End Zone 5: sea ice concentration

We are entering the final phase of the melting season. Extent decrease rates are getting lower and lower and soon we will start seeing the first days of extent growth, followed soon after by minimum extent. I figured it might be interesting to have a look at what happened in other years, specifically the years of the 'new Arctic era': 2007, 2008 and 2009. Perhaps we'll see some parallels that give us an idea of when and how the 2010 melting season will end.

I have downloaded a lot of images from different sources and combined them to make animations of the period August 25th-September 24th. The final date is based on when 2007 reached minimum extent. 

This is the final End Zone instalment (unless someone proposes some other aspect that should be covered). Previous instalments were:

• End Zone 1: air temperature
• End Zone 2: ice displacement
• End Zone 3: atmospheric pressure
• End Zone 4: sea surface temperature

For sea ice concentration I downloaded images from the excellent University of Bremen archive. Although I sometimes dislike the fact that these maps have a tendency to suddenly blink whole swathes of green and yellow colours (arousing the alarmist in me) and then blink back again to high concentration pink and purple, these images are still one of the best to monitor and work with IMO.

So, let's have a look:

 

The animated triptych is a bit too big to fit on most computer screens, but if I make it any smaller the resolution will be too low, I fear.

There's not much more I can say about these images than the obvious: 2007 got compacted a lot because of that persistent Arctic Dipole Anomaly and thus we see high sea ice concentration all through the remaining ice pack. The pack gets smaller and smaller at the edges, all the way until minimum extent is reached on the 24th of September.

2008 initially has more regions of ice with low concentrations, but these get compacted and refreeze during the first week of September and disappear completely after September 10th, the date minimum extent was reached. Or actually I should say September 11th, because of the leap year. The same more or less goes for 2009 that has a similar shape to 2008, but with a bigger bulge towards the Chukchi Sea.

And how is 2010 looking from August 25th onwards?

 

The shape looks quite a bit like that of the ice pack in 2008, but with a large part of that ice pack protruding into the East Siberian Sea. It remains to be seen if that ice will melt out as it consists of multi-year ice that was transported there last winter. Another thing to notice is the large swathes of yellow and green within the central ice pack, especially towards Fram Strait. These are not blinking so much, so I think 2010 has some great compaction potential. But it all depends on the winds now (and to a lesser extent SSTs).

I think 2010 has some elements of 2007 (high SSTs, maybe atmospheric patterns for the coming 10 days), but some elements of 2008 as well (general shape, maybe atmospheric patterns for the coming days). Two to three more weeks and we'll know everything!

Comments

[Neven]

PS I'll be gone for a few days. I hope the End Zone animations help a bit in determining 2010's direction towards minimum extent. See you in the next SIE extent update on Friday.

[Guillaume Tell]

A similar story unfolds less frenetically on Cryosphere Today's sea ice comparison (>30% concentration) pairs. Just compare Aug 28ths to minimums (they're close). Then compare all four Aug 28ths to each other.
2010 has a much larger proportion of lower concentration (the red is 60%) ice.

[JackTaylor]

I have a question about "movement" of concentrated ice and hoping someone more knowledgeable than myself will help answer.

"Somewhere it seems I read the period (cycle) of the Beaufort Gyre is approximately Four (4) Years to move (rotate) the thick compacted (concentrated) ice of the Canadian Archipelago into a good export position within the Transpolar Drift. Is this period very close to 4 years or does it have several months variation plus or minus up to six (6) months?" etc...etc...

[Artful Dodger]

Jack: The time required to complete a rotation of the Beaufort Gyre varies with distance to the center. It can take between 3 - 7 years, with 4 years being average. This is why thick multi-year ice piled up against the Canadian Archipelago in 2008 is now stubbornly melting in the East Siberian Sea.

[JackTaylor]

Lodger Thanks. Picking me out some buoys here
http://iabp.apl.washington.edu/maps_daily_track-map.html
and see how far they make it during expected life span ( 3 years ).

Hope some new ones are placed near where they die to watch for up to 7 years.
How's that for planning ahead?

Will pick out some older ones from tables and look at their routes while alive.

[Andrew Xnn]

Between IJIS and Cyrosphere today; who is leading and who is lagging?

Asking because have noticed a growing anomaly on Cyrosphere today
and suspect it leads IJIS, which shows a somewhat stalling sea ice extent.

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.arctic.png

http://www.ijis.iarc.uaf.edu/seaice/extent/AMSRE_Sea_Ice_Extent_L.png

Thanks again Neven and others for the great blog site!

[Timothy Chase]

Andrew Xnn -- I think a large part of the difference you are seeing in the trend from Cryosphere Today (where the trend is still headed down) and IJIS (where "melting" seems to have stalled) is that Cryosphere Today is looking sea ice area whereas IJIS is looking at extent. If the sea ice is melting in a given grid cell, but the sea ice in that cell remains above 15% that still counts as 100% extent for that cell. Alternatively, if 30% in one cell spreads out so that it is 15% in two cells then total extent goes up, counting 100% of both cells rather than just one. Of course, I would prefer to be looking at volume rather than either extent or area but as David Barber would tell you that is a little tougher to "observe" and at this point seems to require boots on the ice.

