From Frank Lansner at Hide the Decline
From DMI (Danish Meteorological Institute) we learn, that Arctic 80N-90N temperatures in the melt season this year is colder than average. This was the case last year too, while earlier years in the DMI analysis period (1958-2010) hardly ever shows Arctic melt season temperatures this cold.
This is how DMI temperature averages for Arctic 80N-90N melt season appears when plotted to allow compare over time:
Fig2 (When i speak of “the melt season” i refer to the period where temperatures 80N-90N are above zero Celsius. The green line above is the DMI temperature average, a little over 0,9 Celsius)
It seems that average Arctic temperatures 80N – 90N in melt season of the years 2004, 2009 and 2010 are around 0,4-0,5K whereas the temperatures in 1991 and 1993 where around 1,3 K. In general DMI´s data (if correct) reveals a cooling from the mid 1990´ies till today.
The 80N-90N area of the Arctic is practically always ice covered. Therefore, the 80N-90N is perhaps not so affected by heat from the other areas of the Arctic that has been still more ice free in the period 1995-2007. Im not sure why DMI shows such a cooling trend for the 80N-90N area, but it could appear as if the ice covered areas of the Arctic has its own history of temperatures? And how should GISS data from distant land stations account for this?
Here´s how GISS temperature appears when comparing 1991 to 2009 for the Arctic Polar region:
Fig3
The Arctic melt season is mostly June and July. For both months the GISS Arctic temperature trend 1991 vs 2009 shows warming around 0,3-0,7K which is in contrast with the DMI trends of cooling of around 0,7K for the region.
Is it basically a convincing idea to use land/city/Airport temperatures for temperatures at sea? Give it a thought:
Imagine you stand on a boat 12 km from land…
Fig4
You want to know the Air temperature in 2 meters altitude. Which temperature would be most precise, the water temperature around the boat or the temperature from land ( measured at the city airport… ) ?
Now imagine the same situation, but this time you are 1150 km from land. Which temperature would you rely most on, the water temperature around the boat or the temperature from land (city/Airport) 1150 km away?
Since 1987, James Hasen, and thus GISS, har used a 1200 km radius in their global temperatures based on meteorological stations and thus extended land temperatures to cover a considerable ocean area.
Below a compare of SST with the temperatures GISS use for ocean areas.
Fig5
1) Left: GISS land temperatures including land temperatures to cover ocean areas.
2) Right: As 1) but now for the ocean areas the actual SST measured by the Hadley centre are shown.
Both pictures are from july 2010. From this illustration we see, that ocean areas represented by SST are poorly reflected by GISS land temperature data and the idea of expanding land temperatures to cover ocean area appears challenged?
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Hm, don’t see the word “model” mentioned here, the “DMI temperatures” are spoken of as if they are data points. And their model changed twice. From their site:
“Calculation of the Arctic Mean Temperature
The daily mean temperature of the Arctic area north of the 80th northern parallel is estimated from the average of the 00z and 12z analysis for all model grid points inside that area. The ERA40 reanalysis data set from ECMWF, has been applied to calculate daily mean temperatures for the period from 1958 to 2002, from 2002 to 2006 data from the global NWP model T511 is used and from 2006 to present the T799 model data are used.”
REPLY: I don’t see your mention here of when we previously covered the issue, so here it is: http://wattsupwiththat.com/2010/07/28/giss-arctic-vs-dmi-arctic-differences-in-method/
There’s far more data in DMI than you might think. – Anthony
” In general DMI´s data (if correct) reveals a cooling from the mid 1990´ies till today.”
If you plot a trend from 1958, you get a steep decline.
…when plotted to allow compare over time…
Should read “…when plotted to allow comparison over time…”
Shouldn’t all temperatures be denominated in C instead of K?
Photographs of the ice correlate very well with DMI temperatures. There has been almost no melting at the pole during the last two cold summers.
marek says:
August 5, 2010 at 2:47 pm
Shouldn’t all temperatures be denominated in C instead of K?
==============
Yes…
Unless the next sound you hear is the atmosphere solidifying… Which you wouldn’t actually hear, since there would be no atmosphere…
This temperature decline since 1990 can’t be right, because CO2 has increased dramatically since then and the IPCC says we will see the first evidence of CAGW at the poles???
Wouldn’t the warm ocean currents coming from the south have more impact on the arctic ice melting than the surrounding air?
Doesnt this aggrevate the CAGW crowd a bit?
Anthony writes:
“Im not sure why DMI shows such a cooling trend for the 80N-90N area, but it could appear as if the ice covered areas of the Arctic has its own history of temperatures? And how should GISS data from distant land stations account for this?”
Sounds like real science. The truth is in the details and they are messy as all get out.
