NOTE: there are some animated GIF’s in this post that may take time to fully load. Patience please.
By Steve Goddard
Monday’s NSIDC Arctic ice extent graph took a turn downwards, and is now showing 2010 a little more than 500,000 km2 higher than 2007. The animation below shows the change from May 1 to May 2.
By contrast, NORSEX shows something very different for May 2. They have no downwards turn, their ice extent measurement is right at the 1979-2006 average, and they show 2010 extent more than 1,000,000 km2 above 2007.
In order to look at this closer up, I superimposed the NORSEX 2010 data (red) on the NSIDC 2010 data (blue) at the same scale, and normalised to 2010, and saw some interesting things. The first problem is that they started to diverge right around the first of April, and as of May 2 they disagree by nearly 500,000 km2.
The next image shows that the X-Y scaling is identical (but normalised) in the two graphs. The grid is from NORSEX. Other colors (besides red) have been removed through chroma keying.
The second discrepancy is that the two sources show a large difference in growth since 2007. The image below normalizes the 2007 data – with identical horizontal and vertical scales. Using this view, NORSEX shows twice as much ice growth as NSIDC since 2007.
The animation below begins normalised to 2010 and finishes normalized to 2007. This technique does not show that either source is in error or has changed their data, rather the animation is done by me to enhance visualization.What it does show is the significant differences between the two records.
I believe that both groups use SSMI so it is difficult to understand what the problem is. Last year we saw something similar. NORSEX has a history of making adjustments in mid-season, so my sense is that NSIDC is probably more accurate. Any ideas from readers?
Dropping. Like. A. Rock.
http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png
Nobody could have seen this coming.
The ice was completely recovered in April.
Just one of those things.
Natural variability.
Chaotic clouds.
This happens every 60 years or so. Maybe 80.
Sunspots are up.
El Nino, PDO, AO are all just right.
Huh.
thanks dbs. The image illustrates a 1 million sq km descrepancy between the monthly averages of NSIDC and JAXA AMSR-E.
R. Gates says:
May 5, 2010 at 10:54 am.
I’m struck by your comment about “The low sea ice volume (even the multi-year ice ice thinner than normal”. What is your source that the multi-year ice is thinner than normal? I don’t believe the new European satellite has been up long enough for such a statement and other measurements are mostly lacking. What is “normal” anyways? Even with the new satellite measurements that are hopefully forthcoming, there’s been a multi-year gap.
Phil, I see the response now. Thanks for the write-up…though I have a couple issues. First, you mentioned the NSIDC report from this month. It states:
“In February, the strongly negative phase of the Arctic Oscillation was associated with a strong Beaufort Gyre, enhancing ice motion from the western to the eastern Arctic. A weaker Transpolar Drift Stream also slowed the movement of ice from the Siberian coast of Russia across the Arctic basin, and reduced ice flow out of Fram Strait. The wind pattern changed in March, when the Arctic Oscillation went into a more neutral phase. As a result, the flow of ice sped up through Fram Strait and along the coast of Greenland.”
In the previous month’s statement, they said:
“the Arctic lost less ice the past two summers compared to 2007, and the strong negative Arctic Oscillation this winter prevented as much ice from moving out of the Arctic. The larger amount of multiyear ice could help more ice to survive the summer melt season.”
It sort of states the obvious when putting the two together….March had an increase of flow through Fram compared to earlier because of the AO rising to near neutral. But I’m not sure how that proves this melt will be any greater than last year or the year before when they had a much heavier flow of ice going out of the Fram straight during the cold season than this year did. Heavily -AO winters have tended to precede higher extent minimums.
Secondly, the other link is a computer model showing what the ice might do this summer. Its a nice illustration of what the ice looks like going out of the Fram Straight and its projected melting pattern, but I’m not sure I find much other use in it.
Thrasher says:
May 5, 2010 at 1:29 pm
Secondly, the other link is a computer model showing what the ice might do this summer. Its a nice illustration of what the ice looks like going out of the Fram Straight and its projected melting pattern, but I’m not sure I find much other use in it.
