Guest post by Steven Goddard
NSIDC Arctic Ice Extent Just a few pixels from “average”.
May 1st is May Day . “Mayday” is a universally understood distress call signifying that an aircraft or other vessel is headed on a collision trajectory. 2009 Arctic ice extent is on a collision trajectory with normal, which could be disastrous for AGW alarmists. “May Day” is an international holiday celebrated on May 1. In the Soviet Union it celebrated the worker’s “liberation” from capitalism, though they hadn’t yet thought up “cap and trade” at that time.
I have more news to report about the ongoing mystery of why NSIDC shows Arctic ice extent much closer to the 1979-2000 average than NANSEN is to the 1979-2007 average. It should be the other way around.
Dr. Walt Meier at NSIDC has again graciously responded to further questions:
Dr. Meier:
It is possible that there could be inconsistency in the Nansen data. I’m not familiar with their processing. I am confident that our dataset is consistent. However, it may simply be due to the ice conditions. Most of the time, the differences between algorithm should be an offset – though this offset can vary over the course of the year (particularly summer vs. winter). However, there can inconsistencies in this depending on the character of the ice cover.
My suspicion is that much of this is due to the Bering. The ice in the Bering is very broken up and, basically, on its last legs. It could be that our algorithm is more sensitive in picking up the ice than the Nansen algorithm. Or it could be that our algorithm is overly sensitive and is not catching open water.
Remember that the threshold for ice extent is 15%. So if you have low concentration ice, even small differences in the algorithms can result in relatively large differences in extent. If Nansen consistently shows 5% less ice that NSIDC, when there is 90% ice, that makes no difference, but where there is ~15% ice, it can make a difference. From other imagery, it looks like there is a lot of area with concentrations in the ballbpark of 15%.
Me:
If it were due to Bering Strait ice, I would expect to see a convergence between the two data sets as the Bering ice melts. It looks to me like they are actually diverging over the last week or two though?
Any ideas from the readers?
UPDATE: Dr. Meier just responded, minutes after posting this article:
Dr. Meier:
It is the Bering Sea, not the Strait and as it begins to melt, with all the old, broken up, sparse ice, you see the divergence. As it melts out completely, I expect that we’ll see things go back to being more consistent.
Addendum from Anthony:
A question to Dr. Meier: When are we going to see a date/time stamp on the NSIDC imagery? NANSEN has one.
This NSIDC graphic above is one of the most widely displayed and quoted on the net today, yet it lacks this most basic feature found in many scientific images presented for public consumption.
I realize the curve itself is marked against the x axis, but it is not easy to determine an exact date. Science is exacting, it would seem prudent to add a date/time stamp. Otherwise, the appearance of exacting science presented to the public is one of sloppiness, IMHO.
The first question I always ask when reading that two people have produced different results from measuring / analysing the same thing is: “are they actually measuring / analysing the same thing?” Do these two organisations actually deal with exactly the same geographical area?
From Bela’s link:
“The most recent Intergovernmental Panel on Climate Change assessment, completed in 2001, predicted the Antarctic ice sheet would gain mass in the 21st century due to increased precipitation in a warming climate. But the new study signals a reduction in the continent’s total ice mass, with the bulk of loss occurring in the West Antarctic ice sheet, said Velicogna.”
So, from that would one not conclude that the climate must be cooling? They can spin stuff anyway they want it seems.
They can spin all they want, as long as they don’t land on Bankrupt or Lose-a-turn. At this rate, though, they will run out of vowels to buy.
Somebody else is ready to solve the puzzle, and they still don’t have a clue.
You don’t suppose all the Antarctic Ice Shelf melting got refrozen on the other side of the world, do you?
Darn sea levels are stuck.
Aunt Artica giveth, Uncle Artic taketh away.
I think the gist is with the satellites measuring mass (ice mass), the data says it’s decreasing. I am not getting much response here. Not sure why.
Bela
Jim Cripwell (09:13:18) sed :
“Please. The call for distress is not Mayday but M’Aide (with an acute accent of the e.”
WHG sed: tomato, tomahto
And the Antarctic corming goes on…
“deadwood (09:06:44) said::
Any bets on how long before they “adjust”?”
Deadwood,
My money is on late Friday (May 8) afternoon!
Robert Wood (16:31:25) :
As to the Polar/Equatorial motion of the jet streams, I recall somewhere reading a theory of Moon orbital variation dragging the high pressure bands along with it. It had a 27 year period, if I recall correctly.
Can someone inform my poor memory?
I believe you’re referring to the e-book:
GlobalWarming – Global Cooling
Natural Cause Found
which can be freely downloaded at:
http://www.globalweathercycles.com/index.html
Flanagan (10:55:11) :
I do not see the point either. So, MAYBE the arctic will come back to its normal extent for a few days in the last 10 years? And are you actually going to make titles with that? This is called in here “l’énergie du désespoir”. For those who understand…
If I were you, I would wait for the summer minimum.
Perhaps you should also wait until the summer minimum to characterize the current condition as “a few days in the last 10 years”. 🙂
I do agree that we will not know the full story until the end of September. However, the trend is definitely towards more ice at the same time that CO2 is just going up and up. That weather is sure fickle.
–Mike Ramsey
Bela (19:54:19) :
Thanks for the link, that study is showing a decrease on the west antarctic peninsular, which may be born of ocean currents more than atmospheric temperatures.
http://tinyurl.com/dnzlok its not a new thing. Long before we had anything to do it.