Another interesting insight:
Researchers discover irrefutable proof that Arctic Sea Ice had disappeared in the mid 1800’s, at the end of the Little Ice Age.
http://www.c3headlines.com/2010/08/researchers-discover-irrefutable-proof-that-arctic-sea-ice-had-disappeared-in-the-mid1800s.html
“There’s far more data in DMI than you might think. – Anthony”
Hi Anthony,
A minor point of clarification. DMI don’t produce this data. The data comes from the initial conditions of the ECMWF weather forecast model after assimilation of observational data. DMI plotted the graph, but weren’t involved in the production of the data.
See my previous comments here:
http://wattsupwiththat.com/2010/07/28/giss-arctic-vs-dmi-arctic-differences-in-method/#comment-442773
Steven Goddard wrote,
“2) Right: As 1) but now for the ocean areas the actual SST measured by the Hadley centre are shown.
“Both pictures are from july 2010”
If they’re both from July 2010, then they’re not Hadley Centre SST data. From December 1981 to present, GISS has used Reynolds OI.v2 SST data, which is an NCDC product.
Looks like the hockey stick is pointing down.
Frank Lansner: Oops. I saw the Arctic reference and assumed the post was written by Steven, sorry. I’ll then redirect my comment to you.
You wrote, “2) Right: As 1) but now for the ocean areas the actual SST measured by the Hadley centre are shown.
“Both pictures are from july 2010″
Wrong! If they’re both from July 2010, then they’re not Hadley Centre SST data. From December 1981 to present, GISS has used Reynolds OI.v2 SST data, which is an NCDC product.
And as Zeke noted in a comment in one of your earlier posts, GISS acknowledges the Land Surface dataset with 1200km radius smoothing reads high. They keep it for sentmental reasons:
http://wattsupwiththat.com/2010/07/17/tipping-point-at-giss-land-and-sea-out-of-balance/#comment-434647
Also, please provide a link to the ERA-40 data you used to create the graph.
Does James Hansen have the satelite readings from 1958 to 1980 to refute this?
Well , on checking the north pole web cam , which I have been assured by a member of the camera crew is correct , it is showing the cameras temperature is 11 centigrade , quite toasty for the north pole , my back yard in England is presently the same temperature – hope we do not mirror the north pole temperatures as we go into winter !!!!!
Steven Goddard: Please disregard my earlier (August 5, 2010 at 3:29 pm) comment. I saw the discussion of the Arctic and the use of the DMI data and assumed, incorrectly, the post was written by you. I’ve redirected the comment to Frank Lansner.
Sorry for the confusion on my part.
Frank Lansner: You wrote regarding Figure 6 in the remainder of your post:
“In the compare above, a few areas (between Sri Lanka and Singapore and around Spitsbergen and slightly more) has GISS ocean temperatures warmer than Hadley SST, but more often the GISS temperatures for oceans are warmer than the Hadley SST.”
First, you compared to the wrong SST dataset. GISS has used Reynolds OI.v2 for almost the last three decades. The differences you’re seeing between the GISS data over the oceans and the HADISST data may be due to the differences between Reynolds OI.v2 and the HADISST data you used incorrectly. Also, GISS includes land surface data from many islands and this may be causing some of the difference.
Bob,
Do you feel that the usage of NCDC or Hadley data would have any impact on Frank’s conclusions?
Bob, i use the options in GISS own utility:
http://data.giss.nasa.gov/gistemp/maps/
Try yourself, first witth empty ocean box. Then with the Had/reyn in the ocean box.
The differences i show are the differences GISS shows themselves. I just focus on the areas where both SST and GISS land temperatures for oceans are available to make it easier to see how huge the differences are.
And yes im aware that GISS has some of their stations on Islands, but non the less, the differences GISS show between their land projections and the SST they use appear considerable.
Data from the North Pole webcam is at:
http://psc.apl.washington.edu/northpole/POPS13_atmos_recent.html
The last temperature recorded was 1.9 C.
And Bob im perfectly aware that GISS has a LOTI index where they dont use these projected land temperatures much – however even in their LOTI index they use their Arctic land projections of temperatures that i focus on in this writing:
http://data.giss.nasa.gov/cgi-bin/gistemp/do_nmap.py?year_last=2010&month_last=6&sat=4&sst=1&type=anoms&mean_gen=06&year1=2010&year2=2010&base1=1951&base2=1980&radius=1200&pol=reg
And even though you think the GISS meteorological index from GISS in only for “sentimental” reasons, these data are still on the net for the public to see and use, and thus should be correct.
Ed Caryl
-1.9C
Bob, DMI does not only use ERA-40, they use to other sources/methods too, so i did the slave-work: I have magnified all DMI-maps to pixel size and counted pixel for pixel, so it took weeks.
I understand that you want the original data to work with, so would I, but still, you should honestly not miss the obvious point that recent years according to DMI has colder temperatures in the melt season than the old years (!)
Go to the DMI site and you will fast conclude that im just telling you what these data actually says quite clearly.