2013 Arctic Sea Ice Extent Maximum

[BornFromTheVoid]

The melt season has finished and so it's time to start looking towards the spring maximum (if we make it past 21/12/12!).

The maximum sea ice extent has typically diminished at a much slower rate than the minimum, with a difference of only around 1.9 million km2 between the lowest and highest maximum (11.3%), compared to 4.2 million km2 for the minimum (55.2%).

The highest maximum extent value recorded was in 1979 at 16,564,600km2, while the lowest was 2011 at 14,689,100km2.

Here's a graph of the annual sea ice extent 1 day maximum based on the NSIDC data

The last 10 years

2003 15.5868

2004 15.2555

2005 14.9462

2006 14.7330

2007 14.7896

2008 15.3052

2009 15.1628

2010 15.2845

2011 14.6891

2012 15.2909

We'll use the NSIDC data to base the minimum on. I don't think this will be submitted to anything, and the voting is set to private, just in case that matters to anyone.

[Gray-Wolf]

I have a hankering after major changes to the ice within the basin this year?

I think we may see the ice factory set up again across Bering if changes to the Arctic's energy budget are it's driver but these will be more than offset by open water remaining in Beaufort, Baffin and Laptev/east Siberian sectors?

i still cannot believe the sst anom off the Alaskan shelf (west of the McKenzie delta?) and cannot put it down to 'faulty readings' as too many measurements are taken in the area? The most 'plausible' explaination I have heard mooted is the extension of a Pacific warm water current into the basin , Via Bering, and it's deflection under Coriolis pressures to the coast where the current grounds out forming the sharp temp spike?

We also have the possible extension of the N.A.D. into Barrentsz and Kara and the 'New' occurences in Laptev which again hints at a warm surface current emerging?

If the Jet so organises this year as to place the 'cold plunges' over land then the accompanying WAA may well help keep ice thin and vulnerable in areas of the basin for long periods through winter?

I also wonder about the mixing that must be occuring from the 'outgassing' under the east Siberian Sea? Last year the thickness there was pegged to under 1m. If this was partly due to outgassing and warm waters mixed back to the surface then this years melt will have only aided this process (remember last sept we were told that features there had grown up to ten times larger than the previous year? has this scale of increase continued this year?).

All in all we may start to see winter ice following the large losses we have seen in summer ice. Whatever happens though I'd guess the volume will be down and that the ice will be spread out thinner than ever?

[BornFromTheVoid]

I just see that after most low minima, there is a jump in the following maxima, so I think this March the extent will climb to just a little below the average of the last 7 or 8 years.

I'd imagine the extra fresh water from the melt may help with a thin refreeze, as well as the strong cold anomalies around the Bering sea from the continuing -ve PDO helping to bolster the ice in that area.

But I'm sure opinions will change if the sea ice growth remains below average for the next few weeks.

[Gray-Wolf]

As with the summer ice i believe that the ice thickness , or lack of it, must impact the winter season once we drop below a certain threshold? We all saw what a strong storm was capable of doing over summer (with open water allowing swells to form) and I feel that below a certain threshold we could find a similar disruption over winter with slabbing and over-riding opening up enough ocean to allow further disruption and mixing in the basin?

Let us also not forget the the wrong synoptics over winter has also lost us a large proportion of the older thicker ice, via export out of Fram, to further weaken the pack/thin the pack.

[songster]

GW: That's an error in the model - has to be. It doesn't even show up in all the models: compare these two:

http://ocean.dmi.dk/...te/index.uk.php

http://polar.ncep.no...y_NPS_ophi0.png

Edit: The Coriolis explanation is from a random commenter on Neven's blog and is absolute drivel. Betrays a fundamental misunderstanding of both Coriolis forces and indeed thermodynamics.

Edited October 1, 2012 by songster

[songster]

Re the above: I sent an email to the query address on the model front page. No reply as yet, but they must have prodded something as the temperatures and anomalies now show saner values.

http://polar.ncep.no...t/rtg_high_res/

http://polar.ncep.no...t_NPS_ophi0.png

http://polar.ncep.no...y_NPS_ophi0.png

A salutary reminder that much of what people like us obsess over on blogs is simply a set of auto-updated web-pages with little manual oversight, which form a very small part of the work being done by the actual scientists involved. Obviously something was wrong here, but not something important enough to come to notice earlier.

Edited October 3, 2012 by songster

[Gray-Wolf]

Thanks for that songster!

It also highlights why we should use more than one source and get a feel for what we ought to be seeing from readings? Kinds like Lincolnshire's 'supercell' on yesterdays 3:30pm MetO radar image!!

[BornFromTheVoid]

Almost forgot about this.

Having reached 14.26 million already, the lowest vote is out of the game. Feeling quite confident about my 14.8-14.9 guess so far.

Less than 3 weeks to the date of the earliest maximum recorded, February 21st in both 1996 and 1987.

[BornFromTheVoid]

Going by the one day NSIDC extent, the maximum appears to be 15.169 million km2. Two people voted for between 15.1 and 15.2 million, so congrats to whoever did!

So overall, 16.66% of the voters got it right, 50% went too high and 33.33% went too low.

If the sea ice extent follows a general linear trend, we could expect the maxima to average below 15 million from next year onward.

Anywho, unless someone decides to do one first, I will probably set up the first minimum prediction poll this weekend.

[knocker]

Easy Question

http://tamino.wordpress.com/2013/03/29/easy-question/?utm_source=dlvr.it&utm_medium=twitter