" phases.

Well, in the past, there have been large increases in ice extent during March. The extent for March is almost certainly going to be below my model prediction. But there could be enough of an increase during the rest of the month that April ends up at my predicted level anyway.

I have serious doubts about attempting to find meaningful predictive relationships in extent, area and volume numbers over time.  It really Does strike me as very similar to trying to predict stock price over time based on the movement of price alone (Trust me on this, it doesn't work).

I have models which predict extent and volume based on correlations over time. Its results are probabilistic, not certainties. Similar to your stock price predictions, my sea ice predictions are good until they are not. However, I have found that my model gives me better results than more heuristic methods of ice prediction. My predictions for the February extent have been accurate to within 150 thousand sq km since last May. (Admittedly, my extent predictions over the summer and my volume predictions at all times were less accurate.)

My conclusions are that it is possible to predict sea ice levels (in the short term) based only on the history of the sea ice, as long as you don't read too much certainty into the predictions. In addition, these predictions should serve as a check on claims that on the basis of this week's weather or daily sea ice numbers, this year's ice minimum will be a record breaking low.

viddaloo

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Re: IJIS/JAXA
« Reply #994 on: March 07, 2015, 07:09:33 AM »
Definitely, Espen.

Current Arctic sea ice extent is now an amazing one MILLION square kilometers lower than all–time low year 2012.


Today, for the first time, the diff is greater than a million even in non–rounded detailed numbers.

Edit: Actually, March 6th is the second time, March 4th was the first time.

Has this ever happened before, ie before Wednesday? :D

Let's look at the numbers!

The answer is nope, never happened before. No year has been a million or more km2 lower than the September minimum record holder at the time on any day of the year, in the IJIS time series, after the 2007 record low minimum was set.

2012, of course, came closest to the million:

Code: [Select]
On sep2, challenger 2012 was 966798 lower than 2007.
Until:

Code: [Select]
On mar4, challenger 2015 was 1010720 lower than 2012.
« Last Edit: March 07, 2015, 07:59:13 AM by viddaloo »
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viddaloo

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Re: IJIS/JAXA
« Reply #995 on: March 07, 2015, 08:06:51 AM »
What this means for the 2015 melt season is of course anyone's guess. Outside, the morning crows are doing their usual song and dance.

But 2012 had its near–million lead on 2007 at the start of September that year.

2015 has its million+ lead on 2012 at the start of March and the entire melt season. It could go anywhere, including a complete meltdown.
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Espen

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Re: IJIS/JAXA
« Reply #996 on: March 07, 2015, 08:10:00 AM »
IJIS:

13,660,208 km2(March 6, 2015)down 4,589 km2 from previous and record low for the date.
Have a ice day!

Espen

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Re: IJIS/JAXA
« Reply #997 on: March 08, 2015, 08:22:37 AM »
IJIS:

13,659,416 km2(March 7, 2015)down 792 km2 from previous and record low for the date.
Have a ice day!

jdallen

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Re: IJIS/JAXA
« Reply #998 on: March 08, 2015, 09:17:22 AM »
IJIS:

13,659,416 km2(March 7, 2015)down 792 km2 from previous and record low for the date.

Average daily drop (2002-2014), this date until April 1st, ~9170KM2.

Average daily increase required to pass the previous max this year, ~36000KM2

Average daily increase required to pass the previous low max, ~42116KM2

Average daily increase required to pass 14,000,000 KM2, ~14,158KM2

History is not with us...
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Re: IJIS/JAXA
« Reply #999 on: March 08, 2015, 09:26:39 AM »
And Papa Bear is coming to chase off the small ones.