By Steve Goddard
Last month, a number of well known web sites and commenters were getting themselves worked up with comments like “Arctic ice dropping at the fastest rate in history” and “Arctic ice is dropping like a rock.” I advised repeatedly that prior to July, looking at the extent graphs is pointless.
July is here now, and the rate of ice extent decline has dropped dramatically over the last week. To put this in perspective, according to JAXA data, the June 28-July 4 rate is -53361 km²/day. In 2007 during the same period, ice was lost at -123104 km²/day.
In other words, 2007 was losing ice 2.31X faster than 2010.
This can be seen most dramatically in the DMI graph, which measures only higher concentration ice (30%.)
http://ocean.dmi.dk/arctic/icecover.uk.php
Close up image below.
So why the dramatic difference in slope? One reason is that sea ice concentration is at the highest level in the satellite record. Compare below vs. 1980, when ice was considered very “healthy.” Current concentration is considerably higher.
Ice concentration is particularly important this time of year because the sun is relatively high in the sky. When the ice concentration is low, sun shines into the water in “Swiss Cheese” holes around the ice, warms it, and corrodes away the edges of the ice. This year, ice concentration has been close to 100% in most of the Arctic – which means very little sunlight is reaching the water in the Arctic Basin. As a result melt will occur more slowly than during low concentration years.
The videos below represent an exaggerated visualization of the process. The first video shows an idealized view of future Arctic Basin melt during 2010 – i.e. a single large circle of ice surrounded by water.
The next video shows what happens in years when the concentration is lower. The sun is heating the water between circles, and because of the smaller circles a much larger surface area of ice is exposed to warm water. Warmer water and more exposed surface area causes melt to proceed faster.
Conclusion : Cold temperatures, cloudy skies, favorable winds and high concentration ice – all point to continued slow melt over the next few days.
Bob Layson says:
July 6, 2010 at 2:13 am
Loss of ice coverage in the arctic may be fully explained by wind direction change, not the temperature of the air, and by the temperature of sea currents arriving at the polar surface waters -which can be higher or lower in temperature without the average global sea temperature having risen.
That’s why melt ponds don’t exist .. oh, they do.
As mentioned above, if it was only wind and sea temps it is strange how it’s always the summer that gets the maximum loss, when temperatures are highest. It’s 17C up in Resolute this week, does ice melt at 17C?
Andy
Leonard Weinstein
The ocean under the ice is stratified and undersea currents have little effect on the ice in the central Arctic. The amount of sunshine and temperature is the key factor. And jcrabb was correct, temperatures are limited by the melting ice in the summer.
NCEP is forecasting below normal temperatures for most of the Arctic over the next two weeks.
[youtube=http://www.youtube.com/watch?v=S2Yin6EQcFk]
Steve,
The problem with your analysis is we need an explanation for the long term trend. Things don’t just happen. At present the favored explanation is GHGs. Chylek recently published “Twentieth century bipolar seesaw of the Arctic and Antarctic surface air temperatures” which suggests 2/3 of Arctic warming might be due to the AMO (1/3 GHGs).
The AMO index is going to remain positive for many years yet, which means that the best non-GHG explanation for the recent Arctic warming is going to continue. It looks unlikely sea ice will return to anything close to 1979 for many years (if at all). With the AMO index possibly at a maximum now the question might be is it going to get much worse over the coming decade.
You may win a small victory this year but your present analysis risks the next year of bad weather in the Arctic will generate the headlines seen in 2007. You’re actually playing the same game the alarmists played in 2007, short-termism.
Cassandra King says:
July 5, 2010 at 11:08 pm
Our Mr Gates is painting himself into the mother of all corners at the moment, if the melt cycle does not comply with his obviously set beliefs then his reputation will be damaged beyond repair and that would be quite sad, I can predict that nobody will listen to him on this blog again. Much better to show doubt and hesitation and humility now than face ridicule later I think.
I don’t see you predicting that “nobody will listen to him on this blog again” if stevengoddard gets his prediction wrong. Why is that ? Isn’t WUWT supposed to be the “real” science blog, as opposed to the politically motivated, hoaxy science of professional climatologists employed by NASA and other institutions ?
