PIOMAS August 2012

The PIOMAS people are early this month with updating the numbers (probably so that the SEARCH people have some extra info for their SIO). Here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

I think it's pretty safe to say that we're going to have a new record volume low, although the difference with 2010 and 2011 has become smaller. Right now it's 1249 and 730 km3 respectively.

Here is Wipneus' version with the calculated "expected" 2012 values (dotted lines), based on the same date values of 1979-2011 and an exponential trend.
A caveat from Wipneus: "Note that the statistical error bars are quite large."

The trend is following the dotted line quite nicely, I would say.

The anomaly has come up a bit compared to last month, it's no longer 4 standard deviations below the linear trend:

I have used my crude method of dividing PIOMAS volume numbers by Cryosphere Today area numbers to calculate the ice pack's average thickness. Again, this is just an indication that allows us to compare with previous years:

That small uptick at the end makes the graph look slightly less alarming.
Thank you, PIOMAS.

Average thickness for July 31st (in m):

• 2005: 2.38
• 2006: 2.41
• 2007: 2.15
• 2008: 2.43
• 2009: 2.06
• 2010: 1.57
• 2011: 1.55
• 2012: 1.48

If the model is correctly assessing sea ice volume in the Arctic, chances of new extent and area records are still very much present. Despite the weather.

As a bonus, Jim Pettit's PIOMAS volume death spiral chart:

Comments

[Al Rodger]

The latest PIOMAS anomaly data graphed up close (if the link works).
Link (usually two clocks to 'download your attachment')

[Jim_pettit]

The PIOMAS "death spiral" chart is looking pretty foreboding today. It won;t be long now...

[Neven]

Thanks, Jim. I've added your chart to the post.

[Jim_pettit]

For anyone interested, I've created a simple but telling animation of the PIOMAS "death spiral" chart:

https://sites.google.com/site/pettitclimategraphs/home/sea-ice-animations

[Ethan O'Connor]

Jim --

I really like the radially plotted charts. Beyond their immediate visual impact, they are an extremely effective way to accurately convey the scope of the decline. The area enclosed by each period's line is the time integral of the volume, in Volume-Days. The relative areas of the plotted regions (and hence the volume-days of each period) are much easier to discern in this format than in a time series.

Of course, a big reason that they work so well for this is the magnitude of the decline relative to the noise, which means we don't have to visually untangle overlap from period to period :(

[Ethan O'Connor]

And, ps: It's scary to look from the summer segments of the recent orbits to the origin and back. How tiny a sliver of the pack remains!

I get the feeling we don't have many more seasons of watching melt pools freeze over on the drifiting cams...

[Al Rodger]

Ethan O'Connor
I think I'm going to have to disagree about the 'area enclosed by each period's line' being a measure of 'volume-days.'
If a fixed period of days is considered to enclose a triangle, it will have an area = half base x height, the height representing the volume h=v. But the base of the triangle is longer for higher volume. Base/height for our triangle therefore has a fixed ratio R:1 and thus base = Rh. So Area = 0.5 R.v^2, a measure of the square of the volume for the period.

[Ethan O'Connor]

Al,

Yeah -- you're right :) Since this is polar integration there's that extra factor of r I dropped. Luckily, people under estimate area relationships for larger circles around small ones, so it sort of compensates for that ;)

No, seriously, thanks for the catch. v*v*t it is!

[Al Rodger]

:-))
Then again, I've just been trawling through guidelines on visual perception. We humans don't necessarily see in a truly linear fashion. I get the impression that the perceived accuracy of any representation can be questioned if you have a mind to question it.

[Seke Rob]

A new charting attempt at integrating volume maximum/minimum and visualizing the amount of melt, in bar form and number labels.

http://i137.photobucket.com/albums/q210/Sekerob/Climate/ArcticSIA-PIOMASv20Max_Min.png

The 2012 minimum data point is open of course, but if August turns in a "through the floor", it will added with an "in progress" indicator. Enough to "lead" the eye.

[Artful Dodger]

Sweet graph, S-R. It reminds me of a double-helix DNA molecule. Peter should approve. :^)

[Timothy Chase]

Seke Rob wrote:

A new charting attempt at integrating volume maximum/minimum and visualizing the amount of melt, in bar form and number labels.

http://i137.photobucket.com/albums/q210/Sekerob/Climate/ArcticSIA-PIOMASv20Max_Min.png

It looks like the annual minimum is just about to cross the max day.