No comments on any of my post then?
The figure I was referring to was the 4th in Goddard’s post, it’s not a model result.
MikeP says:
May 5, 2010 at 1:20 pm
What is “normal” anyways? Even with the new satellite measurements that are hopefully forthcoming, there’s been a multi-year gap.
Multi-year gap ?
ICESat’s last laser failed on October 11, 2009, and they retired the satellite February 2010.
CryoSat-2 was launched April 8, 2010.
And “normal” is definitely > 0 in the summers.
Once it reaches 0 some summer, we’re way out of “normal” territory.
Anu
The wind compacted some ice in the Barents Sea this week. You can take a deep breath now, the Arctic is not melting down.
stevengoddard says:
May 5, 2010 at 2:12 pm
Anu
The wind compacted some ice in the Barents Sea this week.
I don’t think so.
http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png
stevengoddard says:
May 5, 2010 at 2:12 pm
OK, thanks.
I had been fooled by all the talk of the ice “recovering” in April.
I guess we’re just back to normal – “way below average”.
Although the Resident Doomsayer, I wish this Plunge was not occurring.
But 2007’s Big Ice-Melt had 3 Parts:
1. Warmth from an El Nino (April 2010 was still fading slower: ONI=1.2 cf 2007’s 0.1)
see: http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml
2 Wind pushing Ice out, and
3. less Clouds (see:
http://www.arm.gov/science/highlights/pdf/Roo143.pdf from Graeme L. Stephens at Colorado State University ).
Does anyone know if Cloudiness is declining, as in 2007’s 16% ?
does anyone have the actual data these graphs are based on?
We haven’t had an article (or I missed it) on NSIDC’s May Update, where they have to show April way above their trend line for the third year in a row. . . and strain for why a usually positive element (re the Beaufort Gyre) is actually going to be a negative element.
Tho I’m beginning to get a bit more concerned about 2011 than 2010. But then a 4 year unbroken trend is pretty rare anyway, in either direction.
@george E. Smith: “I believe the post said that “lots of depleted Uranium” had been blown up into the atmosphere.”
George, I did not say that exactly. However if you turn U3O8 (or UO2 or etc) into nanometre sized particles they can be suspended in the atmosphere quite well. What I wrote was it depends on the particle size. The finer the size the easier to suspend. Fire a pyrophoric depleted U projectile at something hard and you get lots of fine oxide particulates suspended in the atmosphere.
Search plutonium+ice for example. Plenty of hits. SG of Pu (19.8) is even higher than for U.
My point is that U in Antarctic ice can come from lots of possible sources. U238 as a hypothesis is a nice falsifiable hypothesis because it is easy to test with a mass spec, and is not necessarily less plausible than if the U came from mining activity.
Phil,
The 4th post in Goddard’s link you sent me is the multi-year ice being held into the Beaufort Sea…I’m not sure how that is proof that multi-year ice is being flushed out of the Fram Straight faster than any of the previous few years. I assumed you weren’t even talking about that image. That is older ice making its way back into areas that have had significant melt the last 3 seasons. That is actually an image that supports the idea that the heavily -AO of this past cold season has held in multi-year ice. The Beaufort Sea has been a hostile place for ice the past few years, and that image shows it might make a comeback this year.
Thrasher says:
May 5, 2010 at 10:00 pm
Phil,
The 4th post in Goddard’s link you sent me is the multi-year ice being held into the Beaufort Sea…I’m not sure how that is proof that multi-year ice is being flushed out of the Fram Straight faster than any of the previous few years. I assumed you weren’t even talking about that image. That is older ice making its way back into areas that have had significant melt the last 3 seasons. That is actually an image that supports the idea that the heavily -AO of this past cold season has held in multi-year ice. The Beaufort Sea has been a hostile place for ice the past few years, and that image shows it might make a comeback this year.