“Real” science has to make “real” predictions, not just hand wave about how wind is so hard to predict…
Does this sound like “doubt and hesitation and humility” to you ?
http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png
“…if the melt cycle does not comply with his obviously set beliefs then his reputation will be damaged beyond repair”
Really ?
stevengoddard says:
July 6, 2010 at 4:59 am
Curious Yellow
People can quote me out of context all they want. (The same people who cherry picked the “fastest decline ever” and then scream about me cherry-picking.)
The important thing is what happens over the next eight weeks.
————————-
Comparing 6 days this year with 6 days in 2007 makes no sense, whichever way it is spun and remains what it is, cherry picking. Out of context? What context? Indeed, to the next 8 weeks, we are all subservient, but I take comfort from the fact that we are left with just speculation, wishful thinking if you like, nevertheless unable to influence.
Come mid September, the arctic will do its own talking.
By the way I wasn’t screaming, hardly ever raise my voice.
Curious Yellow
Comparing July from year to year makes perfect sense, because that is when the ice starts to shrink in the Arctic interior.
HR
I am not playing any game. I am just doing an analysis of what is happening in the Arctic this year, compared to previous years. I have no idea what will happen in future years and have never made any claims otherwise.
Leonard Weinstein
“The nearby open water, heated by absorbing sunlight, speeds up the process from the currents.”
Sir, one think’s you have nailled it, hence the prognostications of future decline, seems to me a pretty clear idea of ongoing decline, a ‘feedback’ if you will.
Once I get beyond the simple mechanisms of ice melting the ‘interesting’ rammifications come into play, my favorite Russian Scientist’s discoveries come into effect- Shakarova, her discoveries of Methane emissions from the East Siberian and Laptev seas take these discussions from the realm of the parlour to the sphere of extinction.
She proposes that the thin permafrost layer underneath the East Siberian and Laptev sea has sterted to become unstable, by that I mean simply it has cracked, leading to an increase in Methane release from subterranean resevoirs, formally contained by said barrier. She states there is a resevoir of 340 Gt of Methane ensconsed below the brine, of which 40 Gt is ready, willing and able to be released, ie gaseous, at a moments notice. Apparently a release of 40 Gt is quite sufficient to cause unfortunate effects on terrestrial beings, via a radical increase in the here-to-fore beneficiary Greenhouse effect.
L says:
July 5, 2010 at 11:36 pm
I really disagree with this statement. Although I don’t believe R. Gates’ predictions are correct, he is typically very courteous. I don’t believe he fits the definition of troll either, as he has been posting here for at least several months. He also made his prediction and has stuck with it. While I hope to see that his predictions are wrong, if they are right, then good for him. Whether he is correct or Steve is correct, one year’s ice extent really is not that important in the long run.
-Scott
@Leonard Weinstein saying:
Somehow that’s true, on the other hand the sun isn’t shining at Antarctica in July. That’s why satellites fail to make pictures proving your theory:
http://ice-map.appspot.com/?map=Ant&sat=aqa&lvl=5&lat=-61&lon=-41
There is more sea ice on the dark side and less ice on the sunny side and despite a higher albedo Earth absorbs more energy.
I like the idea of using crowd wisdom and betting on the future. Anybody ready to anticipate algae bloom at higher latitudes than 71° as happened last year?
http://ice-map.appspot.com/?map=Arc&sat=aqa&lvl=6&lat=71.212001&lon=35.456950&yir=2009&day=231
Hopefully in my lifetime there will be never any algae bloom at 90°.
HR says:
July 6, 2010 at 6:30 am
Steve,
The problem with your analysis is we need an explanation for the long term trend. Things don’t just happen. At present the favored explanation is GHGs.
Favored by whom?
How about contemplating these plots from the past?
http://wattsupwiththat.files.wordpress.com/2009/12/noaa_gisp2_icecore_anim_hi-def3.gif
Use your little gray cells too. This is the explanation nature has given us overhalf a million of years at least. CO2, one molecule in 150 is a trace gas has its appropriate contribution, not enough to melt anything . It certainly was not responsible for all the large changes recorded in the ice, and it certainly was not anthropogenic.
Anybody here ever stare at a can of frozen juice because the label said “concentrate?”
R Gates writes:
“Tom, have you ever heard of the Arctic Dipole Anomaly? This is a curious little positive feeback loop that’s developed in the Arctic over the past 10 years or so. Quite unpredicted by any of the GCM’s, just as chaos theory would say such “attractors” would be out there as changes are made in the composition of the atmosphere.
