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Arctic Sea Ice Volume at record low.

Mikemcc said:
The potentially 'scary' part of it is that if this particular short-term trend continues it will mean that the arctic ice is responding to polar temperature changes at a faster rate than anticipated. This will have knock ons with albedo changes, Greenland ice-loss, and hence sea-level change. The effects will still be drawn out over a timescale of decades though.
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Again, not an ideal situation and not necessarily a "good" thing, but when we start using terms like "scary" to define the yet unknown we border on fear mongering.

In this case however, I think the data could be considered "alarming". This is a considerable departure from baseline and certainly could be viewed as an "extreme" weather event.
 
macdoc said:
Better yet, articulate why it's not "scary" using evidence. Since you introduced "scary" then you should be able to easily articulate what is or is not "scary". The onus is on you as you introduced the term.Don't ask Ben to explain your limitations....
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Uhhh, check again ...


Almo said:
That's kind of scary, actually.
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3bodyproblem said:
Again, not an ideal situation and not necessarily a "good" thing, but when we start using terms like "scary" to define the yet unknown we border on fear mongering.

In this case however, I think the data could be considered "alarming". This is a considerable departure from baseline and certainly could be viewed as an "extreme" weather event.
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This graphic puts the data into some perspective imo, at least in relation to the modeling. It is yet another indicator that the modeling, far from being "alarmist" as some have tried to make out, is actually way too conservative.

http://secure90.elinuxservers.com/~projectg/wp-content/uploads/2009/11/arctic-sea-ice1.jpg
 
bit_pattern said:
This graphic puts the data into some perspective imo, at least in relation to the modeling.
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Would you have an attribution with that graph? Is there a paper to go with? Looks like it would be interesting to read. Thanks!
 
Dancing David said:
There is a big difference in the farther out you go from an SD, and the current volume is much lower.

Close by what standard? :)
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By my calibrated eye.

:)

By looking at the graph of the sea ice model output, I see about 3,500 km^3 less than the trend in 1982, and about 4,400 km^3 less than the trend currently.

These numbers are close, especially when talking about model output, calibrated and validated or not.

If I interpret the data correctly, the trend was at ~24,500 km^3 in 1982; and about 16,000 km^3 this year. Now, the deviation as a percentage of the trend at each time point is much greater now than it was in 1982.

I don't know if that is unusual or if it is to be expected as the ice volume slowly decreases over time.

The whole point of my initial muddled posts was to point out that the difference from the anomaly was also large in 1982.

Now in terms of SD, remember:

I think that the SD that I can determine from the graph is about 1,400 km^3

Fraction Number of Standard
of Data Deviations from Mean

50.0% .674
68.3 1.000
90.0 1.645
95.0 1.960
95.4 2.000
98.0 2.326
99.0 2.576
99.7 3.000

3,500 km^3 is about 2.5 SD, or about 98.5%. 4,400 km^3 is about 3.1 SD, or about 99.8%. So, about 1.5% of the data will exceed the 1982 anomaly deviation, and about 0.2% of the data will exceed the current anomaly deviation.

This is assuming a normal distribution, which seems like a valid assumtion for this modelled data set.

If we were talking differences between say 1SD and 3SD, I would call that a "big difference".
 
Thanks, Pixie,

I think you are right.

Looks like good reading material for my breaks today!
 
That paper that Pixie posted also seemed to make some sense when briefly discussing the reason for Antarctic ice not being lost like Arctic ice.
 
Skeptical Greg said:
You have zero data with which to establish the limits of my imagination, so I suggest you limit your comments to things with which you do have data ..

I'm still waiting for the ' scary ' part ..
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And we're still waiting for you to say anything substantial at all. Not with bated breath, obviously. Life's short enough as it is.
 
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