I had planned to do a post yesterday evening about how sea ice area and extent had returned to very near normal levels. But I was tired, so I saved off the graphs from the NANSEN arctic sea ice site.
This morning I was shocked to discover that overnight, huge amounts of sea ice simply disappeared. Fortunately I had saved the images and a copy of the webpage last night. Here is the before and after in a blink comparator:
There is no mention on the NANSEN website as to this change. So either it is an automation error or an undocumented adjustment. Either way, since this is for public consumption, NANSEN owes the public an explanation.
And there is more, see additional blink comparator graphs I’ve added below:
After examining the above, it appears the issue only manifests itself when comparisons to the 1979-2000 monthly average are made. The adjustment starting point appears to start around September 10th – at the summer minimum for both area and extent.
This could be a data processing error, though if so, it is so blatantly obvious to anyone who follows the NANSEN presentation that it immediately stands out. Many people commenting on this blog and others also saw the change without the benefit of my handy-dandy blinkj comparator above.
That fact that it occurs on a weekend could be viewed as suspicious due to fewer eyes on the website , or an indication that they have sloppy quality control there at NANSEN and this was published via automation with no human inspection prior to the update.
Steven Goddard writes via email:
The explanation (if one is offered) will be interesting to say the least.
UPDATE:
I received this email from Stein Sandven at Nansen in response to my query:
Dear Anthony,
The ice area calculation has been too high since about 22 October, causing too steep slope of the 2008 curve. We corrected for this yesterday and recalculated the ice area for 2008. The slope of the 2008 curve should now be correct and can be compared with 2007 and the previous mean monthly ice area.Best regardsStein
For my opinion though it seems to be an incomplete answer, generating even more questions.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
NSIDC.ORG is now flat-lining for four days from 11th December on ice extent.
Is this to make them consistent with NANSEN?
Don’t know…….but it sure raises questions…..in the interest of science.
I can believe a minor change went wrong. Happens all the time. Been there, got the T shirt. Lesson 1. run the new script over old data as you know what the output should look like. Lesson 2. It is less painful to own up with a readme /release note than to wait to be caught.
That said, why has extent leveled of over the last few days? Is it real? Wind compacting?
Dec 10 11650000
Dec 11 11678594
Dec 12 11681563
Dec 13 11662813
Dec 14 11640625
Dec 15 11682813
Source IJIS web site today.
“” Phil. (07:48:48) :
George E. Smith (11:50:04) :
“” crosspatch (19:07:45) :
Arctic sea ice is frozen sea water but the longer it lives the more the salt works out of it. The older it gets, the fresher it gets. “”
………….
But there really isn’t any “outsalting” process that goes on once the water is frozen. The very concept of solid means that the molecules are NOT free to move about in the solid, so any small amount of salt in the solid is not going to move about and get ejected from the solid.
Actually George crosspatch is right, see here for example: http://www.nsidc.org/seaice/characteristics/brine_salinity.html “”
Well Phil, I guess it depends on your point of view. I would have to agree with what crosspatch said; only to the extent, that if you grabbed a chunk of that ice/brine cocktail and ate it, that you would get the benefit of the brine salt.
But brine is not ice; and the ice, sans brine, is fresh water of quite high purity.
If you dig up your potatos or yams, and you don’t pay attention to not collecting the weeds between them; then you could reasonably claim that potatos or yams have a lot of weed content.
But touch! crosspatch ! ; I never pass up an opportunity to learn something myself.
George
Well Phil, I guess it depends on your point of view. I would have to agree with what crosspatch said; only to the extent, that if you grabbed a chunk of that ice/brine cocktail and ate it, that you would get the benefit of the brine salt.
Only if it were new ice, multiyear ice will have expelled the brine by the mechanism referred to and is essentially fresh.
I believe I did say “if you grabbed a chunk of the ice/brine cocktail”.
That would not be the old ice that has shed its brine.
Al Gore is correct, we all need to pay alot more tax and buy carbon offsets to stop this melting.
http://news.yahoo.com/s/usnews/20081217/ts_usnews/arcticicemeltingatalarmingpace
Hmmm, HANSEN sounds suspiciously like NANSEN? Just a co-incidence?
Of course global warming is nothing more than a huge tax scam with CO2 the revenue meter.
The warmist campaign is not scientific but political. The UK Climate Change Bill went through its 3rd reading without debate and with only a handful of Nay votes.
One needs to do more than write comments in pages such as this before the media etc is totally silenced. Stop the carbon con and don’t be affraid of being called a flat earther or other stupid names.
One day the cat will be out of the bag but how much will it cost us all before then and how long will the jail term be for Gore and co for fraud on a world wide scale? A political pardon me thinks.