It’s actually broken up MY ice from the canadian coast where it’s been stuck for a few years. Like the major breakup of Beaufort sea MY ice in 2008 it will either melt there or be transported in the transpolar drift and out the Fram. You should try reading what I actually wrote rather than just guessing, communication works better that way.
Here it is try again:
http://wattsupwiththat.com/2010/05/04/500000-km2-discrepancy-between-nsidc-and-norsex/#comment-383841
Anu
This is average :
http://arctic-roos.org/observations/satellite-data/sea-ice/observation_images/ssmi1_ice_ext.png
This is about one std dev below average
http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png
i.e. statistically normal.
Neither is “way below average.” What did you study at MIT, anyway?
The sea ice volume data look very interesting to know.
http://psc.apl.washington.edu/ArcticSeaiceVolume/IceVolume.php
Yes part of it is a model, but they have had NASA ICESat satellite data from 2003 to 2007 mapped on it.
If the sea ice extent is “normal” compared to the 30 year or so average but the volume (ie: thickness) is less today, does it mean that the arctic is showing warming despite the extent being not that bad?
I was looking at the discovery channel last nigh and a NASA scientist was explaining how they use different kind of instruments aboard a plane to measure the volume of ice and according to their research, the loss of volume is still pointing to warming.
I think this is the information:
http://www.nasa.gov/centers/dryden/Features/G-III_uavsar_09.html
But again, is this related in any way to man-made CO2 or part of a natural cycle?
Simon Filiatrault
Ice volume is low in the Arctic because most of the thick multi-year ice blew out into the North Atlantic during 2007-2008, and melted.
NSIDC has explained this in their May Sea Ice News:
http://nsidc.org/arcticseaicenews/
stevengoddard says:
May 5, 2010 at 11:27 pm
Anu
This is average :
http://arctic-roos.org/observations/satellite-data/sea-ice/observation_images/ssmi1_ice_ext.png
But as I explained in my first post on this topic ArcticROOS data has been cr*p since their sensor problems last year.
stevengoddard says:
May 5, 2010 at 11:27 pm
This is “way below average”:
http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png
Now look at this chart:
http://nsidc.org/images/arcticseaicenews/20091005_Figure2.png
The 2009 arctic sea ice extent as July started was “far below average” (about two std devs). By mid September, the 2009 ice extent was “very far below average”.
Mid September 2008 sea ice extent was “far, far below average”.
Mid September 2007 sea ice extent was “incredibly below average”.
When it hits 3 million km^2, that will be “incredibly far below average”.
The summer that hits 2 million km^2 will be “dangerously below average”.
At 1 million km^2, we are “dangerously far below average”.
And when it hits 0 million km^2, that will be “completely below average”.
It’s important to speak precisely, Steven.
Or, just use numbers and graphics.
Nick says:
May 5, 2010 at 2:57 am
“NORSEX baseline is 1979-2006…NSIDC uses 1979-2000.”
Awfully short periods to compare what is normal – but if we try to compare apples with oranges, what does “normal” look like if we do NORSEX 1985-2006 to make each 21 years?
Also, normalization is not a panacea, and does have its own perils. For instance, the rate of melt is not linear with respect to ice thickness, but is higher order polynomial because of the tremendous heat capacity of ice. In other words, it takes a great deal more than three times the heat input to melt a three foot thick slab of ice than a one foot slab.
RE:
stevengoddard says:
May 5, 2010 at 2:12 pm
“Anu
The wind compacted some ice in the Barents Sea this week. You can take a deep breath now, the Arctic is not melting down.”
Well, that is a funny thing to say because the Barents is almost completely ice-free today…?
jakers,
The Barents Sea has about 350,000 sq km of ice cover. The winter max was around 750,000 sq km. I wouldn’t call that “almost completely ice free”.
OK, I’m looking at the Barents Sea on Arctic Terra (satellite image), Scandinavia north to Svalbard, over to Novaya Zemlya. Almost no ice. http://ice-map.appspot.com/
Even here, not much: http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.001.png