By Steve Goddard
August 16, 2010 offered a great opportunity to put all the Arctic data together in a coherent picture. DMI showed a large drop in extent.
http://ocean.dmi.dk/arctic/icecover.uk.php
You can see the drop between August 15 and August 16 clearly in red in the modified NSIDC map below.
So what happened? Did 300,000 km2 of ice suddenly melt?
Not exactly. There were very strong winds pushing the ice in the Beaufort and Chukchi Seas towards the pole on August 15. This compacted the ice, reducing extent while increasing the average thickness.
You can see the August 15 movement of ice in Beaufort Sea in the satellite blink map below. Note how the ice edge is tightening up and compacting.
Will this continue? Probably not. The weather forecast calls for a return to colder and calmer weather in a couple of days. Look for the DMI graph to flatten out by the weekend.
Are there estimates for the average increase in depth for a given decrease in area?
Did Steve or Anthony write this? Either way, it looks like the Arctic’s ice will thicken for next summer, and see even more recovery.
“Look for the DMI graph to flatten out by the weekend.”
Steve accurately predicted the JAXA graph to level out, but can he accurately predict the DMI graph to level out? 😉
REPLY: Steve did, and I was remiss at not putting his author name on it, fixed. – Anthony
Check on the fires in Russia. May have sent up some heat. Russia forecasts a low of 42 degrees Saturday.
Snowlover,
The JAXA leveling prediction was a no-brainer based on the geometry of the ice. This time it is based on the weather forecast, which calls for cooler temperatures and shifted winds in the Chukchi and Beaufort Seas.
Which points to the need for an Arctic ice measurement based on Mass.
Sort of what ACE does for hurricanes.
Call it AIM
Accumulated Ice Mass.
Another 70,000sk decline to yesterday.
At the present rate it will reach Steve’s predicted 5,500,000 by the middle of next week.
noaaprogrammer,
You can see the increase in ice thickness over the last few days here:
https://spreadsheets.google.com/oimg?key=0AnKz9p_7fMvBdHlBZHVWa01OSGRHQ0d2S0ZnSTJCNVE&oid=3&zx=xa9xmg-59di0j
The arctic 2910-melting season is obviously coming to an end. Temps above 80 North are constantly sub-zero (Celsius, that is) already, while the gradient of the melting curve is substantially flatening recently, too.
It’s lowest point may still end up above the 2007-, 2008- and 2009-melts, making it the third melting season ending with a gain, when compared to it’s predecessor.
And last, but not least, some news from from the “Weather is not climate”-department: Here in Germany, the actual weather is more reminiscent of late October than of mid August for almost a week already. Precipitation all over Europe was tremendous during the past week.
By-and-large, we consider this Summer over.
Snowlover123
No matter what the final value of 2010 extent is, there will almost undoubtedly be an increase in MYI over the winter. At this point, the extent discussion is just a (highly entertaining) game.
Quite reassuring, thanks!
I have been wondering about thickness in relation to area; “yes there may be a comparable erea of ice but it is much thinner than it used to be, and so AGW is still an undisputed fact”.
To me it would seem, since a certain amount of arctic ice consists of seperate pieces, smaller or larger ‘ice cubes’ in a way (at least 15% etc), that area would decrease more or less hand in hand with thickness and vice versa.
Are there any coherent thoughts to be shared on this?
There’s no question I’ve been disappointed at what so far looks like a zero contribution of increased multi-year ice in reducing the August melt trend vs 2009.
Michael Schaefer says:
August 18, 2010 at 10:11 am
The arctic 2910-melting season is obviously coming to an end…
Damn!! That was really quick!
;^)
Steve I noticed NSIDC put up a new report yesterday afternoon:
http://nsidc.org/arcticseaicenews/
I was wondering if you’re analyzing it?
I love following the Arctic Ice news this time of year.
snowlover said:
“Steve accurately predicted the JAXA graph to level out…”
______
He did? When was this? I’ve not seen the JAXA graph level out yet this season.
