Over the past few days, Arctic sea ice extent has braked dramatically in the daily loss rate and now has made a sharp right turn, which is rather unusual. Here’s the JAXA extent:
And here is a close up view, note the 2011 red line:
That turn is unique to the record since 2002. Note that in 2007, there was also a turn, though brief, and then melt accelerated.
It is also showing up in the NSIDC plot:
But what is really most interesting is the plot from DMI, which show not only a turn, but a reversal:
What does this mean? The short answer is, probably nothing. When we approach the minimum, and the ice pack becomes more fractured and scattered, it also becomes more susceptible to the vagaries of local and regional wind and weather.
WUWT regular and contributor “Just the facts” suggested in comments that:
One factor appears to be the Greenland Sea, where sea ice began to grow on July 15th and has been trending above average since then.
Source: ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/plots/r07_Greenland_Sea_ts.png
On the other hand, looking at the most recent comparison with 2007, the Arctic ice cover looks a bit more soupy in 2011:
Air temperature is above freezing throughout the Arctic….
…as is fairly normal for this time of year:
Clearly, at present, air temperature in the Arctic is not in any way climatologically abnormal, so the reasons for the current extent being low and making erratic turns must lie elsewhere. Wind, soot deposition/albedo, ocean currents, etc. all factor in.
So, while we may have temporarily avoided a new record minimum (as many in the “Serreze death spiral” camp said we are headed to) there’s still the possibility that the plots will turn to the left again, and resume or even accelerate. It all depends on the weather, and the outcome could go either way at this point. Historically, we have about 7 more weeks before the turn upwards as the Arctic begins the slow re-freeze.
Still, it makes for interesting observation and discussion. The WUWT sea ice page has all the latest stats, updated as soon as they are made available.
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UPDATE: Bill Illis runs his own database, and offers this interesting view in comments.
The last 21 days are the lowest melt since 1973 in my database over the same period. The total ice extent is still well-below average but there are very few periods in the record where the trend is so different than normal for an extended period of time like the current period is.
Matching up a few different datasets back to 1972.
UPDATE2: In the meantime, while extent loss slows, the NSIDC “death spiral team” tries to make a case for a record low average for July, while at the same time admitting that On July 31, 2011 Arctic sea ice extent was 6.79 million square kilometers (2.62 million square miles). This was slightly higher than the previous record low for the same day of the year, set in 2007.
Arctic sea ice at record low for July
Arctic sea ice extent averaged for July 2011 reached the lowest level for the month in the 1979 to 2011 satellite record, even though the pace of ice loss slowed substantially during the last two weeks of July. Shipping routes in the Arctic have less ice than usual for this time of year, and new data indicate that more of the Arctic’s store of its oldest ice disappeared.
Figure 1. Arctic sea ice extent for July 2011 was 7.92 million square kilometers (3.06 million square miles). The magenta line shows the 1979 to 2000 median extent for that month. The black cross indicates the geographic North Pole. Sea Ice Index data. About the data.
—Credit: National Snow and Ice Data CenterHigh-resolution image
Overview of conditions
Average ice extent for July 2011 was 7.92 million square kilometers (3.06 million square miles). This is 210,000 square kilometers (81,000 square miles) below the previous record low for the month, set in July 2007, and 2.18 million square kilometers (842,000 square miles) below the average for 1979 to 2000.
On July 31, 2011 Arctic sea ice extent was 6.79 million square kilometers (2.62 million square miles). This was slightly higher than the previous record low for the same day of the year, set in 2007. Sea ice coverage remained below normal everywhere except the East Greenland Sea.
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“http://nsidc.org/arcticseaicenews/ . . . “Arctic sea ice at record low for July”
Simplified English translation
“The sky is falling, the sky is falling”
– provide at no charge of course.
Arctic sea ice mostly melts from the bottom up. The ice can lose half its thickness but you won’t be able to tell just by standing on the surface (you have to drill a hole).
I’m a big AGW skeptic, and I hope it really is turning and I bet on that a couple of months back, but I’m guessing that this blip is noise. Everybody calm down.
So we now have Death Spirals that trend upward and outward. This is most certainly unprecedented.
