NOTE: This post has several images, including two animations. Those on slower connections, please be patient while they load.
This week, I suppose the best word to describe the status of Arctic sea ice would be “uncertainty”. I alluded to this uncertainty (due to weather) in Sea Ice News 22 saying:
While the vagaries of wind and weather can still produce an about-face, indications are that the 2010 Arctic sea ice melt season may have turned the corner, earlier than last year.
By all indications it certainly looked like we reached a minimum, the extent data went up for three days straight and NSIDC officially called the minimum on 9/15:
The Arctic sea ice cover appears to have reached its minimum extent for the year. It was the third-lowest extent recorded since satellites began measuring minimum sea ice extent in 1979. This year’s minimum extent fell below the 2009 minimum extent and above the minimum extents in 2008 and 2007.
Then defying even the experts, it started back down again.
The only thing that has gone down and stayed down this past week is Arctic temperature above 80°N as seen in this DMI plot:
The good news is that Arctic Ice extent has not gone below the 2008 value yet, and seems to be making a slight turn up again:
Here’s a zoomed view:
Here’s the most recent JAXA data, including the preliminary Sept 19th data, which will be updated again at 8AM PST Sept 20th.
09,01,2010,5332344 09,02,2010,5304219 09,03,2010,5245625 09,04,2010,5192188 09,05,2010,5136094 09,06,2010,5093281 09,07,2010,5027188 09,08,2010,4989375 09,09,2010,4972656 09,10,2010,4952813 09,11,2010,4986406 09,12,2010,5005000 09,13,2010,5008750 09,14,2010,4998594 09,15,2010,4948438 09,16,2010,4890938 09,17,2010,4842031 09,18,2010,4813594 09, 19,2010, 4822500
The US Navy Ice Thickness forecast plot shows that we still have a lot of 2 and 3 meter thick ice, but that it is mainly concentrated near Northern Canada and Greenland:
What I find most interesting though is the wind driven sea ice displacement plots. For example this one from the NAVY PIPS output:
The strongest vectors of the wind driven displacement are where the NAVY PIPS thickness plot show the greatest areas of thickness, Northern Canada near Ellesmere Island and Northern Greenland.
An overlay of the thickness and wind driven displacement vectors shows where the ice is being pushed to. The longest vectors show the greatest displacement in the direction of the arrow:
While the graphic overlay I made is not a perfect match, it is very close.
Since in the first temperature graphic from DMI, it is clear that average temperatures at 80°N and above are well below the freezing point of saltwater/seawater, which is approximately 271.15 kelvin (-2°C) See the line I’ve added below in magenta.
And that the majority of the remaining arctic ice is at 80°N or above in latitude, as seen in the PIPS map above and backed up by this map from UUIC/Cryosphere Today:
It suggests that like in 2007, wind is a more significant factor in sea ice depletion than from melting, especially this past week where the DMI temperature drop shows well below freezing point of sea ice temperature at 80°N and above.
WUWT regulars may recall I reported on this NASA JPL study that suggests winds may play a key role in pushing Arctic sea ice into lower latitudes where it melts. The author suggests winds may be the dominant factor in the 2007 record low ice extent:
Nghiem said the rapid decline in winter perennial ice the past two years was caused by unusual winds. “Unusual atmospheric conditions set up wind patterns that compressed the sea ice, loaded it into the Transpolar Drift Stream and then sped its flow out of the Arctic,” he said. When that sea ice reached lower latitudes, it rapidly melted in the warmer waters.
Interestingly we can now watch this actually happen thanks to an animation of AMSER-E satellite 89Ghz sounder images. Koji Shimada of JAMSTEC (Japan Agency for Marine-Earth Science and Technology ). See the animation below (note- size is 7.1 MB, this may take awhile to fully load):
If you want more detail, a full sized Video animation is available here as a flash video or here as an AVI file (highest quality 7.3 MB) A hat tip to WUWT commenter Bill and to Thomas Homer-Dixon for this video.
What is interesting about this video is that you can watch sea ice being flushed out of the Arctic sea and pushed along Greenland’s east coast, where it then finds its way into warmer waters and melts. Also note how in the lower right, in the Beaufort sea, older multiyear ice gets fractured and broken up as winds and currents stress it.
While indeed we can watch some of the Arctic sea “melt in place” during this animation in the fall of 2007, we can also see that winds and currents are a significant contributor to breaking up the sea ice and transporting it to warmer latitudes.
I’m hoping JAXA will produce a similar video for the 2010 melt season.
UPDATE: Ron de Haan reports in comments this finding below. He says “sea ice has grown”. It sure looks like thickness has increased, doesn’t it?
He notes this from Pierre Gosselin’s No Tricks Zone. Pierre writes:
But now take a look at the following chart that compares September 1 ice to September 18 ice. Which would you prefer to be standing on?
These charts are taken from: http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi
Which ice looks thicker?
Don’t sweat the ice area statistics. The thickness is much greater today, and we could even say the volume is likely more. Arctic temperatures above 80°N have been colder this summer and September. The ice area will rebound quickly, of course. I projected a 5.75 million sq km min. for 2011 a couple weeks back. I’m sticking to it.
Finally, WUWT readers may recall that earlier in the week, I caught NOAA saying that 2010 was the “second lowest extent on record” when it wasn’t, and with the help of Dr. Walt Meier of NSIDC got them to correct that blunder.
The screencap of the NOAA Environmental Visualization Laboratory also had another apparent error on it. Note the ice depicted withing the red “Average Extent 1979-2009” line below.
A number of WUWT readers pointed out that the presentation was biased and it appears that the ice edge was based on a 90% or greater extent, and not the 15% everyone else in the sea ice business uses. I fired off another letter to Walt Meier on the issue, but I never heard anything concrete back from him on the issue. But, it appears the message got through one way or another.
Now have a look at that web page today:
Notice anything different? Here’s the blink comparator of the before and after sea ice extent visualization image. NOTE: You may have to click on it if not blinking in your browser.
Looks like somebody at NOAA had to fess up to the fact that what they were presenting earlier in the week was grossly biased in the way it presented Arctic sea ice extent, making it look like there was far less ice than there actually is.
Again I ask, why is it us bloggers and members of the public are the ones that have to keep pointing these things out? Maybe we should be the ones getting compensated for our time.
To the credit of the NOAA Vizualation Lab, they fixed the problems we pointed out to them, and reasonably quickly. My thanks to Dr. Walt Meier of NSIDC for his help. Compare the response this week to that of Dr. Mike Mann with his still inverted Tiljander proxies and stations with messed up latitude and longitude that are still in his supplemental data years later, after numerous people have pointed it out.