Poll: 2017 PIOMAS Maximum Monthly Figure

[DavidR]

We are approaching the end of the freezing season with PIOMAS set to peak next month. Probably at record low levels.  We could be as low as 20K km^3 at the maximum. Twice recently  we lost 19.5K Km^3 in a year.

Jim Pettit’s excellent graphs on Arctic Volume at
     https://sites.google.com/view/pettitclimategraphs
show how close we are coming to the point where the volume of ice lost in the year will equal the volume at the peak of the freeze.

So as a change  from a poll on extent here is a poll on peak volume. Closes on the 21st March to allow all the February data to become available.
Votes can be changed up until then.

The result will be the figure used at http://psc.apl.washington.edu/research/projects/arctic-sea-ice-volume-anomaly/ which is the one Jim uses in his graphs.

[oren]

Excellent idea, and I love the overlapping ranges. May I also suggest to:
Add some more categories at the bottom, that is where the action will be since we are currently running much lower than all previous years.
Post the actual maximum numbers of the last ten years, not just the (excellent) chart. I know they are easily available but it would help the lazy peeps (myself included).
Clarify that we are discussing the monthly average rather than the maximum daily figure.
And most importantly the ability to edit your vote...

[Pmt111500]

voted for +23K because "it'll be great, you see". I know Arctic Ocean isn't traditionally regarded part of Trumpistan but does the glorious leader know this? Maybe I'll change my vote after hangover. Have a good March, people. 

[slow wing]

Voted 20.5-21.0 x 10^3 km^3.


At day 59 we were at 18.6 in those units.

Archimid posted on the PIOMAS update thread that, in past years, the average gain to maximum from there has been 2.1. Taking the average gives 18.6 + 2.1 = 20.7 - hence the choice of bin.


It could be argued that the Arctic Basin hasn't been as cold as usual this year, with FDDs way down. That trend may well continue over the next month or two.

On the other hand, I see lots of potential for adding volume in the 'ice factory' on the Russian side of the Arctic Basin. Offshore winds there have been, and still are, exposing new sea surface there which is rapidly freezing over and thickening.

So I think taking the average gain from day 59 to maximum ice volume is reasonable.

[DavidR]

Excellent idea, and I love the overlapping ranges. May I also suggest to:
Add some more categories at the bottom, that is where the action will be since we are currently running much lower than all previous years.
Post the actual maximum numbers of the last ten years, not just the (excellent) chart. I know they are easily available but it would help the lazy peeps (myself included).
Clarify that we are discussing the monthly average rather than the maximum daily figure.
And most importantly the ability to edit your vote...

As I can't find a way to alter the voting conditions( I thought vote changing had been allowed) I  am reluctant to  change the number of levels.  With a range of 500K  I  suspect the graphic provides enough information. Trends aren't going to  help  much  this year.
If we go  below 20K we will be in serious trouble.

[magnamentis]

hey,

finallly an overlapping poll, well observed and much easier to choose :-) thx

i'm here: 20.50 - 21.00 K km^3

i'm a bit surprised how pessimistic the majority is, i'm in for a new lowest "high" of course, chances are huge, but by such a margin ? i dunno, hence game on once more :-)

enjoy the weekend @all

[oren]

I voted 20-20.5 but I would move it one or two bins higher if Neven would somehow work his magic on the editability of votes.

[DrTskoul]

Wow. Looks like on average nobody has a clue what the maximum will be. A crapshoot....

[jdallen]

Wow. Looks like on average nobody has a clue what the maximum will be. A crapshoot....

Actually, I'm pretty confident in my 20.0 - 20.5; we're only at about 18.5, and previous years appear to have rarely had more than 2.0K growth between now and the volume maximum.

I'm also assuming that the weather, which has been warm, will continue to drop us into unknown country vis-a-vis FDD's.  All in all, a pessimistic outlook for our max volume.

[icefisher]

With quiet weather in the Arctic the next 2 weeks ice volume growth and extent should both increase.  If  storms stay out of the picture thru spring, melt volume from below slows down and a late maximum near 21MM seems likely. 