The increase in sea ice may also be showing a shift in currents.
Robert Wood (15:43:06) :
Jim Cripwell @09:13:18
It’s M’aidez!! The imperative, old man, the imperative!
Robert, if you think “M’aidez” is the imperative, what do you suppose “Aidez-moi” is?
Vernon, Squidly, and gary gulrud — Thanks for the explanation! I misread the graph (accustomed to seeing moving averages on graphs).
Radar expresses my question better than I did (i.e., correctly). The baseline period includes the trend, which gives a poor basis for comparison. Comparing the current datapoint vs. a long moving average (e.g., 5 years) would show the trend far better than using a fixed average.
The historical trend is clearly seen in the graph of Average March extent since 1979. One outlier in this noisy data might not indicate a break in the down trend. Take the graph, draw the March average of aprox 15.5. The March 2009 was almost at the average (15.2 roughly), but still showing a downward trend. If the march 2009 dot was at the average, the trend would still be clearly down.
http://nsidc.org/images/arcticseaicenews/20090406_Figure3.png
Steve Goddard: “The Stock Market has been declining for 30 years, and is currently at the 30 year mean.”
If the base period is part of the trend, this is perfectly consistent with a falling market. Which is why technical analysts (using price patterns to predict future prices) use moving averages (or more sophisticated methods, like relative strength or stocastics), not fixed averages.
CodeTech: “Actually, Fabius has demonstrated a truly unique way of reading graphs. Apparently this is the “new” AGW method.”
I recommend not jumping to conclusions, nor copying the clubhouse antics of RealClimate. I have written 55 articles, on this topic — all skeptical about AGW.
I asked a question, got a correction, then someone re-stated the issue more clearly. Which is why this is such a great site, and far superior to RealClimate.
George E. Smith (10:47:00) :
🙂 🙂 🙂
Got this pic from ICECAP, of a “NASA Observatory” image that seems to show some Arctic ice detail, and compared it to Cryosphere. Anyone see a clear discrepancy?
http://www.examiner.com/x-1586-Baltimore-Weather-Examiner~y2009m4d29-NASAs-Earth-Observatory-10th-anniversary-top-10-images
-see the 4th picture in the slide show
compare with
http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=09&fd=11&fy=2005&sm=09&sd=11&sy=2005
actually it’s m’aidez, it derives from french which means: help me.
As english speakers don’t speak french to well its become garbled.
The increase in sea ice may also be showing a shift in currents.
A little sign of a solid ice condition in the arctic:
First take a look at the NSIDC arctic situation:
http://nsidc.org/data/seaice_index/images/daily_images/N_daily_extent_hires.png
In general we are close to normal. And there is a little thing that will support the arctic anomaly curves for a while more at least.
The Okhotsk sea, east of Siberia is perhaps the main reason that we have not yet actually crossed the normal line for ice anomaly.
This is indeed interesting because, the Okhotsk sea will allways melt totaly around June. This means, the the negative anomaly from that area will be omitted within a good month or so.
Get the point?
Never mind what happends, the Okhotsk sea in the coming 5 weeks will contribute with perhaps 0,3-0,5 mio kvm2 + in sea ice anomaly.
Ice anomaly will go from negative to zero in that area.
Here the Okhotsk trends on Cryosphere, but please be aware that Cryosphere uses sea ice concentration and not sea ice area, so the approx -0,17 mio kvm2 og present negative ice anomaly is perhaps half the number in NSIDC calculation.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.14.html
Cheers!
TonyB (16:19:08) :
I remember a few years ago, at the time when I didn’t doubt AGW (because I had not checked), I read an article in American Scientist which surprised me. We were always taught in school that the relative warm climate in Europe was due to the gulf stream. However, I always wondered how it could be that winter temperatures could vary by 20 degrees centigrade or more over short time periods if the sea temperatures controlled the air temperatures exclusively.
Here is the article
The Source of Europe’s Mild Climate
The notion that the Gulf Stream is responsible for keeping Europe anomalously warm turns out to be a myth
http://www.americanscientist.org/issues/feature/2006/4/the-source-of-europes-mild-climate/1
It explains that the jet streams plays a major role for temperatures in Europe.
Why is the verage taken from 1979 to 2000? Is there anything special about this time frame? Thanks for filling me in even if it turns out to be a silly question.
Fabius Maximus
You host an interesting site. Although I’m Australian I shall visit regularly. Part of the joy of visiting sites such as WUWT, you find links you would never otherwise have known existed.
There was not just one speaking of mass loss. Here are a sample of more links:
http://earthobservatory.nasa.gov/Newsroom/view.php?old=2006030221819
http://www.ens-newswire.com/ens/mar2006/2006-03-03-03.asp
http://www.upi.com/Science_News/2009/04/28/ESA-Wilkins-Ice-Shelf-is-now-unstable/UPI-86731240946372/
Watts up with this?
Bela
The problem is that the Barents sea, which makes almost all the difference with previous years, is always completely ice-free in the summer.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.6.html
It is filled rightnow with multi-year ice that drifted from northern latitudes
http://i302.photobucket.com/albums/nn107/Sprintstar400/Drift-1.jpg
So there are two possibilities
1- there is an inversion of he wind pattern and the ice will be pushed back to where it comes from
2- the ice stays there and will completely melt in the summer, which would greatly reduce the amount of multi-year ice
Mass/volume loss, if accurate, is much more significant than stable area don’t you agree?
Bela
Bela,
Ice area is what controls the albedo and thus affects the “climate.”