Please support this Forum and Neven's Blog

Author Topic: Stupid Questions :o  (Read 250562 times)

Ned W

  • ASIF Citizen
  • Posts: 184
    • View Profile
Re: Stupid Questions :o
« Reply #1200 on: July 25, 2017, 09:12:36 PM »
In terms of effects on climate, 1 million is much closer to ice free than to the previous ice/climate regime, so I think it's a good proxy.


Ultimately, any numerical threshold (other than actual zero) is pretty arbitrary.  Whether one says that 0.5 or 1.0 or 1.5 million km2 is "ice-free" doesn't really matter to the physical processes. 

But we want to be able to point to some specific date and say "OK, on this day, the Arctic Ocean was ice free" with perhaps a "(for all practical purposes)" footnote if we're Walt Meier.  It doesn't matter to the climate, but for this kind of "social" purpose everyone seems to have settled on 1.0 million, and I'm OK with that. 

But I think it would produce less cognitive dissonance in the general populace if people had settled on a lower threshold.  That 1 million km patch will look pretty large when people look at it on a map.  We all know people will look at it and say "Hey, that scientist claimed the Arctic Ocean is ice-free but there's a great big patch of ice there!"  I don't mean denialist-types who would complain regardless; I just mean ordinary non-experts who are in good faith but confused.

The 0.5 million patch is still there, but it's smaller and less confusion-inducing.  Just IMHO.

Re-posting the map below, since this has spilled over onto a new page:


greatdying2

  • ASIF Middle Class
  • Posts: 555
    • View Profile
Re: Stupid Questions :o
« Reply #1201 on: July 25, 2017, 11:48:00 PM »
Volume is reducing at a significantly higher rate than extent. One year extent must collapse. But when !!??**
Yes, they have to reach zero at the same time, but there is more than one way that could happen:

* Extent could speed up to match volume
* Volume could slow down to match extent
* They could meet in the middle
I agree with gerontocrat. :) Extent loss will eventually speed up to match volume, at the very end dramatically, like a blender full of ice cubes in a warm room.
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

greatdying2

  • ASIF Middle Class
  • Posts: 555
    • View Profile
Re: Stupid Questions :o
« Reply #1202 on: July 25, 2017, 11:55:34 PM »
We all know people will look at it and say "Hey, that scientist claimed the Arctic Ocean is ice-free but there's a great big patch of ice there!"  I don't mean denialist-types who would complain regardless; I just mean ordinary non-experts who are in good faith but confused.
They're going to be confused regardless, when the extent "recovers" a few weeks later, once winter sets in (unless we lose the halocline). In my opinion a larger rather than smaller threshold would have been better for public policy, which needs a swift kick in the behind.
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

Dharma Rupa

  • ASIF Lurker
  • Posts: 22
    • View Profile
Re: Stupid Questions :o
« Reply #1203 on: July 26, 2017, 12:13:20 AM »
But we want to be able to point to some specific date and say "OK, on this day, the Arctic Ocean was ice free" with perhaps a "(for all practical purposes)" footnote if we're Walt Meier.  It doesn't matter to the climate, but for this kind of "social" purpose everyone seems to have settled on 1.0 million, and I'm OK with that. 

Ice free (in all its forms) is something we care about and they do not.  When cargo crosses the Arctic and doesn't have to deal with either the NW Passage or the Northern Sea Route then the general public -- and the people with money -- will notice.  (I'd say when they didn't have to deal with national borders, but I think the Bering Strait messes that up.)

BTW -- what was the question?

numerobis

  • ASIF Citizen
  • Posts: 192
    • View Profile
Re: Stupid Questions :o
« Reply #1204 on: August 02, 2017, 04:01:24 PM »
On the main thread, Daniel B questions whether the ice trend since 2007 is flat. It's a bit OT for that thread so I'll paste it into here, but overall I'm just citing tamino from October 2015, who says that on some measures it might be (but it might also be shrinking, just at a slower rate than the early 2000s), but on other measures it definitely isn't.

The extent trend is very much down, but if you take a chart of just the last 10 years 2007-2016, and just of the extent minima, you will see a relatively flat chart.