What happens then?

;-)

I am using dual axis charts at work. The color formatting of the tick marks on the right will help to associate the max day with the right axis -- once the reader realizes two vertical axes are being used.

[Timothy Chase]

Seke Rob, another dual axis that might be interesting would be sea ice extent and sea ice area on the left with sea ice volume on the right. All three measures at the same time. Just a thought.

[Timothy Chase]

PS to August 26, 2012 at 17:29

Actually I would put sea ice volume on the left and both extent and area on the right. That would put volume "front and center", as is fitting since area and extent are quite literally superficial to it.

[Twemoran]

Seke

Another brilliant chart!

You always manage to pack such a large amount of related data onto a single chart.

Terry

[Seke Rob]

Timothy... there's a thing called axis scaling ;P. The right hand tick marks were color coded, but fattened them up a bit, and covering up the rest of the axis, for the zero doubt effect "what belongs to which" ;O

Think I can accommodate the volume/extent/area integration quite readily... do that when the 7 of 9 braincells have regenerated :).

Terry, you haven't seen the integrated TSI/Sunspot/CO2/Temp/Arctic SIE/SIA chart yet [It's a bit overdue for updating... last was 2009, with HadCrut3v]. Will add to the ATCC site and inform when A), can retrace it in the 100 tabs, B) time is on my side, C) Am satisfied that HadCrut4v data have been assimilated.

Thanks all for nods.

P.S. Working actually 3 dimensional for some stuff to trick the graphic system to for instance get trend lines and bar charts to appear in one image. How... that is my trade secret, but will reveal that each time series can be associated to a different graph type [there being limits to this in the very commercial application software] :]

[Steve C]

Seke Rob-

That PIOMAS volume graph is indeed a masterpiece of graphical representation. It represents a powerful argument for the timescale of disappearance of the Arctic ice cap.

I'd suggest that that second Y-axis data detracts from the impact. I'd also suggest that extending the length of the X-axis to show the trend-lines intersection with zero volume would be useful.

[Timothy Chase]

Seke Rob wrote:

Timothy... there's a thing called axis scaling ;P. The right hand tick marks were color coded, but fattened them up a bit, and covering up the rest of the axis, for the zero doubt effect "what belongs to which" ;O

I should go out and get some coffee then get to work. I am putting together a package for generating a dual axis with banding, two lines and stacked bar. Not as pretty or the subject quite as fascinating, but it needs to be done soon nevertheless.

[Seke Rob]

Version 1.1 of PIOANC

http://i137.photobucket.com/albums/q210/Sekerob/Climate/ArcticSIA-PIOMASv20Max_Min.png

Addresses various points / suggestions made, to include imminent crossing of the minimum volume represented on the Y1 axis, and the maximum dates, represented on the Y2 axis [now, the latest max date occurred coincides with axis top... May 1]. The "In progress" was added with the standing melt value as at July 31. Not an artist, but don't expect that level with software of Euro 39.99. (No Moncktonian photoshopping, all live plotted from data). Hope to not have ruined the Human DNA impact we all know there to be [with exceptions]. Ready for the "practically ice free" dreaded future, on paper :o|

[Artful Dodger]

CT SIA for Aug 27 was 2.594 M km^2. If we assume PIOMAS volume is concurrently 3,000 km^3, then the average sea ice thickness works out to 1.156 meters.

Sounds quite plausible, even though we'll have to wait until the first week of October to find out.

[Artful Dodger]

Hi folks,

I wonder if anybody would be interested in creating a cool sea ice visualization? If you have the technical ability, you could create a 3D version of Jim Pettit's famous PIOMAS 2D "Death Spiral" graph, here:

http://iwantsomeproof.com/extimg/sia_5.png

My concept is to plot each PIOMAS data point in a 3D grid according to its spherical co-ordinates, as follows:

• the Date being the height on the Z-axis, with the oldest date at the top of the grid range, then spiraling down to the latest value on the bottom.
• the Day-of-Year being the clock-wise angle from the Origin, Jan 1st
• the radial axis representing PIOMAS Volume, shown as the distance from the central (vertical) axis
• the Z-axis must be extended enough to show (0,0,0) - the First Ice-free Day

You could then animate the data, moving forward through time as the data is painted on the 3D grid.

Just a thought! But I bet it'd look WAY COOL!

