UPDATE: Dr. Walt Meier of NSIDC writes in with some information, seethe end of the article.
I’m getting weary of answering this question in comments, so here it is front page. Note the little bump right about June 1st.
Rick W asks:
Can anyone explain the upward bump in the sea ice extent that seems to occur each June? Apologies if previously covered.
Answer:
This is a seasonal adjustment to compensate for meltwater on top of the ice, which would ordinarily be viewed as “open water”. Right about now, the Arctic sea ice gets melt pools forming on the surface. If these are not compensated for, sea ice extent will read artificially low.
That being said, I wonder why we don’t see the same adjustment at NSIDC:
I don’t know the answer, but it could be in the difference between SSMI and AMSR-E satellite sensors (NSIDC uses SSMI, JAXA uses AMSR-E).
We also don’t see an adjustment at Cryosphere Today, and they also use SSMI:
Nor does NANSEN:
Click for larger images
If anyone knows why JAXA does the adjustment but the others do not, I’m all ears. My theory is that it is sensor related, but we should find out for sure. I’m swamped today, so I’ll leave this puzzle for WUWT readers to solve.
UPDATE
Dr. Walt Meir writes in with this:
Since you mentioned it on your blog, I can fill in at least some info:
You are correct. When the melt season kicks in the surface water changes
the contrast between ice and water. To more accurately measure the
area/extent, you should adjust coefficients to account for this.
This is done for SSM/I. However, because the SSM/I algorithm is
different from the AMSR-E algorithm (and other differences between the
sensors) the adjustment is different. In SSM/I, the adjustment is
smoother and thus there isn’t that “bump”.
You have to remember that AMSR-E is a research sensor and the algorithms
are still being refined. That is one reason we don’t use AMSR-E for the
long-term timeseries (though the more important reason is the
inconsistency between the two sensors and algorithms).
– Walt
Thank you Mike Abbott. You beat me to the punch. I watch the Jet Stream to see if Arctic ice will be shoved anywhere near warmer rays and water. I have no worries, even if all the ice gets blown outa there. It’s the wind folks. Learn it. The slow melt had nothing whatsoever to do with cold weather. The wind wasn’t blowing up and out Arctic skirts. Therefore the melt was slow because it stayed in the frig. But if you get spinning ice and air flow out of the basin, ice melts like there is no tomorrow. This is so simple. I don’t get why there are arguments over this.
Tom in Texas (17:46:45) :
“I didn’t want to explain it to him” or her.
Mmm Tom. Apart from New-World, ex-colonial deviations from acceptable standards and the travesty of ‘Saturday Night Fever’ the name Sandy is 100% bloke.
OT, but it is with great sadness that I report that Jack Eddy passed away yesterday.
According to UAH the world hasn’t yet resumed warming
http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps
interesting that the SST’s this year bottomed out around Febuary and the temps. hasn’t started following it upward yet, maybe a certain thingy we know as the Sun is helping to depress temps 😉
Thank you, Pamela for explaining that better than I did. And as I keep saying, you can see it with your own eyes in the animations Anthony posted. I wish I could remember the name of the guy who created it to give him credit.
I assumed that it is a fiscal year thing.
Lots of strange things happen at the end of the fiscal year.
Mike Abbott (17:50:46) :
.. but the alarmists couldn’t have cherry-picked a better starting point…
And that’s why I believe that the ‘unprecedented’ possibility of a NW passage being shown to be a recent and repeated actuality totally TRUMPS the STATISICAL SNARKS of the denio-sphere that is epitomized by Gavins real climate fantasy!
Add a T if you’re a pedant
timetochoseagain: this is the link to the new book the Climate caper by Paltridge
http://www.connorcourt.com/catalog1/index.php?main_page=product_info&cPath=29&products_id=113
BTW Ian plimers book has reached number 1 bestseller here in Australia. Its now going to the USA.
Jack Eddy passed away yesterday.
Those, whom we have loved and pass on – live on in our minds until we become like them and loved by others as we loved them.