So what? That is just plain cherry-picking. Of course you will get a flat trend, if you start in a year with an exceptional low value and use only a short period of time (so that the overall long-term trend will not beat that short-term variation).This is exactly the same as people bragging about that there was no global warming since 1998 or in the last 10-15 years.
https://skepticalscience.com/graphics.php?g=47

But those trends are not statistically significant, not even close. There is nothing you can get out of such an "analysis". The only thing you see is short-term variation. If you just include 2006 in your time-span, the trend is already strongly downward, so if you have such a dramatic change by just including one more data point, you certainly know, that you have to included to few data points in the first place.


By your method the entire satellite trend is not statistically significant.  That does not mean that it does not exist.  Look at your graph.  This highest data point was 1996, and the lowest was 2012.  Can you confidently say that the entire graph shows a linear decline?  Longer-term data sets show that the extend in 1996 was not too different from that 60 years prior. 

http://neven1.typepad.com/.a/6a0133f03a1e37970b01b7c809c471970b-pi


This is Tamino's post that I was thinking of (among the dozen or two other posts he's done on sea ice):
https://tamino.wordpress.com/2015/10/01/arctic-sea-ice-2/

This is two years old; it'd be interesting to see with 1-2 years of extra data.

On annual average extent, he finds that it collapsed 2003-2007, then went back to a rate that's simultaneously indistinguishable from zero AND indistinguishable from the statistically significant rate in the earlier part of the record. So Tamino does see statistical support for a change in trend occurring in 2007.

On annual minimum, he finds a change point in the mid-90s, but not recently. He notes this data is noisier and a smooth does suggest that maybe there's a change point more recently, but you'd need more years before you could be sure (I'm not sure if one more year is enough).

On annual maximum, he finds no support for any change in trend.

In all cases, the trend is down.

I note that Neven frequently posts his volume graph, which looks pretty much like a straight line down. It's not mathematically possible for all of area, volume, and thickness to all be linear trends down, except that every curve looks linear if you focus in close enough.

deconstruct

  • ASIF Lurker
  • Posts: 21
    • View Profile
Re: Stupid Questions :o
« Reply #1205 on: August 02, 2017, 09:09:13 PM »
On annual average extent, he finds that it collapsed 2003-2007, then went back to a rate that's simultaneously indistinguishable from zero AND indistinguishable from the statistically significant rate in the earlier part of the record. So Tamino does see statistical support for a change in trend occurring in 2007.
That doesn't make any sense (and IMO Tamino does not claim that). When the trend after 2007 is indistinguishable from the former trend, than there is no statistical support that the former trend has changed in the first place. For that to claim, the later trend rate would need to have an uncertainty range, so that the former trend rate would be outside of that range.

As Tamino wrote in his conclusion:
"All we can say for sure is that it was trending downward, and all the evidence points to the fact that it still is."

But it would be interesting, if that would change when one includes the two additional years since then, however I doubt that i would.
« Last Edit: August 02, 2017, 09:22:10 PM by deconstruct »

greatdying2

  • ASIF Middle Class
  • Posts: 555
    • View Profile
Re: Stupid Questions :o
« Reply #1206 on: August 02, 2017, 09:49:27 PM »
That doesn't make any sense (and IMO Tamino does not claim that).

See box pot here: https://tamino.files.wordpress.com/2015/09/fig03.jpeg

What Tamino is saying is that although the average rate of decline 2006-2015 is slower than the average rate of decline 1979-2002 (big dots on the plot), the error bars from 2006-2015 overlap both zero and the 1979 error bars (indeed, they overlap the error even in the opposite direction). So yes, by that analysis, 2006-2015 is not statistically different from zero nor the 1979-2002 trend.

It does make sense because the 2006-2015 error bars are large compared to those of 1979-2002 due to having far fewer data points in the analysis. I.e., Even disregarding the cherry-picking (a major no-no), you can't draw very strong conclusions from so few data points with highly variable data. This is the main point.
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

numerobis

  • ASIF Citizen
  • Posts: 192
    • View Profile
Re: Stupid Questions :o
« Reply #1207 on: August 02, 2017, 10:38:29 PM »
If someone came to you and claimed the trend was the same from 2007-2015 as it was from 1980-2003, you'd say "sure, that seems reasonable" because the error bars include that value. But if someone else claimed the trend from 2007-2015 was nil, you'd be forced to admit "seems unlikely, but it might be" because again the error bars include that value (according to tamino).

