Arctic Sea Ice : Forum

Cryosphere => Arctic sea ice => Topic started by: viddaloo on September 20, 2014, 06:07:39 PM

Title: Annual Average Thread
Post by: viddaloo on September 20, 2014, 06:07:39 PM
Edit December 2014: This thread follows particularly the development of the Annual Average Volume, as calculated from PIOMAS volume data from 1979 to 2014. The use of the word 'average' is based on the everyday sense of the word, as defined by Wikipedia: The sum of a list of numbers divided by the size of the list, in other words the arithmetic mean.

Inherent in this thread and in the following summary graph is the claim that the annual average volume is the most telling or central statistic for the state of the Arctic sea ice.

Perhaps even for the Earth's climate as a whole? In any case, following the AAV is exciting!

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D994.0%3Battach%3D12506%3Bimage&hash=826aaee4be20c6ed78bb7d7d5d5f43a4)

The following below this line are earlier versions of this top post.

Edit: I changed the name of this thread, as the focus shifted from the 365 Day Mean volume to the 5 Year Cycle of both extent and volume. This graph took some time ironing out, but it got there, and it's both scary and impressive:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D994.0%3Battach%3D11163%3Bimage&hash=f090e488a57719da7ec22c6b21697fb7)

What follows is the original start of the thread:

I wanted to strip away all seasonal variation from the graph, to get rid of the wave shape. How to do it? Just calculate the daily 365 day mean for the date. This is what I got.
Title: Re: 365 Day Mean Volume
Post by: viddaloo on September 20, 2014, 06:28:22 PM
As you can see, 2012's main achievement is to start low (and go slightly lower). Unlike 2007, 2010 and 2011, that really melt away a great deal of ice from their starting points. 2007 is still the leader in this respect, followed by 2010.
Title: Re: 365 Day Mean Volume
Post by: viddaloo on September 21, 2014, 03:28:44 AM
Because a mean of 365 days is calculated for each data point, the graph is pretty stable and one–directional. It doesn't go up and down from day to day, as that would mean that the ice volume of a day would be higher than last year one day of a week, and then lower than last year the next. Naturally, that doesn't happen very often. This means that the graph in the top post really only changes direction (down to up, or up to down) about 5 times:

After descending since (at least*) January 2007, the mean ice volume starts ascending in January 2008, then it grows until March 2009, when a major shift happens that will last more than 2 ½ years and remove almost 3000 km³ of Arctic sea ice from the 365 day mean volume. This amounts to a loss of 18% of the mean ice mass during the record descent period of 33 months from March 2009 to December 2011. Then ice packs for ½ year until May 31st 2012, where a shift in early June starts the 8 month descent down to May 13th 2013 (a record low 365 day mean volume of 13395 km³), which also includes the all–time low minimum volume of 3673 km³ on September 18th 2012. Since mid–May 2013 it's been up–up, packing–packing, more and more ice. So we're still waiting for the graph to turn into a new descent. The previous one brought an all–time low minimum, just like the one before that, in fact, all the descents from 2007 forward have given all–time low minima records at that time, each of them even lower than the previous descent.

Whatever happens on March 14th 2009 lasts 1006 days, to December 14th 2011, exactly 33 months to the day, melts almost 3000 km³ from the Arctic sea ice and sets 2 new all-time low minimums, on September 15th 2010 and September 10th 2011. This huge 1006 day melt was also highly instrumental for the current all-time low minimum of September 18th 2012.

*) Actually, the 2007 major ice loss event starts as early as March 2002, lasts until January 2008, 70 months, and melts even more ice, nearly 5000 km³, than the 2010 event (2009–2012).
Title: Re: 365 Day Mean Volume
Post by: viddaloo on September 21, 2014, 07:10:29 AM
Thanks. The averages are not centered, but 365 days almost a year ago till the date in the graph.
Title: Re: 365 Day Mean Volume
Post by: viddaloo on September 21, 2014, 12:28:55 PM
One last graph for the day, even though it is of course preliminary for 2014, not final.

This one shows the yearly mean volumes for each calendar year. For 2014 it shows the average for the year so far, plus the rest of the year (as an estimate) from last year. This means the 2014 data point at the end of the graph could go a bit higher — or lower — when real data arrive.

As the graph highlights average volume during a year — which is of course higher than the yearly minimum in September — future ice–free September minima could very well come in a 12 000 km³ average year. Average doesn't have to be zero for Autumn to hit zero. However, when the X axis is extended to the right, into the future, it shows the yearly mean volume hitting zero in 2031.

Yup. That means no Arctic sea ice at all on any day of the year by 2031. Not even in the CAA.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on September 29, 2014, 01:00:00 AM
I changed the name of this thread, as the focus shifted from the 365 Day Mean volume to the 5 Year Cycle of both extent and volume. This graph took some time ironing out, but it got there, and it's both scary and impressive:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D994.0%3Battach%3D10867%3Bimage&hash=005e24de1ba1360659218e8e29dfaa71)

We're at the start of a big, 1000–day, descent in yearly average ice extent. At least that's the working hypothesis!
Title: Re: Five Year Cycle Thread
Post by: Rick Aster on September 29, 2014, 01:36:24 AM
The five-year cycle is a reasonable hypothesis and certainly something I will want to watch for.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on September 29, 2014, 01:43:03 AM
We are so much lower on average ice now, that even the (then) record low September 2010 (blue line, end of Year4) is way above the current 2014 yearly average. A 1000 day long descent now will mean a crash for Summer ice.
Title: Re: Five Year Cycle Thread
Post by: jdallen on September 29, 2014, 08:21:44 AM
Intriguing hypothesis. Last years numbers during the freeze spent disturbing lengths of time in the bottom three low years.

Title: Re: Five Year Cycle Thread
Post by: kingbum on September 30, 2014, 06:25:03 AM
Just a fresh idea I have....maybe this 5-year cycle actually follows the ebb and flow of the 11 year solar cycle....its a possible relationship worth investigating I think...
Title: Re: Five Year Cycle Thread
Post by: viddaloo on September 30, 2014, 09:08:55 PM
OK? But if so, why would it have two heat maxima during those 11 years?
Title: Re: Five Year Cycle Thread
Post by: jdallen on September 30, 2014, 10:54:24 PM
OK? But if so, why would it have two heat maxima during those 11 years?

Very doubtful it could.  There's no clear mechanism(s) to explain the changes in heat flow and weather.  I don't see the changes in insolation being significant enough.
Title: Re: Five Year Cycle Thread
Post by: carmiac on October 01, 2014, 04:37:49 AM
Dumb question: Would it be possible to go back from the 5 year cycle prediction to a daily number? To see if it looks at all realistic?
Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 01, 2014, 06:19:31 AM
Absolutely, carmiac! And that will be my next new coding project; today's rainy in Hardanger and thus perfect for such activities. Plus, I need to rest after visiting my local alpine glacier yesterday :)
Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 01, 2014, 06:21:44 PM
Low (IJIS) Extent Years, Including 5YC Forecasts.
Title: Re: Five Year Cycle Thread
Post by: carmiac on October 01, 2014, 06:35:46 PM
Thanks! I think this is an interesting analysis.

That's a completely reasonable looking 2015. Let's see how it goes!
Title: Re: Five Year Cycle Thread
Post by: ChrisReynolds on October 01, 2014, 07:34:16 PM
I don't think there is a five year cycle. There are two events, the lows of 2007 and 2012 which drive the lows of the claimed cycle. There is no evidence that 2007 and 2012 were periodic events.

Sorry.

The following plot shows NSIDC extent data from 2000, with a lagging 365 day running mean applied from 30/12/2000, the five year periods 2007 to 2011 and 2012 onwards are shown in different colours.
Title: Re: Five Year Cycle Thread
Post by: idunno on October 01, 2014, 08:32:13 PM
Hi everybody,

(Sorry real life has prevented me from paying proper attention for some time. I've been lurking sporadically.)

I am rather dubious also that 2 repetitions of a low would constitute a cycle.

I DO think that a 365 day average of the data is a very excellent idea.

Perhaps one could posit that the possibility that any one year is now going to see a spectacular crash is round about 20%? So about 2 per decade, with, I would assume at present, higher odds as time goes on that any one particular crash year might actually result in a seasonally ice free Arctic?

At any rate, removing the seasonal component in the data is, imho, an excellent idea.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 01, 2014, 10:39:41 PM
That's perfectly all right, folks. This thread is for discussing whether there is a cycle, and if so, what causes it.

At the moment, I'm only looking at the statistics of it, I really have no idea why there seems to be such a pattern.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 02, 2014, 05:46:06 AM
The following plot shows NSIDC extent data from 2000, with a lagging 365 day running mean applied from 30/12/2000, the five year periods 2007 to 2011 and 2012 onwards are shown in different colours.

I'm assuming some sort of regime change in the pack ice around the time iPhone was first introduced, a new level of ice loss, hence the start of the first cycle in 2007. I've laid out in previous posts that the descent that ended in the 2007 minimum record lasted 70 months and started as early as 2002, so I'm not ignoring the past. In fact, one of my main points has been that yearly mean descents are very long–lasting, and that we can expect a 1000 days when it finally gets going. Per 2002 to 2007, of course, way more than 1000 days.

Quote
Until 2007, it was unheard of for walruses (http://www.theguardian.com/environment/2014/oct/01/walrus-alaska-beach-trampled-death) to leave the sea ice for dry land for prolonged periods of time. But the retreat of sea ice has seen “drastic changes” in behaviour, Jay said. Walruses have struck out for beaches in six of the last eight years.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fstatic.guim.co.uk%2Fsys-images%2FGuardian%2FPix%2Fpictures%2F2014%2F10%2F1%2F1412197952147%2Fbe221d14-5429-47de-a3da-c15afe5bfd15-460x276.jpeg&hash=e59c33bef1cedba3ccf4e1605c068423)

I DO think that a 365 day average of the data is a very excellent idea. [...] At any rate, removing the seasonal component in the data is, imho, an excellent idea.

Thanks, idunno, I thought so, too! :)

We'll see what applications can be built from that starting point. A sort of half–reliable prediction of a record minimum one year in advance seemed too cool to NOT try :D

That's a completely reasonable looking 2015. Let's see how it goes!

Maybe too reasonable?! Unfortunately, there was an error in my equation, producing the smooth 2015 graph I posted yesterday. It looked so right and reasonable that I didn't bother to control the calculations made by the script.

In real life, it's more of a bumpy ride, I'm afraid. Some of the drops and gains imposed by the yearly mean cyclic model are impossible for the ice to carry out in the real world. You can get a general idea, though, from this graph:
Title: Re: Five Year Cycle Thread
Post by: crandles on October 02, 2014, 01:52:57 PM
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D994.0%3Battach%3D10867%3Bimage&hash=005e24de1ba1360659218e8e29dfaa71)

This seems to show some similarity of pattern.

Here is PIOMAS 365 day trailing average shown similarly:

(https://farm4.staticflickr.com/3929/15231757850_b7e975f0f9_s.jpg) (https://flic.kr/p/pcYJWE)Piomas5yearcycle (https://flic.kr/p/pcYJWE) by crandles2011 (https://www.flickr.com/people/67566729@N07/), on Flickr

This is nowhere near as much of a pattern match. If it was the other way around that PIOMAS showed a similar pattern but extent less so, then I might be more inclined to believe there is a possible pattern to watch out for.