Leif, American scientists were few and far between in his cohort. He will be missed. I wonder. Did you have any conversations with him regarding his theory that certain solar variations are tied to climate?
1878 Adolf Erik Nordenskiöld travelled the length of the NE Passage.
Then a 150 years of AGW and there is an increase in ice in 2009.
I see a pattern.
http://en.wikipedia.org/wiki/Adolf_Erik_Nordenski%C3%B6ld
Thanks VG.
Off topic, but interesting. “Chilly spring cools crop outlook: Canadian Wheat Board”.
http://www.cbc.ca/money/story/2009/06/11/crop-outlook-cwb.html
Off topic, but I have an itch.
O/T but it should be posted somewhere:
Prof. Ian Plimer interview [Part 1 of 3; you can find parts 2 & 3 below, at the end of the first interview].
Well, maybe if there was a ‘interesting finds of the last 72 hours’ page that people could post links and studies for the review of others it would make for less interrupting the threads.
RoyFOMR, my sister’s name is Sandra – guess what her nickname is.
Pamela Gray (18:29:18) :
Leif, American scientists were few and far between in his cohort. He will be missed. I wonder. Did you have any conversations with him regarding his theory that certain solar variations are tied to climate?
Yes, many. We knew each other well. I think his last public talk on this subject was an after-dinner talk at the SORCE 2003 meeting in Sonoma, Calif http://lasp.colorado.edu/sorce/news/2003ScienceMeeting/Dec03ScienceMeeting.html
Program here: http://lasp.colorado.edu/sorce/news/2003ScienceMeeting/dec03_meeting_final_science_program.html and picture of Jack Eddy [and other luminaries]: http://lasp.colorado.edu/sorce/news/sns/2003/sns_dec_2003.pdf
The theme of the talk was that when he proposed that the Maunder minimum was related to the Little Ice Age, it was believed that variations of TSI [the solar ‘constant’] was as large as 1% which would make sense energetically [result in 0.7 degree global cooling with possible greater effect regionally]. When it turned out to be ten times smaller, Eddy effectively [as every good scientist would do] abandoned that idea. He didn’t find the various claims of ‘feedback’ or ‘amplifications’ credible, because they were invoked after the 0.1% was already established.
He’ll be greatly missed.
Happy is the man who has a scratch for every itch.
Kindest Regards
It seems like today, both Unisys and NOAA shows the PDO cool area gone. I hope that a previous post on this site is right and is one of those temporary reversals that pepper cool phases according to the PDO index graph, otherwise people may start thinking AGW is real after all. 🙁
AndyW35: “Why doesn’t WUWT report sea ice levels are back to 2007?”
The Sea Ice Graphs are on the front page of this website everyday… this article has multiple graphs showing where the sea ice levels are at. Somehow polar bears and mankind survived 2007 sea ice levels. Are we supposed to get some Armageddon article from WUWT on this? Thankfully, the posts on here are so much more interesting than the your suggested content.
Off topic, but I have a scratch.
Leif, sorry to hear about your friend and colleague.
I remember you saying that “the Eddy Minimum” was a good name for the current minimum, should it continue.
Perhaps you could post a tribute here?
Shawn Whelan (18:32:52) :
1878 Adolf Erik Nordenskiöld travelled the length of the NE Passage.
Then a 150 years of AGW and there is an increase in ice in 2009.
I see a pattern.
http://en.wikipedia.org/wiki/Adolf_Erik_Nordenski%C3%B6ld
I see a pattern too Shawn. I see a pattern that repeatedly demonstrates that the word ‘unprecedented’ when uttered by a climate ‘scientist’ is as ‘meaningful as the numerology of ‘110%’ when claimed by a footballist!
Your references, as I interpret them, follow another pattern. The NW passage has been broached in the past, currently they are impassible. Your argument. AFAIU, predicates that arctic sea-ice, in the historically-verifiable and undisputable,pre-industrial era was at a level that allowed for NW passaging.
Gosh – Gav’ll no be chuffed.
Pamela, flirting as always.