Tuesday 2 April 2013

It's Pin the Tail on the Donkey time.

Neven has published a pole on this years minimum: What will the CT 2013 Arctic SIA minimum be?
CT means Cryosphere Today, and the question at hand is what will the daily minimum be.

Here's a link to the CT Area data. Here's a link to a thread I've written on spreadsheeting this sort of Arctic sea ice data. And if you don't want to build such a spreadsheet yourself then the first line of the top post there gives a link to such a spreadsheet. I'll be updating that at least once a month with the new data, probably more often later in the season if this year's melt season turns out to be as exciting as I anticipate. Feel free to use/modify/whaddeva, as you need - I don't own the data.

Anyway, here's a link to my answer - what I think this year's minimum will be, or at least the range I think it will be in. In a nutshell it's:

I've voted between 1 and 2 M km^2, this is what I see as most likely, if I had a second vote it would be 2.234 to 2 M km^2. But I now rate the probabilities as around 75% and 25% respectively, with a probability distribution peaking between 1.75 and 2, and a slim tail extending down towards 1M km^2.

There's no numerical backup, just a qualitative argument. I just thought it worth recording here so I can keep a check on progress.

No need to click more...

...there is no more. ;)


Kevin O'Neill said...

Hey Chris,

Just saw the PIOMAS data for March and while it's too soon to make any concrete judgements, we may be seeing the volume max stabilize. This makes 3 years in sucession with a near identical max.

I can envision an Arctic Ocean that refreezes every winter to the same value as the past three winters, with increasing losses throughout summer and fall. This would be analagous to a northern inland lake that freezes over completely every winter and melts out completely every summer.

This scenario may be a quasi-stable state. As the temperatures continue to increase in the arctic it might reach a bifurcation point where even winter ice cover in any significant amount is untenable.

I expect to see SIE drop to 2.25 km^2 this year. I would be surprised if it is much larger than that and not surprised at all if it is significantly less. I'd love to know what Maslowski's model is predicting right now.

Chris Reynolds said...


You've just said one point I was going to make in my March Status blog post. But I'll be going further. Could it be that we will see a stabilisation of summer volume? With a remnant small amount of FYI, a result of area not reaching zero at the end of the year.

Have I 'switched sides' too early?

On balance I suspect not, I still think this year will see a new record and will be below 2M km^2 due to the prevalence of FYI. But the opposite interpretation is worth considering.

I think my post will have to wait until tomorrow. Been calibrating network and spectrum analysers today and my head's battered.

Kevin O'Neill said...

I don't see any evidence yet that summer volume has or will stabilize. Of course reaching zero summer volume is a 'stable' value unless there's a negative feedback large enough to make it oscillate from zero to non-zero.

I believe area/extent/volume are no longer sufficient measures to monitor changes in the arctic sea ice. I suspect strength and temperature are where the interesting changes are occurring. The widespread fracturing seen this season tells us something about the ice's strength; though salinity complicates the equation, I believe it also tells us something about the ice's temperature. If we reach another record year for area/extent (with weather 'normal'), then the preconditioning of weak, 'warm' ice surely has to be the reason.

I've passed the point of being concerned about the loss of arctic sea ice - now I'm rooting for it to all melt away. There's absolutely no chance of politician's doing anything to mitigate the situation unless their lapdog pseudo-scientists are shown to be the charlatans they are. Seeing the ice suddenly disappear would be one large step in that direction.

Chris Reynolds said...

You know me, I always like to use new info and explore its possibilities.

I've got somewhat derailed from writing my March blog post.

Consider this little graphic.

It shows the volume growth in response to the area at minimum.

Now consider this one.

It shows the percentage of thinning during the season (rel to April thickness) vs the % of open water in Sept, because it's PIOMAS gridded that's monthly average.

I'm too tired to do anything more tonight, getting nowhere but here's what I've been pondering:

All the actors are on the stage, whatever factors will play a role in the future are already active. By this September I reckon this statement will be all the more true. We'll have ha d a melt season where most of the pack behaves like a seasonally sea ice free winter pack melt will.

So is there a statistical way to get relationships like the graphs and fit eauqtions above and use them to make a simple model to tell us if autumn ice gain can overcome spring loss?

Anonymous said...

Hallo Chris,

can I use this as a kind of open thread? Not related to the post.

You´re referring to our situation as being in a "Rapid Ice Loss Event" (taken from some literature, a while back). Then, the following paper will interest you, which has come out in Ocean Science, just this March.


"Arctic Rapid Sea Ice Loss Ebents in regional coupled climate scenario experiments" by R. Döscher + T Koenigk.

Maybe you have seen it already (wouldnt surprise me)

Beste groeten, m.