By Steve Goddard
There has been an active discussion going on about the validity of GISS interpolations. This post compares GISS Arctic interpolation vs. DMI measured/modeled data.
All data uses a baseline of 1958-2002.
The first map shows GISS June 2010 anomalies smoothed to 1200 km. The green line marks 80N latitude. Note that GISS shows essentially the entire region north of 80N up to four degrees above normal.
The next map is the same, but with 250 km smoothing. As you can see, GISS has little or no data north of 80N.
Now let’s compare the GISS 1200 km interpolation with the DMI data for June 2010.
Daily mean temperatures for the Arctic area north of the 80th northern parallel, plotted with daily climate values calculated from the period 1958-2002.
http://ocean.dmi.dk/arctic/meant80n.uk.php
DMI shows essentially the entire month of June below the 1958-2002 mean. GISS shows it far above the the 1958-2002 mean. Yet GISS has no data north of 80N.
Conclusion : GISS Arctic interpolations are way off the mark. If they report a record global temperature by 0.01 degrees this year, this ↑↑↑↑↑↑↑ is why.
——————————————————————
Straight from the horse’s mouth.
the 12-month running mean global temperature in the GISS analysis has reached a new record in 2010…. GISS analysis yields 2005 as the warmest calendar year, while
the HadCRUT analysis has 1998 as the warmest year. The main factor is our inclusion of estimated temperature change for the Arctic region.
– James Hansen
In other words, the GISS record high is based on incorrect, fabricated data. Why did Hansen apparently choose to ignore the DMI data when “estimating” Arctic temperatures? GISS Arctic anomalies are high by as much as 4 degrees, and yet he claims a global record measured in hundredths of a degree. As Penn and Teller would say …. well I guess I can’t say that here.
Julienne Stroeve says:
July 28, 2010 at 3:08 pm
Some interesting numbers that I just looked at, the difference between the maximum ice extent in winter and the most recent ice extent (i.e. July 27th):
1979-2000: 6.79 million sq-km
2007: 7.91 million sq-km
2008: 7.41 million sq-km
2009: 7.97 million sq-km
2010: 8.09 million sq-km
Ever thought it might be because the winter extent is increasing more than the summer extent is falling?
stevengoddard says:
July 28, 2010 at 12:15 pm
GeoFlynx
Ice loss in July has actually been the lowest in the JAXA record.
GeoFlynx – In the eight years of the JAXA set I would agree that this is the lowest loss in ice extent for July. We may some differences of opinion, but it is nice to know we both appreciate the PAWS movie. Wow, the ITP buoy really takes off. Not a place I’d like to camp.
Julienne
The last few winters have been very cold with lots of snow and ice. Last winter had the second greatest snow extent on record in the Northern Hemisphere. Ice extent reached it’s peak at the end of March.
When you start at the top of a high hill, it is a longer drop to the valley below.
Chris G says:
July 28, 2010 at 2:54 pm
BTW, You guys claiming it can’t be 4 C above normal there, please follow my link and note the 11 C temperature and the meltwater.
Still digging, Chris G?
RockyRoad says:
July 28, 2010 at 10:34 am
————Reply:
My intent here is not to be insulting, but I’m certain you know nothing about “modeling”.
Not to be insulting, but your use of the words “certain” and “nothing” was surprising. Actually, I do modeling for a living — though it’s military parts inventory, not anything to do with climate.
People seem to be missing my point. Let me try again.
Suppose someone uses a smoothing algorithm to apply point measurements of temperature to large areas (e.g., 250 km or 1200 km smoothing). Suppose further that they use the word “model” to describe this method. You might argue that the word “model” is inappropriate for a simple algorithm; I would too. But their use of the word “model” (especially if from a nation where English is not the native tongue) does not fundamentally change anything.
Steve…I agree that if GISS shows surface temperatures on the ice of 3-5C that is too high.
As for the winter maximum:
1979-2000 = 15.75
2007 = 14.74
2008 = 15.26
2009 = 15.19
2010 = 15.34
It would be hard to argue that 2010 is not continuing a pattern of more seasonal ice loss seen in recent years. In addition, having more winter ice extent should influence summer ice loss somewhat in the sense that you still need to first remove that most southerly ice before you can start losing the interior ice (i.e. taking the southerly ice away leads to more lateral and basal melting, warmer near-surface air temperatures, changes in ice motion, etc.).
Chris G
“Internal temperature”
Billy, here’s a comparison of July 27th ice extents:
1979-2000 = 8.96
2007 = 6.83
2008 = 7.85
2009 = 7.26
2010 = 7.25
Julienne,
Your own forecast has ice extent increasing for three years in a row. I believe you are correct.