Given that 2016 and 2017 had record-low extent for a good part of each year (just not at the minimum in 2016), I'd guess that if tamino threw the new data in, he'd find increased support for the proposition that trend is negative, and reduced support for the proposition that the new trend is zero.

This is all just stats, there's no physics. Physics obviously suggests the ice is going to melt; the debate is merely about how fast.

deconstruct

  • ASIF Lurker
  • Posts: 21
    • View Profile
Re: Stupid Questions :o
« Reply #1208 on: August 03, 2017, 08:25:17 AM »
It does make sense because the 2006-2015 error bars are large compared to those of 1979-2002 due to having far fewer data points in the analysis. I.e., Even disregarding the cherry-picking (a major no-no), you can't draw very strong conclusions from so few data points with highly variable data. This is the main point.
That is what i said. And therefore it is IMO just wrong to say (and to that i was refering):
"So Tamino does see statistical support for a change in trend occurring in 2007."
No, he does not.

deconstruct

  • ASIF Lurker
  • Posts: 21
    • View Profile
Re: Stupid Questions :o
« Reply #1209 on: August 03, 2017, 08:39:20 AM »
I'd guess that if tamino threw the new data in, he'd find increased support for the proposition that trend is negative, and reduced support for the proposition that the new trend is zero.

That is what I showed in my graphic. If you include 2016, the trend over 2007-2016 is even upward.
But that won't change the fact, that the error bars will still overlap. Just including one more year (2006) makes the trend-rate clearly downward (shown also in my graphic, and that is indicative of how uncertain the trend-rate over such a short period of time is).

And what the effect of including 2017 is, that is still unknown. It could very well be, that including 2017 would make the trend-rate (2006-2017) go downward.



This is all just stats, there's no physics. Physics obviously suggests the ice is going to melt; the debate is merely about how fast.

But we won't find that out by looking on time-periods so short, that the trend-rate is so uncertain, that it could be anything, from growing to melting like hell.

And that is even more true, when other parameters, like ice volume, were still decreasing strongly in that period of time and that makes it even more probable, that the slower ice/area decrease in that 10-year-period is just a random fluctuation (i.e. that is was just weather that led to those years having more ice at the minimum, and not a climatic change). And weather and climate are still two different things.



Steven

  • ASIF Citizen
  • Posts: 368
    • View Profile
Re: Stupid Questions :o
« Reply #1210 on: August 03, 2017, 12:54:09 PM »
https://tamino.wordpress.com/2015/10/01/arctic-sea-ice-2/

This is two years old; it'd be interesting to see with 1-2 years of extra data.


Here is an update of that graph for annual average extent, with data up to July 2017:




I used annual averages from August to July.  So the last data point is Aug 2016 to July 2017.

Note that Tamino used annual averages from October to September, so the values in his graph are somewhat different from mine.  Moreover he used data from Oct 1978 onward whereas I started with Aug 1979.

I used this tool to calculate the piecewise linear fit.  The algorithm finds two change-points (where the slope changes): one near 2002 and another one near 2006.

Alternatively, the calculation could be done with only a single change-point.  In that case the change-point is near 1998 and the graph would look like this: http://i.imgur.com/SgtlXrE.png.

magnamentis

  • ASIF Upper Class
  • Posts: 1192
    • View Profile
    • Nexpaq Modular ARA iOS Software Mobile Computing Phones Philosophy Ethics Numerology Mikrocirkulation Vaskular Therapie Gesundheit Blut Gesundheit Schmerzen Multipelsklerose Diabetes Immunsystem Fibromyalgie
Re: Stupid Questions :o
« Reply #1211 on: August 03, 2017, 05:11:26 PM »
the terms:

1) TREND

2) SHORTTERM

contradict each other, even though all kind of thinking is welcome and allowed it would not even spend a second to read anything from short periods in a graph. value is close to zero on the positive side while all the discussions it often is causing makes it inefficient at best IMO.

nobody is meant, this is meant to be a general statement to consider for those who do like to use their resources in time and energy efficiently ;)
« Last Edit: August 03, 2017, 06:31:08 PM by magnamentis »
http://magnamentis.com
Knowledge, Understanding & Insight Are Among The Best Sources For Personal Freedom & Vitality !