I find it interesting to note that for AGW skeptics, when the ice extent is declining rapidly, it is never the temps, but all the “wind” but when it is slowly declining, it is always the DMI temps “declining rapidly”.
Here is the right ice map,
http://satellite.ehabich.info/arctic.htm
ice area is bigger than NOOA’s map
http://www.agu.org/journals/ABS/1991/91JC02334.shtml
In areas with greater amounts of nilas and young ice, we found that the NASA team algorithm underestimates ice concentrations by as much as 9%
Comparison of sea ice algorithms
http://arctic-roos.org/observations/comparison-of-algorithms
Sea Ice Area and Extent obtained from algorithms: Norsex, NASA Team, Bootstrap, ASI, Bristol, Swift, CalVal and TUD
Steve, before returning to my classroom (which is just round the corner, this Tuesday), I wanted to give you props for keeping this discussion going and putting it out there. It has been both entertaining and instructive, a feat not easily done during the slow Summer months. By the way, your picture comparison of the two days looking at the affect of wind was excellent. I have been beating the drum of ice compaction for what, two years now? Or has it been three. Hard to remember but I sure have enjoyed the thread. Again, thanks so much for you courage, time, and efforts.
Karen
Thanks for the heads up. Looks like NSIDC is saying pretty much the same thing I am. The one area of disagreement is North Pole temperatures. As I was discussing with Julienne yesterday, they use 925 mb (which is probably above the low clouds) and I use colder DMI 1000 mb numbers (below the low clouds.)
John W. says:
August 18, 2010 at 10:18 am
Michael Schaefer says:
August 18, 2010 at 10:11 am
The arctic 2910-melting season is obviously coming to an end…
Damn!! That was really quick!
;^)
——————————
D-u-h!
T-o-o–m-u-c-h–c-o-f-f-e-e–t-o-d-a-y!
😉
R. Gates
You congratulated me on July 1 for calling the “dropping like a rock” flattening – to the day. Remember?
Maybe this is OT.
Maybe not.
When the Northern Hemisphere was suffering massive coldwaves and frozen precipitation in December, January, and February, we were curtly and dismissively informed that “Weather is not climate”.
But now that it is hot in the summer, and there are various floods and droughts plaguing areas historically plagued with floods and drought, we are informed that this weather is climate!
That certain weather is climate while other weather does not count.
Eff this stuff already.
geo
Are you confusing melt with compaction? Loss of ice extent this time of year is primarily due to compaction.
Jimash
Hot weather is climate. Cold weather is weather. El Nino is climate. La Nina is weather.
Typical religion. They can always find facts which support their belief system, and ignore the ones which don’t.
Pamela,
Thanks. Much appreciated. My main goal is to provide tools and ways to think about these problems.
Science is for everybody, especially for children who have not lost their curiosity yet.
Just looked at the NSIDC August report.
Most of the year they’ve only been showing 2007 and 1979-2000 average for comparison. The August report shows 2008 and 2009 as well.
At the moment, it is relatively striking how the recent (last few weeks) trend is signficantly flatter (and more what I would have expected re my comment upstream) at NSIDC vs JAXA. I wonder why?
The problem with this typical WUWT Arctic thread is that a false claim is always introduced in that when the winds blow from the south it is always stated that it is all due to compacting of the ice.
However, winds from the south are warm winds at this time of year and so melt also occurs. If you look at 2007 and watch the decrease you can see most of the loss is due to melt not compaction until the end
http://www.zen141854.zen.co.uk/2007.wmv
If that was due to simply compacting ice then the PIPS model would have shown a massive increase in thickness due to the large loss in extent for that year, did it?
[img]http://www.zen141854.zen.co.uk/difference.jpg[/img]
No it did not. There is some thickening but niles away from where all the action was that year.
I know melt is dirty word for closed minds though …
Andy