Don't think we are in a position to conclude the extent pattern match is not just random chance:

You could try to characterise the shape as having 2 three way choices: Firstly change over year being increase, decrease or similar. Secondly is there a hump, trough or nothing much in the middle of the year compared to the general trend of the year. If with 3 years of overlap, all 6 features matched would this be a 1 in 3^6 (1 in 729) chance of happening by chance? I don't think so. There is the choice of how many years before the cycle repeats so the first year is bound to match or we wouldn't be doing this analysis. So forget first year. Second year does have increase over the year but 2013 has a dip relative to that which 2008 didn't. 2010 and 2014 look fairly similar so far but it is possible that the decline over the year will be larger than the extent decline of 2012. Therefore to say 3 out of 4 1 in 3 chances appears to me to be pushing it and there is a 9.8% chance of that happening by chance. So I don't think we can rule out the similarities just being chance.


BTW the red and blue vary in distance between each other but end with the gap about the same. Why does the orange '5 year cycle prognosis' line then decline at a faster rate than the blue line to about double the size of the gap? Shouldn't it follow the blue line?

Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 02, 2014, 03:25:44 PM
Thanks, crandles, I'll be making a similar 5-year view when(**) the PIOMAS data arrives. PIOMAS was where this thing started, by the way, and I checked out the possible extent similarity to this pattern only in frustration that the volume data wasn't daily, but monthly. I was amazed to find the same pattern in the extent data.

PS: I guess the answer to your question about the increasing gap, is that the gap has been increasing for about a year now, and that I've built this into the prognosis. So the Cycle is the basis of the prognosis, but realism and basis in the data means the gap will grow. The starting point of the prognosis will always be the latest day of data, so if the gap was to decrease in the observations, that would also propagate down into the prognosis period.

** Make that an IF, not a When. Issues over at NCEP continue to be uncertain, and no official date (or explanation) has yet been given for a return of the input data for the PIOMAS model.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 05, 2014, 03:14:16 PM
I guess the big gap is interesting whether or not you believe the 5-year cycle to be real? Note how the 2012-2016 curve is consistently lower than the 2007-2011 curve, and how that implies that any prolonged descent from this starting point - comparable to the 2009-2011 descent - is likely to end up very, very low. And being very low in average ice extent means pretty big chances of a total meltdown  in Autumn.

In this way, making these 5-year cycle graphs is a bit like making 5-year average Autumn minimum plots or decade average plots for the Autumn minimum, in that you clearly see the steady and relentless decline as time goes by. The seasonal wave-shape element kind of clouds this insight, and the clarity disappears, as seasonal variations are so overwhelming compared to the tiny ups and downs of each year in that wavy seasonal curve.

I'm sure improvements and variations can be made. For instance, you could make a plot where each year starts on zero on January 1st, "forgetting" the extent level that the previous year delivered to it. That way you might see even more clearly how each new year performs, if it melts or builds ice, relative to the other years.

That said, I still "believe" the 2014 to 2016 descent will be dramatic and widen the gap even more to the 2009 to 2011 descent. Close-up views of this descent compared to 5 years ago is something I want to make later in the month, once certain hardware issues are resolved.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 08, 2014, 07:18:48 PM
Yearly Mean Volume is up 3.8 km³/day, up 27 km³/week and up 122 km³/month per September 30th. This means no yearly average descent has started yet for ice volume, even though daily deltas are trending towards zero.

Yearly Mean Extent is down 985 km²/day, down 4677 km²/week and down 1954 km²/month. Daily deltas for extent are also trending downwards, meaning more negative, increasing the size of the descent.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 09, 2014, 08:31:25 AM
At 1054 km² down on October 8th, the yearly mean extent is for the first time breaking the 1000 km² per day limit during this descent. Following the Big Descent closely, it will be exciting to see how big these daily drops will get, as we go further down the 1000 day slope.

Yearly Mean Extent is down 1054 km²/day, down 5111 km²/week and down 3461 km²/month. Daily deltas for extent are still trending downwards, meaning towards more negative daily deltas, increasing the size and speed of the descent.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 15, 2014, 03:56:18 PM
I've added the very first 1000–Day Descent in the IJIS data series, so that the graph now covers all the data in IJIS. (Half the first year, 2002, has only -9999 error values, and so you need a whole year of real values after that before you can get a yearly average value.)

Looks like we're in for the Big Melt, folks! I am pretty sure this is the first time in recorded history that A MILLION km² disappears from the average in one single melt/descent period.
Title: Re: Five Year Cycle Thread
Post by: crandles on October 15, 2014, 05:13:04 PM
Don't you think that makes that widening gap look even more unlikely?

The red to orange gap looks to start and end at about 0.3. The gap goes narrower, wider, narrower then wider again. Why would you think the last wider again is the only pattern to follow? That makes no sense to me (and smells of inappropriate cherry picking a short period to give the result you want to me).

(Also why start the blue line half way through the second year?)

Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 15, 2014, 05:26:23 PM
Don't you think that makes that widening gap look even more unlikely?

The red to orange gap looks to start and end at about 0.3. The gap goes narrower, wider, narrower then wider again. Why would you think the last wider again is the only pattern to follow? That makes no sense to me (and smells of inappropriate cherry picking a short period to give the result you want to me).
As I've already explained that, I am more than happy to repeat (paste):

«I guess the answer to your question about the increasing gap, is that the gap has been increasing for about a year now, and that I've built this into the prognosis. So the Cycle is the basis of the prognosis, but realism and basis in the data means the gap will grow. The starting point of the prognosis will always be the latest day of data, so if the gap was to decrease in the observations, that would also propagate down into the prognosis period.»

(Also why start the blue line half way through the second year?)
As I've already explained that, too, I am more than happy to repeat (paste):

«(Half the first year, 2002, has only -9999 error values, and so you need a whole year of real values after that before you can get a yearly average value.)»
Title: Re: Five Year Cycle Thread
Post by: crandles on October 15, 2014, 07:22:26 PM

(Also why start the blue line half way through the second year?)
As I've already explained that, too, I am more than happy to repeat (paste):

«(Half the first year, 2002, has only -9999 error values, and so you need a whole year of real values after that before you can get a yearly average value.)»
Sorry missed that.

(You could use NSIDC
ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/ )

Don't you think that makes that widening gap look even more unlikely?

As I've already explained that, I am more than happy to repeat (paste):

I had seen that explanation, but didn't think your explanation was adequate and thought the extra blue line made the criticism even more obvious and worth repeating.

Why use 'last year' when you can use last 3 years? Using just 1 year is likely to be open to causing large spurious trend, when using 3 years would be much less susceptible to such a problem.

Alternately use average of red and blue lines' movements would also seem a sensible possibility given the way they stay pretty parallel.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 15, 2014, 07:34:12 PM
I had seen that explanation, but didn't think your explanation was adequate and thought the extra blue line made the criticism even more obvious and worth repeating.

Why use 'last year' when you can use last 3 years? Using just 1 year is likely to be open to causing large spurious trend, when using 3 years would be much less susceptible to such a problem.

Alternately use average of red and blue lines' movements would also seem a sensible possibility given the way they stay pretty parallel.
I assumed that in your world an extra thousand days repeating the same pattern would increase the criticism and make the 5–Year Cycle hypothesis seem more unlikely. I think this may be another issue where you and I should rather agree to disagree, instead of trying to explain to each other why 1000 extra days is more/less reaffirming. The other thing of course being the utter unlikeliness of any more sea ice ever melting again in the future, compared to 2010-2012. We obviously come from differing traditions of thought and logic.

For the "1000–Day Forecast" I think we'll just wait it out and see what happens. It could be accurate or less accurate. So far it's been overwhelmingly successful and over-performing compared to the initial prognosis. I expect it to turn the other way and narrow the gap, too, at some point. It will be exciting to follow as we go into 2015 and 2016!
Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 21, 2014, 12:24:28 AM
For the record: I expect Yearly Average Extent to drop for a long time, about a 1000 days, I don't expect 2015–2019 to be an exact replica of 2010–2014. I'm also ready to throw the whole Five Year Cycle hypothesis in the bin the minute someone can show me a more plausible 5–year outlook.

The fact that 2012 followed 5 years after 2007, and that 2008–2010 YAE was higher than 2007 YAE and 2013-2014 YAE higher than 2012 YAE may be random, but 2007 and 2012 are the only such events in the IJIS series.

I'd say we could just as likely have an 07/12 event in 2016 as in 2017, but for now we only have 2 such events, and the years after them seem to follow in some sort of 'after–shock'.

What causes the whole system to leave an all–time low YAE in 2006 to go to a new low in 2007 and then higher than 2006 in 2008 and 2009 before ending up roughly equal to 2006 in 2010, would be fun to hear thoughts about. To a complete amateur it seems like the 'price' of having a record year like 2007 is 'three steps back', as in one step forward and three steps back, but that 2011 ends up much lower than 2006 in YAE, before the whole pattern starts over.

However, I'm assuming that as we go so low as the 5–Year Cycle Prognosis for 2015 indicates, there will be a change in patterns. Something will break, and I'm thinking of another extreme melt event, as 2015 YAE will be the lowest we've been ever.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 21, 2014, 04:33:55 AM
Some day during October or November I'm expecting a drop to start even in Yearly Average Volume — it usually follows extent for most years — but 2014 is NOT like most years.

Will be exciting to see in 2 weeks.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 25, 2014, 01:49:50 AM
Here is PIOMAS 365 day trailing average shown similarly:

(https://farm4.staticflickr.com/3929/15231757850_bb13aac97f_o.png)

This plot is more complete for Average Volume:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D997.0%3Battach%3D11352%3Bimage&hash=e9965ecd0a7cb083dc19f4d1047bc58e)

Data points for October are of course estimated values.
Title: Re: Five Year Cycle Thread
Post by: Rubikscube on October 25, 2014, 01:51:45 PM
What causes the whole system to leave an all–time low YAE in 2006 to go to a new low in 2007 and then higher than 2006 in 2008 and 2009 before ending up roughly equal to 2006 in 2010, would be fun to hear thoughts about.

This effect is most certainly caused by the low winter extent in 2006 and 2007. Why 2006 in particular had such a low extent throughout the entire winter is not easy to answer, and it might perhaps be random. Extent in Bering can be PDO related, which may explain some of the recent rebound in winter extent, but this rebound is also partly caused by Baffin/Newfoundland. It might be a little bit far fetched to relate that region's winter extent to increased freshwater runoff from glaciers (both CAA and Greenland), I don't know how much difference it could really make.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 25, 2014, 02:25:38 PM
Thanks, Rubik. I'm thinking of it in terms of "sustained decline, only broken by 2007+2 years and 2012+2 year". Sounds silly, but it's the best way I can put it right now:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D997.0%3Battach%3D11274%3Bimage&hash=99db7cd72d4c9a9cbe10e3aaef819ecc)

I see 2006 as low because it follows 2005, 2004, 2003 which are all going fast downhill. Then 2007 breaks every record the year after. But the dramatic way in which this 2007 thing happens, causes 2008 and 2009 to go way back up again (higher than 4 years ago, but not higher than 5 years ago).