Shared Humanity

  • ASIF Upper Class
  • Posts: 2017
    • View Profile
Re: Stupid Questions :o
« Reply #1212 on: August 03, 2017, 05:19:00 PM »
https://tamino.wordpress.com/2015/10/01/arctic-sea-ice-2/

This is two years old; it'd be interesting to see with 1-2 years of extra data.


Here is an update of that graph for annual average extent, with data up to July 2017:




I used annual averages from August to July.  So the last data point is Aug 2016 to July 2017.

Note that Tamino used annual averages from October to September, so the values in his graph are somewhat different from mine.  Moreover he used data from Oct 1978 onward whereas I started with Aug 1979.

I used this tool to calculate the piecewise linear fit.  The algorithm finds two change-points (where the slope changes): one near 2002 and another one near 2006.

Alternatively, the calculation could be done with only a single change-point.  In that case the change-point is near 1998 and the graph would look like this: http://i.imgur.com/SgtlXrE.png.


Nice chart. Another interesting way to capture trends.

Pavel

  • ASIF Lurker
  • Posts: 75
    • View Profile
Re: Stupid Questions :o
« Reply #1213 on: August 03, 2017, 08:01:35 PM »
What is the Laptev bite? Is it the same as "Великая Сибирская полынья" ("The Great Siberian polynya") or what?
« Last Edit: August 03, 2017, 08:37:00 PM by Pavel »

Jim Hunt

  • ASIF Governor
  • Posts: 3248
    • View Profile
    • The Arctic sea ice Great White Con
Re: Stupid Questions :o
« Reply #1214 on: August 03, 2017, 08:27:44 PM »
What is the Laptev bite?


The term was coined a few years ago now. It refers to open water in the CAB north of the Laptev Sea:

http://neven1.typepad.com/blog/2011/09/some-more-flash-melting.html
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Pavel

  • ASIF Lurker
  • Posts: 75
    • View Profile
Re: Stupid Questions :o
« Reply #1215 on: August 03, 2017, 08:48:50 PM »
Thanks Jim Hunt. So the Laptev bite is even more Great than "The great Siberian polynya" - the polynya that usually opens near New Siberian islands

gerontocrat

  • ASIF Middle Class
  • Posts: 510
    • View Profile
Re: Stupid Questions :o
« Reply #1216 on: August 05, 2017, 02:41:51 PM »
Stupid questions that have nothing to do with Arctic Sea Ice.

I am currently an ASIF citizen. I like being a citizen.
But if I keep on posting I will become "middle class".

Will that make me a Trump supporter ?
If I delete a load of my old posts will that keep me as a citizen? (some of those early posts are embarassingly full of ignorance).



Neven

  • Administrator
  • ASIF Governor
  • *****
  • Posts: 3954
    • View Profile
    • Arctic Sea Ice Blog
Re: Stupid Questions :o
« Reply #1217 on: August 05, 2017, 05:47:44 PM »
As long as it doesn't say 'Goldman Sachs employee', you should be fine.  ;)
Il faut cultiver notre jardin

numerobis

  • ASIF Citizen
  • Posts: 192
    • View Profile
Re: Stupid Questions :o
« Reply #1218 on: August 11, 2017, 07:31:38 PM »
I'd guess that if tamino threw the new data in, he'd find increased support for the proposition that trend is negative, and reduced support for the proposition that the new trend is zero.
That is what I showed in my graphic.

the terms:

1) TREND

2) SHORTTERM

contradict each other,...

You both are arguing that throwing away most of the data and doing very short-term trends is silly, which of course is true. This is indeed not what tamino argues.