Chris G says:
July 28, 2010 at 2:54 pm
BTW, You guys claiming it can’t be 4 C above normal there, please follow my link and note the 11 C temperature and the meltwater.
==================
WOW, this is AGW science of its finest, please follow my idea and do the math if you can.
I’m on the North Pole in Floater Suit ( I use it for ice fishing). Every pocket is filled with “Big oil money”. The temperature in my pocket is waaaaaay above 11 C ( to make it easy for you it is 25C). The question is how much ice the pockets full of big oil money can melt?
Sorry Anthony for this post , I promise it won’t happen again
Julienne Stroeve says:
July 28, 2010 at 4:20 pm
Thank you. A slightly different picture than you were trying to paint.
@ur momisugly John Finn;
The LT should be amplified quite a bit compared to SAT during an El Nino. Historically that is the case, so why would it be any different in 2010 in the Arctic during this El Nino?
Steve,
On the page you link to GISS also show a graph of the zonal mean for June 2010 showing the average anomoly by latitude. That graph puts the arctic June 2010 anomoly at around 1 to 1.25 degrees C.
(Hopefully the links below work)
In fact Steve GISS are in some ways consistent with DMI. People can use this tool ( http://data.giss.nasa.gov/gistemp/maps/ ) to generate annual, seasonal and monthly trends from GISS if they want. Here (roughly) are the temperature changes from 1951 to 2009 on a seasonal basis.
Summer (JJA) 0.7oC
Autumn (SON) 2.0cC
Winter (DJF) 1.6oC
Spring (MAM) 1.6oC
Which give an overall annual change from 1951-2009 of about 1.5oC.
June itself has only seen an ~0.8oC temperature increase from 1951-2009. Stating GISS’s June anomoly is running upto 4oC is a little misleading and is worth a correction to the actual figure. There is no point exxagerating the GISS exxageration.
The trends outside of summer in the arctic are probably the main concern for the warmists and worth challenging.
stevengoddard says:
July 28, 2010 at 9:31 am
It is trivial to prove that the GISS data is wrong and the DMI data is correct. If temperatures at the North Pole really were 4C above normal in June, the ice would have been melting like crazy. Webcams showed that it wasn’t.
Those in the real world know the answer. Those in the virtual/global warming world can’t come up with the right answer. Fine with me. That just shows every day folk what global warming is all about. Thank you global warming for showing us your cards.
Julienne Stroeve says:
July 28, 2010 at 12:48 pm
It makes sense that temperatures in June were anomalously warm
I thought it was about July?
Billy, I’m not trying to paint any picture but to show the actual data. There is a lot of discussion on this site trying to argue that the summer ice cover in the Arctic is recovering, and the data do not support this (note that currently 2010 is the 2nd lowest ice extent at this time of year since routine monitoring began by multichannel passive microwave sensors in October 1978). Seasonal ice loss remains higher than it was 10-20-30 years ago.
It seems that talking about ice in the Arctic from 1979 to ~1984 and comparing it to how much ice there is there now is not a fair comparison. Arctic ice from 1979-1983 was coming out of a PDO (-) and ice there now is coming out of a PDO (+). Of course there will be a difference in numbers.
For a fairer comparison, a fairer base line, 1979to ~1983 should be taken out.
Shouldn’t the headline read “GISS Polar Interpretation” instead?
HR
Ice only melts in situ in the Arctic during the summer.
Julienne,
Two weeks from now, 2010 will be ahead of 2007-2009.
DR says:
July 28, 2010 at 5:01 pm
@ur momisugly John Finn;
The LT should be amplified quite a bit compared to SAT during an El Nino. Historically that is the case, so why would it be any different in 2010 in the Arctic during this El Nino?
This is true for the tropics but not in the arctic. Plot the UAH tropics anomalies and the NoPol anomalies. There’s a clear ENSO sign;l in the tropics – nothing in the arctic. In any case, my main point is that this whole thing has been overblown. The red region represents a temp range of 2-4 deg – NOT 4 deg. What’s more the red region is barely 25% of the region above 80 degN.
The GISS June anomaly for the region above 80N is 1 to 1.3 deg depending on which base period you use.
John Finn
It is thermodynamically impossible to have summer anomalies of +2-4C in the region above 80N.
stevengoddard says:
July 29, 2010 at 5:08 am
John Finn
It is thermodynamically impossible to have summer anomalies of +2-4C in the region above 80N.
Which of course is not true, you can’t make such sweeping categorical statements Steve!
Phil,
Which of course is true, as Julienne and Gavin Schmidt have both pointed out.