I wouldn't be as curious to find out what part of the 2007 event that causes the 2008/09 rebound, if it wasn't for the fact that we see a similar thing happen with 2012 and 2013/14.

I would say the 5 years between 2007 and 2012 is random, but my gut feeling says the 2 following rebound years are caused by the sharp drops (and/or the whole 4–year decline that ends with 2007/12).

As a total amateur on the physical side of things, I'm only guessing what the causes may be, for instance the Beaufort Gyre changing direction, so I definitely need everyone's help here!  8)
Title: Re: Five Year Cycle Thread
Post by: viddaloo on October 30, 2014, 08:29:17 AM
New plot using all the yearly averages you can get from the PIOMAS series.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on November 23, 2014, 04:09:59 PM
A little intro to my (admittedly) *speculative* 5–Year Cycle prognosis:

The 5YC prognosis assumes that the delta between the attached gap in annual extent and the corresponding gap 5 years ago, stays the same for the rest of the 5–year period (end 2016).

Yesterday, the 2014/13 gap was 85152 km², and a corresponding gap ~5 years ago will not be this big until June 6th, according to the script, meaning we're 196 days 'ahead of schedule'.

Another way of putting this is to say that we're losing sea ice extent much faster in 2014 than we did 5 years ago.
Title: Re: Five Year Cycle Thread
Post by: jdallen on November 23, 2014, 08:57:00 PM
New plot using all the yearly averages you can get from the PIOMAS series.

Quick thought - yearly annual volume does strike me as a good reflection of system enthalpy and the annual arctic heat budget.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on November 23, 2014, 10:39:40 PM
It is, but the difference from volume (attached) to extent (see above) kind of suggests we're looking at a different heat budget for the CAB from that of the Southern oceans.
Title: Re: Five Year Cycle Thread
Post by: jdallen on November 24, 2014, 09:33:00 AM
It is, but the difference from volume (attached) to extent (see above) kind of suggests we're looking at a different heat budget for the CAB from that of the Southern oceans.

Without question, for reasons both orbital and topographic.  The orbital effect is to make southern hemisphere summers slightly warmer, and southern hemisphere winters slightly cooler.

The additional twist is in the fact that the south pole is a land mass surrounded by water, whereas the north is water surrounded by land mass.  The permanent ice on the south pole, combined with the isolation provided by stronger circumpolar circulation pretty much guarantees less heat will be taken up during summer.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on November 24, 2014, 09:38:05 AM
It is, but the difference from volume (attached) to extent (see above) kind of suggests we're looking at a different heat budget for the CAB from that of the Southern oceans.

Without question, for reasons both orbital and topographic.  The orbital effect is to make southern hemisphere summers slightly warmer, and southern hemisphere winters slightly cooler.

The additional twist is in the fact that the south pole is a land mass surrounded by water, whereas the north is water surrounded by land mass.  The permanent ice on the south pole, combined with the isolation provided by stronger circumpolar circulation pretty much guarantees less heat will be taken up during summer.

Umm, let me rephrase that: It is, but the difference from volume (attached) to extent (see above) kind of suggests we're looking at a different heat budget for the CAB from that of the Southern Arctic oceans.
Title: Re: Five Year Cycle Thread
Post by: jdallen on November 24, 2014, 09:47:18 AM
It is, but the difference from volume (attached) to extent (see above) kind of suggests we're looking at a different heat budget for the CAB from that of the Southern oceans.

Without question, for reasons both orbital and topographic.  The orbital effect is to make southern hemisphere summers slightly warmer, and southern hemisphere winters slightly cooler.

The additional twist is in the fact that the south pole is a land mass surrounded by water, whereas the north is water surrounded by land mass.  The permanent ice on the south pole, combined with the isolation provided by stronger circumpolar circulation pretty much guarantees less heat will be taken up during summer.

Umm, let me rephrase that: It is, but the difference from volume (attached) to extent (see above) kind of suggests we're looking at a different heat budget for the CAB from that of the Southern Arctic oceans.

AH!, yes, that makes a considerable difference  ;D

I'll need to ponder that a bit.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on November 25, 2014, 07:08:10 AM
Umm, let me rephrase that: It is, but the difference from volume (attached) to extent (see above) kind of suggests we're looking at a different heat budget for the CAB from that of the Southern Arctic oceans.

AH!, yes, that makes a considerable difference  ;D

I'll need to ponder that a bit.
Please do. Compared to 5 years ago, this gap is as big as it was on April 25th — meaning average volume is 213 days 'late'. While average extent has a gap the size of June 8th, 196 days 'early'.

It seems to me that not only is extent exceptionally early — meaning it disappears faster than expected — volume is also exceptionally late — meaning it probably has it coming — giving a total distance of 409 days between the two.

Some sort of leveling is to be expected, and with the exceptionally warm Southern Arctic oceans, I expect that leveling to happen mostly in the CAB.
Title: Re: Five Year Cycle Thread
Post by: viddaloo on December 04, 2014, 12:12:09 AM
Annual volume gap to last year is now +881 km³, similar to April 29 five years ago +217 days.
Annual extent gap is –96015 km², similar to June 13 four years ago –193 days.

With a 410 day diff between volume and extent, this means the annual average volume gap is contributing the most to the growing diff, while the negative extent gap is narrowing, in terms of days. You could say the extent anomaly is being normalized, which is also supported by extent being up +60217 km² during December compared to the 2002—2013 average.

The annual average volume gap is getting smaller in terms of km³, but not as fast as five years ago, which is why it's up from 213 days a week ago to 217 yesterday.
Title: Re: Annual Average Thread
Post by: viddaloo on December 05, 2014, 01:16:25 PM
I've reconsidered (based largely on feedback from this forum and new data from the Arctic) and made a new auto–zoom function for the annual average graphs. This means you are now zoomed straight to the center of the action, with yesterday always centered on the chart.

Among the features is an automatic choice of year for comparisons. These days the zoom chooses 2010, as the 2010 graph is both below 2014 in annual average volume, and above 2014 in annual average extent. This makes it ideal for visual comparisons, which is the focus here.

Theoretically, at least, the 'gold standard' year for comparisons could change every day, but it always stays the same for extent and volume: They choose the year closest to both of them in common. Also, in real life, it won't change very often, probably about once a year.

This also means I've ditched the old '5–year Cycle' thing for comparisons (yey!), as its merits were frankly limited. I'm hoping the new closer and more visual reference will make it easier to see how today's annual extent/volume is developing, and co–developing.

Currently, we have an average extent similar to that in 2010 + 43 days (Jan 16), and an average volume similar to Aug 10 2010 (116 days).

The extent gap is decreasing (by 1 day since yesterday) and the volume gap increasing (also by 1 day per day). The total diff between the two on the new 2010 scale is 159 days. If annual extent wasn't so low (because of quicker meltout in the periferal seas) and volume so high (because of slower melt in the CAB), you'd expect this diff to be about zero.

Other automatic features of the new graphs: They automatically include all the relevant years that are 'in the area' of the plot, not just the ones I remember! For instance, 2006 is featuring strong on the extent graph, soon to morph into record–breaking 2007.

The lines are also automatically coloured through the Google Charts scheme, meaning orange is 3rd lowest, green 4th, purple 5th etc, even though the bottom 2 years are still not in our zoomed view at this moment.

And besides, all the tags and annotations are also added automatically and driven by the data (that goes for chart heading as well — nothing is written by hand or manually).

Basically, the width or horizontal scope of the graph is determined by the gap between the current year and the 'gold standard' year, in our case 2010, so that the day it levels with the current year is always in view. Vertical scope is also determined by these two years that are being compared, and all other years are just shown simply because they are 'in the area'.

It was fun coding it! Hope you will enjoy the new posting series, too :)
Title: Re: Annual Average Thread
Post by: viddaloo on December 08, 2014, 12:10:08 PM
Great (and sufficiently clear for my use) comment and questions, Peter.

I don't know why many of you assume such things. IMO none of you have explained this sufficiently. In 2013 you had 365 days. Each of those days had their total ice volume figure. Add day 1 + day 2 ... + day 365 into a year total and divide by 365. Et voila!

Yes, but you are then projecting that forward, and you need to be clear in your own mind (and in your posts) about what that projection entails. When you predict that (say) 2020 will be 3.5x10^6 km^3 lower than 2015, how is that actually playing out in terms of day to day volume?

As the Roadmap shows we're at about 15.2 thousand km³ yesterday, going to a 2020 3.5 million km³ lower will be a tough one. Frankly, I don't think it's physically possible, as that would entail huge areas with thousands of km³ of negative packice!  ;D

(OK, that was the humorous short answer — I will return with a longer and serious one tonight.)
Title: Re: Annual Average Thread
Post by: Peter Ellis on December 08, 2014, 02:39:11 PM
Sorry, I had millions instead of thousands.

Since the summer minimum is of the order of a few thousand, then lowering everything by (say) three thousand across the board is possible, and corresponds to an ice-free summer.

However, lowering everything by 14 thousand across the board is not possible, since that corresponds to a summer volume of -10 thousand!  Ergo in order for the annual average to go down by 14 thousand (which is what you're projecting by 2031), then the summer and winter must both drop to zero - a loss of  a few thousand km^3 of summer ice and tens of thousands of km^3 of winter ice.
Title: Re: Annual Average Thread
Post by: crandles on December 08, 2014, 03:59:26 PM
Quote
If your objection is about the trendline, then please suggest a different sort of trendline that you believe is more plausible, plus the reasoning behind this.

How about we start with reasoning rather than trendline. From Lindsay and Zhang 2004:


1. Preconditioning. During this period, 1948 to approximately 1989, warming winter air temperatures reduced the thickness of undeformed ice while the thickness of ridged ice increased. Undeformed ice is that which has thickened thermodynamically, as heat is lost through the ice to the atmosphere new ice grows on the underside of ice floes. Critical to this ice formation is the heat flux through the ice which is set by the temperature difference between the ice/ocean boundary at the underside of the ice (freezing point) and the temperature of the atmosphere at the ice surface, changes in atmospheric temperature dictate thermodynamic freezing. Ridged (or deformed) ice thickens as mechanical compression of ice causes the ice to buckle under compression and form ridges. So as the air warmed over this early period it reduced the thickening of ice over winter by reducing heat flux through the ice and reducing growth of new ice.

2. Trigger: (Approximately 1990 to 1995) During the 1990s the Arctic Oscillation and Pacific Decadal Oscillation lead to a shift in the strength and centre of action of the Beaufort Gyre, from 1990 this lead to larger amounts of open water in summer. Due to export of ice through the Fram Strait (as noted by other authors, e.g. Rigor et al) there is a large drop in deformed ice thickness as multi-year ice North of Greenland and the Canadian Arctic Archipelago (CAA) was reduced by large volumes exporting out of the Fram Strait. This period can be seen in the first graphic of this post as a succession of large interannual variations in NSIDC sea ice extent.

3. Feedback. (Approximately 1996 onwards) Following the thinning of the pack in the Preconditioning and Trigger phases, the stage was set for ice albedo feedback to take effect. Ice was thin enough such that in the marginal oceans summer thinning was able to open up more open water and lower concentrations of ice, allowing heat gain within the open water.