Tamino's analysis uses all the data, and finds support for the claim that on some metrics, the rate of decline in Arctic ice is not linear. You do see it speed up significantly for a few years last decade, then slow down (but still, as Steven shows, down). You see that either with a smooth or with a piecewise linear fit.

The critical assumption that tamino makes is that his non-linear fit should be continuous. Implicitly, if you're computing short-term trends by throwing data away, you allow the trend you're calculating to be discontinuous. That assumption of continuity is the key difference between his analysis and the bad analysis that deconstruct and magnamentis are arguing against.

On the flip side, if you insist that there must be one single linear trend line through the data, you implicitly insist that there's no possibility for the rate of change to either accelerate or decelerate. I'm sure you both disagree with that assumption in the long term (because ice hasn't been melting continuously forever, and because ice can't melt once there's no ice left). Tamino shows you have good reason to disagree with it even from data just in the satellite era.

More recently he's been doing the same analysis with sea level rise, showing that it's also not been a straight line -- but over a longer term. And before his 2015 post about sea ice he was doing the same analysis on temperatures, notably using it to argue that actually there was no pause at all.

greatdying2

  • ASIF Middle Class
  • Posts: 555
    • View Profile
Re: Stupid Questions :o
« Reply #1219 on: August 17, 2017, 07:28:58 AM »
Question #1: Is there a way to block comments from specific users, and if so how?

Question #2: What thread do stupid questions like #1 belong in?

Thanks.
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

oren

  • ASIF Upper Class
  • Posts: 1482
    • View Profile
Re: Stupid Questions :o
« Reply #1220 on: August 17, 2017, 07:43:57 AM »
Question #2: What thread do stupid questions like #1 belong in?
I'd say in "The forum" section. Find an existing thread or start a new one.
https://forum.arctic-sea-ice.net/index.php/board,22.0.html

greatdying2

  • ASIF Middle Class
  • Posts: 555
    • View Profile
Re: Stupid Questions :o
« Reply #1221 on: August 17, 2017, 07:46:48 AM »
Already looked there. Can't find a thread with a posting this year that seems appropriate. And I don't like starting threads just to ask a question.
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

Neven

  • Administrator
  • ASIF Governor
  • *****
  • Posts: 3954
    • View Profile
    • Arctic Sea Ice Blog
Re: Stupid Questions :o
« Reply #1222 on: August 17, 2017, 08:24:41 AM »
Yeah, the topic where this is discussed, is buried on page 2 of the Forum board. But here's the solution:

If you view your Profile, there's an option for "Buddies/Ignore List" under Modify Profile. Not the most obvious place, true.
Il faut cultiver notre jardin

greatdying2

  • ASIF Middle Class
  • Posts: 555
    • View Profile
Re: Stupid Questions :o
« Reply #1223 on: August 17, 2017, 09:45:33 AM »
Thanks Oren and Neven.
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

Pavel

  • ASIF Lurker
  • Posts: 75
    • View Profile
Re: Stupid Questions :o
« Reply #1224 on: August 18, 2017, 05:31:31 PM »
What is the Garlic Press somewhere in CAA? I still don't get it and couldn't find the answer myself

ghoti

  • ASIF Middle Class
  • Posts: 555
    • View Profile
Re: Stupid Questions :o
« Reply #1225 on: August 18, 2017, 06:35:17 PM »
What is the Garlic Press somewhere in CAA? I still don't get it and couldn't find the answer myself
The straits between the northern islands where the old ice gets squeezed through once the more southern ice melts out each melt season. Animated gifs of the ice movement are reminiscent of garlic being squeezed through a press.

Pavel

  • ASIF Lurker
  • Posts: 75
    • View Profile
Re: Stupid Questions :o
« Reply #1226 on: August 18, 2017, 06:42:03 PM »
Thanks ghoti

Gray-Wolf

  • ASIF Middle Class
  • Posts: 591
    • View Profile
Re: Stupid Questions :o
« Reply #1227 on: August 20, 2017, 01:55:06 AM »
I'm struggling to find a NSIDC EMail response to a query on the 15% cut off for extent/Area? I think it was raised at the back end of last year by one of our better known posters but my 'searches' are not pulling up the exchange?