Sorry warmistas no one believes anything you say or do anymore well at least 70% especially if you happen to be a “climate Scientist” ice is not melting abnormally and has not been previously or in the future get a life….
http://www.rasmussenreports.com/public_content/politics/current_events/environment_energy/69_say_it_s_likely_scientists_have_falsified_global_warming_research
Ah yes. Ye olde right-the-right-side-of-the-wrong-road controversy.
Lettuce remind all reader (and a few writers) that the Brit’s are right in being properly left out of the road controversy. (Unless one is discussing the good drovers of AuZ or NZ or SA or the Falklands Isles. Robert notes that British influence down under must be a function of gravity … since the southernmost parts of every continent seem to attracts the UK’s left-over-road drivers. (Which brings up the side-of-road issues for the northern end of Antarctica, but that is a whole ‘nother subject.))
Down under, on the wrong side of the equator, as they cling desperately to the ground lest they be fling centripetally into the hopeless obscurity of higher latitudes, we who are attracted to the center of earth’s well-being should take a moment to pause and reflect on their difficulties. They are not only trying to drive on the wrong side of the road (when viewed from the opposite direction at least) but doing so while upside down. Yes, gravity is a mean beast, it is so self-centered. Note too that the wrong side of the road controversy seems least critical on the few metalled roads of the Falklands, where internet driving recommendations all stress more the need to stay in the middle of few roads are present, rather than emphasizing which side of the road one can drive.
More to the point of the graph, if the view is from the direction of the progress of the line, then one would have to conclude that the line is curving left and Anthony’s critics are dead right!
commieBob,
Correctomundo. It’s not due to CO2, it’s due to H2O.
Blame the Tea party for a sharp shift to the right
Here is a headline from Bloomberg/energy news this morning:
“Arctic Ice Melt Near Record Clears Ship Route to Asia, Russian Agency Says”
Link Here:
http://www.bloomberg.com/news/2011-08-03/arctic-ice-melt-at-near-record-clears-shipping-route-to-asia-russia-says.html
Looks like Pulteney on the rocks.
It’s called DIVERGENCE. When the ice is concentration is low in a wide area (or “soupy” as Anthony called it), and the winds and currents are right, the ice can spread out or diverge, causing these very sudden and radical turns in extent. In fact, considering that temperatures have not been extremely cold, the only physical explanation for this sudden turn is divergence. Right now, the only direction for the ice to diverge is pretty much in to open warmer waters futher south. We’ve been seeing a lot of open water early in the season and had record warmth these areas, such as the Beaufort sea. As the ice diverges into these areas, it will melt. Expect an equally sudden turn downward in extent in the next week or so, and it could be especially sharp if high pressure, a stronlgy negative AO, or a stronger dipole anamoly sets up.
BTW, this entire discussion watching of sea ice extent (and area) is interesting, and can give us a rough metric (and sometimes very rough) of how the sea ice is doing, but by far the best metric is one that measures total volume. And since we are still using models for this (though with CryoSat 2 it’s getting better). We still need an accurate guage of long-term trends in sea ice volume.
“Warm,
Why are you linking to July? That’s old news. […]”
???
[b]August 3, 2011[/b]
Arctic sea ice at record low for July
http://nsidc.org/arcticseaicenews/
Smokey says CO2 has nothing to do with Arctic sea ice”
This is another non-scientific statement Smokey – the make-up of the atmosphere clearly impacts climate. It is impossible for there not to be an impact – the question is now much as the composition of the atmosphere changes.
In order to understand the ups and downs of the Arctic sea ice numbers you need to understand that depending on the site they do not count any areas that have less than 15% or 30% ice coverage. What also needs to be understood is that the sea ice can be blown about by the wind. This ignoring of ice that does not meet the 15%. 30% criterion means that with a little wind concentrating the ice, it looks like more sea ice has formed,or in reverse it looks like the sea ice has melted.
The swing upwards is more about the wind moving ice around and being counted than more ice forming.
kent
As I understand it [or not!] Ice extent is determined by :
[1] Wind blowing ice in to the Atlantic and Pacific
[2] Solar heating, directly and indirectly
[3] ‘Global Warming’ via melting by heat from the atmosphere.
