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.
stevengoddard says:
August 18, 2010 at 2:56 pm
George E. Smith
The reason I think that the ice is piling up is because PIPS shows a higher average thickness than it did a week ago.
Steve,
Keep in mind PIPS showing a higher average does not necessarily imply ice pileup.
Examples:
Thicknesses A: 1, 2, 1, 2, 1, 1,4, 10, 10, 9
Average A: 4.01
Assuming uniform loss of 1:
Thicknesses B: 1, 1, 3, 9, 9, 8
Average B: 5.2
So you can see the average ‘thickness’ has gone up, while the total amount of ‘ice’ has declined.
Anu says:
August 18, 2010 at 11:24 pm
Yet this seems to be the way science works in our generation. True for several fields, and especially true for global warming research. Remember that evidence of global warming is not evidence for global warming, because of the above statement you make. With that statement in place, how many papers out there actually show that global warming is due to manmade CO2 and not due to other factors?
-Scott
Akira Shirakawa says:
August 18, 2010 at 11:13 am.
Akira, having spent quite a few years outdoors in the winter above the arctic circle, my observation is that the pond is frozen solid. What you see in the pictures is rather strong winds shifting the snow around. You may also notice that the wind blows the snow onto the lens at times. No melt going on there.
Looking at the pictures, I am glad I am indoors with a hot coffe rather than next to that camera 😉
cclarke says:
August 18, 2010 at 9:03 pm
Here’s a nice clear picture of part of the NWP today:
http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r04c02.2010230.terra
Indeed and the outflow from the Byams channel is very clear.
Great blink comparator, really shows the process – very similar to sand bank / coastal sand drift, which you can see on low long coasts (I’m thinking east anglia UK which is constantly on the move).
Thanks for this clarification, Steve Goddard. I was wondering, and surprised, about this sudden drop in extend.
“Dropping like a rock” Anu reappears to try to rewrite his own history.
JAXA and DMi have both taken a turn to the right. So one could ask is the leveling happening?
How many of us ever thought they’d pay this much attention the the wind in the Arctic?
I see that despite my previous strictures Anu continues to demonstrate a complete lack of manners in his writings here.
No matter who is right or wrong there is no need to display such appaling rudeness. It is hard to believe that he attended any university, but if he did I am sure it would be ashamed to own him.
stevengoddard says:
August 18, 2010 at 11:04 pm
If the winds keep blowing, it will go below 5.5.
——
Oh those sneaky sneaky winds. Odd that they started showing up in 2007.
Who would have guessed that Zephyrus was an AGW supporter?
For one, I’m glad that in dmi Mr Goddard has recently found a reliable provider of climatic data.
That data will I hope more than compensate for the unfortunate & continuing off-line status of the Cryosphere Today SSM/I small scale comparison maps.
I downloaded the data from IARC-JAXA, and the difference between august 15th and 16th is nowhere near 300000 sq. km. In fact, a 300000 sq. km lost would really be a record melting day.
The lost from the previous day on (for the Arctic in sq. km) :
aug. 14th has been 63281
aug. 15th has been 39688
aug. 16th has been 72500
aug. 17th has been 79687
I don’t understand how you managed to end up with 300000sq. km for one single day – or there’s an error in the graph you are looking at. Again that is based on the data from JAXA.
You explained about the contraction/compaction caused by the wind. That is true all year long, but it is more noticeable at this time of the year where there’s more open sea available for the ice chunks to move around – still it is the same thing every year, so yes it does explain why we see spikes both lows and highs, but that’s normal behavior.
Previous comments said the melt will be ending early this year. Currently there’s no sign showing an early end of the melt season. The downslope of the temps is about the average, the melting rate is also about the average (if i compare to the last 10 years). Even with temps below the freezing point, the ice pack will continue to move around and loose chunks (escaping out the cooler areas) – that is not a sign of an early end of melting.
There’s still more/less about a month of melting to go and it’ll all depends on local weather (clouds, wind, sun, temps). We’ll see then (only then) when it actually ended and what was the lowest count.