Other papers have then noted
4. Failure of 'Beaufort gyre flywheel'
This lead to larger areas of open waters in Chukchi and East Siberian Sea which set the stage for multi-year ice (MYI) to fail to survive passage around the Beaufort Gyre. This lead to both a rapid loss of MYI area and to thinning of the MYI towards just 2m thick.

5. 2008 to 2014 or a few years beyond.
The rapid loss of thick MYI above 2m has to come to an end as the volume of ice above 2m thick runs out. Even if an area ceases to be MYI the winter is cold and long enough for FYI nearly that thick to form each year. So the fast rate of loss during 1996 to 2007 starts to slow down. Instead of having both loss of thick MYI above 2m and slow decrease in thickness of FYI, the rate slows down to just the effect of slow decrease in thickness of FYI.

So there is some of the reasoning. This leads to a trendline that not only accelerates downwards (1996 - 2007) but also subsequently becomes less steep. (Something like graph I have previous posted.)

Maybe you would prefer a simpler story that allows you to construct and defend a trendline that just gets steeper. Unfortunately reality is likely to be a little more complicated.
Title: Re: Annual Average Thread
Post by: Unmex Chingon on December 08, 2014, 05:01:48 PM
Quote
"If your objection is about the trendline, then please suggest a different sort of trendline that you believe is more plausible, plus the reasoning behind this."

I am by no means a mathematician thus can't give you a trendline.  However, I am a basic logical person.  As you say - humans make mistakes and I as well as you are human. 

I believe we are discussing ANNUAL average and not ONE day of ZERO Ice, correct?   Then it is my opinion that even IF there were 6 months of ZERO ice - there would be a winter refreeze.  If I were to follow your projection under this scenario:

I would have to ascertain what your model would have as the lowest amount of winter ice.
I would guess you would have Zero for summer ice.
Then combine these 2 to make a limit line above zero.
Title: Re: Annual Average Thread
Post by: viddaloo on December 08, 2014, 08:20:43 PM
Sorry, I shouldn't have said anything. My mistake.
Title: Re: Annual Average Thread
Post by: viddaloo on December 09, 2014, 12:00:14 PM
Quote from: Wikipedia
In colloquial language average (http://) usually refers to the sum of a list of numbers divided by the size of the list, in other words the arithmetic mean. However, the word "average" can be used to refer to the median, the mode, or some other central or typical value. In statistics, these are all known as measures of central tendency. Thus the concept of an average can be extended in various ways in mathematics, but in those contexts it is usually referred to as a mean (for example the mean of a function).

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D119.0%3Battach%3D12301%3Bimage&hash=7b5eb5b5c23294f4957b8bfff371ee08)

Let's zoom in on the same graph to the next 12 months, shall we? There we see that the auto–prediction yesterday rather amazingly went from Apr4 to May3 for when the annual volume will go from 5th to 6th lowest. This happened in just one day. The auto is based on weekly gain and how fast that weekly gain will take the annual volume above the current 6th lowest year.

My gut feeling prediction for the next 7 months, however, says we will cross the line somewhere between May 3rd and August 1st. Really, it's amazing that the purple graph has been rising for as long as it has, and 'gravity' should soon pull it back downwards, but likely not until it crosses the pink 2010 line.
Title: Re: Annual Average Thread
Post by: viddaloo on December 11, 2014, 02:14:05 PM
Daily estimates fluctuate up and down the late–March — early–May blue line, which isn't that strange, as this part of the blue 2007/08 line is pretty much aligned and it doesn't take much in the form of variation to the weekly gain to switch from one side of the spectrum to the other.

I don't think the annual average will ever go higher than the blue line, though. In fact, I think when the AAV finally turns around and goes down again, it will never again be as high as at that turning point. These are probably the very last days/months above 15 k km³.

The only aspect of excitement is how high we will go and how long it will be before the turn.
Title: Re: Annual Average Thread
Post by: crandles on December 11, 2014, 02:48:47 PM
Added annual average and more gridlines.

Don't want to put words in your mouth but this seems like what you are proposing. Not impossible to believe that. When 4 people jump to an assumption, is the correct response to blame them for making that assumption or to think maybe your beliefs could be more clearly explained and this is just a suggestion for what you could try.

Title: Re: Annual Average Thread
Post by: viddaloo on December 11, 2014, 02:58:07 PM
2029, crandles. So your crash dates are off by at least a year.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D1086.0%3Battach%3D12332%3Bimage&hash=b1f69fedd0ce8b8a8df5371c73efd67a)
Title: Re: Annual Average Thread
Post by: crandles on December 11, 2014, 03:24:47 PM
2029, crandles. So your crash dates are off by at least a year.

Yes, you are right they are off, my mistake. But then there could well be other things wrong. For instance, there is quite a sharp turn in the max month trend, why would that happen now? Is it supposed to wait until there is a year with no ice before turning? There might also be a few other ways of dealing with that.

As I said I don't want to put words in your mouth so want to see what you think rather than demand that you think what I think you might think. So it was more a sketch of what you could show if you wanted.
Title: Re: Annual Average Thread
Post by: viddaloo on December 11, 2014, 03:35:47 PM
2029, crandles. So your crash dates are off by at least a year.

Yes, you are right they are off, my mistake. But then there could well be other things wrong. For instance, there is quite a sharp turn in the max month trend, why would that happen now?

Well, the main other things that are wrong are your max and min volume graphs, that you claim that I claim will turn like this. For anyone who reads closely, they'll see I don't say anything about those graphs, only that the total will hit zero in '29 if the choice of trendline is plausible.

So far I've seen no other trendlines attached to the Annual Average graph, so it will be exciting to see if such a suggestion arises, for instance from persons who disagree with my posted choice of trendline. That said, I won't hold my breath!  ;D
Title: Re: Annual Average Thread
Post by: crandles on December 11, 2014, 05:38:41 PM

Well, the main other things that are wrong are your max and min volume graphs, that you claim that I claim will turn like this. For anyone who reads closely, they'll see I don't say anything about those graphs, only that the total will hit zero in '29 if the choice of trendline is plausible.

So far I've seen no other trendlines attached to the Annual Average graph, so it will be exciting to see if such a suggestion arises, for instance from persons who disagree with my posted choice of trendline. That said, I won't hold my breath!  ;D

re the first sentence. I didn't show anything about what you thought the min would do. I did make a suggestion about the max which I wanted you to correct assuming that was necessary. (purple line is just a remnant that perhaps should have been deleted.)

Re second sentence. That seems a remarkably different version of event to what I understood before.

Above is a clear conditional on 'if the trendline is plausible' which seems to accept no responsibility for whether the trendline is plausible or not.

That seem to be you distinctly distancing yourself from such a rapid transition prediction.

Contrast that with:

The way I read the data from PIOMAS, it will be a decade tops from the first ice–free day till the first ice–free year.

note that you said "will be" not "might only be"

Oh, it shows what I think it shows, all right!

Is also very definite not conditional.

Posting just the annual average quadratic fit is not enough to show ' it will be a decade tops from the first ice–free day till the first ice–free year.'

Four people have assumed from that graph that it is more likely the average will become less steep when the min reaches zero somewhat like as suggested below rather than the max trend suddenly getting steeper as in the suggested graph previously posted.

I suggest that first you need to decide whether you are claiming there will be a rapid transition or not and make this clear.

If you want to stick to predicting a rapid transition but don't want to predict that the max volume trend will turn sharply steeper then it is hard to understand how you can believe the rapid transition belief and you would need to explain how such positions are not contradictory.
Title: Re: Annual Average Thread
Post by: viddaloo on December 11, 2014, 05:59:14 PM
I suggest that first you need to decide whether you are claiming there will be a rapid transition or not and make this clear.

Hilarious!

I don't know if you'd call perennial open waters by mid–2029 a rapid transition or not, as obviously I have no access to your line of thinking here. But for what it's worth, I do distance myself and I have distanced myself several times already from the 2029 figure: I think it's much too conservative.
Title: Re: Annual Average Thread
Post by: Peter Ellis on December 11, 2014, 06:56:08 PM
Viddaloo: 
What we know at this point is that you are predicting annual average to hit zero around 2029 or before.  From this we can deduce that the winter maximum must also hit zero around 2029 or before.

I think it would help us all if you could draw a graph like crandles' graph, showing all three figures - i.e. summer min, winter max and annual average - making clear what your predictions actually are, and confirming whether you think the implied crash in winter maximum is physically plausible.

At the very least, this will allow us to test your predictions to some extent over the coming few years.


Well, the main other things that are wrong are your max and min volume graphs, that you claim that I claim will turn like this. For anyone who reads closely, they'll see I don't say anything about those graphs, only that the total will hit zero in '29 if the choice of trendline is plausible.
But you are claiming the max volume graph will turn like this - whether you realise it or not!  If the total annual average hits zero in '29, then the max volume must also hit zero in '29, because the average of any positive number plus zero is greater than zero. So, when you claim "the total will hit zero in '29" it is your job to realise what that prediction actually implies, and to evaluate its plausibility based on those implications.

Or are you somehow predicting that the annual average will hit zero before the winter maximum hits zero?  If so, I may have some important information for you about, well, how maths works.
Title: Re: Annual Average Thread
Post by: viddaloo on December 11, 2014, 07:19:00 PM
LOL! Nice try, guys.

PS: I have enough data and an adequate method to say something about the annual average hitting zero. I don't have that for neither minimum nor maximum, so I just won't speculate. It's funny how guys who deny others the right to speculate freely change back and forth from that and to demanding that others speculate, when they explicitly do not want to speculate. Must be a higher form a logic that I just don't have access to yet!  ;D



PPS:
Title: Re: Annual Average Thread
Post by: Peter Ellis on December 12, 2014, 01:44:25 AM
You're missing the point again.

I take issue with your (3). Your zero date for the annual average is not remotely plausible, and nor is the path to that zero.

The reason your predicted path to zero is not plausible is because having an annual average of zero necessarily implies an annual maximum of zero.

Therefore, in order for the annual average to follow your predicted path, the winter maximum will have to undergo a much faster drop - and there is absolutely no physical basis for any such prediction.

Like it or not, you are making a prediction about the winter maximum (to wit, that it will be zero on or around 2029), with no evidence and no reasoning. I disagree with you.

I don't think there's any basis in pursuing this further.
Title: Re: Annual Average Thread
Post by: crandles on December 12, 2014, 02:32:20 PM
You're missing the point again.

Like it or not, you are making a prediction about the winter maximum (to wit, that it will be zero on or around 2029), with no evidence and no reasoning. I disagree with you.

I don't think there's any basis in pursuing this further.

+1

Title: Re: Annual Average Thread
Post by: viddaloo on December 12, 2014, 02:49:09 PM
You're missing the point again.

I take issue with your (3). Your zero date for the annual average is not remotely plausible, and nor is the path to that zero.

The reason your predicted path to zero is not plausible is because having an annual average of zero necessarily implies an annual maximum of zero.

Yeah, well, I guess I should have written that you should also read my point 4). 'My mistake'. LOL.

I think it would help us all if you could draw a graph like crandles' graph, showing all three figures - i.e. summer min, winter max and annual average - making clear what your predictions actually are, and confirming whether you think the implied crash in winter maximum is physically plausible.

At the very least, this will allow us to test your predictions to some extent over the coming few years.

