This is the same exercise I have been doing for the last three days – since before NSIDC changed their data. I overlaid the current DMI graph (black) on the original version of the April 16 NSIDC graph (blue – no longer available online.) It shows that ice extent has not declined for more than a week, and has now crossed the 1979-2000 mean.
Further confirmation of this is that yesterday’s NSIDC map showed more area of excess ice than missing ice.
NSIDC says that they have introduced a two day lag into their graph. Bottom line – if NSIDC doesn’t cross the mean in the next two days – their graph is wrong.
Next they should include the standard 30-year window in the climatology, by showing the 1979-2009 mean.
I guess 2011 is quite a lot higher than that.
Using a new average…to show less noise…..will show less ice
If they don’t go back to the very beginning and do it all over to match….
…it will show more ice in the past, and less ice now
Didn’t Walt say the raw data was going to be made available?
If so, and interesting plot, IMHO would be raw data, and standard deviation plus/minus continuously updated. Why?
To answer that, I’ll pose another question: What is the right/correct/natural amount of ice the arctic should have? Oh, we don’t really know? Hmmmmm.
Maybe we should just be looking at, first off, getting the measurements right, and second, looking at delta ice over time.
If they really make the data available may I’ll do it. (Darn day job!).
May
Ice extent is interesting, but what about ice volume? After all, surface is only a two-dimensional measure, and ice has three, if I’m not mistaken. Here you have: http://math.ucr.edu/home/baez/temperature/arctic_sea_ice_volume_PIOMAS_2011.jpg
Alex,
Is PIOMAS a measurement or a model?
Hi Greg,
You’re right, it’s a model. But various observations confirm that ice is getting younger and thinner. There is no way you can claim that Arctic is recovering. Skeptics demand sound science, so why be so sloppy?
And as I say below, this is cherry picking. We all know that if the ice extent is particularly low next year, Steven will talk about some region of Antarctica, or some glacier, or whatever fits his views.
Perhaps if you actually read the blog, you wouldn’t feel the need to make misinformed comments
http://www.real-science.com/piomas-trying-to-unpaint-themselves-out-of-their-corner
And if you look at last year’s curve (http://nsidc.org/arcticseaicenews/files/2012/04/Figure2.png), you’ll see ice extent was much lower. So what are you arguing exactly? That a change over one single year is disproving global warming? That would be ridiculous, so what’s the point exactly?
Alex, the point is: “Bottom line – if NSIDC doesn’t cross the mean in the next two days – their graph is wrong.”
it does not matter what the graph shows, the graph is wrong.
You cannot disprove something that has not been proved.
That is what this site is about. At least that is the way I see it.