News Release: Thick Arctic Sea Ice Goes Missing
November 27th, 2009
http://umanitoba.ca/news/blogs/blog/2009/11/27/news-release-thick-arctic-sea-ice-goes-missing/

David Barber et al. (2009) The perennial pack ice in the southern Beaufort Sea was not as it appeared in the summer of 2009, pp. 2-4, 2009 Sea Ice Outlook: Pan-Arctic Summary Report, Study of Environmental Arctic Change
http://www.arcus.org/search/seaiceoutlook/2009_outlook/summary_report/downloads/regional/pdf/sio-2009-summary-report-regional-combined_rev.pdf

[JackTaylor]

Have made and put onLine an expanded (magnified) 'Flash' animation of the University of Bremen images, cropped and rotated with Asia side of Arctic on top.
Three (3) days before the IJIS data listed an uptick in the ice, AUG 26 and will update to the end of minimum extent, at least every 3 days.
http://www.polk-nc.com/agw/breA26end.swf

Normal scale at http://www.polk-nc.com/agw/breA26end.html

[Neven]

Awesome animation, Jack! Love the detail!

Lots of blinking as usual with Uni Bremen, but overall the yellow and green seems to be sticking.

[r w Langford]

Nice animation Jack
The "Blue Lagoon" just south west of the pole is clearly visible for the last three days. Strange that far north at this time of year. It is also easy to see the transport of ice out the Fram. It appears that a lot of old ice is moving out and melting quickly.

[Christoffer Ladstein]

The ice "left" in the Beaufort and the East Siberian Sea looks very vulnerable and fragile, and the combination of seatemperature and winddirection towards the Fram Strait, will most likely bring the minimum "far" below the 5,0 mill. mark.

More interesting then will be how much old ice is left this season compared to latter years. The ice north of Greenland and Canada looks "everlasting". Anyone can tell me how thick this ice is? 2 or 4 meters? But I`m correct when i say that ice in 3-4 years move over to hotter zones of the Arctic area.

[JackTaylor]

"Lots of blinking as usual with Uni Bremen, but overall the yellow and green seems to be sticking" Neven | September 04, 2010 21:06

Yes, also there appears to be some ghost pixels or shadows or hysteresis in areas such as around Wrangel Island as an example. But, with their capabilities they can account for things that blink at me. I'm amazed with the separation in the percentage and concentration they do provide to us.

How, ever I prefer some melodrama before the Fat Lady sings, so using the
IARC-JAXA Sea Ice Concentration
http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi
where an animation is available, but the scale - resolution does not meet my criteria for "a dramatic form that does not observe the laws of cause and effect and that exaggerates emotion and emphasizes plot or action at the expense of characterization"
http://dictionary.reference.com/browse/melodrama

Crop & rotate of the IARC-JAXA images, starting on August 15th, about a month before average minimum extent reached, five (5) days for 15 - 20 -25, then everyday to the minimum extent. Browser "maximized" for expanded - magnified view at
http://www.polk-nc.com/agw/arcA15end.swf
with normal scale at
http://www.polk-nc.com/agw/arcA15end.html
will try to remember to update regularly (add each days new image)
unless cheap server hosting package runs out of (exceeds) bandwidth.

[r w Langford]

Jack
I really appreciate the IARC-JAXA images you have put together. They seem to give the best visual to the effect of strong winds pushing the ice onto northern Greenland and the Queen Elizabeth Islands. The amount of ice that has moved out of the northern Beaufort appears to be the reason for the SIE losses in the last few days. As long as these winds continue we should see more ice move across Canada and Greenland and out the Fram. I might also speculate that warm suface water is being pushed along with these winds and ending up against the ice front and then beneath it adding to melt. The fat lady must be getting anxious to get on stage.

[JackTaylor]

r w Langford | September 04, 2010 at 21:39
"The "Blue Lagoon" just south west of the pole is clearly visible for the last three days. Strange

that far north at this time of year. It is also easy to see the transport of ice out the Fram. It appears that a lot of old ice is moving out and melting quickly."

Yes to that and your other post at September 06, 2010 at 19:05, thanks for the note of appreciation. Just trying to contribute to what I hope remains a "non-political" blog (hint-hint to others). BTW, both my aninations IARC-JAXA (University of Alaska Fairbanks) and University of Bremen have been updated through 7th September.

But my current opinion is the "Albedo Effect" is now the strongest influence for decrease. Be careful with these animation-images-pictures, for I'm exposing myself as Uncle Clarence used to say, "a pretty picture, but it's really for the less analytical mind."

Much happening south of latitude 80N. Except for the Canadian Archipelago, it seems everywhere else along the periphery and especially 75N to 80N at 165E to 180 the rotten ice from 2009, as in David Barber mentioned above, is disintegrating or disappearing. Maybe Neven will do us a topic on the "Disappearing Act at the Opera" before the Fat Lady Sings, then things continue and she will be called back for at least one encore.

If some visual is to your liking, how far will my "cone of uncertainty" extend, date wise, on the top chart - graph at
http://www.polk-nc.com/arctic-tenXten.html
hint me some "predicted" rates per day and end dates and I'll do a chart-graph with them. Why I don't know, but I like pictures.

[Neven]

Here's the updated University of Bremen animation. Great stuff, Jack!

[r w Langford]

Another great visual Jack. It is impressive to see the slope of the lines each september. All other years seem quite consistent in their slopes. This septembers slope is much steeper. The slope depends on the first and last data point though so the slope to the end of the season may be similar to other years. Solar energy is the major controlling factor in summer melt but at this time of year sea temperatures, currents, wind strength and wind direction determine the final outcome. It appears as if wind strength and direction has had a major influence this last ten days.I will be interested in seeing the final slope in your graph in about two weeks time if you use the same starting and end dates for each september.