I agree that being able to test an estimate over the coming years is good. That's why I test my estimate every day, in fact. When I'm posting the zoomed–in annual average graphs, I am publishing those tests. The best thing, however, is probably the fact that you can do this yourself. You can test my estimates every day, if you like, for the coming few years. I've been kind enough to show you how, by detailing my method.

PS: The problem with testing my estimates for winter maximum volume is that I haven't made any. If, on the other hand, I had made such estimates, then you would have been able to test those once a year. Now you are left instead with the possibility to test my average volume assumptions every day of every year.
Title: Re: Annual Average Thread
Post by: viddaloo on December 13, 2014, 03:17:48 PM
For the first time in 6 days, the annual average is not closing in 52 km³ on 2007, but 50 km³. But the weekly gain is still 27 km³, so the explanation is 2007 falling slower towards us. In any case, the estimate is now for an April 8th shift from 5th lowest average volume to 6th lowest.

But, as stated before, I think we'll cross the pink 2010 line, and not the blue 2007/8 line, somewhere between May and August. We should soon be getting the first estimates suggesting such a 'pink' crossing instead of the blue.
Title: Re: Annual Average Thread
Post by: viddaloo on December 14, 2014, 05:42:59 AM
But, as stated before, I think we'll cross the pink 2010 line, and not the blue 2007/8 line, somewhere between May and August. We should soon be getting the first estimates suggesting such a 'pink' crossing instead of the blue.
Title: Re: Annual Average Thread
Post by: viddaloo on December 14, 2014, 09:17:33 AM
Back to the 2029 collapse graph for average volume: We shall have to go through all of these three orange boxes during 2015—2020 for the '29 collapse estimate to be realized. If we don't, the estimate may be considered falsified.

For the lower of the three boxes, this means the annual average needs to go below 10 k km³ within the next five years. The average is currently at 15.2.

Going through all of these three will probably entail some pretty heavy dents to the winter maximum volume during ~2016—2019.
Title: Re: Annual Average Thread
Post by: viddaloo on December 15, 2014, 05:47:01 PM
May 11th.
Title: Re: Annual Average Thread
Post by: Unmex Chingon on December 15, 2014, 11:29:04 PM
LOL! Nice try, guys.

PS: I have enough data and an adequate method to say something about the annual average hitting zero. I don't have that for neither minimum nor maximum, so I just won't speculate. It's funny how guys who deny others the right to speculate freely change back and forth from that and to demanding that others speculate, when they explicitly do not want to speculate. Must be a higher form a logic that I just don't have access to yet!  ;D


You have enough data and method to say something about annual average hitting Zero, Correct? (just copying your quote)

IF the annual average is close to Zero - does that not imply 365 consecutive days of nearly Zero?  So the Maximum and Minimum would have to be close to Zero every single day of 2029 - am i missing something in my math different than yours?  You don't have to speculate the maximum and minimum if you know annual average is Zero - as those would have to be Zero as well.

Title: Re: Annual Average Thread
Post by: viddaloo on December 16, 2014, 02:58:29 AM
Correct, Unmex. For the July 17th 2029 zero date, the volume for all days half a year earlier to half a year later would be exactly zero. That makes an arithmetic mean (or average) of 0.0.
Title: Re: Annual Average Thread
Post by: viddaloo on December 16, 2014, 03:05:19 AM
Some fairly major news, folks: There is now reason to believe the purple line has already started its long awaited (and likely long–lasting) descent, as ESA's Cryosat program reports a significantly lower sea ice volume for October compared to last year, and a slightly lower volume for November compared to last. See the PIOMAS thread (http://forum.arctic-sea-ice.net/index.php/topic,119.msg41511.html#new) for more detail.

This means that this graph should probably be targeting the orange 2014 line instead of the pink 2010 line, that is if annual volume isn't already lower than it was about 12 months ago:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D994.0%3Battach%3D12388%3Bimage&hash=2906324bc6868887edf6259fb3fb7f11)
Title: Re: Annual Average Thread
Post by: viddaloo on December 16, 2014, 05:48:53 AM
Quote
«Between (https://agu.confex.com/agu/fm14/meetingapp.cgi#Paper/15471) autumn 2010 and spring 2013, there was a 14% and 5% reduction in autumn and spring Arctic sea ice volume, respectively, in keeping with the long-term decline in extent.»
Autumn 2010 to autumn 2012: 14% drop in sea ice volume.
Spring 2011 to spring 2013: 5% drop in sea ice volume.

Quote
«However (https://agu.confex.com/agu/fm14/meetingapp.cgi#Paper/15471), since then there has been a marked 41% and 9% recovery in autumn and spring sea ice volume, respectively, more than offsetting losses of the previous three years.»
Autumn 2012 to autumn 2014: 41% increase in sea ice volume.
Spring 2013 to spring 2014: 9% increase in sea ice volume.

Add to that a 15% drop in reported October sea ice volume (http://forum.arctic-sea-ice.net/index.php/topic,119.msg41511.html#new) from 2013 to 2014 and a 6% drop by 1st or 15th December from 2013, and you have a picture of an annual average ice volume that clearly peaked somewhere between 'spring' 2014 (still up 9% over the previous year) and October 2014 (down 15%), and that is very different from the PIOMAS AAV depicted here:
Title: Re: Annual Average Thread
Post by: Unmex Chingon on December 16, 2014, 04:28:24 PM
Correct, Unmex. For the July 17th 2029 zero date, the volume for all days half a year earlier to half a year later would be exactly zero. That makes an arithmetic mean (or average) of 0.0.

Wow!  Your belief is that in 15 years - all through the winter - the arctic will be enjoying warm weather so that NO ice will form or refreeze.   8)
Title: Re: Annual Average Thread
Post by: jdallen on December 16, 2014, 06:12:47 PM
Correct, Unmex. For the July 17th 2029 zero date, the volume for all days half a year earlier to half a year later would be exactly zero. That makes an arithmetic mean (or average) of 0.0.

Wow!  Your belief is that in 15 years - all through the winter - the arctic will be enjoying warm weather so that NO ice will form or refreeze.   8)
Unmex, I think you'll find that's an extreme minority opinion on the board here, and Vidd is leading you into a trap.  He's suggesting for the July 17 date calculation to be *true*, the numbers would need to line up as he suggests.  Whether he believes we'll have weather which will support year-round ice-free conditions is a separate question.


Title: Re: Annual Average Thread
Post by: viddaloo on December 16, 2014, 09:12:23 PM
No trap, JD. I'm just explaining grown–up human beings how zero divided by 365 is zero. Strangely, people take weeks on end to understand how 0/x = 0, and sound like they want to burn your house down because you've acquired the secret mathematical knowledge of calculating an average.

PS: Of course, with the data from Cryosat, we're looking at a much earlier collapse year than 2029.
Title: Re: Annual Average Thread
Post by: Peter Ellis on December 16, 2014, 09:42:48 PM
No trap, JD. I'm just explaining grown–up human beings how zero divided by 365 is zero. Strangely, people take weeks on end to understand how 0/x = 0, and sound like they want to burn your house down because you've acquired the secret mathematical knowledge of calculating an average.

No, that's the exact opposite of the truth.  Various people on this board have been pointing out to you the fact that zero average implies zero max, and asking - initially politely and later more sarcastically - whether (a) you really meant to make that prediction, and (b) you had any evidence at all to justify it.  After all, it's hard to credit that anyone would be that naive, so we gave you the benefit of the doubt.

However, we've now established that the answers are (a) yes, and (b) no, so we're ignoring you except when you're in danger of confusing other people. Or at least, that's what I'm doing.
Title: Re: Annual Average Thread
Post by: ChrisReynolds on December 16, 2014, 09:45:45 PM
No trap, JD. I'm just explaining grown–up human beings how zero divided by 365 is zero. Strangely, people take weeks on end to understand how 0/x = 0, and sound like they want to burn your house down because you've acquired the secret mathematical knowledge of calculating an average.

No, that's the exact opposite of the truth.  Various people on this board have been pointing out to you the fact that zero average implies zero max, and asking - initially politely and later more sarcastically - whether (a) you really meant to make that prediction, and (b) you had any evidence at all to justify it.  After all, it's hard to credit that anyone would be that naive, so we gave you the benefit of the doubt.

However, we've now established that the answers are (a) yes, and (b) no, so we're ignoring you except when you're in danger of confusing other people. Or at least, that's what I'm doing.

Ditto.
Title: Re: Annual Average Thread
Post by: viddaloo on December 16, 2014, 09:53:29 PM
Correct, Unmex. For the July 17th 2029 zero date, the volume for all days half a year earlier to half a year later would be exactly zero. That makes an arithmetic mean (or average) of 0.0.

Wow!  Your belief is that in 15 years - all through the winter - the arctic will be enjoying warm weather so that NO ice will form or refreeze.   8)

No, Unmex. I know this is very hard for you, so I'll explain this very slowly: I'm saying after all your questions about very, very simply things if you know what a calculator is, that an annual average volume of zero in July 2029 would require all 365 days around that date to have zero volume. Somehow that's very, very hard for you to understand, so you keep asking, and keep asking, and when you finally get it, you dream up some story about warm weather every day, which you then suppose is my story, because it's your story.

I've said time and time again that I personally don't believe this will happen in 2029. I think it will happen much earlier. The recent data from the AGU also seems to suggest a year closer to the mid–twenties.
Title: Re: Annual Average Thread
Post by: Unmex Chingon on December 16, 2014, 09:59:21 PM
No trap, JD. I'm just explaining grown–up human beings how zero divided by 365 is zero. Strangely, people take weeks on end to understand how 0/x = 0, and sound like they want to burn your house down because you've acquired the secret mathematical knowledge of calculating an average.

PS: Of course, with the data from Cryosat, we're looking at a much earlier collapse year than 2029.

I will continue for a little - since this is not a trap.

The math part I get - I know the formula.  My question is not regarding the formula calculation but the fact that variable X has to be Zero.  X/365=0 so  viddaloo - it is your prediction that X will be zero by 2029 or now even sooner?  Does viddaloo believe X will be zero in 2029 or sooner?  Does viddaloo thinks for 365 straight days Arctic sea ice will not exist around 2029?
Title: Re: Annual Average Thread
Post by: ChrisReynolds on December 16, 2014, 10:06:05 PM
Correct, Unmex. For the July 17th 2029 zero date, the volume for all days half a year earlier to half a year later would be exactly zero. That makes an arithmetic mean (or average) of 0.0.

Wow!  Your belief is that in 15 years - all through the winter - the arctic will be enjoying warm weather so that NO ice will form or refreeze.   8)

No, Unmex. I know this is very hard for you, so I'll explain this very slowly: I'm saying after all your questions about very, very simply things if you know what a calculator is, that an annual average volume of zero in July 2029 would require all 365 days around that date to have zero volume. Somehow that's very, very hard for you to understand, so you keep asking, and keep asking, and when you finally get it, you dream up some story about warm weather every day, which you then suppose is my story, because it's your story.

I've said time and time again that I personally don't believe this will happen in 2029. I think it will happen much earlier. The recent data from the AGU also seems to suggest a year closer to the mid–twenties.

ROFLMAO.

Thanks Viddaloo, I always like to have a good laugh before bedtime, you just had me hooting.  ;D

Sorry for breaking my policy of no comment, but there's only so much a man can take. The only  alternative would have been to PM various people, and I don't like talking behind people's backs.