Has anyone done a guesstimate of how much additional ice could be melted by global warming based on thermodynamic principles?
For example, if you have cubic metre of ice at -1C in a perfectly insulated container, how many cubic metres of air at +2C would be required to melt the ice? Air temperature varies with height so the amount of air above freezing will be limited. Calculate the amount of air available above freezing in the Arctic and work out how many cubic metres of ice could be melted.
This is where the problems start. All the air would now be at freezing point and would need an external energy source before more ice could be melted. The wind could blow in warmer air from elsewhere, but would cause cooling in the source area. However I would have thought that the most likely source of heat would be the sea water heated by the sun, with the wind transfering the heat to the ice, so would be part of the solar heating input, not ‘global warming’. Air is a poor store of heat so I am dubious as to how much effect it could actually have.
Thinking about it, solar heating seems complicated. As the albedo of ice is so much greater than water I would have thought the melting by the sun would be slow until fractures appear. At this point the water will absorb a larger amount of heat and accelerate melting at the fracture points. As the gaps grow wider then the wind would, as mentioned, transfer heat from the water to the ice.
Hopefully you get the jist. Can anyone quantify this?!
It will be interesting to see if google news tries to suppress this story extremely damaging to the whole AGW. This one may actually stop it in its track lets see
http://www.rasmussenreports.com/public_content/politics/current_events/environment_energy/69_say_it_s_likely_scientists_have_falsified_global_warming_research
So far there is no news in Google…
I would surmise that telekinetic effect of a lot of people all concentrating to steer it to the left is at least as influential as CO2 steering it to the right.
I’ve been looking at it for the last few days – and I also noticed that the temp plot wasn’t showing as many (none actually!) spikes through the summer so far….compared to what I remember from last year…
Looks like the start of another hockey stick.
Bunch o’ comics on this thread… i love WUWT.
Bystander, let me put it in the form of a hypothesis: CO2 is not causing the decline in Arctic sea ice. Do your best to falsify that statement. Models do not apply; models are tools, they are not evidence. Provide empirical, testable evidence, according to the scientific method, showing that it is CO2 causing the decline. That would falsify my hypothesis.
Contrary to your assumption, that is scientific. The ball is in your court. Falsify my hypothesis – if you can – or admit that you can’t. And don’t forget to provide testable evidence. Without empirical evidence, all you have is a conjecture; a baseless opinion.
Right turn? Left turn? Right turn? Wrong turn? I suppose it depends on whether you’ve got your radar configured “north up” or “head up”.
A commenter – I think it was on this blog – observed that this “wiggle watching” was “like watching TV through a microscope”. I like that well enough to repeat it even though I can’t credit it properly. Good one, whoever said it!
A turn towards “more ice” or “towards Ice Age” is great if we just want the warmists to be wrong. For human wellbeing, a turn “away from Ice Age” might be better.
If the Arctic became ice-free, and I didn’t “read about it in the paper”, how would I know it had happened? What dire effect would I notice first?
See you in September!
Best,
Frank
With the greatest respect, Anthony – and nobody has more respect for you than I have – I think your “But if complaining about left/right is the best commentary you can muster, save it.” remark is a little harsh. I don’t think it was a complaint. I think it was a “really wanting to know” comment, which I too was about to make, until I was beaten to it. I’m sorry if this too causes you to be angry with us, but some of us are mere mortals, and I think we are entitled to ask about something which confuses us. Just my point of view – no offence intended. 🙂
anticlimactic: The energy to melt the ice comes from the sea, not the atmosphere. The atmosphere can be well below freezing and the ice will still get thinner. In fact, the ice is making the air warmer not vice versa. For the 1052nd time, arctic sea ice melts from the bottom up.
We keep thinking of 2007 as the death-bed of Arctic ice extent. I wonder what the minimum was over the past 150 years? Being 300,000 over the 2007 level isn’t reassuring if one believes 2007 really was a “bad” year for Arctic ice (unprecedented).
@R Gates. If ice volume is the important metric and if Arctic ice really is the canary in the coal mine of global warming and we (the world) can’t be bothered to measure Arctic ice volume, well doesn’t that say a lot about our real perception of the urgency of this “problem”?