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.
more here
Roy says:
August 3, 2011 at 9:14 am
Wind.
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Yep, isn’t this the time of the year when the winds calm down….
…then pick up again later
LoLs…. Perhaps you shoulda used nautical terms Anthony….. Avast ye scurvy dogs… Tis ta port I be sayin’ to ya’s…… Harrrrr….;-)
Smokey says “CO2 is well mixed in the global atmosphere, so it cannot be the cause of Arctic ice decline. Otherwise, Antarctic ice would be experiencing a similar decline.”
That is a non-scientific statement Smokey – these are distinct regions and behave differently.
The Antarctic is in some ways the precise opposite of the Arctic. The Arctic is an ocean basin surrounded by land, which means that the sea ice is corralled in the coldest, darkest part of the Northern Hemisphere. The Antarctic is land surrounded by ocean. Whereas Northern Hemisphere sea ice can extend to roughly 40 degrees north, Southern Hemisphere sea ice can extend to roughly 50 degrees south. Moreover, Antarctic sea ice does not extend southward to the pole; it can only fringe the continent.
http://earthobservatory.nasa.gov/Features/SeaIce/page4.php
Quite amusing, neverless, that Surreal Climate chose July 20th (just before the turn) to post an “arctic doom” item with a live updating JAXA plot.
http://www.realclimate.org/index.php/archives/2011/07/arctic-sea-ice-discussions/
Needless to say, comments have been sparse in the last few days.
Two weeks ago, sea ice extent was running over 250,000 sq km BELOW 2007. As of today it is over 300,000 sq km ABOVE, which only goes to show how darned unpredictable the whole shooting match can be, especially in the short-term.
Based on recent years melting between 2nd August and mid-September, a final figure close to 4.75m sq km looks most likely, but I am going to quote an uncertainty of +/- 0.5m sq km, so I don’t wind up wiping egg off my face (:-
(Anthony, I hate to point this out, but if the observed turn of the curve is said to be right by us, it will be claimed as left by the “scientists”.)
From my limited knowledge of physics, and what I observe, if the arctic makes the northern hemisphere cold, what makes the arctic cold? Loss of heat? Is it possible that the loss of heat (and subsequent cooling) of the arctic is underestimated by the models, and our observations aren’t sufficient to catch it?
No matter what, it’s a most interesting blip in the trend.
from the Rub-a-dub-dub, eight men in a tub polar rowboat team came this yesterday about the wind:
“Since OLD PULTENEY departed from Resolute, the support boats have been ever at hand. They’ve provided great company for the first leg of this ocean rowing journey. Fingers crossed they’ve got some great images to bring back to Resolute and share with you all. From now on thou, we are on are own. The support boats have turned around and are sailing back to Resolute.
“We don’t envy their trip home. We’ve been hammered by strong winds all day. It’s got up to 26 knots (31km/hour), which is mighty gusty. We’ve been pinned into the Bay, having made almost no progress since the morning. Similarly the support boats made it a few coves south, where they took shelter. A good decision too, as winds near Resolute are forecast to hit 70km/hour. Everyone’s using two anchors tonight.”
http://www.rowtothepole.com/
The most important question is clearly:
What does this mean for the Row to the Pole expedition?
/sarc
IJIS-JAXA recorded a -2.5 K melt yesterday which is extremely unusual. The ECMWF looks ideal for little melting in the future as well.
It’s great fun anyway you look at it. Over at Real Climate, they were wetting themselves over the prospect of a new summer minimum. And this turn (right or left) has spoiled all their fun.
BTW, early August in 2007 saw huge loses (on the order of 100,000k) every day.
dont care if it is left or right rotate the graph 45 degrees anti clockwise
it’s ahockey stick
Current odds at Intrade on there being more ice this year than in 2007: 86%. Overconfident? I think so.
https://www.intrade.com/v4/markets/contract/?contractId=744206
Why don’t we splice in some pine cone data to make the curve head downward in a more definite way?
Watching very short term changes in Artic sea ice is like zen buddist meditation. Or maybe not.
John
I am also seeing a left turn ;0)
As you say: “soupy”. Could be a setup for a crash, it’s still a ways to go to the belly of the curve.
I weep for all the drowning polar bears but rejoice that all the Arctic row boaters had a wonderful July of ice free exploring.
Driving in the UK is on the left hand side of the road. That is on the right side. If a driver should find himself on the right hand side, he would be on the wrong side. The reverse is true for the US.
Hopefully its gods way of stopping those loons from rowing to the magnetic pole, if only there was some way of telling them.
And Jim G, we in the UK drive on the correct side of the road, its the rest of you who got it wrong.
It is not possible for Anthony to see a LEFT turn ! 🙂
By the way, NSIDC report:
http://nsidc.org/arcticseaicenews/
“Arctic sea ice at record low for July”
http://nsidc.org/images/arcticseaicenews/20110803_Figure3.png
Bystander responded to my comment: “Is it time to panic yet?”
Obviously Bystander is in panic mode, while scientific skeptics know the natural variability of the Arctic is the null hypothesis, which has never been falsified. CO2 has nothing to do with Arctic sea ice, which is far below freezing. But everyone is entitled to their opinion, no matter how strange it is.
I have some questions.
Suppose you have a single piece of ice which has a surface area of one sqare mile, and then suppose, without melting, it fractures into many small pieces, which spread out until they cover an area of five square miles. If you add up the surface area of the many small pieces, the sum remains one square mile.
My questions are:
How would the above change change the area graph?
How would the above change change the extent graph?
One last question that often comes up.
Can the satellite tell the difference between open water and a large, deep puddle on the surface of the ice?
I am seeing an upturn.
Smokey says:
August 3, 2011 at 9:21 am
“Looks like its turning upward.”
No! It’s a new ice age! It’s now everyone’s duty to generate as much CO2 as possible in order avert this disaster!! (I’ll do my part by increasing my running mileage this week ;^).
/sarc-iceage
Warm,
Why are you linking to July? That’s old news. This article is updated to August.
Anyway, the Arctic is just experiencing regional variability. There’s nothing to panic about. It’s happened many times before, and it will naturally happen again.