[Neven]

I voted 20-20.5 but I would move it one or two bins higher if Neven would somehow work his magic on the editability of votes.

Fixed now.

[DavidR]

Based on the February data the smallest increase from February to April could see a low of around 19.5 K and a couple of other increases put the value below 20K. I have added those buckets. The maximum increase in that period would put us well below the current record low. 

[Cid_Yama]

We aren't in Kansas anymore. What has happened in years before, or even last year, may not be indicative of what will happen this year.

I believe we will see a March surprise.     

[gerontocrat]

Moved down two places to 20.25 to 20.75 as feb anomaly increased for 4th month in row and cannot see any reason for anomalously high freezing in next  two months.

But what do I know ?

[oren]

Thank you Neven, and thank you DavidR, and here's my own contribution, a list of previous April averages for folks to consider. Now my wish list is complete.
2000   27.153
2001   27.632
2002   27.428
2003   27.244
2004   25.75
2005   26.045
2006   25.105
2007   23.752
2008   24.983
2009   24.944
2010   24.097
2011   22.5
2012   23.119
2013   23.122
2014   22.935
2015   24.23
2016   22.459

2017 Feb Average is 17.4
Average gain from Feb to April since 2000 is 3.18, range is 2.635-3.804

Considering that we are running about 1800 km³ below normal as of day 59, but that on the other hand cold conditions have settled over a part of the arctic recently, we could end up at 1000-1500 below the previous lowest maximum. I will be keeping my vote at 20.0-20.5 after all. I am modifying my vote to 20.25-20.75 to better fit the known data.

Edit Reason: wrong numbers.

[Archimid]

I voted 20.25 - 20.75 K km^3

I don't see a reason why we shouldn't get 2 k km^3. The one thing that can inhibit that growth is an area like the Bering melting much earlier than usual.

[longwalks1]

How many significant digits is the data good for?

From the PIOMAS web site.

Model Validation and Uncertainty

PIOMAS has been extensively validated through comparisons with observations from US-Navy submarines, oceanographic moorings, and satellites. In addition model runs were performed in which model parameters and assimilation procedures were altered.  From these validation studies we arrive at conservative estimates of the uncertainty in the trend of  ± 1.0 103 km3/decade. The uncertainty of the  monthly averaged ice volume anomaly is estimated as ±0.75  103 km3. Total volume uncertainties are larger than those for the anomaly because model biases are removed when calculating the anomalies. The uncertainty for October total ice volume is estimated to be  ±1.35 103 km3 .  Comparison of winter  total volumes with other volume estimates need to account for the fact that the PIOMAS domain currently does not extend southward far enough to cover all areas that can have winter time ice cover.  Areas in the Sea of Okhotsk and in the Gulf of St. Lawrence are partially excluded from the domain.  Details on model validation can be found in Schweiger et al. 2011  and (here). Additional information on PIOMAS can be found (here)

And from the PIOMAS web site cited paper on "Volume time series and uncertainties:"
http://psc.apl.uw.edu/wordpress/wp-content/uploads/schweiger/pubs/Schweiger-2011-Uncertainty%20in%20model.pdf

Uncertainty in modeled Arctic sea ice volume
Axel Schweiger, 1 Ron Lindsay, 1Jinlun Zhang, 1 Mike Steele, 1 Harry Stern, 1 and Ron Kwok 2
Received 25 February 2011; revised 27 April 2011; accepted 7 June 2011; published 27 September 2011.

In general PIOMAS,
relative to observations, appears to overestimate the thickness
of thin ice and underestimate the thickness of thick ice.

[DavidR]

How many significant digits is the data good for?

For the purposes of the poll we are using the estimates provided by PIOMAS which are given in Km^3.  All measures of ice are estimates and it is the long term trends not individual data points that  are significant. 

[Cid_Yama]

Since we are looking at predominantly thin ice, and PIOMAS overestimates the volume of thin ice, I believe we may have an early collapse in the offing.  We may be seeing ice that is not there (volumewise).