‘“Dropping like a rock” Anu reappears to try to rewrite his own history.’
Btw, Anu is a common female name in Finnish. Could be a god as well, and supposedly all Babylonian gods are fierce by their nature.
Anu says:
August 18, 2010 at 11:24 pm
“I have many other citations, but I suspect even a 4 page paper is too much to ask of most of “your readers”.
GFY
Regg_upnorth
The drop was shown in the DMI graph
Virveli says:
August 19, 2010 at 8:32 am
‘“Dropping like a rock” Anu reappears to try to rewrite his own history.’
Btw, Anu is a common female name in Finnish. Could be a god as well, and supposedly all Babylonian gods are fierce by their nature.
Here’s a bit of a clue – its not British and its probably female:
Anu says:
August 18, 2010 at 11:24 pm
p.s. Did England do poorly at the World Cup this summer because of The Wind ? Seems to be trouble for you blokes…
Updated JAXA 08/18 number is in and daily loss was only 33125 km^2. This may just be an anomaly (honestly, likely is), but people can hope it’s a sign of a slowdown. With that number, current extent is predicting a minimum extent of 4.99e6 km^2.
We’re now 32500 km^2 higher than 2008, so it will indeed require a record loss (in JAXA dataset) from here until the minimum to go below 2008’s value.
-Scott
On a slightly different track, I’ve noticed that there isn’t a lot of NW Passage talk in the MSM this year.
YFNWG says:
August 19, 2010 at 10:34 am
On a slightly different track, I’ve noticed that there isn’t a lot of NW Passage talk in the MSM this year.
It’s not news anymore now it opens every summer.
Scott said
We’re now 32500 km^2 higher than 2008, so it will indeed require a record loss (in JAXA dataset) from here until the minimum to go below 2008′s value.
Well not really. 32500km^2 ”catch up” can be achieved in a single day (and lost again the other) with the way the ice extent is calculated and ice pack movements – and it’s quite easy if you look at it on a daily basis as you got days where you can have up to 100000km^2 lost this year when it was 30000km^2 on that same day from a previous year. And the same goes the other way as well of course.
StevenGoddard said :
The drop was shown in the DMI graph
Obviously that was a ”typo” in the plot – 300000km^2 is quite a number to reach for a single day, even more at this time of the year. lol.
In fact, the largest lost of ice recorded for a single day i could find on AJAX, is 201875km^2 on july 3rd 2007, and the largest gain in ice has been 266094km^2 on october 13th 2006 .
The past days DMI also showed a sudden rise of Mean Temperature above 80°N. Could this, at least partly, be connected to the large drop in extent?
Martian
The same southerly winds which compacted the ice also blew warmer air to the pole.
GFY
QED
On a slightly different track, I’ve noticed that there isn’t a lot of NW Passage talk in the MSM this year.
The Norwegian adventurers in the Trimaran have made it through the last band of ice blocking the Northern Sea Route and are already making progress towards the Northwest Passage, which is very clear of ice (especially for this time of the year).
There’s a very good chance they will be the first in recorded history to circumnavigate the Arctic in one single season. Quite a feat, I’d say. The only thing potentially thwarting them – besides a bout of extreme bad luck of course – is all that multi-year ice that is being pushed through the Queen Elizabeth Islands and might reach and block the NWP before melting out.
There’s quite a bit of transport there, as is shown by the buoy map of the University of Washington. Look at those two fellers speeding throught the Prince Gustaf Adolf Sea since about 10 days ago.
All the ridges blocking the multi-year ice have broken up and ice floes are flowing in. Counter-intuitively, his is good news for people who don’t want AGW to be true, as there is a good chance this multi-year ice will block the NWP in years to come. A pretty welcome argument I would think after all those times it has opened up in the past 5 years.
Amazing what you can do with ice breakers in front of you, satellites, phones, planes helicopters, a climate controlled cabin and GPS navigation. Just like the Vikings.
Günther,
The Northwest Passage has been open repeatedly in the past. Great article. See especially the Conclusion.
[BTW, your last name translates as “cherry-tree,” doesn’t it?☺]