Back to no comment. :-X
Title: Re: Annual Average Thread
Post by: viddaloo on December 16, 2014, 11:22:49 PM
If you average the official sea ice volume numbers on a 365–day basis this is what you get. Just add a trendline and voila; July 2029.

Any person with a basic skill in math anywhere in the world could repeat this and get the exact same result. So your beef is really with math, not with me as a person.
Title: Re: Annual Average Thread
Post by: Peter Ellis on December 17, 2014, 12:06:58 AM
Viddaloo:  There are many trendlines you can fit to the data - quadratic ones, exponential ones, cubic ones, higher order polynomials, logarithmic ones, Gompertz ones, etc...

All of these will fit the data equally well, but give very different predictions.  If you want us to take your predictions seriously, you have to explain why you have chosen the type of trendline you have.  The equation of that trendline implies some kind of model for how ice is formed and lost.  Different types of trendline may be more or less plausible, depending on the types of physical model implied by each trendline.

Yours is incredibly implausible.
Title: Re: Annual Average Thread
Post by: Peter Ellis on December 17, 2014, 01:29:24 AM
Further comment:

You have projected a trendline based on average yearly volume.  From this you predict an average yearly volume of zero before 2029, and from that deduce that the yearly maximum volume will have to undergo an unprecedented crash (through unidentified mechanisms).

You could equally well project a trendline based on winter max volume, from which you would predict a yearly max volume of zero some time around ~2040, and from that deduce that the drop rate of the yearly average volume will have to level off some time between now and then.

What leads you to favour one over the other?  Why is a naive extrapolation of yearly average volume so much more credible to you than a naive extrapolation of winter maximum volume?  Why are both of these so much more credible to you than predictions grounded in real understanding and modelling of the relevant physics?
Title: Re: Annual Average Thread
Post by: viddaloo on December 17, 2014, 02:17:14 AM
Title: Re: Annual Average Thread
Post by: Unmex Chingon on December 17, 2014, 03:31:55 AM
If you average the official sea ice volume numbers on a 365–day basis this is what you get. Just add a trendline and voila; July 2029.

Any person with a basic skill in math anywhere in the world could repeat this and get the exact same result. So your beef is really with math, not with me as a person.

What does you trendline state the avg will be from 2029 to 2040?
Title: Re: Annual Average Thread
Post by: Peter Ellis on December 17, 2014, 10:10:18 AM
1)  You could easily get it.  Other people here have been plotting it.  If you asked nicely, I'm sure they'd tell you where to find it.

2) a) If I collected 12,000 points by measuring the Arctic extent every 15 minutes from April through July, I would get a very nice trend forecasting a melt-out some time in about November.  Would this be accurate?  No, because it would not be grounded in physics.  The Earth has a yearly cycle which means that naively forecasting a trend is not necessarily a good predictor of the future.  There may or may not be cycles in average yearly extent: there are _certainly_ physical factors which you are ignoring that will alter the shape of the trendline for average yearly extent.

2) b) As previously stated, there are many different trendlines you could fit to your 12,000 points, with completely different results.  Why have you chosen exponential (or was it quadratic) ahead of Gompertz, say?

3+4) No it isn't, for reasons we're trying to explain to you.

5) Finally something we can agree on!

6) No, you can't.  Well, you can say it, but that doesn't make you right, or even plausible.

7) Being revoltingly patronising doesn't exactly help your cause.  We all know what an average is.
Title: Re: Annual Average Thread
Post by: viddaloo on December 17, 2014, 03:48:03 PM
Amid suggestion the purple graph could be already dropping, like the green graph, the target is now moving down the pink graph from May 13th to May 16th. But we could just as well be looking at the orange graph from below. Will we ever know, and how soon will we grow accustomed to the deafening silence?
Title: Re: Annual Average Thread
Post by: viddaloo on December 18, 2014, 06:42:23 AM
In just one week from December 11th to yesterday, the 17th, the target (for crossing the line to 6th lowest) has moved all the way from March 29th on the blue line to May 18th on the pink one.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D994.0%3Battach%3D12348%3Bimage&hash=2e2b05ef4d163caae73b310b6860dd2e)

It will be interesting to see how far down the line it will finally go, and whether it could instead cross the orange graph into 4th lowest instead of 6th.
Title: Re: Annual Average Thread
Post by: jai mitchell on December 18, 2014, 08:59:21 PM
I have a question Mr. Vid,

When do you think that lake superior will move into perpetual ice free 365 averages?

http://www.ec.gc.ca/glaces-ice/63B7FBDE-2248-11DF-B4D8-D0179CC4CB1F/lksuper_rmax_ct_1973_2014_1204_0514_1981_2010_1230x780_nonrml_nomdn_notrnd_nohlt_scl_nowarn_nowrn_0_en.png (http://www.ec.gc.ca/glaces-ice/63B7FBDE-2248-11DF-B4D8-D0179CC4CB1F/lksuper_rmax_ct_1973_2014_1204_0514_1981_2010_1230x780_nonrml_nomdn_notrnd_nohlt_scl_nowarn_nowrn_0_en.png)
Title: Re: Annual Average Thread
Post by: viddaloo on December 19, 2014, 04:38:43 AM
I have a question Mr. Vid,

When do you think that lake superior will move into perpetual ice free 365 averages?

I have absolutely no data on Lake Superior, dude  ;D

I dunno why you would expect that.
Title: Re: Annual Average Thread
Post by: viddaloo on December 19, 2014, 04:39:44 AM
Target moving on down to May 19th.
Title: Re: Annual Average Thread
Post by: jai mitchell on December 19, 2014, 06:11:44 PM
That is a pathetic copout,

either you think that the arctic has a much higher likelihood of a perpetual ice free state than lake superior or you don't.

And if you hold an unfounded belief that the arctic will move to equitable temperatures in 2029 then reason follows that Lake Superior would also experience this change in temperature regime at or before this time.

It makes me a bit sad to see you post such nonsense on this board.

you can't have an annual average of zero until you have a winter maximum of zero.  If you don't get this. . .well then maybe you should revisit some basic arithmetic classes, I suggest 10th year finishing school.

http://lmgtfy.com/?q=calculating+the+mean&l=1 (http://lmgtfy.com/?q=calculating+the+mean&l=1)

unless you can magically come up with a negative value for daily sea ice volume, I suggest you revisit your calculus.
Title: Re: Annual Average Thread
Post by: viddaloo on December 19, 2014, 06:25:30 PM
Well, merry Christmas to you too, Jai!

First, the Lake Superior is a lake. The name is really a giveaway here. It wouldn't be called Lake Superior by almost everyone if it wasn't a lake.

Being a lake means it's not connected to the warming ocean. Thus the ocean may warm without the lake warming much.

Apart from that, I thought everyone had now got the point I've stressed several times about all 365 days surrounding the estimated date for ice–free year by definition needing to have zero volume. I have not made an exception for April days or September days. Thus max and min must of course also be zero.

Please take the time to read what I write before launching such pathetic attacks. Thank you  ;D
Title: Re: Annual Average Thread
Post by: ChrisReynolds on December 19, 2014, 06:27:54 PM
Viddaloo,

So that you can have some ammunition to oppose Jai's allegation of a cop-out, here is the April Volume for Hudson Bay. April is the month of peak volume, so for Hudson Bay to be ice free one need only look at when Hudson bay is ice free in April.

Year  Volume (k km^3)
1978   1.809
1979   1.799
1980   1.730
1981   1.701
1982   1.824
1983   1.859
1984   1.938
1985   1.891
1986   1.817
1987   1.805
1988   1.787
1989   1.911
1990   1.943
1991   1.956
1992   1.988
1993   1.968
1994   2.002
1995   1.895
1996   1.895
1997   2.004
1998   1.922
1999   1.684
2000   1.704
2001   1.736
2002   1.871
2003   1.931
2004   1.768
2005   1.814
2006   1.739
2007   1.634
2008   1.741
2009   1.828
2010   1.380
2011   1.649
2012   1.595
2013   1.765
2014   2.033

Q1) When does your trend extrapolation reach zero?

Q2) Why is this different from the Arctic Ocean?

A good place to start would be to look at volume from ice above and below 2.2m thick in April for the Arctic Ocean (not the seas outside the Arctic Ocean).

Year   <2.2m   >2.2m
4/1978   4.802   24.467
4/1979   4.544   24.774
4/1980   4.001   24.319
4/1981   5.104   22.055
4/1982   6.598   18.385
4/1983   6.072   20.016
4/1984   6.156   19.886
4/1985   5.112   21.589
4/1986   5.517   21.789
4/1987   4.920   23.003
4/1988   4.870   22.638
4/1989   6.600   20.067
4/1990   6.440   19.587
4/1991   5.639   21.243
4/1992   6.242   19.553
4/1993   5.539   20.956
4/1994   5.568   20.045
4/1995   5.459   19.203
4/1996   7.693   16.430
4/1997   7.034   18.471
4/1998   5.777   19.641
4/1999   5.336   19.194
4/2000   6.891   16.661
4/2001   7.128   16.881
4/2002   8.609   15.093
4/2003   8.743   14.945
4/2004   9.586   12.947
4/2005   8.425   14.234
4/2006   7.167   14.516
4/2007   9.988   10.302
4/2008   11.076   10.066
4/2009   12.211   9.032
4/2010   8.898   11.906
4/2011   12.678   6.647
4/2012   9.111   10.278
4/2013   12.407   7.150
4/2014   12.587   6.702

Q3) With regards the loss of volume that gives rise to the exponential loss you are extrapolating to give a year round sea ice free state before 2029:

Where is this volume loss coming from?
a) From all thicknesses of ice.
b) From ice below 2.2m thick.
c) From ice above 2.2m thick.

Q4) What does the behaviour of ice above and below 2.2m thick tell us about the future of the exponential trend of loss of winter volume?

Q5) In view of the above data, why would one expect radically different profiles of loss between the Arctic Ocean and a seasonal ice pack such as Hudson Bay (or Lake Superior).



Thanks Jai, that was a very intelligent angle you used. I spotted what you were getting at as soon as you posted, so it was not unreasonable to expect it to be understood and to be straightly addressed.
Title: Re: Annual Average Thread
Post by: viddaloo on December 19, 2014, 06:33:23 PM
Merry Christmas to you too, CR.

I don't want to sound boring, but I suggest you two go ahead and create a new thread about the inland lakes of North America, where your posts will be more on–topic.

This thread is about annual averages for the Arctic sea ice, it's posted in the Arctic sea ice forum and generally concerns matters related to Arctic sea ice.

Therefore, should you have a burning issue on your mind concerning something other than Arctic sea ice, I suggest you post it elsewhere. That way we can focus more in this thread on annual averages of the Arctic sea ice.
Title: Re: Annual Average Thread
Post by: ChrisReynolds on December 19, 2014, 06:34:58 PM
I see an errant reliance on warming oceans is being made. If this is seen as a problem, here is Bering Sea March volume (March being the peak volume for Bering Sea).