Especially with reports of 'rotten' swiss cheese ice full of holes.  PIOMAS gets it's data on the condition of the ice from the Near-real-time Ice and Snow Extent (NISE) data set, which is an   SSM/I-SSMIS product.  I do not believe the satellite sensors can tell the difference between solid ice and rotten ice.   

I'm betting on the max average being in March.

[Dave C]

21.037

[Paddy]

20.5 to 21.0, based on a 21st century average volume growth from end Feb of 2.1.

[Juan C. García]

The 1979-2016 average monthly increase from February to April is 3.058 k km³, so adding 17,400 we have a total of 20,458 km³.

I choose the 20.25-20.75 km³ range. 

[Pmt111500]

Changed me vote to expect 1Kkm3 loss between ENSO episodes as 1999 - 2002 were the years of apparent lack of loss since Alaska and Siberia were on the way of ice melt.

[oren]

To anyone who has used my numbers from years past, they were March numbers by mistake, as pointed out by the relentless DavidR... my post is now corrected. I hope. 

[Pmt111500]

I'll keep my vote  where it is to keep up the reputation of this alarmist site.

[Gray-Wolf]

I'll keep my vote  where it is to keep up the reputation of this alarmist site.

Same here, a very alarmist 2.5 below where we'll probably top out at!

[epiphyte]

There's a huge area on the Pacific side which is thin enough to put on larger than normal volume under anywhere near normal conditions. So for now I'm going higher than the consensus... 21-21.5

[DavidR]

  Just  one week  left to  vote or modify  your vote!

[Neven]

Thanks for the reminder, DavidR. I have voted 20.75 - 21.25 K km^3.

PS I'm voting for the April monthly average, right? Not the daily figure that is highest.

[Cid_Yama]

My understanding was that of peak monthly volume, whatever month that occurred in.  Be that March or April.

Clarification please.

[DavidR]

Thanks for the reminder, DavidR. I have voted 20.75 - 21.25 K km^3.

PS I'm voting for the April monthly average, right? Not the daily figure that is highest.

The poll is for the highest monthly average this year, which usually falls in April.  However if the March average was higher than April the March figure would be the winner. 

[epiphyte]

@neven... glad you pointed that out.  I'm dropping two buckets to one below you

[crandles]

Hasn't ever not been April for highest month on record.

Lowest April 2016 22.471
Latest value:
2017  59  18.608
Previous lowest day 59:
2016  59  20.570
2011  59  20.459
2012  59  20.707
2014  59  20.865
2013  59  20.903

So 1.851 below lowest day 59

If we stay 1.851 below lowest ever that would make 20.62.
With low volume the same FDD would be expected to grow more ice volume so slipping above 20.75 seems quite plausible. So the two most popular choices of 20.5-21 and 20.75-21.25 do seem pretty likely.

I am sticking with my 20.75-21.25 choice.

[seaicesailor]

The 1979-2016 average monthly increase from February to April is 3.058 k km³, so adding 17,400 we have a total of 20,458 km³.

I choose the 20.25-20.75 km³ range. 

+1

[Cid_Yama]

Hasn't ever not been April for highest month on record.

There has never been better conditions for a March highest average month.

Remember we are talking highest monthly average, meaning you are also betting on a significant amount of ice sticking around until MAY.

[seaicesailor]

Hasn't ever not been April for highest month on record.

There has never been better conditions for a March highest average month.

Remember we are talking highest monthly average, meaning you are also betting on a significant amount of ice sticking around until MAY.

Most of ice of the Arctic proprr keeps thickening until June, regardless if later it melts precipitously or not. If the daily average temperature stays under -2C, sufficiently far from the edges, the ice layer keeps growing at the bottom, and even when it goes above freezing it takes a while (some days) for the heat to reach the bottom and this stop growing. Something Jim Hunt shows in the forum neatly every year with the buoy data.
I don't think the anomalous warming is still enough to displace the volume max a whole month, but we have been witnessing pretty weird things so...
Edit. Now that we are at it I found the animation of 2015F temperature data last year. This infelice buoy was in the CAB (toward Beaufort sea) and did not see bottom melting until end of June, its surface melting being a few centimeters I think before dying for unknown reasons

[Cid_Yama]

We won't have long to wait to see.