Anyway, the DA is a wind event, caused by warming, the in turn, causes more, warming, and so forth…”
Really your meteo skills are quite tainted by models, statistics and alarmism. Should you look at synoptic realities over the last 50 years, the picture is quite different and perfectly logical. But for this, you need to take off your AGW glasses…
noiv,
The positive Antarctic anomaly remains in the summer, and is at lower latitudes than Arctic ice, so it has much more impact on earth’s albedo that a September Arctic minimum – when the sun is very low in the sky.
“I’d imagine that this fact is well established in the scientific community. So the question would seem to be – what is causing this ice loss?”
Summer!
An excellent article on the difference between dynamic and thermodynamic causes of ice thickness. In my opinion, Gates, and the meat of most models, depends on an understanding of the thermodynamics of ice thickness, a rather stable entity relatively speaking and can be modeled. However, if too one-sided in model design, such a one note model runs the risk of underestimating volume.
Steven is asking us to consider the dynamic causes of ice thickness (the other half of ice volume consideration and damn hard to model). This is the variable elephant in the room and would likely require a super computer to model all the variations possible for predictive purposes.
It all comes down to which side of the fence you are on or are you sitting astraddle. If your model (or mind experiment) focuses on the thermodynamics of ice volume you will likely predict quite a melt. If you hold fast to the dynamics of ice volume you will likely predict not much melt. If you sit astraddle, you will likely be unimpressed with melting or recovery.
http://epic.awi.de/Publications/Haa2010a.pdf
For those that think R Gates should be sent away, I disagree. I find that his “skepticism” and counter discussion results in additional and clearer arguments for lay people like me from Steve Goddard and others. The exchange between them seems to be in the true spirit of scientific debate (with occasional equally spirited lapses) and I applaud Anthony for permitting it to take place on his blog.
vukcevic said
“July 6, 2010 at 1:28 am
Amino Acids in Meteorites
Thanks for the suggestion, worth considering for someone having required skill and knowledge, not to mention charisma. In my case would turn out into an unmitigated disaster. Old doc Svalgaard would delight in a new opportunity for a public ridicule.”
It’s a good idea to put stuff on You Tube etc but perhaps it needs to be presented by actors. I am willing to interview Elle Mcpherson for the job and see if she can wave the flag for us sceptics in a sincere and responsible manner.
Tonyb
Scott
I have also defended R Gates. He does not fit the definition of a troll and is invariably courteous. We need to debate with people who can put another point of view and show them the error of their ways.
tonyb
Anna
Nice graphs. Presumably it was a power point presentation but it goes much too fast for me and I can seee no way to go through each frame individually. Can you point me to the means to do that so I can examine each graph and keep as necessary?
tonyb
R. Gates has a few debating skills yet to learn (Gates, in scientific debate, don’t talk down to your opposition – bad form, that only works in political debate and then only in moderation) but I would not ever think of him as a troll.
Regarding talking down, here is an example. One of the more subtle ways of talking down to your opposition is giving them a “good job” comment. It is usually used to denote superiority upon the compliment giver, as in teacher to student. If one waits long enough, the compliment will likely become hollow as the speaker then delves into why the opposition is also all wet.
I thought it might be interesting to view the change in the sea ice extent (JAXA data) in a slightly different context.
stevengoddard says:
July 6, 2010 at 7:09 am
HR
I am just doing an analysis of what is happening in the Arctic this year, compared to previous years. I have no idea what will happen in future years and have never made any claims otherwise.
If you have no idea what will happen in future years, then you have no idea if Dr. Maslowski’s prediction of ice free Arctic summers by 2016 ± 3 years will be correct or not:
http://soa.arcus.org/sites/soa.arcus.org/files/sessions/1-1-advances-understanding-arctic-system-components/pdf/1-1-7-maslowski-wieslaw.pdf
It’s refreshing to hear such honesty from a “skeptic” – “I have no idea what will happen in future years.”
Maybe some scientists really do know something about what they have been working on for decades. Maybe the Arctic amplification, the thinning ice soon to be measured by Cryosat-2, and the Death Spiral really are taking place just as many scientists say.
I’m glad to see this new doubt and hesitation and humility in Steve. Hopefully it will inspire some of his readers.
Steve, it was mostly the Hudson Bay area that did this big drop in the past weeks, isn’t it? Northeast Canada had that warmer spot over it last winter.