393.881
264.152
441.839
408.697
268.870
447.083
500.402
327.796
427.384
432.688
475.580
170.865
558.116
502.564
570.366
388.179
457.388
492.380
225.962
359.942
458.874
492.491
372.084
217.526
417.706
284.063
301.725
272.981
404.980
473.026
607.092
409.370
557.639
260.688
644.290
533.281
301.837

You can easily substitute that for Hudson in the above post.
Title: Re: Annual Average Thread
Post by: jai mitchell on December 20, 2014, 12:24:24 AM
however,

even if the summer sea ice minimum reaches zero around  2020-2025 and we start experiencing august minimums of zero by 2029.  This will cause profound changes in Jetstream and associated weather disruptions throughout the northern hemisphere.

So maybe vid is right in context, though not in scope.

All things being equal, when we start seeing august 15th sea ice minimums, there will be hell to pay for consistent water and agriculture resources for about 85% of the Human population.
Title: Re: Annual Average Thread
Post by: ChrisReynolds on December 20, 2014, 06:16:17 PM
Jai,

I know we still disagree on the implications of autumn volume increase in response to low sea ice in summer. I had hoped that this would mean you'd have more success with Viddaloo, it seems not.

However none of the above pre-supposes a long tail. The above observations were factors in my previous opinion that we'd see a fast transition in the 2020s. As for the impact of autumn/winter growth, I think we'll just have to agree to disagree as we see what happens.
Title: Re: Annual Average Thread
Post by: viddaloo on December 20, 2014, 08:37:31 PM
Though the daily gain is highest since December 15th, target's still moving south: May20.
Title: Re: Annual Average Thread
Post by: ChrisReynolds on December 20, 2014, 08:59:48 PM
Merry Christmas to you too, CR.

I don't want to sound boring, but I suggest you two go ahead and create a new thread about the inland lakes of North America, where your posts will be more on–topic.

This thread is about annual averages for the Arctic sea ice, it's posted in the Arctic sea ice forum and generally concerns matters related to Arctic sea ice.

Therefore, should you have a burning issue on your mind concerning something other than Arctic sea ice, I suggest you post it elsewhere. That way we can focus more in this thread on annual averages of the Arctic sea ice.

So you edited it to add a load of waffle.

Jai is correct, you have no interest in open discussion so it's back to ignoring you, you have nothing of value to add to this forum. Anyone with average intelligence and average understanding of sea ice would have got why Jai posted the reference to Lake Superior. You didn't get it, and when presented with the chance to think critically you ran away (again).

By the way, 5 year cycle?

2007 1
2008 2
2009 3
2010 4
2011 5
2012 And there we have the five year cycle.

But as the events of 2007 and 2012 occured due to seperate processes, the only underlying causal factor being the overall thinning of the ice, there is no five year cycle. It is as meaningless as your curve extrapolation.

How about you keep this thread as the one where you talk to yourself to avoid impairing the other threads? Especially with the meaningless and incomprehensible graphs you keep posting, as above.
Title: Re: Annual Average Thread
Post by: viddaloo on December 21, 2014, 08:36:26 PM
Moving on down to May 21st.
Title: Re: Annual Average Thread
Post by: ChrisReynolds on December 21, 2014, 11:25:20 PM
Viddaloo has just accused me of collusion with Jai Mitchell.

I have told him where to go. But will publicly explain how I got data out so fast.

Open 'codemaster', the spreadsheet I use to process and contain data derived from PIOMAS gridded.
Select region required from a drop down list.
Select month from a drop down list.
The speadsheet then uses 'vlookup' to automatically populate data and update graphs.
Cut and paste data. 

All that in minutes.

For the record, there was no collusion.
Title: Re: Annual Average Thread
Post by: viddaloo on December 21, 2014, 11:41:04 PM
I believe you told me to 'go fuck myself', and not where to go per se.

I understand that Christmas is celebrated differently in different cultures around the world.
Title: Re: Annual Average Thread
Post by: ChrisReynolds on December 21, 2014, 11:51:34 PM
So you don't think an allegation of collusion is likely to make someone rather angry? Of course not, such allegations against the scientific community come from you on a regular basis.

I don't know why I put up with you when I have a blog I don't post on regularly enough. I'm off.
Title: Re: Annual Average Thread
Post by: viddaloo on December 22, 2014, 12:03:22 AM
I made a necessary change to the Arctic Sea Ice Collapse graph, the center of the latest controversy.

I put the explanation about the latest data added to the graph in the chart legend, so that the date for the last annual average volume is left alone in the graph annotation. Hopefully, this will make the graph a bit easier to understand for all, regardless of their math or science background.
Title: Re: Annual Average Thread
Post by: Peter Ellis on December 22, 2014, 12:27:23 AM
Stop pretending we don't understand your insultingly simplistic graph, you drivelling loon.
Title: Re: Annual Average Thread
Post by: Neven on December 22, 2014, 12:38:16 AM
Ah, so I don't understand it because it's simplistic? That's a relief.  ;D

I agree that viddaloo's game of statistical extrapolation without physical basis or explanation annoys the hell out of people who want to know how the damn thing works, but please try to ignore and not insult. At least out here in threads, but in PMs as well, if at all possible.

Viddaloo, I've told you before: you can't make a prediction based on statistics only, you need to explain how it will come about. Arctic sea ice loss? Sure. AGW is the cause? OK, fine. But how exactly? Only if we know the how, we can start saying something about the when.
Title: Re: Annual Average Thread
Post by: viddaloo on December 22, 2014, 12:57:40 AM
Yes, I think a lot of ice will melt faster and faster because of warming and insolation. I thought that was obvious, LOL.
Title: Re: Annual Average Thread
Post by: Unmex Chingon on December 22, 2014, 01:01:10 AM
Yes, I think a lot of ice will melt faster and faster because of warming and insolation. I thought that was obvious, LOL.

No you think ALL the ice will melt.  "All" vs "A lot" is huge difference.
Title: Re: Annual Average Thread
Post by: Peter Ellis on December 22, 2014, 12:22:47 PM
Sorry Neven, it just gets me really annoyed that whenever someone calls out viddaloo to defend his projections, or expresses incredulity over whether he can really make that big a prediction from that little evidence, he immediately accuses them of not knowing what an average is and retreats behind his one graph. Which is obviously magic and explains everything because Averages Are Amazing (TM), and if you don't get it, it's because you don't understand the graph or don't know what an average is.

He's been insulting every single reader of this site with his "Don't you understand how averages work?" schtick for months - and that's a pretty serious insult despite the lack of actual invective - and I'm fed up of it.
Title: Re: Annual Average Thread
Post by: Neven on December 22, 2014, 01:09:20 PM
Peter, I agree with what you say. But even though someone can be insulting, we have the choice to feel insulted or not (or just a little). We went through the statistics in the first two years of the Arctic Sea Ice Blog, and agreed that a Gompertz fit, for instance, would be more realistic than a linear or exponential fit (see my favourite graph (https://sites.google.com/site/arctischepinguin/home/piomas/grf/piomas-trnd1.png?attredirects=0) by Wipneus that shows all possible trend lines). The mechanics behind it is what makes Arctic sea ice interesting, as statistics can be worse than damned lies.

Quote
Yes, I think a lot of ice will melt faster and faster because of warming and insolation. I thought that was obvious, LOL.

But there are negative feedbacks as well that will inevitably hinder the faster and faster part. Chris Reynolds is doing groundbreaking stuff on that. I mean, scientists before him have done most of the groundbreaking stuff, but Chris brings it all together. I personally find his explanation of the thickness-growth feedback very convincing, and I wish I had had the insight before.

You should really read Chris' latest blog post and other stuff on his blog carefully. Much better than fucking yourself.

Or so they say. I've never tried it.  ;D
Title: Re: Annual Average Thread
Post by: viddaloo on December 22, 2014, 02:24:44 PM
Yes, I really feel like reading the blog of the gentleman who told me to go fuck myself now. He seems like a calm, measured and reasonable guy, who wouldn't go all nuts and show his true colours to the world just because a graph was posted that disagreed with his own long–held feelings about some ice.

I will certainly give it a thought during Christmas dinner. Maybe I'll read it on my smartphone in the cathedral? As you said, this gentleman (who more or less coincidentally and randomly told me to go fuck myself), calm, measured etc, has written even more these days, so of course I'll rush over there to see what it may be.

I just hope it's not about how the ice will melt slower because it can no longer remember how insulted it's been. If it is, I shall seriously have to go fuck myself.
Title: Re: Annual Average Thread
Post by: viddaloo on December 22, 2014, 02:53:29 PM
Target is set on the same day, that is annual average volume will be 6th lowest on May 21st.
Title: Re: Annual Average Thread
Post by: crandles on December 22, 2014, 04:52:55 PM
Peter, I agree with what you say. But even though someone can be insulting, we have the choice to feel insulted or not (or just a little).

I think there is plenty of evidence that Viddaloo just likes winding people up. If he derives some form of pleasure from this then that is pretty sad. Getting wound up doesn't serve much purpose other than possibly giving him what he wants.

He has shown willing to put in some effort into creating graphs. (even if they seem vague/unintelligible or uninteresting to most.) This a bit different from some trolls who are not willing to put in ant effort so people have attempted to explain or discuss the science with him but it is clear this gets nowhere as he is happy to ignore anything that may cause any sort of challenge to his beliefs. Such effort perhaps deserves some leeway to express opinion but I suggest he has already done enough to run out of that leeway.

3 possibilities spring to mind:
1. Everyone should ignore him. This allow him to post his stuff all over the blog lowering the signal to noise ratio that is usually so high on this blog.
2. Restrict him to a thread or two (this one and Arctic CH₄ Levels Winter 2014—2015) deleting any posts he makes not on these threads.
3. Prevent further posts.

I would suggest 1. hasn't worked well so far and if the majority want more action to keep the signal to noise ratio high then this should be a more important consideration than any concerns about censorship. I don't really mind 2. or 3. 3. is easier to implement than 2.

------

[inline response from me so as to not clog the thread: I don't want to discuss that here. I've given viddaloo ample warning a while ago, because he was losing his temper too much. This has improved.

I try to be flexible and tolerant, but I won't hesitate to take drastic measures when needed. In this case I really think it's best to ignore. Viddaloo can decide for himself whether he wants to keep focusing on stats exclusively, or profit from other people's knowledge and speculation wrt mechanisms and basic physical properties of Arctic sea ice. N. ]
Title: Re: Annual Average Thread
Post by: Unmex Chingon on December 22, 2014, 06:54:30 PM
I made a necessary change to the Arctic Sea Ice Collapse graph, the center of the latest controversy.

I put the explanation about the latest data added to the graph in the chart legend, so that the date for the last annual average volume is left alone in the graph annotation. Hopefully, this will make the graph a bit easier to understand for all, regardless of their math or science background.

Viddaloo I asked this before - What does your math trendline calculate the average to be in 2030 and in 2031?
Title: Re: Annual Average Thread
Post by: viddaloo on December 23, 2014, 05:05:43 PM
Today's Autozoom map displays the perfect zoomed view of the situation for the annual average extent: 2014 is on a collision course with 2010, and the crash will happen way before January 9th.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D994.0%3Battach%3D12601%3Bimage&hash=99acf640a1cc21e6323595fad223932c)

The Roadmap view gives us the approximate date, and it now looks like it will happen before the end of the year:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D994.0%3Battach%3D12602%3Bimage&hash=eb03b7f8f67b395b2362bed8369ef181)

The significance of this shift from 4th lowest average extent to 5th lowest, is that it follows average volume, that went from 4th to 5th on September 19th. The change may indicate that we're moving into a safer place for the Arctic sea ice, although one must remember that the massive 389078 km² Abrupt Loss of 2007 happened from a higher average extent than we're at this year, meaning such losses can happen at any time.