Past results are not an indication of future performance.  Especially after this last winter.

You are betting on things being like they have been in the past, but we've already seen we aren't in Kansas anymore. 

[gerontocrat]

We won't have long to wait to see.

Past results are not an indication of future performance.  Especially after this last winter.

That is the question.
Are we seeing a sea-change or an anomaly ?

[DavidR]

Hasn't ever not been April for highest month on record.

There has never been better conditions for a March highest average month.

Remember we are talking highest monthly average, meaning you are also betting on a significant amount of ice sticking around until MAY.

Even in a friendly poll like this it pays to make the winning value clear. It is the highest monthly average this year, regardless of weather it is , March, April, May or December.  If you  hold out  for a winning figure in December you  may  be on your own I  suspect.

[oren]

Seaicesailor, thanks for re-posting that wonderful buoy temp animation. Very instructive.

[gerontocrat]

20,173,000 km3 and April average only a tiny tiny bit more than March average. (Got the exact answer by reading Nostradamus).

[gerontocrat]

I am an idiot. Remove the 000 from my prediction - Sunday morning and brain in standby mode.

[Neven]

Gerontocrat, you can modify your own comments. It's a feature for idiots, which I initially installed for myself. But it seems everyone makes use of it now. 

[gerontocrat]

Gerontocrat, you can modify your own comments. It's a feature for idiots, which I initially installed for myself. But it seems everyone makes use of it now. 

Thanks.
I will learn as it is a necessity for me since I am breaking my own rule - think and  check before pressing send.

[DavidR]

The earliest volume maximum since 1979 appears to have been the 2nd of April 1995, the latest the 1st of May twice in the 1980's.  However the increase between Mar and April has only varied between 0.467K (1995) and and1.393K. Although there is a slight trend towards an earlier maximum it seems it will be some time before is an annual monthly maximum in March.

Just  a couple of days left to change your vote if you want to. 

[DavidR]

The Feb -> Mar increase was 2200 km^3 and typically the Mar -> Apr figure is about half the Feb -> Mar figure. This suggests the monthly average for April will be around 20.7 K. The daily maximum will be a couple of hundred above the average.

From that  point a decline of 17 K will put 2017 on a par with 2012. The daily minimum in September is typically a few hundred below the September average.

We have only seen a decline of less than 17K once in the last 10 years with the average being 18K and the trend figure 18.5. 

[gerontocrat]

In defiance of all evidence and logic I am sticking with my April  average prediction of 20,173 km3 (because it is too late to change it).

[DavidR]

In defiance of all evidence and logic I am sticking with my April  average prediction of 20,173 km3 (because it is too late to change it).

It's within the realms of possibility with an early start to volume loss.  Both 1990 and 1995  had increase in average volume between Mar and Apr that would result in an average Apr volume  less than that.

[crandles]

In defiance of all evidence and logic I am sticking with my April  average prediction of 20,173 km3 (because it is too late to change it).

It's within the realms of possibility with an early start to volume loss.  Both 1990 and 1995  had increase in average volume between Mar and Apr that would result in an average Apr volume  less than that.

Last value day 90 is 20.398. Are there any years where April average is less than value on day 90 by more than 200km^3? I doubt it.

Too late to change it given that the poll closing date has past seems like valid logic to me so surely it can't be in defiance of all logic can it? 

[DavidR]

Last value day 90 is 20.398. Are there any years where April average is less than value on day 90 by more than 200km^3? I doubt it.

1995 comes close with the April average at 0.117 K below the Mar 31 value.  Gerontocrat only  needs the average to be 0.225 below the March 31st figure.

Thats the only year  up to to 1996 where the April average is lower than March 31st.