Cheers,
Lodger

P.S. I mentioned this idea to Jim Pettit some time ago, but have not heard back from him. Offer's still open, Jim!

P.P.S. (this idea is a cross-post from the 'anyone cold' thread ;^)

[Artful Dodger]

Andy Lee,

Thanks for rising to my graphing challenge with your comment on August 29, 2012 at 09:18. Here's a little bit more detail fleshing out of my concept for the PIOMAS 'Death Spiral' 3D graph.

To be rigorous, I should specify the use of a Cylindrical coordinate system: (click image for larger picture)

"A cylindrical coordinate system with origin O, polar axis A, and longitudinal axis L. The dot is the point with radial distance ρ = 4, angular coordinate φ = 130°, and height z = 4."

So then:

• radial distance = PIOMAS Volume
  
• angular coordinate = Day-of-Year
  
• height z = Julian Date, descending

Thanks again for stepping up. Looking forward to the first result!

Cheers,
Lodger

[Artful Dodger]

Bah, x-posted again in the wrong thread, so repeating here...

Hi Andy,

There's some canned Python code here used to create the graph above, if it's any help:

#! /usr/bin/python -t
# _*_ coding: iso-8859-1 _*_
# Last edited on 2009-05-03 18:12:55 by stolfilocal

PROG_NAME = "make-coord-system-figure"
PROG_DESC = "Generates an SVG illustration for the Wikipedia articles on coord systems"
PROG_VERS = "1.0"

<snip> yada, yada, ...

Cheers,
Lodger

[Andy Lee Robinson]

I'll have a go at a few variations over the next few days - hopefully be ready in time for new PIOMAS data.

[Artful Dodger]

:)

[Wipneus]

PIOMAS update: I have updated my graphics at ArctischePinguin for the August data:

Monthly data:
https://sites.google.com/site/arctischepinguin/home/piomas/piomas-trnd2.png

Daily data:
https://sites.google.com/site/arctischepinguin/home/piomas/piomas-trnd4.png

Daily data with a "prediction" based on exponential trend:
https://sites.google.com/site/arctischepinguin/home/piomas/piomas-trnd4-1.png

[Seke Rob]

Wow, that's quicker than the silver rider. Lets see how this translates into the Arctic-DNA likened chart.

[Twemoran]

Wipneus

Your exponential extrapolations are proving extraordinarily exact.

Alliteratively Yours
Terry

[Wipneus]

Terry:

I am amazed myself. The great cyclone seems to make only a temporary dent.

[Seke Rob]

Not quite the record yet, but very very close to proceed to first spot of annual melt.

http://bit.ly/PIOM05

Sets a new record (in progress) minimum of 3,599 and a melt to date of 18,331 km^3

The Jun-Aug Seasonal Average dropped from 9,810 cubic km in 2011 to 9,370 cubic in 2012... -440.

http://bit.ly/PIOSIV

Think a good lot will have seen this before: Imagine There's No Global Warming http://www.youtube.com/watch?v=TF5F6eYho8

[Jim_pettit]

Following in Wipneus' footsteps, I've also updated my own PIOMAS charts:

Volume "death spiral":
http://iwantsomeproof.com/extimg/sia_5.png

Annual volume maximum and annual volume loss:
http://iwantsomeproof.com/extimg/sia_10.png

Annual percentage loss of maximum ice volume:
http://iwantsomeproof.com/extimg/sia_12.png

In terms of overall volume lost, it's true that 2012 is still behind first place 2010. But in terms of the percentage of volume lost, 2012 is clearly in first place, with 83.59% (to 2010's 81.71%).

[Jim_pettit]

Yeesh. I can see I haven't had my afternoon coffee yet; here are the correct links:

Volume "death spiral":
http://iwantsomeproof.com/extimg/sia_5.png

Annual volume maximum and annual volume loss:
http://iwantsomeproof.com/extimg/sia_10.png

Annual percentage loss of maximum ice volume:
http://iwantsomeproof.com/extimg/sia_11.png

[Artful Dodger]

PIOMAS Volume for 2012 - Day 238 (Aug 25, 2012) was 3,599 km^3

Using historical data for 2007-2011, avg volume drop from Aug 25 to Sep 15 is -488 km^3

This implies a Sep 15 PIOMAS volume of approx. 3,110 km^3, +/- 250 km^3 for 1 Stdev.