Now that 2015 will start with both AAE and AAV in the same position, the next move up or down for any of them will be an interesting indicator for where the icepack is really heading in the second half of the 2010s. Of course, the longtime trend suggests down.
Title: Re: Annual Average Thread
Post by: Unmex Chingon on December 23, 2014, 07:01:48 PM
Viddaloo I asked this before - What does your math trendline calculate the average to be in 2030 and in 2031?
Title: Re: Annual Average Thread
Post by: jai mitchell on December 23, 2014, 08:47:54 PM
AGU 2014 Nye Lecture by James White

ABRUPT CLIMATE CHANGE: THE VIEW FROM THE PAST, THE PRESENT AND THE FUTURE

https://virtualoptions.agu.org/media/C23D-01.+Nye+Lecture%2C+Presented+By+James+White/0_r289t1qf (https://virtualoptions.agu.org/media/C23D-01.+Nye+Lecture%2C+Presented+By+James+White/0_r289t1qf)

This video presentation by James White lends credence to Viddaloo's conceptualization that the arctic is now, more than any other time in the last 120,000 years primed for abrupt collapse.

login info:  email witsendnj@yahoo.com, password agupass1
Title: Re: Annual Average Thread
Post by: viddaloo on December 23, 2014, 10:10:11 PM
I suppose I should add that:

Title: Re: Annual Average Thread
Post by: werther on December 24, 2014, 12:35:34 AM
Thanks Jai, for the link.
I'll come back later on it through the "weird weather" thread, which seems more appropriate.
Title: Re: Annual Average Thread
Post by: Unmex Chingon on December 24, 2014, 05:09:56 PM
I suppose I should add that:

  • the post–2012 annual average extent position has already peaked at 6th lowest in 2013
  • post–2007 it peaked at 5th lowest in 2009 (returning to Lowest in 2011)
  • positions are a bit deceiving, as more and more years compete as time goes by
  • annual average volume peaked at 3rd lowest post–2007 and (perhaps) 5th post–2012
  • aae and aav were both 5th lowest already briefly for 27 days from Sep19 to Oct15

viddaloo - I am not real good at math and need your help.  What does you math trendline calculate the Average to be in both 2030 and 2031?
Title: Re: Annual Average Thread
Post by: Unmex Chingon on December 25, 2014, 05:36:29 AM
I suppose I should add that:

  • the post–2012 annual average extent position has already peaked at 6th lowest in 2013
  • post–2007 it peaked at 5th lowest in 2009 (returning to Lowest in 2011)
  • positions are a bit deceiving, as more and more years compete as time goes by
  • annual average volume peaked at 3rd lowest post–2007 and (perhaps) 5th post–2012
  • aae and aav were both 5th lowest already briefly for 27 days from Sep19 to Oct15

viddaloo(p) answer me please!
viddaloo - I am not real good at math and need your help.  What does you math trendline calculate the Average to be in both 2030 and 2031? 
Title: Re: Annual Average Thread
Post by: Unmex Chingon on December 25, 2014, 05:51:46 AM
Merry Xmas to all... except to viddaloo if he can not answer my question!
Title: Re: Annual Average Thread
Post by: viddaloo on December 31, 2014, 11:54:03 AM
Extreme autozoom close–up. Guess what will happen on this very last day of the year?
Title: Re: Annual Average Thread
Post by: Unmex Chingon on December 31, 2014, 05:49:49 PM
Extreme autozoom close–up. Guess what will happen on this very last day of the year?

I like this closeup a lot!  Can you do one like this with your trendline to show a close up of your math at 2030 and 2031 for annual average?
Title: Re: Annual Average Thread
Post by: viddaloo on January 01, 2015, 08:17:12 AM
Extreme autozoom close–up. Guess what will happen on this very last day of the year?
Title: Re: Annual Average Thread
Post by: viddaloo on January 02, 2015, 12:27:03 AM
Yeah, thanks for all the brilliant, beautiful graphs, vid! You've shown creativity and ingenuity in 2014, and even learnt to remain calm in the face of harsh attack waves. I hope you will carry on posting these updates on the sea ice also as we go into 2015.
Title: Re: Annual Average Thread
Post by: Unmex Chingon on January 02, 2015, 06:29:00 AM
Yeah, thanks for all the brilliant, beautiful graphs, vid! You've shown creativity and ingenuity in 2014, and even learnt to remain calm in the face of harsh attack waves. I hope you will carry on posting these updates on the sea ice also as we go into 2015.

Are you talking to yourself?
Title: Re: Annual Average Thread
Post by: viddaloo on January 11, 2015, 07:09:34 PM
Annual extent is now dropping for the 3rd consecutive day, as you can also see in the turn of the autozoom graph:

(https://d22d7v2y1t140g.cloudfront.net/m_13481004_UNyg23NTVM80.png)
Today's drop of 363 km² is the biggest since October, and there's even a weekly drop of 154 km² a week, the first weekly drop in annual average extent in 2015.
Title: Re: Annual Average Thread
Post by: viddaloo on January 13, 2015, 09:06:38 AM
Biggest weekly drop since October.

(https://d22d7v2y1t140g.cloudfront.net/m_13489559_q1OYOUEW95y9.png)
Title: Re: Annual Average Thread
Post by: viddaloo on January 19, 2015, 06:20:31 PM
Looking again at the annual average extent and volume for 2015, in–between them the closest year for comparisons is 2011, which is thus auto–chosen for the scope of these close–up autozoom graphs.

For the AAE, the weekly downturn has now ended, and we're up 461 km²/week. The annotation says dec30 +19 days, which means 2011 was higher on Dec30, 19 days ago. This is also why the chart shows yesterday's date + only 19 days ahead, because we are that close to 2011.

(https://d22d7v2y1t140g.cloudfront.net/m_13520365_bNnSTS8nrKVG.png)

For the AAV, we are of course still up, as we've been since last spring. The annotation says jul15 +187 days, which means 2011 was last higher on Jul15, 187 days ago. This is also why the chart shows yesterday's date + 187 days ahead, and not a close–up like for the AAE.

The chart shows the prognosis will cross the 2008 graph on Mar25, which means we'll be 6th lowest from this date.

If PIOMAS — for any reason — is exaggerating the amount of sea ice, by as much as 1000 km³, our true position today will be 3rd lowest, and we'll then cross the 2012 graph on May11, which means we'll be 2nd lowest from this date. Remains then only 2013 to be beat, as that year was still lowest on May 11th, at an annual average volume of 13.4 km³, mostly thanks to the huge drop of 2012.

(https://d22d7v2y1t140g.cloudfront.net/m_13520369_zwzr2OgMzKW6.png)
Title: Re: Annual Average Thread
Post by: viddaloo on January 25, 2015, 05:27:13 PM
The fascinating saga of the Arctic goes on, and today I found myself puzzled by this:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13545279_TVDJYPExqN2F.png&hash=34a88009743546e8bd9696ab83639a4d)

And this:

Code: [Select]
2011 0.2 6.45 6.64
2007 -0.35 -10.73 11.08
2014 -0.88 5.75 6.63
2008 2.36 -1.12 3.48 [*may29*]
2006 -1.47 -14.04 15.51
2010 -1.95 -4.34 6.29

The average extent prognosis bowing downward for the first time, but when does it cross the nearest graph, and what year might that graph belong to? Obviously it's way outside the scope of this chart, and the little 'cheat sheet' above suggests it is 2008's graph that is crossed by the prognosis arc on May 29. I didn't even know 2008 was below us! But clearly it is, and it's really not very strange, in January, after the record low 2007 season, that 2008 average extent is very low.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13545308_kr30PolxhVFG.png&hash=78e95c1f0faf3d047c9ad530058095ac)

The prognosis arc for the AAE is based on the development over the last fortnight, and as we move forward in the next days, it's expected to become even steeper downward, and I would guess a crossing of the 2011 graph within the scope of the AAE chart will become apparent in the next few days, provided daily AAE deltas are still negative.

The average volume prognosis is back into June territory, meaning the 2015 annual average volume will not go from 5th to 6th lowest before the pink graph is crossed, perhaps on June 2nd?

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13545321_zJFgN6wJ3h5o.png&hash=db5adb5d2565837b2c3f8121a991059f)

My cheat sheet again indicates some interesting facts not shown in the chart:

Code: [Select]
[-1242] -375 -42 266 552 758 782 461 -106
[16.89] 17.51 17.73 17.94 18.1 18.31 18.34 18.04 17.55

First that the weekly delta is lower than 7 days ago, a fact that implies the prognosis arc is actually going down again in the far end to the right, way outside the chart. Second that we will most likely see the prognosis going down for the first time within the scope of the chart within the next few days, thus going further into June on the pink graph, and possible even into the green. In which case we're looking at a transition into 4th lowest instead of 6th lowest, which is the implication of crossing the pink.

Of course, having the prognosis arc bowing down like that within the near future of the chart, also carries a very real possibility that the main purple non–prognosis graph will also be down at some point during this spring. That will be for the first time in about a year.

Newbie hint: Remember, you cannot have record low ice during the year without these annual average graphs first turning downward at some point.
Title: Re: Annual Average Thread
Post by: viddaloo on January 26, 2015, 07:15:05 AM
With these prognoses, prospects for a very low sea ice year in the Arctic look reasonable good:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13548387_51OtsO0SKcqX.png&hash=8402aea29f8f8e064f5c7253f1849a30)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13548016_TSQUh92g1pBy.png&hash=e12fd85f9dcc42433f0230e5fe7f4458)

I was astonished to see the latter (volume) prognosis managing to sneak in there between 2010 and 2014 at the far end of the chart, but there you go: Never trust the Arctic to stay within the bounds of your charts! Looking at the cheat sheet again:

Code: [Select]
2011 0.2 6.49 6.69 [*feb28*]
2007 -0.38 -10.7 11.08
2014 -0.88 5.73 6.62 *[sep12]*

we see that the average extent prognosis arc will cross the green 2011 graph (and be 4th lowest) on Feb 28, while the average volume prognosis crosses the green 2014 graph (and becomes 4th lowest) on Sep 12.

The reason for this abrupt change of outlook is the rapid slowdown of the winter refreeze in the Arctic. And to be fair, these prognoses are programmed to assume that the weekly slowdown — this latest weekly delta compared to the previous weekly delta — will continue at the same pace and then accelerate. For annual average volume this means in clear terms that a gain of 18 km³ per week dropping to a 17 km³ per week gain now, will first continue into an AAV gain of 16 km³ per week in 7 days, and then a gradually accelerating slowdown. Obviously leading to a drop starting in a number of weeks.

From the AAV chart we can read that this drop is expected to start on March 30th. Not to be confused with the advent of spring, where actual daily volume will start dropping, although the date in this case may be overlapping. The AAV graph starting to drop on March 30th means that from this day forth, daily 2015 sea ice volume will be lower than the same day in 2014.

Newbie reminder: Remember, you cannot have record low ice during the year without these annual average graphs first turning downward at some point.