I seem to recall NSIDC accepting that the measure was good when it was only dealing with peripheral ice but now, with such a dispensed pack, the measure leads to a positive skew on the numbers?

Helllppp! I'm being trolled and I know a copy of the exchange will end the debate but also secure the reputation of this forum as a 'credible' place for knowledge , learning and growth.
Ta in advance!
Ian.
KOYAANISQATSI

ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
 
VIRESCIT VULNERE VIRTUS

crandles

  • ASIF Upper Class
  • Posts: 1724
    • View Profile
Re: Stupid Questions :o
« Reply #1228 on: August 20, 2017, 03:08:32 AM »
Not sure if it might have been
Sea Ice Index V1 applied this 15% ice concentration threshold twice when computing the monthly average gridded fields. The threshold was applied first to the daily gridded concentration; any grid cell with a concentration less than 15% was set to zero. After the monthly average of those daily grids was determined, the 15% threshold was applied again to define the outer limit of that month's ice. Area and extent data values were calculated from this monthly field. Applying the threshold twice made these values smaller than they would have been with the threshold only applied once. This was updated in V2 so that the threshold is only applied to the monthly data after the gridded average has been computed from the daily data.

from
http://nsidc.org/data/docs/noaa/g02135_seaice_index/#jul-2016

Found above when looking for something different:

The monthly data was using 15% for the whole month so that with more mobile ice there was more cases of some ice being in one location for several days then another location for several days such that both locations passed the 15% threshold.
I thought this was mentioned in an sea ice news and analysis, with suggestion they were considering making a change but I can't find that now.

Wipneus

  • ASIF Governor
  • Posts: 3454
    • View Profile
    • Arctische Pinguin
Re: Stupid Questions :o
« Reply #1229 on: August 20, 2017, 08:57:13 AM »
I'm struggling to find a NSIDC EMail response to a query on the 15% cut off for extent/Area? I think it was raised at the back end of last year by one of our better known posters but my 'searches' are not pulling up the exchange?

I seem to recall NSIDC accepting that the measure was good when it was only dealing with peripheral ice but now, with such a dispensed pack, the measure leads to a positive skew on the numbers?


I am not sure, are you talking about this?
http://forum.arctic-sea-ice.net/index.php/topic,1837.msg109059.html#msg109059

Gray-Wolf

  • ASIF Middle Class
  • Posts: 591
    • View Profile
Re: Stupid Questions :o
« Reply #1230 on: August 20, 2017, 10:05:43 AM »
Thanks for the effort chaps but I do not think this is what I'm after?

I recall it being an actual e Mail response to a question as to whether the current 15% cut off was fit for purpose after we saw the kind of dispersion across the central pack last Min ( 2016)?

I seem to recall the chappie saying they were aware that this measure was not performing well with inner pack ice levels as the measure was devised to deal with the ice edge ( before the notion of swathes of open water between floes in the middle of the pack was a thing?).

I shall continue as I know it was a question that was asked of them in the midst of a debate about just how low last years extent had got when we compared just how 'open' the pack was compared to the other years it was lined up against?

Thanks again, I knew the crew wouldn't leave me hanging!!!

EDIT: Have fired a note off to NSIDC myself regarding the continued use of the measure over the coming , lower ice , years. I'll re-post once I have their answers!
« Last Edit: August 20, 2017, 10:34:15 AM by Gray-Wolf »
KOYAANISQATSI

ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
 
VIRESCIT VULNERE VIRTUS

crandles

  • ASIF Upper Class
  • Posts: 1724
    • View Profile
Re: Stupid Questions :o
« Reply #1231 on: August 20, 2017, 12:29:06 PM »
Wip's answer leads to this (presumably an email) on the blog

Al Rodger wrote
And with all that, NSIDC inform me:-
“We have received similar questions in the recent past about our December numbers, and the science leads have decided to switch the way in which the averaging is completed. The current method is really just a legacy way of doing things as the dataset's original intended purpose was to simply produce coarse resolution figures (c.a. 2007) on a monthly interval for our site. The dataset is now clearly the most popular product we have due to our blog-style publication and thus changes will be made after considering any impact to the community.“